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Fri
8
Mar '13

An outbreak of Shigella sonnei associated with a private bridge club

http://www.cdc.gov/mmwr/preview/mmwrhtml/mm6209a4.htm

Notes from the Field: Outbreak of Infections Caused by Shigella sonnei with Decreased Susceptibility to Azithromycin — Los Angeles, California, 2012

Weekly

March 8, 2013 / 62(09);171-171

In May 2012, the Los Angeles County Department of Public Health’s Acute Communicable Disease Control Unit and Environmental Health, Food, and Milk Program investigated an outbreak of shigellosis associated with a private bridge club. This investigation documented the first known transmission of Shigella sonnei with decreased susceptibility to azithromycin in the United States.

Cases were defined as an illness clinically compatible with shigellosis in a patient or S. sonnei isolated from stool of a person with an epidemiologic link to the bridge club during May 22–26, 2012. Investigators attempted to interview all bridge club workers and members who had visited the bridge club during the week of May 22; they collected stool specimens from workers who handled food and from workers and members with diarrhea who had not already submitted a stool specimen for culture at a health facility. Thirty-nine cases were identified among club members with diarrhea and four among club workers; of the four workers, two, including one who handled food, reported no symptoms. The average age of affected persons was 75.3 years (range: 54–98 years); 55% were female. Among those with symptoms, the duration of illness averaged 5.9 days (range: 1–14 days). Common symptoms included diarrhea in 95% of patients, abdominal cramps in 70%, and fever in 56%. Thirty-one (72%) persons sought medical care, and 10 (23%) were hospitalized. No specific exposures implicated a source for the outbreak.

Among the 43 cases, 14 were culture-confirmed; 10 isolates underwent pulsed-field gel electrophoresis (PFGE), yielding indistinguishable patterns. Four isolates submitted to CDC’s National Antimicrobial Resistance Monitoring System (NARMS) displayed resistance to streptomycin, sulfisoxazole, tetracycline, and trimethoprim-sulfamethoxazole. Unlike most Shigella isolates tested by NARMS, these isolates also showed elevated azithromycin minimum inhibitory concentrations (MICs) of >16 µg/mL (1) and harbored a plasmid-encoded macrolide resistance gene, mphA (2).

CDC’s PulseNet identified two additional isolates indistinguishable from the outbreak PFGE pattern. One was from a man in Pennsylvania aged 23 years who had visited Los Angeles in April, and the other from a man in Hawaii aged 53 years who visited Los Angeles during April and May; both men were hospitalized with diarrhea. Neither case was epidemiologically linked to the bridge club or to each other.

Although sporadic cases of shigellosis caused by Shigella strains with increased azithromycin MICs have occurred, this is the first outbreak documented in the United States and might indicate increasing circulation of such strains (1). Illnesses in this outbreak tended to be severe; however, the affected population was much older than the general U.S. population. Clinical management of such illnesses is likely to be complex; although azithromycin currently is recommended for treatment of infections caused by multidrug-resistant Shigella, options for alternative treatment among children with such infections primarily include parenteral antimicrobial medications (3,4).

Guidelines for azithromycin susceptibility testing and criteria for interpretation of MICs for Shigella species have not been published. Clinicians are urged to report azithromycin treatment failure among shigellosis patients to public health authorities and to retain Shigella isolates from such cases for further analysis.

References

  1. Howie RL, Folster JP, Bowen A, Barzilay EJ, Whichard JM. Reduced azithromycin susceptibility in Shigella sonnei, United States. Microb Drug Resis 2010;16:245–8.
  2. Karlsson MS, Bowen A, Reporter R, et al. Outbreak of infections caused by Shigella sonnei with reduced susceptibility to azithromycin in the United States. Antimicrob Agents Chemother 2013;57:1559.
  3. American Academy of Pediatrics. Shigella infections. In: Pickering LK, Baker CJ, Kimberlin DW, Long SS, eds. Red book: 2012 report of the Committee on Infectious Diseases. Elk Grove Village, IL: American Academy of Pediatrics; 2012:645–7.
  4. World Health Organization. Guidelines for the control of shigellosis, including epidemics due to Shigella dysenteriae type 1. Geneva, Switzerland: World Health Organization; 2005. Available at http://whqlibdoc.who.int/publications/2005/9241592330.pdf Adobe PDF fileExternal Web Site Icon.

 

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Mon
28
Nov '11

Shigella sonnei outbreak in Norway

http://www.eurosurveillance.org/ViewArticle.aspx?ArticleId=20007

Guzman-Herrador B, Vold L, Comelli H, MacDonald E, Heier BT, Wester AL, Stavnes TL, Jensvoll L, Lindegård Aanstad A, Severinsen G, Aasgaard Grini J, Werner Johansen Ø, Cudjoe K, Nygard K. Outbreak of Shigella sonnei infection in Norway linked to consumption of fresh basil, October 2011. Euro Surveill. 2011;16(44):pii=20007.

Shigella sonnei outbreak of 46 cases that occurred in Norway during October 2011.  A large cluster of 42 cases was concentrated in north Norway.  A small cluster of 4 cases occurred in the south-east region.

The outbreaks ere linked to the consumption of imported fresh basil.

The product has been withdrawn from the market.

No further cases have been reported.


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Sun
6
Nov '11

Norway: Shigella sonnei outbreak from fresh basil

http://www.eurosurveillance.org/ViewArticle.aspx?ArticleId=20007

Guzman-Herrador B, Vold L, Comelli H, MacDonald E, Heier BT, Wester AL, Stavnes TL, Jensvoll L, Lindegård Aanstad A, Severinsen G, Aasgaard Grini J, Werner Johansen Ø, Cudjoe K, Nygard K. Outbreak of Shigella sonnei infection in Norway linked to consumption of fresh basil, October 2011. Euro Surveill. 2011;16(44):pii=20007. Available online: http://www.eurosurveillance.org/ViewArticle.aspx?ArticleId=20007

*Shigella sonnei outbreak of 46 cases that occurred in Norway during October 2011.

*Two municipalities were involved.

*42 cases were concentrated in north Norway,

*A small cluster (4 cases) occurred in the south-east region. Epidemiological evidence and traceback investigations have linked the outbreak to the consumption of imported fresh basil.

*It’s been withdrawn from the market.

*No further cases have been reported since 25 October.

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Sun
20
Apr '14

CDC: Foodborne disease continues to be an important problem in the United States.

http://www.cdc.gov/mmwr/preview/mmwrhtml/mm6315a3.htm?s_cid=mm6315a3_w

Incidence and Trends of Infection with Pathogens Transmitted Commonly Through Food — Foodborne Diseases Active Surveillance Network, 10 U.S. Sites, 2006–2013

 Weekly

April 18, 2014 / 63(15);328-332

Stacy M. Crim, MPH1, Martha Iwamoto, MD1, Jennifer Y. Huang, MPH1, Patricia M. Griffin, MD1, Debra Gilliss, MD2, Alicia B. Cronquist, MPH3, Matthew Cartter, MD4, Melissa Tobin-D’Angelo, MD5, David Blythe, MD6, Kirk Smith, DVM7, Sarah Lathrop, PhD8, Shelley Zansky, PhD9, Paul R. Cieslak, MD10, John Dunn, DVM11, Kristin G. Holt, DVM12, Susan Lance, DVM13, Robert Tauxe, MD1, Olga L. Henao, PhD1 (Author affiliations at end of text)

Foodborne disease continues to be an important problem in the United States. Most illnesses are preventable. To evaluate progress toward prevention, the Foodborne Diseases Active Surveillance Network* (FoodNet) monitors the incidence of laboratory-confirmed infections caused by nine pathogens transmitted commonly through food in 10 U.S. sites, covering approximately 15% of the U.S. population. This report summarizes preliminary 2013 data and describes trends since 2006. In 2013, a total of 19,056 infections, 4,200 hospitalizations, and 80 deaths were reported. For most infections, incidence was well above national Healthy People 2020 incidence targets and highest among children aged <5 years. Compared with 2010–2012, the estimated incidence of infection in 2013 was lower for Salmonella, higher for Vibrio, and unchanged overall.† Since 2006–2008, the overall incidence has not changed significantly. More needs to be done. Reducing these infections requires actions targeted to sources and pathogens, such as continued use of Salmonella poultry performance standards and actions mandated by the Food Safety Modernization Act (FSMA) (1). FoodNet provides federal and state public health and regulatory agencies as well as the food industry with important information needed to determine if regulations, guidelines, and safety practices applied across the farm-to-table continuum are working.

FoodNet conducts active, population-based surveillance for laboratory-confirmed infections caused by Campylobacter, Cryptosporidium, Cyclospora, Listeria, Salmonella, Shiga toxin–producing Escherichia coli (STEC) O157 and non-O157, Shigella, Vibrio, and Yersinia in 10 sites covering approximately 15% of the U.S. population (an estimated 48 million persons in 2012).§ FoodNet is a collaboration among CDC, 10 state health departments, the U.S. Department of Agriculture’s Food Safety and Inspection Service (USDA-FSIS), and the Food and Drug Administration (FDA). Hospitalizations occurring within 7 days of specimen collection are recorded, as is the patient’s vital status at hospital discharge, or at 7 days after specimen collection if the patient was not hospitalized. Hospitalizations and deaths that occur within 7 days are attributed to the infection. Surveillance for physician-diagnosed postdiarrheal hemolytic uremic syndrome (HUS), a complication of STEC infection characterized by renal failure, is conducted through a network of nephrologists and infection preventionists and by hospital discharge data review. This report includes 2012 HUS data for persons aged <18 years.

Incidence was calculated by dividing the number of laboratory-confirmed infections in 2013 by U.S. Census estimates of the surveillance area population for 2012.¶ Incidence of culture-confirmed bacterial infections and laboratory-confirmed parasitic infections (e.g., identified by enzyme immunoassay) are reported. A negative binomial model with 95% confidence intervals (CIs) was used to estimate changes in incidence from 2010–2012 to 2013 and from 2006–2008 to 2013 (2). Change in the overall incidence of infection with six key foodborne pathogens was estimated (3). For STEC non-O157, only change since 2010–2012 was assessed because diagnostic practices changed before then; for Cyclospora, change was not assessed because data were sparse. For HUS, incidence was compared with 2006–2008. The number of reports of positive culture-independent diagnostic tests (CIDTs) without corresponding culture confirmation is included for Campylobacter, Listeria, Salmonella, Shigella, STEC, Vibrio, and Yersinia.

Cases of Infection, Incidence, and Trends

In 2013, FoodNet identified 19,056 cases of infection, 4,200 hospitalizations, and 80 deaths (Table). The number and incidence per 100,000 population were Salmonella (7,277 [15.19]), Campylobacter (6,621 [13.82]), Shigella (2,309 [4.82]), Cryptosporidium (1,186 [2.48]), STEC non-O157 (561 [1.17]), STEC O157 (552 [1.15]), Vibrio (242 [0.51]), Yersinia (171 [0.36]), Listeria (123 [0.26]), and Cyclospora (14 [0.03]). Incidence was highest among persons aged ≥65 years for Cyclospora, Listeria, and Vibrio and among children aged <5 years for all the other pathogens.

Among 6,520 (90%) serotyped Salmonella isolates, the top serotypes were Enteritidis, 1,237 (19%); Typhimurium, 917 (14%); and Newport, 674 (10%). Among 231 (95%) speciated Vibrio isolates, 144 (62%) were V. parahaemolyticus, 27 (12%) were V. alginolyticus, and 21 (9%) were V. vulnificus. Among 458 (82%) serogrouped STEC non-O157 isolates, the top serogroups were O26 (34%), O103 (25%), and O111 (14%).

Compared with 2010–2012, the 2013 incidence was significantly lower for Salmonella (9% decrease; CI = 3%–15%), higher for Vibrio (32% increase; CI = 8%–61%) and not significantly changed for other pathogens (Figure 1). Compared with 2006–2008, the 2013 incidence was significantly higher for Campylobacter and Vibrio (Figure 2). The overall incidence of infection with six key foodborne pathogens was not significantly different in 2013 compared with 2010–2012 or 2006–2008.

Compared with 2010–2012, the 2013 incidence of infection with specific Salmonella serotypes was significantly lower for Enteritidis (14% decrease; CI = 0.2%–25%) and Newport (32% decrease; CI = 17%–44%) and not significantly changed for Typhimurium. Compared with 2006–2008, however, the 2013 incidence of infection was significantly changed only for Typhimurium (20% decrease; CI = 10%–28%).

Among 62 cases of postdiarrheal HUS in children aged <18 years (0.56 cases per 100,000) in 2012, 38 (61%) occurred in children aged <5 years (1.27 cases per 100,000). Compared with 2006–2008, the incidence was significantly lower for children aged <5 years (36% decrease; CI = 9%–55%) and for children aged <18 years (31% decrease; CI = 7%–49%).

In addition to culture-confirmed infections (some with a positive CIDT result), there were 1,487 reports of positive CIDTs that were not confirmed by culture, either because the specimen was not cultured at either the clinical or public health laboratory or because a culture did not yield the pathogen. For 1,017 Campylobacter reports in this category, 430 (42%) had no culture, and 587 (58%) were culture-negative. For 247 STEC reports, 59 (24%) had no culture, and 188 (76%) were culture-negative. The Shiga toxin–positive result was confirmed for 65 (34%) of 192 broths sent to a public health laboratory. The other reports of positive CIDT tests not confirmed by culture were of Shigella (147), Salmonella (69), Vibrio (four), Listeria (two), and Yersinia (one).

Discussion

The incidence of laboratory-confirmed Salmonella infections was lower in 2013 than 2010–2012, whereas the incidence of Vibrio infections increased. No changes were observed for infection with Campylobacter, Listeria, STEC O157, or Yersinia, the other pathogens transmitted commonly through food for which Healthy People 2020 targets exist. The lack of recent progress toward these targets points to gaps in the current food safety system and the need for more food safety interventions.

Although the incidence of Salmonella infection in 2013 was lower than during 2010–2012, it was similar to 2006–2008, well above the national Healthy People target. Salmonella organisms live in the intestines of many animals and can be transmitted to humans through contaminated food or water or through direct contact with animals or their environments; different serotypes can have different reservoirs and sources. Enteritidis, the most commonly isolated serotype, is often associated with eggs and poultry. The incidence of Enteritidis infection was lower in 2013 compared with 2010–2012, but not compared with 2006–2008. This might be partly explained by the large Enteritidis outbreak linked to eggs in 2010.** Ongoing efforts to reduce contamination of eggs include FDA’s Egg Safety Rule, which requires shell egg producers to implement controls to prevent contamination of eggs on the farm and during storage and transportation.†† FDA required compliance by all egg producers with ≥50,000 laying hens by 2010 and by producers with ≥3,000 hens by 2012. Reduction in Enteritidis infection has been one of five high-priority goals for the U.S. Department of Health and Human Services since 2012.§§

In 2013, the incidence of Vibrio infections was the highest observed in FoodNet to date, though still much lower than that of Salmonella or Campylobacter. Vibrio infections are most common during warmer months, when waters contain more Vibrio organisms. Many infections follow contact with seawater (4), but about 50% of domestically acquired infections are transmitted through food, most commonly oysters (5). Foodborne infections can be prevented by postharvest treatment of oysters with heat, freezing, or high pressure, by thorough cooking, or by not eating oysters during warmer months (6). During the summers of 2012 and 2013, many V. parahaemolyticus infections of a strain previously traced only to the Pacific Northwest were associated with consumption of oysters and other shellfish from several Atlantic Coast harvest areas.¶¶ V. alginolyticus, the second most common Vibrio reported to FoodNet in 2013, typically causes wound and soft-tissue infections among persons who have contact with water (7).

The continued decrease in the incidence of postdiarrheal HUS has not been matched by a decline in STEC O157 infections. Possible explanations include unrecognized changes in surveillance, improvements in management of STEC O157 diarrhea, or an actual decrease in infections with the most virulent strains of STEC O157. It is possible that more stool specimens are being tested for STEC, resulting in increased detection of milder infections than in the past. Continued surveillance is needed to determine if this pattern holds.

CIDTs are increasingly used by clinical laboratories to diagnose bacterial enteric infections, a trend that will challenge the ability to identify cases, monitor trends, detect outbreaks, and characterize pathogens (8). Therefore, FoodNet began tracking CIDT-positive reports and surveying clinical laboratories about their diagnostic practices. The adoption of CIDTs has varied by pathogen and has been highest for STEC and Campylobacter. Positive CIDTs frequently cannot be confirmed by culture, and the positive predictive value varies by the CIDT used. For STEC, most specimens identified as Shiga toxin–positive were sent to a public health laboratory for confirmation. However, for other pathogens the fraction of specimens from patients with a positive CIDT sent for confirmation likely is low because no national guidelines regarding confirmation of CIDT results currently exist. As the number of approved CIDTs increases, their use likely will increase rapidly. Clinicians, clinical and public health laboratorians, public health practitioners, regulatory agencies, and industry must work together to maintain strong surveillance to detect dispersed outbreaks, measure the impact of prevention measures, and identify emerging threats.

The findings in this report are subject to at least five limitations. First, health-care–seeking behaviors and other characteristics of the population in the surveillance area might affect the generalizability of the findings. Second, some agents transmitted commonly through food (e.g., norovirus) are not monitored by FoodNet because clinical laboratories do not routinely test for them. Third, the proportion of illnesses transmitted by nonfood routes differs by pathogen; data provided in this report are not limited to infections from food. Fourth, in some fatal cases, infection with the enteric pathogen might not have been the primary cause of death. Finally, changes in incidence between periods can reflect year-to-year variation during those periods rather than sustained trends.

Most foodborne illnesses can be prevented, and progress has been made in decreasing contamination of some foods and reducing illness caused by some pathogens since 1996, when FoodNet began. More can be done; surveillance data provide information on where to target prevention efforts. In 2011, USDA-FSIS tightened its performance standard for Salmonella contamination of whole broiler chickens; in 2013, 3.9% of samples tested positive (Christopher Aston, USDA-FSIS, Office of Data Integration and Food Protection; personal communication; 2014). Because most chicken is purchased as cut-up parts, USDA-FSIS conducted a nationwide survey of raw chicken parts in 2012 and calculated an estimated 24% prevalence of Salmonella (9). In 2013, USDA-FSIS released its Salmonella Action Plan that indicates that USDA-FSIS will conduct a risk assessment and develop performance standards for poultry parts during 2014, among other key activities (10). The Food Safety Modernization Act of 2011 gives FDA additional authority to regulate food facilities, establish standards for safe produce, recall contaminated foods, and oversee imported foods; it also calls on CDC to strengthen surveillance and outbreak response (1). For consumers, advice on safely buying, preparing, and storing foods prone to contamination is available online.

1Division of Foodborne, Waterborne, and Environmental Diseases, National Center for Emerging and Zoonotic Infectious Diseases, CDC; 2California Department of Public Health; 3Colorado Department of Public Health and Environment; 4Connecticut Department of Public Health; 5Georgia Department of Public Health; 6Maryland Department of Health and Mental Hygiene; 7Minnesota Department of Health; 8University of New Mexico; 9New York State Department of Health; 10Oregon Health Authority; 11Tennessee Department of Health; 12Food Safety and Inspection Service, US Department of Agriculture; 13Center for Food Safety and Applied Nutrition, Food and Drug Administration (Corresponding author: Olga L. Henao, ohenao@cdc.gov, 404-639-3393)

Acknowledgments

Workgroup members, Foodborne Diseases Active Surveillance Network (FoodNet), Emerging Infections Program. Communications team, Division of Foodborne, Waterborne, and Environmental Diseases, National Center for Emerging and Zoonotic Diseases; Enteric Diseases Laboratory Branch, Division of Foodborne, Waterborne, and Environmental Diseases, National Center for Emerging and Zoonotic Diseases, CDC.

References

  1. Food and Drug Administration. FDA Food Safety Modernization Act. Washington, DC: US Department of Health and Human Services, Food and Drug Administration; 2011. Available at http://www.fda.gov/food/guidanceregulation/fsma/ucm247548.htmExternal Web Site Icon.
  2. Henao OL, Scallan E, Mahon B, Hoekstra RM. Methods for monitoring trends in the incidence of foodborne diseases: Foodborne Diseases Active Surveillance Network 1996–2008. Foodborne Pathog Dis 2010;7:1421–6.
  3. Henao OL, Crim SM, Hoekstra RM. Calculating a measure of overall change in the incidence of selected laboratory-confirmed infections with pathogens transmitted commonly through food, Foodborne Diseases Active Surveillance Network (FoodNet), 1996–2010. Clin Infect Dis 2012;54(Suppl 5):S418–20.
  4. Shapiro RL, Altekruse S, Hutwagner L, et al. The role of Gulf Coast oysters harvested in warmer months in Vibrio vulnificus infections in the United States, 1988–1996. J Infect Dis 1998;178:752–9.
  5. CDC. National enteric disease surveillance: COVIS annual summary, 2011. Atlanta, Georgia: US Department of Health and Human Services, CDC; 2013. Available at http://www.cdc.gov/ncezid/dfwed/pdfs/covis-annual-report-2011-508c.pdf Adobe PDF file.
  6. Vugia DJ, Tabnak F, Newton AE, et al. Impact of 2003 state regulation on raw oyster-associated Vibrio vulnificus illnesses and deaths, California, USA. Emerg Infect Dis 2013;19:1276–80.
  7. Dechet AM, Yu PA, Koram N, Painter J. Nonfoodborne Vibrio infections: an important cause of morbidity and mortality in the United States, 1997–2006. Clin Infect Dis 2008;46:970–6.
  8. Cronquist AB, Mody RK, Atkinson R, et al. Impacts of culture-independent diagnostic practices on public health surveillance for bacterial enteric pathogens. Clin Infect Dis 2012;54(S5):S432–9.
  9. US Department of Agriculture, Food Safety and Inspection Service. The Nationwide Microbiological Baseline Data Collection Program: Raw Chicken Parts Survey, January 2012–August 2012. Washington, DC: US Department of Agriculture, Food Safety and Inspection Service; 2013. Available at http://www.fsis.usda.gov/wps/wcm/connect/a9837fc8-0109-4041-bd0c-729924a79201/baseline_data_raw_chicken_parts.pdf?mod=ajperesExternal Web Site Icon.
  10. US Department of Agriculture, Food Safety and Inspection Service. Strategic Performance Working Group Salmonella action plan. Washington, DC: US Department of Agriculture, Food Safety and Inspection Service; 2013. Available at http://www.fsis.usda.gov/wps/wcm/connect/aae911af-f918-4fe1-bc42-7b957b2e942a/sap-120413.pdf?mod=ajperesExternal Web Site Icon.

* Additional information available at http://www.cdc.gov/foodnet.

† The overall incidence of infection combines data for Campylobacter, Listeria, Salmonella, STEC O157, Vibrio, and Yersinia, six key bacterial pathogens for which >50% of illnesses are estimated to be transmitted by food.

§ FoodNet personnel regularly contact clinical laboratories to ascertain all laboratory-confirmed infections in residents of the surveillance areas.

¶ Final incidence rates will be reported when population estimates for 2013 are available.

** Additional information available at http://www.cdc.gov/salmonella/enteritidis/index.html.

†† Additional information available at http://www.fda.gov/food/guidanceregulation/guidancedocumentsregulatoryinformation/eggs/ucm170615.htmExternal Web Site Icon.

§§ Additional information available at http://www.hhs.gov/strategic-plan/appendixb3.htmlExternal Web Site Icon.

¶¶ Additional information available at http://www.cdc.gov/vibrio/investigations/index.html.

What is already known on this topic?

The incidences of infection caused by Campylobacter, Salmonella, Shiga toxin–producing Escherichia coli O157, and Vibrio are well above their respective Healthy People 2020 targets. Foodborne illness continues to be an important public health problem.

What is added by this report?

In 2013, a total of 19,056 infections, 4,200 hospitalizations, and 80 deaths were reported to the Foodborne Diseases Active Surveillance Network (FoodNet). For most infections, incidence was highest among children aged <5 years. In 2013, compared with 2010–2012, the estimated incidence of infection was unchanged overall, lower for Salmonella, and higher for Vibrio infections, which have been increasing in frequency for many years. The number of patients being diagnosed by culture-independent diagnostic tests (CIDT) is increasing.

What are the implications for public health practice?

Reducing the incidence of foodborne infections requires greater commitment and more action to implement measures to reduce contamination of food. Monitoring the incidence of these infections is becoming more difficult because some laboratories are now using CIDTs, and some do not follow up a positive CIDT result with a culture.

TABLE. Number of cases of culture-confirmed bacterial and laboratory-confirmed parasitic infection, hospitalizations, and deaths, by pathogen — Foodborne Diseases Active Surveillance Network, United States, 2013*
Pathogen Cases Hospitalizations Deaths
No. Incidence Objective§ No. (%) No. (%)
Bacteria 
Campylobacter 6,621 13.82 8.5 1,010 (15) 12 (0.2)
Listeria 123 0.26 0.2 112 (91) 24 (19.5)
Salmonella 7,277 15.19 11.4 2,003 (28) 27 (0.4)
Shigella 2,309 4.82 N/A¶ 450 (19) 3 (0.1)
STEC O157 552 1.15 0.6 210 (38) 2 (0.4)
STEC non-O157 561 1.17 N/A 76 (14) 2 (0.4)
Vibrio 242 0.51 0.2 55 (23) 2 (0.8)
Yersinia 171 0.36 0.3 55 (32) 4 (2.3)
Parasites
Cryptosporidium 1,186 2.48 N/A 227 (19) 4 (0.3)
Cyclospora 14 0.03 N/A 2 (14) 0 (0.0)
Total 19,056     4,200   80  
Abbreviations: N/A = not available; STEC = Shiga toxin–producing Escherichia coli.* Data for 2013 are preliminary.

† Per 100,000 population.

§ Healthy People 2020 objective targets for incidence of Campylobacter, Listeria, Salmonella, STEC O157, Vibrio, and Yersinia infections per 100,000 population.

¶ No national health objective exists for these pathogens.

FIGURE 1. Estimated percentage change in incidence of culture-confirmed bacterial and laboratory-confirmed parasitic infections in 2013 compared with average annual incidence during 2010–2012, by pathogen — Foodborne Diseases Active Surveillance Network, United StatesThe figure above shows estimated percentage change in incidence of culture-confirmed bacterial and laboratory-confirmed parasitic infections in 2013 compared with average annual incidence during 2010–2012, by pathogen, in the United States. Compared with 2010–2012, the 2013 incidence was sig¬nificantly lower for Salmonella (9% decrease; 95% confidence interval = 3%–15%), higher for Vibrio (32% increase; 95% confidence interval = 8%–61%) and not sig¬nificantly changed for other pathogens.Abbreviations: CI = confidence interval; STEC = Shiga toxin–producing Escherichia coli.

* No significant change = 95% CI is both above and below the no change line; significant increase = estimate and entire CI are above the no change line; significant decrease = estimate and entire CI are below the no change line.

Alternate Text: The figure above shows estimated percentage change in incidence of culture-confirmed bacterial and laboratory-confirmed parasitic infections in 2013 compared with average annual incidence during 2010–2012, by pathogen, in the United States. Compared with 2010–2012, the 2013 incidence was significantly lower for Salmonella (9% decrease; 95% confidence interval = 3%–15%), higher for Vibrio (32% increase; 95% confidence interval = 8%–61%) and not sig¬nificantly changed for other pathogens.

FIGURE 2. Relative rates of culture-confirmed infections with Campylobacter, STEC* O157, Listeria, Salmonella, and Vibrio compared with 2006–2008 rates, by year — Foodborne Diseases Active Surveillance Network, United States, 2006–2013The figure above shows relative rates of culture-confirmed infections with Campylobacter, Shiga toxin–producing Escherichia coli O157, Listeria, Salmonella, and Vibrio compared with 2006–2008 rates, by year, in the United States during 2006–2013. Compared with 2006–2008, the 2013 incidence was significantly higher for Campylobacter and Vibrio.* Shiga toxin–producing Escherichia coli.

† The position of each line indicates the relative change in the incidence of that pathogen compared with 2006–2008. The actual incidences of these infections cannot be determined from this figure.

Alternate Text: The figure above shows relative rates of culture-confirmed infections with Campylobacter, Shiga toxin–producing Escherichia coli O157, Listeria, Salmonella, and Vibrio compared with 2006–2008 rates, by year, in the United States during 2006–2013. Compared with 2006–2008, the 2013 incidence was significantly higher for Campylobacter and Vibrio.

 

Sun
26
May '13

Diarrhoeal disease in infants and young children in developing countries

Kotloff KL, Nataro JP, Blackwelder WC, et al. Burden and aetiology of diarrhoeal disease in infants and young children in developing countries (the Global Enteric Multicenter Study, GEMS): a prospective, case-control study. Lancet 2013 May 14

“……[M]ost attributable cases of moderate-to-severe diarrhoea were due to four pathogens: rotavirus, Cryptosporidium, enterotoxigenic Escherichia coli producing heat-stable toxin (ST-ETEC; with or without co-expression of heat-labile enterotoxin), and Shigella. ………….Odds of dying during follow-up were 8·5-fold higher in patients with moderate-to-severe diarrhoea than in controls (odd ratio 8·5, 95% CI 5·8—12·5, p<0·0001); most deaths (167 [87·9%]) occurred during the first 2 years of life.

Pathogens associated with increased risk of case death were ST-ETEC (hazard ratio [HR] 1·9; 0·99—3·5) and typical enteropathogenic E coli (HR 2·6; 1·6—4·1) in infants aged 0—11 months, and Cryptosporidium (HR 2·3; 1·3—4·3) in toddlers aged 12—23 months……”

NASA:  Earthrise

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Sat
11
May '13

Food-borne illness in Canada

http://www.phac-aspc.gc.ca/efwd-emoha/efbi-emoa-eng.php

Estimates of Food-borne Illness in Canada

The Public Health Agency of Canada estimates that each year roughly one in eight Canadians (or four million people) get sick due to domestically acquired food-borne diseases. This estimate provides the most accurate picture yet of which food-borne bacteria, viruses, and parasites (“pathogens”) are causing the most illnesses in Canada, as well as estimating the number of food-borne illnesses without a known cause.

In general, Canada has a very safe food supply; however, this estimate shows that there is still work to be done to prevent and control food-borne illness in Canada, to focus efforts on pathogens which cause the greatest burden and to better understand food-borne illness without a known cause.

About the estimates of food-borne illness in Canada

Findings

The Public Health Agency of Canada estimates that each year roughly one in eight Canadians (or four million people) get sick with a domestically acquired food-borne illness.

The Agency has estimates for two major groups of food-borne illnesses:

  • Known food-borne pathogens: There are 30 pathogens known to cause food-borne illness. Many of these pathogens are tracked by public health systems that monitor cases of illness.
  • Unspecified agents: Because you can’t “monitor” what is not yet identified, estimates for this group of agents were developed by first looking at the health effects or symptoms that they are most likely to cause—acute gastrointestinal illness (AGI) (i.e. vomiting and diarrhea). Unspecified agents were defined as: agents with insufficient data to estimate agent-specific burden; known agents not yet identified as causing food-borne illness; microbes, chemicals, or other substances known to be in food whose ability to cause illness is unproven; and agents not yet identified.

To estimate the total number of food-borne illnesses, the Agency estimated the number of illnesses caused by both known food-borne pathogens and unspecified agents.

 

Table 1. Estimated annual number of domestically acquired food-borne illnesses due to 30 known pathogens and unspecified agents transmitted through food in Canada, circa 2006Table 1 – Footnote 1
Food-borne agents Estimated annual number of illnesses
(90% credible interval)
%
Table 1 – Footnote 1
The data used were based on the 2000-2010 time period, and the 2006 Canadian Census was used as a referent population thus the estimates are based circa the year 2006.
30 known pathogens 1.6 million (1.2–2.0 million) 40
Unspecified agents 2.4 million (1.8–3.0 million) 60
Total 4.0 million (3.1–5.0 million) 100
Table 2. Top four pathogens causing domestically acquired food-borne illnesses in Canada, circa 2006
Pathogen Estimated annual number of illnesses
(90% credible interval)
%
Norovirus 1,047,733 (679,576 – 1,434,048) 65
Clostridium perfringensExternal Link 176, 963 (95,225 – 270,160) 11
Campylobacter spp.External Link 145,350 (95,686 – 212,971) 8
Salmonella, nontyphoidal 87,510 (58,832 – 125,525) 5
Subtotal   89

 

Journal publication

The full article entitled “Estimates of the Burden of Food-borne Illness in Canada for 30 Specified Pathogens and Unspecified Agents, circa 2006External Link” is published in the journal Foodborne Pathogens and DiseasesExternal Link.

If you would like a copy of the article in either English or French please contact: enteric.surveillance.entérique@phac-aspc.gc.ca.

Methods and Data Sources

Surveillance and Data Systems

Many surveillance systems are used in Canada to provide information about the occurrence of food-borne illness. Most of the Agency’s surveillance systems rely on data from provincial/territorial and local public health ministries/units/authorities. Systems focus on specific pathogens likely to be transmitted through food to detect outbreaks, monitor trends and risk factors.

Each surveillance system plays a role in detecting and preventing food-borne illness and outbreaks.

 

Table 3. Surveillance systems used in developing Canadian Estimates for Food-borne IllnessTable 3 – Footnote 1
Data Source Description Geographic Coverage Timeframe of data used
Table 3 – Footnote 1
Though PulseNet Canada and the Canadian Integrated Program for Antimicrobial Resistance Surveillance (CIPARS) were not used in developing these estimates they are other important surveillance systems for food-borne illness in Canada.
Canadian Notifiable Disease Surveillance System (CNDSS) Collects the number of laboratory confirmed illnesses reported to local public health units/regions to provincial public health authorities and to the national level on an annual basis. National 2000-2008
National Enteric Surveillance Program (NESP) Collects detailed case level data from invasive listeriosis cases in participating provinces. National 2000-2010
Enhanced National Listeriosis Surveillance Collects aggregate counts of laboratory isolates of select enteric pathogens (species and subtype) reported through the provincial laboratories on a weekly basis. National 2010-2012
Provincial Reportable Disease Surveillance System Collects the number of laboratory confirmed illnesses reported from local public health units/regions to provincial public health authorities only. Provincial 2000-2010
National Studies on Acute Gastrointestinal Illness (NSAGI) Population Surveys Population surveys asking Canadians about vomiting and diarrhea. Ontario, British Columbia 2001-2002, 2002-2003, and 2005-2006
C-EnterNet Surveillance An integrated enteric pathogen surveillance system based on a sentinel site surveillance model that collects information on both cases of infectious gastrointestinal illness and sources of exposure within defined communities. This system provides detailed case information on clinical illness and risk factors. Waterloo Region, Ontario 2005-2010

 

Under-reporting and under-diagnosis

In general, to be captured in a Canadian surveillance system a sick individual must: seek care; have a sample (stool, urine or blood) requested; and submit a sample for testing. In addition, the sample must be tested with a test capable of identifying the causative agent; and finally the positive test result must be reported to the surveillance system (Figure 1). Surveillance systems only capture a small portion of total illnesses given all these necessary steps (i.e. there is under-diagnosis and under-reporting taking place).

Figure 1 Burden of illness pyramid

Figure 1 Burden of illness pyramid

Text Equivalent – Figure 1

Methodological Approaches

Estimating Canadian food-borne illnesses for 30 known food-borne pathogens

Two main methods were used to estimate the number of Canadian food-borne illnesses for the Listing of 30 known pathogens.

The first approach:

For each pathogen with surveillance data, we used data from various surveillance systems and corrected for under-reporting and under-diagnosis. We then multiplied the adjusted number by the proportion of illnesses acquired in Canada (that is, not acquired during international travel) and the proportion transmitted by food, to estimate the number of illnesses that are domestically acquired and food-borne (Figure 2).

The second approach:

For common pathogens that are not part of standard surveillance, we estimated the number of Canadians who would experience symptoms (e.g. diarrheal illness) and the proportion of those symptoms that is related to the particular pathogen. We then multiplied this number by the proportion of illnesses acquired in Canada and the proportion transmitted by food, to yield an estimated number of illnesses that are domestically acquired and food-borne (Figure 3).

Alternative approaches were used to estimate illnesses where suitable data from surveillance or data on proportion of symptoms attributed to the pathogen were not available.

Then, the estimates for each of the pathogens were added together to arrive at an overall pathogen specific total. An uncertainty model to generate a point estimate and 90% credible interval (i.e. upper and lower limits that account for variability and uncertainty of the data) was used.

Figure 2Figures 2 and 3 – Footnote * First approach: For pathogens where laboratory-confirmed cases were scaled up

Figure 2 First approach: For pathogens where laboratory-confirmed cases were scaled up

Text Equivalent – Figure 2

 

Figure 3Figures 2 and 3 – Footnote * Second approach: For pathogens where Canadian population was scaled down

Text Equivalent – Figure 3

Footnote *
Probability distributions were used to model uncertainty in each data inputs. Point estimates were bounded by a 90% credible interval.

Listing of 30 known pathogens by estimation method

Pathogens for which laboratory-confirmed illnesses were scaled up

National reportable disease data

  • Brucella spp.
  • Campylobacter spp.
  • Clostridium botulinum
  • Cryptosporidium spp.
  • Cyclospora cayetanensis
  • VTEC O157
  • Giardia sp.
  • Hepatitis A
  • Salmonella spp., nontyphoidal
  • Salmonella Typhi
  • Shigella spp
  • Vibrio cholera
  • Vibrio spp., other
  • Vibrio vulnificus

Provincial reportable disease data

  • Trichinella spp.
  • Listeria monocytogenes
  • Vibrio parahaemolyticus
  • Yersinia enterocolitica

Pathogens for which Canadian population scaled down

  • Adenovirus
  • Astrovirus
  • Norovirus
  • Rotavirus
  • Sapovirus
  • Toxoplasma gondii
  • Clostridium perfringens

Other methods

  • E. coli, other diarrheagenic
  • ETEC
  • VTEC non-O157
  • Bacillus cereus
  • Staphylococcus aureus

Estimating Canadian food-borne illnesses for unspecified agents

Unspecified agents that cause acute gastrointestinal illness fall into four general categories:

  • Agents with insufficient data to estimate agent-specific burden
  • Known agents not yet recognized as causing food-borne illness
  • Microbes, chemicals, or other substances known to be in food that could at some time be shown to cause illness Agents not yet described
  • Agents not yet described

To estimate food-borne illnesses from unspecified agents, we used symptom-based data from surveys to estimate the total number of episodes of acute gastrointestinal illnesses (AGI) and then subtracted the number of illnesses accounted for by known AGI pathogens. We then multiplied this number by the proportion of domestically acquired illnesses and of illnesses attributable to food, just as we did for the known agents. Finally, as with the known-pathogens estimate, we used an uncertainty model to generate a point estimate and 90% credible interval (upper and lower limits) (Figure 4).

Food-borne illnesses due to chemicals that cause acute gastrointestinal illness are included in the estimate of illnesses due to unspecified agents. However, chemicals or unspecified agents that do not cause acute gastrointestinal illness are not included in the estimates.

Figure 4Figures 4 – Footnote * Approach for unspecified agentsApproach for unspecified agents

Text Equivalent – Figure 4

 

Footnote *
Probability distributions were used to model uncertainty in each data input. Point estimates were bounded by a 90% credible interval.
Footnote **
Estimated proportions were based on 25 known pathogens that cause acute gastrointestinal illness. Five pathogens were not included because their primary symptoms are not acute gastrointestinal illness.

Improvements to previous estimates

The Agency’s 2013 estimates of illnesses from food-borne diseases in Canada are more accurate than the estimates published in 2008 of 11 million episodes of food-borne illness each year based on better data and methodologies. The 2008 estimates used values from earlier United States Centers for Disease Control and PreventionExternal Link estimates applied to a Canadian estimate of the average number of episodes of acute gastrointestinal illness per person occurring each year. In addition, the methodology used for the 2013 estimates is different from that used in 2008. As a result of these differences, no strict side-by-side comparison can be made between the two sets of estimates. The 2013 estimates do not mean that there is less food-borne illness occurring, but rather, that more accurate estimates are now possible.

The 2013 estimates of illnesses from food-borne disease in Canada reflect improvements in methodology since 2008. Perhaps most importantly, these new estimates identify and rank the most important bacteria, viruses and parasites (“pathogens”) responsible for causing food-borne illness. These more specific estimates can further inform policy and regulatory priorities to prevent future illnesses.

The following list highlights the major differences in data and methodology between the new estimates and those published in 2008, and how they affect the estimates of illnesses from food-borne diseases in Canada.

Differences between 2008 and 2013 methodology

2008

  • Included international travel-related illnesses.
  • Did not estimate illness for individual pathogens.
  • Utilised 1.3 episodes per person/year based on the following AGI case definition: any diarrhea or vomiting in the past 28 days excluding those with chronic conditions.
  • 36% = Proportion applied to rate of acute gastrointestinal illness (known pathogens and the unspecified agents included) estimated to be food-borne (based on the US 1999 estimates).
  • Uncertainty and variability of each input was not calculated.

2013

  • Excluded international travel-related illnesses.
  • Estimates of illness for 30 known pathogens.
  • Pathogen-specific multipliers used to adjust for under-reporting and under-diagnosis.
  • Pathogen specific proportion domestically acquired and food-borne applied.
  • Utilised 0.63 episodes per person/year based on the following AGI case definition: 3 or more loose stools in 24 hours or any vomiting in the past 28 days excluding those with chronic conditions, or concurrent symptoms of coughing, sneezing, sore throat or runny nose.
  • 20% = Proportion of the unspecified agents estimated to be food-borne (based on pathogen specific information on proportion food-borne).
  • The Agency used many data sources, with varying degrees of reliability, to determine the estimates of food-borne illnesses. For each estimate, a formula was used to account for the cumulative effect of uncertainty and variability of the data inputs.

Effects of Difference

  • 2013 estimate focused on food-borne illnesses acquired in Canada: 2013 estimates were limited to food-borne illnesses that were acquired in Canada, which reduced the number of food-borne illnesses in 2013 vs. 2008.
  • 2013 estimated number of illnesses caused by known pathogens: more accurate: Utilising specific multipliers and proportion domestically acquired and food-borne for the 30 known pathogens yielded more accurate estimates for each known pathogen and, ultimately, greater accuracy in the overall estimate of food-borne illness.
  • 2013 estimate of acute gastrointestinal illnesses (AGI): more precise: A more specific case definition for AGI was used to be more precise in the estimate and to minimize the chance of estimating illness that was not infectious (i.e. related to chronic illnesses such as Crohn’s disease) and not truly gastrointestinal (i.e. symptoms related to a respiratory infection). The impact of this is a lower overall estimate in 2013 vs. 2008.
  • 2013 estimate used a smaller proportion of unspecified AGI determined to be food-borne: Reduced the number of food-borne illnesses in 2013 vs. 2008.
  • 2013 estimate accounted for uncertainty: The results were upper and lower 90% credible limits, (i.e. a 90% credible interval). This means that 90% of the time the true value of the estimate falls within the upper and lower values.

Although we cannot compare these estimates to determine trends, we can turn to other data sources for information about trends in some important infections that are transmitted commonly through food.

Trends

Data from the Canadian Notifiable Disease Surveillance System (CNDSS) and National Enteric Surveillance Program (NESP) provide the best measures of disease trends. Although these systems include only a portion of the pathogens that make up the estimates, it does allow us to see changes over time for these important food-borne pathogens.

According to these systems some food-borne illnesses have dropped substantially over the past decade, but infections caused by one of the most common pathogens – Salmonella have not declined.

Trends in food-borne illness for 2011 compared to the 1998-2000 baseline period:

  • No significant change in the rate of Salmonella infection (NESP).
  • 35% decrease (95%CI 33-36%) in the rate of campylobacteriosis (CNDSS)
  • 68% decrease (95%CI 65-71%) in the number of O157 Verotoxigenic Escherichia coli (VTEC) infections (NESP)
  • 27% decrease (95%CI 22-32%) in the rate of shigellosis (CNDSS)

Other important pathogens commonly transmitted through food (e.g. norovirus, Clostridium perfringens, Toxoplasma gondii) are not tracked in part because they cause mild symptoms of short duration and because of current limitations in laboratory capacity and techniques. Common prevention measures (e.g. safe food handling) that would decrease illness caused by tracked pathogens would also decrease illness caused by pathogens not currently being tracked.

Figure 5 Relative rates of laboratory-confirmed infections with Campylobacter, VTEC O157, Salmonella, and Shigella compared with 1998–2000 rates, by year, 2001–2011, CNDSS and NESP

Figure 5 Relative rates of laboratory-confirmed infections with Campylobacter, VTEC O157, Salmonella, and Shigella compared with 1998–2000 rates, by year, 2001–2011, CNDSS and NESP

Text Equivalent – Figure 5

 

Comparison to US methodology and results

Canada used similar methodologies as the United States Centre for Disease Control and Prevention (US-CDC) for estimating the burden of food-borne illness in their country.

Findings

The overall total estimate (specified and unspecified agents) for Canada is slightly less than the US-CDC estimate with approximately one in eight Canadians compared to the US-CDC estimate of one in six Americans, experiencing food-borne illness per year.

Top 4 Pathogens contributing to total domestic food-borne illness in:

Canada

  • Norovirus
  • Clostridium perfringens
  • Campylobacter spp
  • Salmonella spp., non-typhoidal

The United States

  • Norovirus
  • Salmonella spp., non-typhoidal
  • Clostridium perfringens
  • Campylobacter spp.

Methods

Canada

  • Inclusion of adenovirus and exclusion of Mycobacterium bovis and Streptococcus Group A (pathogens excluded are not relevant to Canada’s domestic food supply).
  • Incorporated duration of illness and bloody diarrhea to define severe cases for some pathogens.
  • Ratio of Bacillus cereus and Staphylococcus aureus to Clostridium perfringens using reported provincial data was applied to the estimate obtained through the population incidence of Clostridium perfringens from UK study.
  • Estimated rotavirus, astrovirus and sapovirus for the total population.
  • Included illnesses due to viruses for the total population as part of specified pathogen estimate.

The United States

  • Did not include adenovirus but did include Mycobacterium bovis and Streptococcus Group A.
  • Included only bloody diarrhea in definition of severe cases for some pathogens.
  • Used data from outbreak reporting system and then applied an outbreak to sporadic ratio for Bacillus cereus, Staphylococcus aureus and Clostridium perfringens.
  • Estimated rotavirus, astrovirus and sapovirus for < 5 years of age only.
  • Illnesses related to viruses for those greater than 5 years of age are included in the unspecified agents’ estimate.

Effects of Methods

  • Pathogens causing food-borne illness included in the estimate: Minimal impact to differences in overall estimates.
  • Canadian definition of severity of illness included duration: Results in a higher proportion of cases being considered severe, and ultimately in a lower estimate of under-diagnosis in Canada compared to the United States.
  • Approach to estimating bacterial food-borne toxins: Different approaches therefore difficult to compare the effect.
  • Viruses calculated for total population: Reduced the number of cases in the unspecified portion as these were now part of the number of viruses estimated within the specified pathogens portion for Canada compared to the United States. Results in a lower total food-borne estimate for Canada compared to the US as these viruses have a low proportion food-borne.
  • Unspecified agents: Reduced the number of cases estimated in the unspecified portion (60% of total) compared to the US (80% of total). Also reduces proportion food-borne (20%) compared to US (25%) applied to AGI caused by unspecified agents

Additional Information

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Foodborne Diseases Active Surveillance Network, 10 U.S. Sites, 1996–2012

http://www.cdc.gov/mmwr/preview/mmwrhtml/mm6215a2.htm?s_cid=mm6215a2_e

Incidence and Trends of Infection with Pathogens Transmitted Commonly Through Food — Foodborne Diseases Active Surveillance Network, 10 U.S. Sites, 1996–2012

What is already known on this topic? The incidence of infections transmitted commonly by food that are tracked by the Foodborne Diseases Active Surveillance Network (FoodNet) has changed little in recent years. Foodborne illness continues to be an important public health problem.

What is added by this report? Preliminary surveillance data show that the incidence of infections caused by Campylobacter and Vibrio increased in 2012, whereas incidence of other foodborne infections tracked by FoodNet was unchanged (i.e., Cryptosporidium, Listeria, Salmonella, Shigella, Shiga toxin–producing Escherichia coli O157, and Yersinia).

What are the implications for public health practice? Reducing the incidence of foodborne infections will require commitment and action to implement measures known to reduce contamination of food and to develop new measures. Farmers, the food industry, regulatory agencies, the food service industry, consumers, and public health authorities all have a role.

Weekly

April 19, 2013 / 62(15);283-287

Foodborne diseases are an important public health problem in the United States. The Foodborne Diseases Active Surveillance Network* (FoodNet) conducts surveillance in 10 U.S. sites for all laboratory-confirmed infections caused by selected pathogens transmitted commonly through food to quantify them and monitor their incidence. This report summarizes 2012 preliminary surveillance data and describes trends since 1996. A total of 19,531 infections, 4,563 hospitalizations, and 68 deaths associated with foodborne diseases were reported in 2012. For most infections, incidence was highest among children aged <5 years; the percentage of persons hospitalized and the percentage who died were highest among persons aged ≥65 years. In 2012, compared with the 2006–2008 period, the overall incidence of infection† was unchanged, and the estimated incidence of infections caused by Campylobacter and Vibrio increased. These findings highlight the need for targeted action to address food safety gaps.

FoodNet conducts active, population-based surveillance for laboratory-confirmed infections caused by Campylobacter, Cryptosporidium, Cyclospora, Listeria, Salmonella, Shiga toxin–producing Escherichia coli (STEC) O157 and non-O157, Shigella, Vibrio, and Yersinia in 10 sites covering 15% of the U.S. population (48 million persons in 2011).§ FoodNet is a collaboration among CDC, 10 state health departments, the U.S. Department of Agriculture’s Food Safety and Inspection Service (USDA-FSIS), and the Food and Drug Administration (FDA). Hospitalizations occurring within 7 days of specimen collection date are recorded, as is the patient’s vital status at hospital discharge, or at 7 days after the specimen collection date if the patient was not hospitalized. All hospitalizations and deaths that occurred within a 7-day window are attributed to the infection. Surveillance for physician-diagnosed postdiarrheal hemolytic uremic syndrome (HUS), a complication of STEC infection characterized by renal failure, is conducted through a network of nephrologists and infection preventionists and by hospital discharge data review. This report includes 2011 HUS data for persons aged <18 years.

Incidence was calculated by dividing the number of laboratory-confirmed infections in 2012 by U.S. Census estimates of the surveillance population area for 2011.¶ A negative binomial model with 95% confidence intervals (CIs) was used to estimate changes in incidence from 2006–2008 to 2012 and from 1996–1998 to 2012 (1). The overall incidence of infection with six key pathogens for which >50% of illnesses are estimated to be foodborne (Campylobacter, Listeria, Salmonella, STEC O157, Vibrio, and Yersinia) was calculated (2). Trends were not assessed for Cyclospora because data were sparse, or for STEC non-O157 because of changes in diagnostic practices. For HUS, changes in incidence from 2006–2008 to 2011 were estimated.

Incidence and Trends

In 2012, FoodNet identified 19,531 laboratory-confirmed cases of infection (Table 1). The number of infections and incidence per 100,000 population, by pathogen, were as follows: Salmonella (7,800; 16.42), Campylobacter (6,793; 14.30), Shigella (2,138; 4.50), Cryptosporidium (1,234; 2.60), STEC non-O157 (551; 1.16), STEC O157 (531; 1.12), Vibrio (193; 0.41), Yersinia (155; 0.33), Listeria (121; 0.25), and Cyclospora (15; 0.03). As usual, the highest reported incidence was among children aged <5 years for Cryptosporidium and the bacterial pathogens other than Listeria and Vibrio, for which the highest incidence was among persons aged ≥65 years (Table 2).

Among 6,984 (90%) serotyped Salmonella isolates, the top three serotypes were Enteritidis, 1,238 (18%); Typhimurium, 914 (13%); and Newport, 901 (13%). Among 183 (95%) Vibrio isolates with species information, 112 were V. parahaemolyticus (61%), 25 were V. vulnificus (14%), and 20 were V. alginolyticus (11%). Among 496 (90%) serogrouped STEC non-O157 isolates, the most common serogroups were O26 (27%), O103 (23%), and O111 (15%). Among 2,318 (34%) Campylobacter isolates with species information, 2,082 (90%) were C. jejuni, and 180 (8%) were C. coli.

The estimated incidence of infection was higher in 2012 compared with 2006–2008 for Campylobacter (14% increase; confidence interval [CI]: 7%–21%) and Vibrio (43% increase; CI: 16%–76%) and unchanged for other pathogens (Figure 1). In comparison with 1996–1998, incidence of infection was significantly lower for Campylobacter, Listeria, Shigella, STEC O157, and Yersinia, whereas the incidence of Vibrio infection was higher (Figure 2). The overall incidence of infection with six key pathogens** transmitted commonly through food was lower in 2012 (22% decrease; CI: 11%–32%) compared with 1996–1998 and unchanged compared with 2006–2008.

The incidence of infections with specific Salmonella serotypes in 2012, compared with 2006–2008, was lower for Typhimurium (19% decrease; CI: 10%–28%), higher for Newport (23% increase; CI: 1%–50%), and unchanged for Enteritidis. Compared with 1996–1998, the incidence of infection was significantly higher for Enteritidis and Newport, and lower for Typhimurium.

Among 63 cases of postdiarrheal HUS in children aged <18 years (0.57 cases per 100,000 children) in 2011, 33 (52%) occurred in children aged <5 years (1.09 cases per 100,000). Compared with 2006–2008, the incidence was significantly lower for children aged <5 years (44% decrease; CI: 18%–62%) and for children aged <18 years (29% decrease; CI: 4%–47%).

Hospitalizations and Deaths

In 2012, FoodNet identified 4,563 hospitalizations and 68 deaths among cases of infection with pathogens transmitted commonly through food (Table 1). The percentage of patients hospitalized ranged from 15% for Campylobacter to 96% for Listeria infections. The percentage hospitalized was greatest among those aged ≥65 years for STEC O157 (67%), Vibrio (58%), Salmonella (55%), Cyclospora (50%), Shigella (41%), STEC non-O157 (34%), Cryptosporidium (33%), and Campylobacter (31%). At least 95% of patients with Listeria infection in each age group†† with cases were hospitalized. The percentage of patients who died ranged from 0% for Yersinia and Cyclospora to 11% for Listeria infections. The percentage that died was highest among persons aged ≥65 years for Vibrio (6%), Salmonella (2%), STEC O157 (2%), Cryptosporidium (1%), Shigella (1%), and Campylobacter (0.2%).

Reported by

Debra Gilliss, MD, California Dept of Public Health. Alicia B. Cronquist, MPH, Colorado Dept of Public Health and Environment. Matthew Cartter, MD, Connecticut Dept of Public Health. Melissa Tobin-D’Angelo, MD, Georgia Dept of Public Health. David Blythe, MD, Maryland Dept of Health and Mental Hygiene. Kirk Smith, DVM, Minnesota Dept of Health. Sarah Lathrop, PhD, Univ of New Mexico. Shelley Zansky, PhD, New York State Dept of Health. Paul R. Cieslak, MD, Oregon Health Authority. John Dunn, DVM, Tennessee Dept of Health. Kristin G. Holt, DVM, Food Safety and Inspection Svc, US Dept of Agriculture. Susan Lance, Center for Food Safety and Applied Nutrition, Food and Drug Admin. Stacy M. Crim, MPH, Olga L. Henao, PhD, Mary Patrick, MPH, Patricia M. Griffin, MD, Robert V. Tauxe, MD, Div of Foodborne, Waterborne, and Environmental Diseases, National Center for Emerging and Zoonotic Infectious Diseases, CDC. Corresponding contributor: Stacy M. Crim, scrim@cdc.gov, 404-639-2257.

Editorial Note

In 2012, the incidence of infections caused by Campylobacter and Vibrio increased from the 2006–2008 period, whereas the incidence of infections caused by Cryptosporidium, Listeria, Salmonella, Shigella, STEC O157, and Yersinia was unchanged. These findings highlight the need to continue to identify and address food safety gaps that can be targeted for action by the food industry and regulatory authorities.

After substantial declines in the early years of FoodNet surveillance, the incidence of Campylobacter infection has increased to its highest level since 2000. Campylobacter infections are more common in the western U.S. states and among children aged <5 years (3). Although most infections are self-limited, sequelae include reactive arthritis and Guillain-Barré syndrome.§§ Associated exposures include consumption of poultry, raw milk, produce, and untreated water, and animal contact (4,5).

Declines in U.S. campylobacteriosis during 1996–2001 might have been related to measures meat and poultry processors implemented to comply with the Pathogen Reduction and Hazard Analysis and Critical Control Points (HACCP) systems regulations issued by USDA-FSIS in the late 1990s.¶¶ In 2011, USDA-FSIS issued new Campylobacter performance standards for U.S. chicken and turkey processors.*** Continued FoodNet surveillance can help to assess the public health impact of these standards and other changes. Detailed patient exposure information coupled with information on strain subtypes could help in assessing the relative contribution of various sources of infection and the effectiveness of control measures.

Although a significant increase was observed in reported Vibrio infections, the number of such infections remains low (6). Vibrios live naturally in marine and estuarine waters, and many infections are acquired by eating raw oysters (7). These infections are most common during warmer months, when waters contain more Vibrio organisms. Infections can be prevented by postharvest treatment of oysters with heat, freezing, or high pressure (8), or by thorough cooking. Persons who are immunocompromised or have impaired liver function should be informed that consuming raw seafood carries a risk for severe Vibrio infection. Vibrios also cause wound and soft-tissue infections among persons who have contact with water; for example, Vibrio alginolyticus typically causes ear infection (9).

The decrease in incidence of HUS in 2011 compared with 2006–2008 mirrors the decrease in the incidence of STEC O157 infection observed in 2011. The incidence of STEC O157 infection, which had declined since 2006, was no longer decreasing in 2012, and now exceeds the previously met Healthy People 2010 target of one case per 100,000 persons. The continued increase in STEC non-O157 infections likely reflects increasing use by clinical laboratories of tests that detect these infections.

FoodNet surveillance relies on isolation of bacterial pathogens by culture of clinical specimens; therefore, the increasing use of culture-independent tests for Campylobacter and STEC might affect the reported incidence of infection (10). Data on persons with only culture-independent evidence of infection suggests that in 2012, the number of laboratory-identified Campylobacter cases could have been 9% greater and the number of STEC (O157 and non-O157) cases 7%–19% greater than that reported (CDC, unpublished data, 2013). The lack of recent decline in STEC O157 incidence is of concern; continued monitoring of trends in the incidence of HUS and use of culture-independent testing might aid in interpreting future data on STEC O157 incidence.

The findings in this report are subject to at least four limitations. First, health-care–seeking behaviors and other characteristics of the population in the surveillance area might affect the generalizability of the findings. Second, many infections transmitted commonly through food (e.g., norovirus infection) are not monitored by FoodNet because these pathogens are not identified routinely in clinical laboratories. Third, the proportion of illnesses transmitted by nonfood routes differs by pathogen, and the route cannot be determined for individual, nonoutbreak-associated illnesses and, therefore, the data provided in this report do not exclusively relate to infections from foodborne sources. Finally, in some cases counted as fatal, the infection with the enteric pathogen might not have been the primary cause of death.

Most foodborne illnesses can be prevented. Progress has been made in decreasing contamination of some foods and reducing illness caused by some pathogens, as evidenced by decreases in earlier years. In 2010, FDA passed the Egg Safety Rule,††† designed to decrease contamination of shell eggs with Salmonella serotype Enteritidis. In 2011, USDA-FSIS tightened its performance standard for Salmonella contamination to a 7.5% positive rate for whole broiler chickens.§§§ Finally, the Food Safety Modernization Act of 2011 gives FDA additional authority to improve food safety and requires CDC to strengthen surveillance and outbreak response.¶¶¶ Collection of comprehensive surveillance information further supports reductions in foodborne infections by helping to determine where to target prevention efforts, supporting efforts to attribute infections to sources, guiding implementation of measures known to reduce food contamination, and informing development of new measures. Because consumers can bring an added measure of safety during food storage, handling, and preparation, they are advised to seek out food safety information, which is available online.****

Acknowledgments

Workgroup members, Foodborne Diseases Active Surveillance Network (FoodNet), Emerging Infections Program; communications team, Div of Foodborne, Waterborne, and Environmental Diseases, National Center for Emerging and Zoonotic Diseases, CDC.

References

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  3. Samuel MC, Vugia DJ, Shallow S, et al. Epidemiology of sporadic Campylobacter infection in the United States and declining trend in incidence, FoodNet 1996–1999. Clin Infect Dis 2004;38(Suppl 3):S165–74.
  4. Friedman CR, Hoekstra RM, Samuel M, et al. Risk factors for sporadic Campylobacter infection in the United States: a case-control study in FoodNet sites. Clin Infect Dis 2004;38(Suppl 3):S285–96.
  5. Taylor EV, Herman KM, Ailes EC, et al. Common source outbreaks of Campylobacter infection in the USA, 1997–2008. Epidemiol Infect 2012;15:1–10 [Epub ahead of print].
  6. Newton A, Kendall M, Vugia DJ, Henao OL, Mahon BE. Increasing rates of vibriosis in the United States, 1996–2010: review of surveillance data from 2 systems. Clin Infect Dis 2012;54(Suppl 5):S391–5.
  7. Altekruse SF, Bishop RD, Baldy LM, et al. Vibrio gastroenteritis in the US Gulf of Mexico region: the role of raw oysters. Epidemiol Infect 2000;124:489–95.
  8. DePaola A, Jones JL, Noe KE, Byars RH, Bowers JC. Survey of postharvest-processed oysters in the United States for levels of Vibrio vulnificus and Vibrio parahaemolyticus. J Food Prot 2009;72:2110–3.
  9. Dechet AM, Yu PA, Koram N, Painter J. Nonfoodborne Vibrio infections: an important cause of morbidity and mortality in the United States, 1997–2006. Clin Infect Dis 2008;46:970–6.
  10. Cronquist AB, Mody RK, Atkinson R, et al. Impacts of culture-independent diagnostic practices on public health surveillance for bacterial enteric pathogens. Clin Infect Dis 2012;54(Suppl 5):S432–9.

 

* Additional information available at http://www.cdc.gov/foodnet.

† The overall incidence of infection combines data for Campylobacter, Listeria, Salmonella, STEC O157, Vibrio, and Yersinia, six key bacterial pathogens for which >50% of illnesses are estimated to be transmitted by food.

§ FoodNet personnel regularly contact clinical laboratories to ascertain all laboratory-confirmed infections in residents of the surveillance areas.

¶ Final incidence rates will be reported when population estimates for 2012 are available.

** Campylobacter, Listeria, Salmonella, STEC O157, Vibrio, and Yersinia.

†† Age groups defined as <5 years, 5–9 years, 10–19 years, 20–64 years, and ≥65 years.

§§ Additional information available at http://www.who.int/mediacentre/factsheets/fs255/en/index.htmlExternal Web Site Icon.

¶¶ Additional information available at http://www.fsis.usda.gov/oppde/rdad/frpubs/93-016f.pdf Adobe PDF fileExternal Web Site Icon.

*** Additional information is available at http://www.fsis.usda.gov/science/haccp_verification_campylobacter_results_2011/index.aspExternal Web Site Icon.

††† Additional information available at http://www.fda.gov/food/guidanceregulation/guidancedocumentsregulatoryinformation/eggs/ucm170615.htmExternal Web Site Icon.

§§§ Additional information available at http://www.gpo.gov/fdsys/pkg/FR-2011-03-21/pdf/2011-6585.pdf Adobe PDF fileExternal Web Site Icon.

¶¶¶ Additional information available at http://www.fda.gov/food/guidanceregulation/fsma/ucm242500.htm.External Web Site Icon

**** Additional food safety information is available at http://www.cdc.gov/winnablebattles/foodsafety/index.html, http://www.foodsafety.govExternal Web Site Icon and http://www.fightbac.orgExternal Web Site Icon.

 

 

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Fri
25
Jan '13

Foodborne Disease Outbreaks in the US, 2009–2010

http://www.cdc.gov/mmwr/preview/mmwrhtml/mm6203a1.htm?s_cid=mm6203a1_e

Surveillance for Foodborne Disease Outbreaks — United States, 2009–2010

Weekly

January 25, 2013 / 62(03);41-47

Known pathogens cause an estimated 9.4 million foodborne illnesses annually in the United States (1). CDC collects data on foodborne disease outbreaks submitted by all states, the District of Columbia, and Puerto Rico through CDC’s Foodborne Disease Outbreak Surveillance System. Data reported for each outbreak include the number of illnesses, hospitalizations, and deaths; the etiologic agent; the implicated food vehicle; and other factors involved in food preparation and consumption. During 2009–2010, a total of 1,527 foodborne disease outbreaks (675 in 2009 and 852 in 2010) were reported, resulting in 29,444 cases of illness, 1,184 hospitalizations, and 23 deaths. Among the 790 outbreaks with a single laboratory-confirmed etiologic agent, norovirus was the most commonly reported, accounting for 42% of outbreaks. Salmonella was second, accounting for 30% of outbreaks. Among the 299 outbreaks attributed to a food composed of ingredients from one of 17 predefined, mutually exclusive food commodities (2), those most often implicated were beef (13%), dairy (12%), fish (12%), and poultry (11%). The commodities in the 299 outbreaks associated with the most illnesses were eggs (27% of illnesses), beef (11%), and poultry (10%). Public health, regulatory, and food industry professionals can use this information when creating targeted control strategies along the farm-to-table continuum for specific agents, specific foods, and specific pairs of agents and foods. This information also supports efforts to promote safe food-handling practices among food workers and the public.

CDC defines a foodborne disease outbreak as the occurrence of two or more similar illnesses resulting from ingestion of a common food. State, local, tribal, and territorial health department officials voluntarily submit reports of outbreaks investigated by their agency to the Foodborne Disease Outbreak Surveillance System on a standard, Internet-based form.* This report analyzes outbreaks that were reported by August 2, 2012, in which the first illness occurred during 2009–2010. Data reported for each outbreak include the number of illnesses, hospitalizations, and deaths; the etiologic agent (confirmed or suspected†); the implicated food vehicle; factors contributing to food contamination; and the settings of food preparation and consumption. Foods were assigned to one of 17 commodities§ if a single contaminated ingredient was identified or if all ingredients belonged to that commodity (2). Outbreaks identifying foods that could not be assigned to one of the 17 commodities, or for which the report contained insufficient information for commodity assignment, were not attributed to any commodity. Population-based outbreak reporting rates were calculated for each state using U.S. Census estimates of the 2009 and 2010 state populations.¶

Public health officials from all 50 states, the District of Columbia, and Puerto Rico reported 1,527 outbreaks, including 675 in 2009 and 852 in 2010. For the period 2009–2010, the median average annual rate of foodborne outbreaks among states was 3.2 per 1 million population (Figure).

A single confirmed or suspected etiologic agent was identified in 1,022 (67%) outbreaks (790 confirmed and 232 suspected) (Table 1). Among the 790 outbreaks with a single confirmed etiologic agent, bacteria caused 413 (52%) outbreaks, viruses caused 336 (42%), chemicals and toxins caused 39 (5%), and parasites caused 2 (0.2%). Norovirus was the most common cause of outbreaks and illnesses, accounting for 331 (42%) of the confirmed, single-etiology outbreaks and 7,332 (37%) illnesses. Salmonella was next, causing 234 (30%) of confirmed, single-etiology outbreaks and 7,039 (36%) illnesses. Among the 225 confirmed Salmonella outbreaks with a serotype reported, Enteritidis was the most common serotype with 76 outbreaks (34%). Shiga toxin–producing Escherichia coli (STEC) caused 58 confirmed, single-etiology outbreaks, of which 53 were caused by serogroup O157.

Of the 29,444 outbreak-related illnesses, 1,184 (4%) resulted in hospitalization. Salmonella caused the most outbreak-related hospitalizations with 583 (49%), followed by STEC with 190 (16%) and norovirus with 109 (9%). Outbreaks caused by Listeria resulted in the highest proportion of persons hospitalized (82%), followed by Clostridium botulinum (67%), and paralytic shellfish poisoning outbreaks (67%). Among the 23 deaths, 22 were attributed to bacterial etiologies (nine to Listeria monocytogenes, five Salmonella, four STEC O157, three Clostridium perfringens, and one Shigella), and one to norovirus.

A food vehicle was reported for 653 (43%) outbreaks; in 299 (46%) of these outbreaks the vehicle could be assigned to one of the 17 predefined commodities (Table 2). The commodities most commonly implicated were beef, with 39 outbreaks (13%), followed by dairy and fish with 37 (13%) each, and poultry with 33 (11%). Among the 36 dairy-associated outbreaks for which pasteurization information was reported, 26 (81%) involved unpasteurized products. The commodities associated with the most outbreak-related illnesses were eggs with 2,231 illnesses (27%), beef with 928 (11%), and poultry with 826 (10%). The pathogen-commodity pairs responsible for the most outbreaks were Campylobacter in unpasteurized dairy (17 outbreaks), Salmonella in eggs and STEC O157 in beef (15 each), ciguatoxin in fish (12), and scombroid toxin (histamine fish poisoning) in fish (10). The pathogen-commodity pairs responsible for the most outbreak-related illnesses were Salmonella in eggs (2,231 illnesses), Salmonella in sprouts (493), and Salmonella in vine-stalk vegetables** (422). The pathogen-commodity pairs responsible for the most hospitalizations were Salmonella in vine-stalk vegetables (88 hospitalizations), STEC O157 in beef (46), and Salmonella in sprouts (41). The pathogen-commodity pairs responsible for the most deaths were STEC O157 in beef (three deaths), and Salmonella in pork and Listeria in dairy (two each).

Thirty-eight multistate outbreaks were reported (16 in 2009 and 22 in 2010). Twenty-one were caused by Salmonella, 15 by STEC (13 O157, one O145, and one O26), and two by Listeria. The etiologic agent was isolated from an implicated food in 11 multistate outbreaks. Five of the multistate outbreaks were caused by Salmonella (in alfalfa sprouts [two outbreaks], ground turkey, shell eggs, and a frozen entrée [one each]). Six were caused by STEC (in ground beef [two outbreaks], unpasteurized Gouda cheese, multiple unpasteurized cheeses, hazelnuts, and cookie dough [one each]).

Among the 766 outbreaks with a known single setting where food was consumed, 48% were caused by food consumed in a restaurant or deli, and 21% were caused by food consumed in a private home. Forty-three outbreaks resulted in product recalls.†† The recalled foods were ground beef (eight outbreaks), sprouts (seven), cheese and cheese-containing products (six), oysters (five), raw milk (three), eggs (three), and salami (ground pepper), bison, sirloin steak, unpasteurized apple cider, cookie dough, frozen mamey fruit, hazelnuts, Romaine lettuce, ground turkey burger, tuna steak, and a frozen entrée (one each).

Editorial Note

In 2009, the Foodborne Disease Outbreak Surveillance System transitioned to the use of a new reporting form and online data entry interface, the National Outbreak Reporting System (NORS). NORS receives reports of outbreaks of enteric disease transmitted through water, person-to-person contact, contact with animals, environmental contamination, and indeterminate means, as well as through food. Before 2009, only foodborne and waterborne outbreaks were reported to CDC. Following the transition to the new system, the number of foodborne disease outbreaks reported in 2009 and 2010 declined 32% compared with the mean of the preceding 5 years (4).

The decline in foodborne disease outbreak reporting was largely observed among norovirus outbreaks. Norovirus can be transmitted through a variety of routes, including direct contact between persons, through contact with contaminated surfaces, and ingestion of contaminated food or water (5,6). Distinguishing among these modes of transmission in an outbreak can be challenging; some outbreaks involve multiple transmission routes. The advent of NORS, which for the first time enables electronic reporting of nonfoodborne norovirus outbreaks, might have led to more appropriate classification of outbreaks previously reported as foodborne, resulting in fewer reports of foodborne norovirus outbreaks. Other possible explanations for the fewer foodborne disease outbreaks in 2009 and 2010 include resource limitations and competing priorities (e.g., the influenza A [H1N1] virus pandemic in 2009) for state epidemiologic and laboratory resources (7,8).

For STEC O157 and Salmonella serotype Enteritidis, the number of outbreaks reported was not lower than previous years. For STEC O157, the 33 outbreaks in 2009 and 20 in 2010 exceeded the Healthy People 2010 yearly target of 11, and for Salmonella serotype Enteritidis, the 39 outbreaks in 2009 and 37 outbreaks in 2010 exceeded the Healthy People 2010 yearly target of 22 (9).

During 2009–2010, beef, dairy, fish, and poultry were associated with the largest number of foodborne disease outbreaks. During the preceding 11 years, beef, fish, and poultry were consistently among the commodities most commonly associated with outbreaks (4). The large number of outbreaks caused by unpasteurized dairy products is consistent with findings that more outbreaks occur in states that permit the sale of unpasteurized dairy products (10); 60% of states permit sales of raw milk in some form, according to a 2011 survey by the National Association of State Departments of Agriculture.§§

The findings in this report are subject to at least four limitations. First, only a small proportion of foodborne illnesses reported each year are identified as associated with outbreaks. The extent to which the distributions of food vehicles and settings implicated in foodborne disease outbreaks reflect the same vehicles and settings as sporadic foodborne illnesses is unknown (4). Similarly, not all outbreaks are identified, investigated, or reported. Second, many reported outbreaks had an unknown etiology, an unknown food vehicle, or both, and conclusions drawn from outbreaks with a confirmed or suspected etiology or food vehicle might not apply to outbreaks with an unknown etiology or food vehicle. Even when a food is identified, the point of contamination is not always known or reported. Third, CDC’s outbreak surveillance system is dynamic; agencies can submit new reports and can change or delete previous reports as new information becomes available. Therefore, the results of this analysis might differ from those published earlier or from future reports. Finally, because of changes in the surveillance system implemented in 2009, comparisons with preceding years should be made with caution.

Public health, regulatory, and food industry professionals use foodborne disease outbreak surveillance data to target prevention efforts related to pathogens and foods that cause foodborne disease outbreaks. Additional information on outbreaks and the Foodborne Outbreak Online Database are available at http://www.cdc.gov/outbreaknet/surveillance_data.html.

References

    1. Scallan E, Hoekstra RM, Angulo FJ, et al. Foodborne illness acquired in the United States—major pathogens. Emerg Infect Dis 2011;17:7–15.
    2. Painter JA, Ayers T, Woodruff R, et al. Recipes for foodborne outbreaks: a scheme for categorizing and grouping implicated foods. Foodborne Pathog Dis 2009;6:1259–64.
    3. Neil KP, Biggerstaff G, MacDonald JK, et al. A novel vehicle for transmission of Escherichia coli O157:H7 to humans: multistate outbreak of E. coli O157:H7 infections associated with consumption of ready-to-bake commercial prepackaged cookie dough—United States, 2009. Clin Infect Dis 2012;54:511–8.
    4. CDC. Surveillance for foodborne disease outbreaks—United States, 2008. MMWR 2011;60:1197–202.
    5. CDC. Updated norovirus outbreak management and disease prevention guidelines. MMWR 2011;60(No. RR-3).
    6. Hall AJ, Eisenbart VG, Etingue AL, Gould LH, Lopman B, Parashar UD. Epidemiology of foodborne norovirus outbreaks, United States, 2001–2008. Emerg Infect Dis 2012;18:1566–73.
    7. American Public Health Association. The public health workforce shortage: left unchecked, will we be protected? Washington, DC: American Public Health Association; 2006.
  • National Association of County and City Health Officials. Local health department job losses and program cuts: findings from January/February 2010 survey. Washington, DC: National Association of County and City Health Official; 2012.
  • US Department of Health and Human Services. Food safety. Healthy people 2010 (midcourse review). Washington, DC: US Department of Health and Human Services; 2000.
  • Langer AJ, Ayers T, Grass J, Lynch M, Angulo FJ, Mahon BE. Nonpasteurized dairy products, disease outbreaks, and state laws—United States, 1993–2006. Emerg Infect Dis 2012;18:385–91.


* The reporting form and guidance for reporting via the National Outbreak Reporting System are available at

http://www.cdc.gov/nors.

† If at least one etiology was laboratory-confirmed, the outbreak was considered to have a confirmed etiology. If no etiology was laboratory-confirmed, but an etiology was reported based on clinical or epidemiologic features, the outbreak was considered to have a suspected etiology. A guide to confirming foodborne disease diagnoses in outbreaks is available at http://www.cdc.gov/outbreaknet/references_resources/guide_confirming_diagnosis.html.

§ The 17 mutually exclusive food commodities are as follows: fish, crustaceans, mollusks, dairy, eggs, beef, game, pork, poultry, grains-beans, oils-sugars, fruits-nuts, fungi, sprouts, and leafy, root, and vine-stalk vegetables.

¶ Available at http://www.census.gov/popestExternal Web Site Icon.

** Defined as those vegetables that grow on either a vine or a stalk, such as tomatoes, corn, cucumbers, eggplant, green beans, peppers, pumpkin, zucchini, okra, peas, and squash.

†† Additional information on product recalls is available at http://www.fda.gov/safety/recalls/default.htmExternal Web Site Icon and http://www.fsis.usda.gov/fsis_recalls/index.asp.External Web Site Icon

§§ Available at http://www.nasda.org/file.aspx?id=3916External Web Site Icon.

 

What is already known about this topic?

Surveillance for foodborne disease outbreaks can identify opportunities to prevent foodborne diseases, which cause millions of illnesses in the United States each year.

What is added by this report?

Among the 1,527 foodborne disease outbreaks reported in 2009 and 2010, most outbreak-associated illnesses were caused by norovirus or Salmonella. Among outbreaks in which both an etiologic agent and single-commodity food vehicle were identified, most outbreaks were attributed to Campylobacter in unpasteurized dairy products, Salmonella in eggs, and Shiga toxin–producing Escherichia coli O157 in beef. The pathogen-commodity pairs responsible for the most outbreak-related illnesses were Salmonella in eggs (2,231 illnesses), in sprouts (493), and in vine-stalk vegetables (422).

What are the implications for public health practice?

Public health, regulatory, and food industry professionals can use this information when creating targeted control strategies along the farm-to-table continuum for specific agents and foods, and specific pairs of agents and foods. This information also supports efforts to promote safe food-handling practices among food workers and the public.

 

FIGURE. Average annual rate of reported foodborne disease outbreaks per 1 million population* and number of outbreaks,by state and major etiology group§ — Foodborne Disease Outbreak Surveillance System, United States, 2009–2010

The figure shows the number of reported outbreaks and the average annual rate of foodborne disease outbreaks per 1 million population, by state and major etiology group in the United States during 2009-2010. During 2009-2010, public health officials from all 50 states, the District of Columbia, and Puerto Rico reported 1,917 outbreaks, includ¬ing 884 caused by bacteria and 495 caused by viruses. For the period 2009-2010, the median average annual rate of foodborne outbreaks among states was 3.2 per 1 million population.

* Cutpoints for outbreak rate categories determined using Jenks Natural Breaks Optimization in ArcGIS. Legend differs for each major etiology.

† Number of reported outbreaks in each state. In addition to the 50 states, Puerto Rico reported 10 outbreaks, and the District of Columbia reported four outbreaks.

§ Analysis restricted to outbreaks with a single confirmed or suspected etiology.

¶ Includes 38 multistate outbreaks (i.e., outbreaks in which exposure to the etiologic agent occurred in more than one state) assigned as an outbreak to each state involved. Multistate outbreaks involved a median of seven (range: 2–45) states.

Alternate Text: The figure above shows the number of reported outbreaks and the average annual rate of foodborne disease outbreaks per 1 million population, by state and major etiology group in the United States during 2009-2010. During 2009-2010, public health officials from all 50 states, the District of Columbia, and Puerto Rico reported 1,917 outbreaks, includ¬ing 884 caused by bacteria and 495 caused by viruses. For the period 2009-2010, the median average annual rate of foodborne outbreaks among states was 3.2 per 1 million population.

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Thu
3
Jan '13

Foodborne Outbreaks in Canada over the Years

http://www.ingentaconnect.com/content/iafp/jfp/2013/00000076/00000001/art00024

Foodborne Outbreaks in Canada Linked to Produce: 2001 through 2009

Authors: Kozak, G.K.; MacDonald, D.; Landry, L.; Farber, J.M.

Journal of Food Protection®, Number 1, January 2013, pp. 4-183 , pp. 173-183(11

 ”…..The 27 produce-related outbreaks included an estimated 1,549 cases of illness. Bacterial infection outbreaks represented 66% of the total…….Salmonella was the most frequent agent (50% of outbreaks) followed by Escherichia coli (33%) and Shigella (17%). Cyclospora cayetanensis was the only parasite detected and was associated with seven outbreaks. Among the foodborne viruses, only hepatitis A was implicated in two outbreaks. The food vehicles most commonly implicated in outbreaks were leafy greens and herbs (26% of outbreaks), followed by seed sprouts (11%). ….”

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Thu
13
Dec '12

Approximately 179 million cases of acute gastroenteritis (AGE) occur in the United States each year

CDC:   “….During 2009–2010, a total of 2,259 person-to-person AGE outbreaks were reported in NORS from 42 states and the District of Columbia. These outbreaks resulted in 81,491 reported illnesses, 1,339 hospitalizations, and 136 deaths. No etiology was reported in approximately 40% (n = 840) of outbreaks. Of the remaining 1,419 outbreaks with a reported etiology, 1,270 (89%) were either suspected or confirmed to be caused solely by norovirus. Other reported etiologies included Shigella (n = 86), Salmonella (n = 16), Shiga toxin-producing Escherichia coli (STEC) (n = 11), and rotavirus (n = 10). Most (82%) of the 1,723 outbreaks caused by norovirus or an unknown etiology occurred during the winter months, and outbreaks caused by Shigella or another suspected or confirmed etiology most often occurred during the spring or summer months (62%, N = 53 and 60%, N = 38, respectively). A setting was reported for 1,187 (53%) of total outbreaks. Among these reported settings, nursing homes and other long-term–care facilities were most common (80%), followed by childcare centers (6%), hospitals (5%), and schools (5%). ….”

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