April 20th, 2014
posted by Paul Rega, MD, FACEP April 20, 2014 @ 4:13 am
Email This Post
Notes from the Field: Increase in Vibrio parahaemolyticus Infections Associated with Consumption of Atlantic Coast Shellfish — 2013
April 18, 2014 / 63(15);335-336
Anna E. Newton, MPH1, Nancy Garrett1, Steven G. Stroika1, Jessica L. Halpin, MS1, Maryann Turnsek1, Rajal K. Mody, MD1
Vibrio parahaemolyticus (Vp) is found naturally in coastal saltwater. In the United States, Vp causes an estimated 35,000 domestically acquired foodborne infections annually (1), of which most are attributable to consumption of raw or undercooked shellfish. Illness typically consists of mild to moderate gastroenteritis, although severe infection can occur. Demographic, clinical, and exposure information (including traceback information on implicated seafood) for all laboratory-confirmed illnesses are reported by state health departments to CDC through the Cholera and Other Vibrio Surveillance system. Vp isolates are distinguished by serotyping (>90 serotypes have been described) and by pulsed-field gel electrophoresis (PFGE).
Vp serotypes O4:K12 and O4:K(unknown) comprise the Pacific Northwest (PNW) strain and, within the United States, had not been associated with shellfish outside the Pacific Northwest before 2012. During May–July 2012, Vp of the PNW strain associated with shellfish from Oyster Bay Harbor in New York caused an outbreak of 28 illnesses in nine states. Simultaneously, Vp of the PNW strain caused an outbreak of illnesses on a cruise ship docked on the Atlantic Coast of Spain; illness was associated with cooked seafood cooled with ice made from untreated local seawater. All Vp isolates from ill persons in the U.S. and Spanish outbreaks that were further subtyped were indistinguishable by PFGE (2).
In 2013, this same indistinguishable strain was traced from shellfish consumed by ill persons to a larger area of the U.S. Atlantic Coast, causing illness in 104 persons from 13 states during May–September (Figure).
The median age of patients was 51 years (range = 22–85 years); 62% were male.
Six (6%) patients were hospitalized; none died.
Multiple outbreaks appeared to be occurring, accounting for many of these illnesses. Illness was associated with consumption of raw shellfish and seafood traceback was reported for 59 (57%) illnesses. Of these illnesses, 51 (86%) involved seafood that could be definitively traced to a single harvest area. The implicated harvest areas were located in Connecticut (20 illnesses), Massachusetts (15), New York (10), Virginia (four), Maine (one), and Washington (one). The remaining eight illnesses with traceback information involved seafood that could not be definitively traced to a single harvest area (locations reported included harvest areas of the Atlantic Coast of the United States and Canada). In response to the illnesses, four Atlantic Coast states closed implicated harvest areas; two issued shellfish recalls (3).
The number of foodborne Vp cases in the United States traced to Atlantic Coast shellfish was threefold greater in 2012 and 2013 compared with the annual average number reported during 2007–2011.
This PNW strain is possibly becoming endemic in an expanding area of the Atlantic Ocean. The mechanisms for this introduction are not known. During the 2014 Vibrio season, beginning in the spring, clinicians, health departments, and fisheries departments should be prepared for the possibility of shellfish-associated diarrheal illness caused by this strain again. Appropriate actions, such as quick closure of implicated harvest areas, will help prevent additional illnesses. The Interstate Shellfish Sanitation Conference maintains a list of shellfish harvest area closures and recalls.* Clinicians seeking an etiology of diarrhea in a patient who has recently consumed raw or undercooked shellfish should notify the microbiology laboratory that Vp is suspected; the use of special culture media (thiosulfate citrate bile salts sucrose) facilitates identification of Vibrio species. Consumers can reduce their risk for Vp infection by avoiding eating raw or undercooked shellfish, especially oysters and clams.†
- Scallan E, Hoekstra RM, Angulo FJ, et al. Foodborne illness acquired in the United States—major pathogens. Emerg Infect Dis 2011;17:7–15.
- Martinez-Urtaza J, Baker-Austin C, Jones JL, Newton AE, Gonzalez-Aviles GD, DePaola A. Spread of Pacific Northwest Vibrio parahaemolyticus strain. N Engl J Med 2013;369:1573–4.
- CDC. Increase in Vibrio parahaemolyticus illnesses associated with consumption of shellfish from several Atlantic coast harvest areas, United States, 2013. Atlanta, GA: US Department of Health and Human Services, CDC; 2013. Available at http://www.cdc.gov/vibrio/investigations/index.html.
FIGURE. Vibrio parahaemolyticus illnesses (N = 104) associated with consumption of shellfish from Atlantic Coast harvest areas, by week of onset — United States, 2013
Alternate Text: The figure above shows Vibrio parahaemolyticus illnesses (N = 104) associated with consumption of shellfish from Atlantic Coast harvest areas, by week of onset, in the United States during 2013. In 2013, this same indistinguishable strain was traced from shellfish consumed by ill persons to a larger area of the U.S. Atlantic Coast, causing illness in 104 persons from 13 states during May–September.
April 20th, 2014
posted by Paul Rega, MD, FACEP @ 4:10 am
Incidence and Trends of Infection with Pathogens Transmitted Commonly Through Food — Foodborne Diseases Active Surveillance Network, 10 U.S. Sites, 2006–2013
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).
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, email@example.com, 404-639-3393)
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.
- 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.htm.
- 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.
- 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.
- 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.
- 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 .
- 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.
- 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.
- 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.
- 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=ajperes.
- 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=ajperes.
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*
|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 StatesAbbreviations:
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, 2006–2013
* 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.
Email This Post
April 19th, 2014
posted by Paul Rega, MD, FACEP April 19, 2014 @ 12:24 am
CDC data show limited progress in reducing foodborne infections in 2013
National report card on food safety indicates more can be done
The nation’s food safety grades are out and the results are mixed. CDC’s annual report card shows that foodborne infections continue to be an important public health problem in the United States.
The rate of salmonella infections decreased by about nine percent in 2013 compared with the previous three years, bringing it to the rate last observed in the 2006-2008 baseline period. But campylobacter infections, often linked to dairy products and chicken, have risen 13 percent since 2006-2008. Vibrio infections, often linked to eating raw shellfish, were at the highest level observed since active tracking began in 1996; however, rates of infections caused by Vibrio vulnificus, the most severe species, have remained steady. Rates of the other foodborne infections tracked have not changed since the period between 2006 and2008.
“CDC data are essential to gauge how we’re doing in our fight against foodborne illness,” said Robert Tauxe, M.D., M.P.H, deputy director of CDC’s Division of Foodborne, Waterborne and Environmental Diseases. “This year’s data show some recent progress in reducing salmonella rates, and also highlight that our work to reduce the burden of foodborne illness is far from over. To keep salmonella on the decline, we need to work with the food industry and our federal, state and local partners to implement strong actions to control known risks and to detect foodborne germs lurking in unsuspected foods.”
The data for the report card come from the Foodborne Diseases Active Surveillance Network (FoodNet), a group of experts from CDC, ten state health departments, the U.S. Department of Agriculture’s Food Safety and Inspection Service (FSIS), and the U.S. Food and Drug Administration (FDA). In 2013, FoodNet logged just over 19,000 infections, 4,200 hospitalizations, and 80 deaths from the nine germs it tracks. Young children were the most affected group for seven of the nine germs that FoodNet tracks.
New standards for cut-up poultry parts and plans to modernize poultry inspection are already in the works to increase the safety of chicken. Regulations designed to help prevent food safety problems have been proposed for many sectors of the food industry, including produce farms, food facilities, food importers, food transporters, and third-party auditors/certification bodies.
“Steps are underway to address many of the concerns raised in this report, such as our Salmonella Action Planand other plans to modernize food inspection,” said Assistant Administrator for FSIS’ Office of Public Health Science David Goldman, M.D., M.P.H.. “As these actions are being implemented, we are beginning to see progress, and I am confident we will see further improvement over time.”
“The latest information from FoodNet highlights the importance of continuing preventive measures from the farm to the consumer,” said Stephen Ostroff, M.D., the FDA’s acting chief scientist. “We are making significant progress in implementing the FDA Food Safety Modernization Act, having issued seven proposed rules addressing the safety of produce, imported foods, and human and animal food production and transportation. Full implementation of these rules will help prevent these types of infections.”
In addition to new regulations, everyone can help prevent food poisoning. The food industry can require safer ingredients and can implement preventative controls while restaurants and consumers should follow safe practices in the kitchen. These include cooking meat to proper temperatures, washing produce, preparing meat and fresh produce on different surfaces. Consumers should know there are risks to consuming unpasteurized milk, soft cheeses made with unpasteurized milk, and raw oysters, especially for certain populations at risk for foodborne illness. For more information on avoiding illnesses from food, and knowing who is at greatest risk, please visit www.foodsafety.gov.
CDC. Incidence and trends of infection with pathogens transmitted commonly through food—Foodborne Diseases Active Surveillance Network, 10 US sites, 2006-2013. MMWR 2014 Apr 18; 63(15):328-32 [Full text]
Email This Post
April 10th, 2014
posted by Paul Rega, MD, FACEP April 10, 2014 @ 12:22 pm
Notes from the Field: Multistate Outbreak of Listeriosis Linked to Soft-Ripened Cheese — United States, 2013
April 4, 2014 / 63(13);294-295
Mary J. Choi, MD1,2, Kelly A. Jackson, MPH3, Carlota Medus, PhD1, Jennifer Beal, MPH4, Carrie E. Rigdon, PhD5, Tami C. Cloyd, DVM4, Matthew J. Forstner5, Jill Ball6, Stacy Bosch, DVM3, Lyndsay Bottichio, MPH7, Venessa Cantu, MPH8, David C. Melka9, Wilete Ishow10, Sarah Slette, MS11, Kari Irvin, MS4, Matthew Wise, PhD3, Cheryl Tarr, PhD3, Barbara Mahon, MD3, Kirk E. Smith, DVM, PhD1, Benjamin J. Silk, PhD3 (Author affiliations at end of text)
On June 27, 2013, the Minnesota Department of Health notified CDC of two patients with invasive Listeria monocytogenes infections (listeriosis) whose clinical isolates had indistinguishable pulsed-field gel electrophoresis (PFGE) patterns. A query of PulseNet, the national molecular subtyping network for foodborne disease surveillance, identified clinical and environmental isolates from other states. On June 28, CDC learned from the Food and Drug Administration’s Coordinated Outbreak Response and Evaluation Network that environmental isolates indistinguishable from those of the two patients had been collected from Crave Brothers Farmstead Cheese during 2010–2011. An outbreak-related case was defined as isolation of L. monocytogenes with the outbreak PFGE pattern from an anatomic site that is normally sterile (e.g., blood or cerebrospinal fluid), or from a product of conception, with an isolate upload date during May 20–June 28, 2013. As of June 28, five cases were identified in four states (Minnesota, two cases; Illinois, Indiana, and Ohio, one each). Median age of the five patients was 58 years (range: 31–67 years). Four patients were female, including one who was pregnant at the time of infection. All five were hospitalized. One death and one miscarriage were reported.
Case–case analysis of Listeria Initiative* data (1) was conducted, comparing food exposure frequencies among the five outbreak-related cases identified by June 28 with food exposure frequencies in 1,735 sporadic listeriosis cases reported to CDC during 2004–2013. The analysis indicated that any soft cheese consumption during the month before illness onset was associated with outbreak-related listeriosis: five of five (100%) in the outbreak-related cases versus 569 of 1,735 (33%) in the sporadic cases (odds ratio = 10.8; 95% confidence interval = 1.8–∞).
The five patients were reinterviewed to assess their cheese exposures. All five patients had definitely or probably eaten one of three varieties of Crave Brothers soft-ripened cheese (Les Frères, Petit Frère, or Petit Frère with truffles). Three patients had purchased the cheese at three different restaurants, and two had purchased the cheese at two different grocery stores. The cheeses were shipped as intact wheels to the three restaurants and two grocery stores, where they had been cut and served or repackaged and sold to customers.
Testing at the Minnesota Department of Agriculture identified the outbreak pattern of L. monocytogenes in two cheese wedges (Les Frères and Petit Frère with truffles) collected from two different grocery stores in Minnesota. Inspection of the cheese-making facility revealed that substantial sanitation deficiencies during the cheese-making process itself, after the milk was pasteurized, likely led to contamination. On July 1, Crave Brothers halted production of Les Frères, Petit Frère, and Petit Frère with truffles. On July 3, Crave Brothers issued a voluntary recall of these products with a production date of July 1, 2013, or earlier. On July 11, the company voluntarily halted production of all cheese products manufactured at the facility. After product recall, one additional case was identified in Texas through whole genome sequencing, bringing the total case count for the outbreak to six.
This outbreak was linked to soft cheeses that were likely contaminated during the cheese-making process (2,3). Pasteurization eliminates Listeria in milk. However, contamination can occur after pasteurization. Cheese-making facilities should use strict sanitation and microbiologic monitoring, regardless of whether they use pasteurized milk.†
Persons at greater risk for listeriosis, including older adults, pregnant women, and those with immunocompromising conditions, should be aware that certain soft cheeses made with unpasteurized milk, or made under unsanitary conditions, regardless of whether the milk was pasteurized, have been shown to cause severe illness. These soft cheeses include fresh (unripened) cheeses, such as queso fresco (4), and soft-ripened cheeses, such as the cheeses implicated in this outbreak.
1Minnesota Department of Health; 2EIS officer; 3Div of Foodborne, Waterborne, and Environmental Diseases, National Center for Emerging and Zoonotic Infectious Diseases, CDC; 4Coordinated Outbreak Response and Evaluation Network, Food and Drug Administration; 5Minnesota Department of Agriculture; 6Wisconsin Department of Agriculture, Trade, and Consumer Protection; 7Ohio Department of Health; 8Texas Department of State Health Services; 9Center for Food Safety and Applied Nutrition, Food and Drug Administration; 10Chicago Department of Public Health; 11Indiana State Department of Health (Corresponding author: Mary J. Choi, firstname.lastname@example.org, 651-201-5193)
- McCollum JT, Cronquist AB, Silk BJ, et al. Multistate outbreak of listeriosis associated with cantaloupe. N Engl J Med 2013;369:944–53.
- CDC. Vital signs: Listeria illnesses, deaths, and outbreaks—United States, 2009–2011. MMWR 2013;62:448–52.
- CDC. Multistate outbreak of listeriosis linked to imported Frescolina Marte brand ricotta salata cheese (final update). Atlanta, GA: US Department of Health and Human Services, CDC; 2012. Available at http://www.cdc.gov/listeria/outbreaks/cheese-09-12/index.html.
- CDC. Outbreak of listeriosis associated with homemade Mexican-style cheese—North Carolina, October 2000–January 2001. MMWR 2001;50:560–2.
Email This Post
April 10th, 2014
posted by Paul Rega, MD, FACEP @ 12:21 pm
“…….CSPI’s Outbreak Alert! database includes 7,461 unique and solved
outbreaks of foodborne illness that occurred from 1990 through 2011. The report
issued today examined the 3,933 outbreaks that occurred in the most recent
10-year period. Those outbreaks sickened 98,399 people. The CDC estimates that
48 million people are sickened annually, of which 128 thousand are hospitalized
and 3,000 die.”
Email This Post
March 28th, 2014
posted by Paul Rega, MD, FACEP March 28, 2014 @ 3:35 am
Email This Post
March 22nd, 2014
posted by Paul Rega, MD, FACEP March 22, 2014 @ 6:30 am
Email This Post
March 19th, 2014
posted by Paul Rega, MD, FACEP March 19, 2014 @ 3:10 am
Parasite in Live Asian Swamp Eels May Cause Human Illness Released: 3/12/2014 4:52:35 PM
Raw or undercooked Asian swamp eels could transmit a parasitic infection called gnathostomiasis to consumers.
U.S. Geological Survey scientists found parasitic worms known as gnathostomes in Asian swamp eels collected between 2010 and 2012 from ethnic food markets and in Florida waters where the eel species is invasive. If eaten raw or undercooked, these eels could transmit their parasites to people, causing mild to serious disease. Severe cases of the infection can lead to blindness, paralysis or death. The USGS study was published today in the journal Emerging Infectious Diseases.
“Because live Asian swamp eels are commonly imported to the U.S., a person’s dietary history and not just travel history should be considered when diagnosing gnathostomiasis,” said Rebecca Cole, USGS scientist and lead author of the study.
Swamp eels transported live from Southeast Asia are sold in many urban ethnic food markets in the United States, and have been released into waters in Florida, Georgia and New Jersey. During the USGS study, scientists found gnathostome worms in eels collected from markets in Manhattan, N.Y., Atlanta, Ga., and Orlando, Fla., and in wild eels caught in peninsular Florida. All of the infected eels obtained from markets were imported from Bangladesh.
“Consumers should be aware of the risk of contracting gnathostomiasis from Asian swamp eels if they are eating raw or undercooked eels,” Cole said.
Co-author and USGS scientist Leo Nico said it is notable that North American species of gnathostome parasites have infected wild, invasive Asian swamp eels in Florida. Although the North American species found in the wild Florida eels has not been reported as infecting humans, some scientists suggest that all Gnathostoma species can most likely infect people. According to the authors, it is also concerning that this parasite could be transmitted into native fish and wildlife populations and domestic cats or dogs.
Swamp eels are native to Southeast Asia, and wild-caught and domestically-reared eels are widely consumed as food by humans. The eels are a common source of human gnathostomiasis in many parts of Asia. Wild populations of these invasive eels were first found in Florida in 1997, likely the result of the live food trade or aquarium releases. There are five established populations in the continental U.S. — three in Florida, and one each in Georgia and New Jersey. Introduced swamp eels have also been present in Hawaii for many decades.
The eels, which can reach lengths of about three feet, have the potential to become widespread in the U.S., impacting native aquatic and wetland species. The species has few known predators in the U.S., breathes air and can move across land, and can survive in both hot and cold climates.
For more information on USGS zoonotic, or animal-caused, illnesses, please visit the USGS National Wildlife Health Center website. FAQs on Asian swamp eels are available online.
Abstract: In Southeast Asia, swamp eels (Synbranchidae: Monopterus spp.) are a common source of human gnathostomiasis, a foodborne zoonosis caused by advanced third-stage larvae (AL3) of Gnathostoma spp. nematodes. Live Asian swamp eels are imported to US ethnic food markets, and wild populations exist in several states. To determine whether these eels are infected, we examined 47 eels from markets and 67 wild-caught specimens. Nematodes were identified by morphologic features and ribosomal intergenic transcribed spacer–2 gene sequencing. Thirteen (27.7%) M. cuchia eels from markets were infected with 36 live G. spinigerum AL3: 21 (58.3%) in liver; 7 (19.4%) in muscle; 5 (13.8%) in gastrointestinal tract, and 3 (8.3%) in kidneys. Three (4.5%) wild-caught M. albus eels were infected with 5 G. turgidum AL3 in muscle, and 1 G. lamothei AL3 was found in a kidney (both North American spp.). Imported live eels are a potential source of human gnathostomiasis in the United States.
EID, Volume 20, Number 4—April 2014
Email This Post
March 14th, 2014
posted by Paul Rega, MD, FACEP March 14, 2014 @ 3:15 am
Pearn J: Neurology of ciguatera. J Neurol Neurosurg Psychiatry
2001; 70(1): 4-8 [available at
Lewis RJ: The changing face of ciguatera. Toxicon 2001; 39(1):
97-106 [abstract available at
Chateau-Defat ML, Chinain M, Cerf N, et al: Seawater temperature,
_Gambierdiscus_ spp. Variability and incidence of ciguatera poisoning
in French Polynesia. Harmful Algae 2005; 4: 1053-62 [abstract
available at <http://www.ilm.pf/node/1356>].
CDC. Surveillance for foodborne-disease outbreaks – United States,
1998-2002. MMWR 2006; 55(SS-10): 1-34 [available at
Lewis R, Ruff T: Ciguatera: ecological, clinical, and
socioeconomic perspectives. Crit Rev Environ Sci Technol 1993; 23(2):
137-56 [abstract available at
Email This Post
March 6th, 2014
posted by Paul Rega, MD, FACEP March 6, 2014 @ 5:53 am