Food recalls associated with foodborne disease outbreaks, United States, 2006-2016.

About 800 foodborne disease outbreaks are reported in the United States annually. Few are associated with food recalls. We compared 226 outbreaks associated with food recalls with those not associated with recalls during 2006-2016. Recall-associated outbreaks had, on average, more illnesses per outbreak and higher proportions of hospitalisations and deaths than non-recall-associated outbreaks. The top confirmed aetiology for recall-associated outbreaks was Salmonella. Pasteurised and unpasteurised dairy products, beef and molluscs were the most frequently implicated foods. The most common pathogen-food pairs for outbreaks with recalls were Escherichia coli-beef and norovirus-molluscs; the top pairs for non-recall-associated outbreaks were scombrotoxin-fish and ciguatoxin-fish. For outbreaks with recalls, 48% of the recalls occurred after the outbreak, 27% during the outbreak, 3% before the outbreak, and 22% were inconclusive or had unknown recall timing. Fifty per cent of recall-associated outbreaks were multistate, compared with 2% of non-recall-associated outbreaks. The differences between recall-associated outbreaks and non-recall-associated outbreaks help define the types of outbreaks and food vehicles that are likely to have a recall. Improved outbreak vehicle identification and traceability of rarely recalled foods could lead to more recalls of these products, resulting in fewer illnesses and deaths.

Shiga Toxin-Producing Escherichia coli Infections Associated With Romaine Lettuce-United States, 2018.

BACKGROUND: Produce-associated outbreaks of Shiga toxin-producing Escherichia coli (STEC) were first identified in 1991. In April 2018, New Jersey and Pennsylvania officials reported a cluster of STEC O157 infections associated with multiple locations of a restaurant chain. The Centers for Disease Control and Prevention (CDC) queried PulseNet, the national laboratory network for foodborne disease surveillance, for additional cases and began a national investigation. METHODS: A case was defined as an infection between 13 March and 22 August 2018 with 1 of the 22 identified outbreak-associated E. coli O157:H7 or E. coli O61 pulsed-field gel electrophoresis pattern combinations, or with a strain STEC O157 that was closely related to the main outbreak strain by whole-genome sequencing. We conducted epidemiologic and traceback investigations to identify illness subclusters and common sources. A US Food and Drug Administration-led environmental assessment, which tested water, soil, manure, compost, and scat samples, was conducted to evaluate potential sources of STEC contamination. RESULTS: We identified 240 case-patients from 37 states; 104 were hospitalized, 28 developed hemolytic uremic syndrome, and 5 died. Of 179 people who were interviewed, 152 (85%) reported consuming romaine lettuce in the week before illness onset. Twenty subclusters were identified. Product traceback from subcluster restaurants identified numerous romaine lettuce distributors and growers; all lettuce originated from the Yuma growing region. Water samples collected from an irrigation canal in the region yielded the outbreak strain of STEC O157. CONCLUSIONS: We report on the largest multistate leafy greens-linked STEC O157 outbreak in several decades. The investigation highlights the complexities associated with investigating outbreaks involving widespread environmental contamination.

The Role of Adverse Event Reporting in the FDA Response to a Multistate Outbreak of Liver Disease Associated with a Dietary Supplement.

OBJECTIVE: Liver disease is a potential complication from using dietary supplements. This study investigated an outbreak of non-viral liver disease associated with the use of OxyELITE Pro(TM), a dietary supplement used for weight loss and/or muscle building. METHODS: Illness details were ascertained from MedWatch reports submitted to the U.S. Food and Drug Administration (FDA) describing consumers who ingested OxyELITE Pro alone or in combination with other dietary supplements. FDA's Forensic Chemistry Center analyzed samples of OxyELITE Pro. RESULTS: From February 2012 to February 2014, FDA received 114 reports of adverse events of all kinds involving consumers who ingested OxyELITE Pro. The onset of illness for the first report was December 2010 and for the last report was January 2014. Thirty-three states, two foreign nations, and Puerto Rico submitted reports. Fifty-five of the reports (48%) described liver disease in the absence of viral infection, gallbladder disease, autoimmune disease, or other known causes of liver damage. A total of 33 (60%) of these patients were hospitalized, and three underwent liver transplantation. In early 2013, OxyELITE Pro products entered the market with a formulation distinct from products sold previously. The new formulation replaced 1,3-dimethylamylamine with aegeline. However, the manufacturer failed to submit to FDA a required "new dietary ingredient" notice for the use of aegeline in OxyELITE Pro products. Laboratory analysis identified no drugs, poisons, pharmaceuticals, toxic metals, usnic acid, N-Nitroso-fenfluramine, pyrrolizidine alkaloids, aristocholic acid, or phenethylamines in the products. CONCLUSIONS: Vigilant surveillance is required for adverse events linked to the use of dietary supplements.

Outbreak of Salmonella Newport infections linked to cucumbers--United States, 2014.

In August 2014, PulseNet, the national molecular subtyping network for foodborne disease surveillance, detected a multistate cluster of Salmonella enterica serotype Newport infections with an indistinguishable pulse-field gel electrophoresis (PFGE) pattern (XbaI PFGE pattern JJPX01.0061). Outbreaks of illnesses associated with this PFGE pattern have previously been linked to consumption of tomatoes harvested from Virginia's Eastern Shore in the Delmarva region and have not been linked to cucumbers or other produce items. To identify the contaminated food and find the source of the contamination, CDC, state and local health and agriculture departments and laboratories, and the Food and Drug Administration (FDA) conducted epidemiologic, traceback, and laboratory investigations. A total of 275 patients in 29 states and the District of Columbia were identified, with illness onsets occurring during May 20-September 30, 2014. Whole genome sequencing (WGS), a highly discriminating subtyping method, was used to further characterize PFGE pattern JJPX01.0061 isolates. Epidemiologic, microbiologic, and product traceback evidence suggests that cucumbers were a source of Salmonella Newport infections in this outbreak. The epidemiologic link to a novel outbreak vehicle suggests an environmental reservoir for Salmonella in the Delmarva region that should be identified and mitigated to prevent future outbreaks.

Outbreak of hepatitis A in the USA associated with frozen pomegranate arils imported from Turkey: an epidemiological case study.

BACKGROUND: In May, 2013, an outbreak of symptomatic hepatitis A virus infections occurred in the USA. Federal, state, and local public health officials investigated the cause of the outbreak and instituted actions to control its spread. We investigated the source of the outbreak and assessed the public health measures used. METHODS: We interviewed patients, obtained their shopping information, and did genetic analysis of hepatitis A virus recovered from patients' serum and stool samples. We tested products for the virus and traced supply chains. FINDINGS: Of 165 patients identified from ten states, 69 (42%) were admitted to hospital, two developed fulminant hepatitis, and one needed a liver transplant; none died. Illness onset occurred from March 31 to Aug 12, 2013. The median age of patients was 47 years (IQR 35-58) and 91 (55%) were women. 153 patients (93%) reported consuming product B from retailer A. 40 patients (24%) had product B in their freezers, and 113 (68%) bought it according to data from retailer A. Hepatitis A virus genotype IB, uncommon in the Americas, was recovered from specimens from 117 people with hepatitis A virus illness. Pomegranate arils that were imported from Turkey--where genotype IB is common--were identified in product B. No hepatitis A virus was detected in product B. INTERPRETATION: Imported frozen pomegranate arils were identified as the vehicle early in the investigation by combining epidemiology--with data from several sources--genetic analysis of patient samples, and product tracing. Product B was removed from store shelves, the public were warned not to eat product B, product recalls took place, and postexposure prophylaxis with both hepatitis A virus vaccine and immunoglobulin was provided. Our findings show that modern public health actions can help rapidly detect and control hepatitis A virus illness caused by imported food. Our findings show that postexposure prophylaxis can successfully prevent hepatitis A illness when a specific product is identified. Imported food products combined with waning immunity in some adult populations might make this type of intervention necessary in the future. FUNDING: US Centers for Disease Control and Prevention, US Food and Drug Administration, and US state and local public health departments.

Incidence and trends of infection with pathogens transmitted commonly through food--Foodborne Diseases Active Surveillance Network, 10 U.S. sites, 2006-2013.

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). 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.

Response to 2009 pandemic influenza A H1N1 among public schools of Georgia, United States--fall 2009.

BACKGROUND: Little is known about the extent of implementation or the effectiveness of the Centers for Disease Control and Prevention's (CDC) recommended non-pharmaceutical interventions (NPIs) in schools to control the spread of 2009 pandemic influenza A H1N1 (pH1N1). METHODS: A web-based, cross-sectional survey of all public K-12 schools in Georgia, USA was conducted about preparedness and response to pH1N1, and absenteeism and respiratory illness. Schools that reported ≥10% absenteeism and at least two times the normal level of respiratory illness in the same week were designated as having experienced significant respiratory illness and absenteeism (SRIA) during that week. RESULTS: Of 2248 schools surveyed, 704 (31.3%) provided sufficient data to include in our analysis. Participating schools were spread throughout Georgia, USA and were similar to non-participating schools. Of 704 schools, 160 (22.7%) reported at least 1 week of SRIA. Most schools reported implementing the CDC recommendations for the control of pH1N1, and only two schools reported canceling or postponing activities. Schools that communicated with parents about influenza in the summer, had shorter school days, and were located in urban areas were less likely to experience SRIA. CONCLUSIONS: Most Georgia schools in the United States adopted the CDC recommendations for pH1N1 mitigation and few disruptions of school activities were reported. Early and timely communication with parents, as well as shorter school days, may have been effective in limiting the effect of pH1N1 on schools.

Typhoid fever outbreak associated with frozen mamey pulp imported from Guatemala to the western United States, 2010.

BACKGROUND: Fifty-four outbreaks of domestically acquired typhoid fever were reported between 1960 and 1999. In 2010, the Southern Nevada Health District detected an outbreak of typhoid fever among persons who had not recently travelled abroad. METHODS: We conducted a case-control study to examine the relationship between illness and exposures. A case was defined as illness with the outbreak strain of Salmonella serotype Typhi, as determined by pulsed-field gel electrophoresis (PFGE), with onset during 2010. Controls were matched by neighborhood, age, and sex. Bivariate and multivariate statistical analyses were completed using logistic regression. Traceback investigation was completed. RESULTS: We identified 12 cases in 3 states with onset from 15 April 2010 to 4 September 2010. The median age of case patients was 18 years (range, 4-48 years), 8 (67%) were female, and 11 (92%) were Hispanic. Nine (82%) were hospitalized; none died. Consumption of frozen mamey pulp in a fruit shake was reported by 6 of 8 case patients (75%) and none of the 33 controls (matched odds ratio, 33.9; 95% confidence interval, 4.9). Traceback investigations implicated 2 brands of frozen mamey pulp from a single manufacturer in Guatemala, which was also implicated in a 1998-1999 outbreak of typhoid fever in Florida. CONCLUSIONS: Reporting of individual cases of typhoid fever and subtyping of isolates by PFGE resulted in rapid detection of an outbreak associated with a ready-to-eat frozen food imported from a typhoid-endemic region. Improvements in food manufacturing practices and monitoring will prevent additional outbreaks.

Enhanced surveillance of norovirus outbreaks of gastroenteritis in Georgia.

OBJECTIVES: The role of noroviruses in both foodborne and person-to-person outbreaks of acute gastroenteritis (AGE) has been difficult to determine in the U.S. because of lack of routine norovirus testing and of national reporting of person-to-person outbreaks. We conducted a prospective study in one state in which enhanced testing for noroviruses was performed to better understand the relative contribution of all gastroenteric pathogens. METHODS: During the two-year period, 2000-2001, we took all fecal specimens from AGE outbreaks reported in Georgia that were negative for bacteria and tested these for norovirus. RESULTS: We investigated 78 AGE outbreaks, from which suitable fecal samples were collected from 57 of them. Norovirus was identified in 25 (44%) outbreaks, bacteria in 20 (35%) outbreaks, and parasites in one (2%) outbreak. Forty-three (75%) of the outbreaks tested were foodborne, of which 17 (40%) were attributable to norovirus and 18 (42%) were attributable to bacteria. Adjusting for incomplete testing, we estimated that 53% of all AGE outbreaks were attributable to norovirus. A total of 2,674 people were reported ill in the 57 outbreaks, and norovirus infections accounted for 1,735 (65%) of these cases. Norovirus outbreaks tended to be larger than bacterial outbreaks, with a median number of 30 vs. 16 cases per outbreak, respectively (p = 0.057). CONCLUSIONS: This study provides further evidence that noroviruses are, overall, the most common cause of AGE outbreaks in the U.S. Improved specimen collection, reporting person-to-person outbreaks, and access to molecular assays are needed to further understand the role of these viruses and methods for their prevention.

Bioterrorism with zoonotic disease: public health preparedness lessons from a multiagency exercise.

Responding to agricultural bioterrorism with pathogenic agents that are communicable from animals to humans (zoonotic diseases) requires effective coordination of many organizations, both inside and outside of government. Action must be simultaneously taken to address public health concerns, respond to the agricultural dimensions of the event, and carry out the necessary law enforcement investigation. As part of a project focused on examining public health preparedness in Georgia, an exercise was carried out in July 2005 examining the intentional introduction of avian influenza (H5N1) in commercial poultry operations. The attack scenario, which was written to occur during an already severe human influenza season, enabled exploration of a range of issues associated with public health preparedness for major disease outbreaks including pandemic influenza, coordination of a multiagency response operation at multiple levels of government, and effective management of interdisciplinary response activities. The exercise is described and broader policy lessons regarding preparedness planning are discussed.

Shigellosis among swimmers in a freshwater lake.

OBJECTIVE: Shigella infection is highly communicable; however, outbreaks associated with swimming in recreational fresh water are rarely identified. MATERIALS AND METHODS: A cohort study of lake visitors was performed. RESULTS: Seventeen (24.6%) case patients among 69 persons who visited the lake over the holiday weekend were identified. Attack rates increased with increasing exposure to lake water; the risk of illness was greatest among swimmers who reported getting lake water in their mouths (relative risk = 5.37, 95% confidence interval = 2.2, 13.3). Shigella sonnei was isolated from stool samples of four of eight swimmers tested. CONCLUSIONS: The outbreak likely was caused by fecal contamination of lake water by an infected swimmer; there was no evidence of sewage contamination into the lake. Fresh water is a potential source of infection in patients with acute gastroenteritis and recent exposure. Since testing and chlorination of lake water is impractical, prevention relies on avoidance of fecal contamination and/or minimizing ingestion of the water.