--- title: Lethal Hepatitis A Outbreak Traced to Mexican Scallions date: 2005-09-01T07:38:41-07:00 author: Bill Marler canonical_url: "https://marlerclark.com/news_events/lethal-hepatitis-a-outbreak-traced-to-mexican-scallions" section: News --- [All News](/news_events) / # Lethal Hepatitis A Outbreak Traced to Mexican Scallions By Neil Osterweil, Senior Associate Editor, MedPage Today Reviewed by Zalman S. Agus, MD; Emeritus Professor at the University of Pennsylvania School of Medicine. August 31, 2005 Review ATLANTA, Aug. 31-An outbreak of hepatitis A that killed three patrons of a Pennsylvania restaurant and sent at least 124 others to the hospital was caused by contaminated green onions (scallions) from Mexico. Even though the restaurant appeared to follow hygienic practices and none of the employees was found to be the source of the outbreak, about 527 people who ate or worked at the restaurant in November of 2003 contracted hepatitis A. Many of those infected had eaten a mild salsa containing the contaminated vegetable, reported CDC researchers in the Sept. 1 issue of The New England Journal of Medicine. The good news about the virus, wrote Charlotte Wheeler, M.D., M.P.H. and colleagues, is that the incidence of hepatitis A in the United States has declined to an all-time low. The bad news, however, is that “even when transmission within communities is greatly reduced and food is prepared according to recommended hygienic standards, foods imported from communities where transmission of hepatitis A virus remains common can be sources of exposure,” they wrote. The hepatitis A virus is quite capable of remaining infectious on environmental surfaces such as counters and food preparation areas for at least one month, and investigators have reported outbreaks of hepatitis A caused by foods that were contaminated during harvesting or processing. Green onions were also implicated as the source of hepatitis A outbreaks in Ohio in 1999, Kentucky and Florida in 2000, and in Tennessee, Georgia, and North Carolina in 2003, the authors noted. Infection is by the fecal-oral route, either when patients come in direct contact with someone who is infected, or when they eat or drink contaminated food or water. In the U.S., contaminated food accounts for less than 5% of reported hepatitis A infections. But “even a small amount of fecal contamination might result in many hundreds of infectious doses, because concentrations of hepatitis A virus are estimated to reach one billion infectious doses per gram of stool, and because the infectious dose, though unknown, is probably low,” Dr. Wheeler and colleagues wrote. Ironically, the good hygiene that has managed to keep hepatitis A in check in the U.S. also means that fewer people are exposed to the virus in childhood, when the symptoms tend to be mild, if they occur at all. And that means that fewer adults have immunity, write Loriana Di Gimmarino, M.D., and Jules L. Dienstang, M.D., of the Massachusetts General Hospital and Harvard Medical School, in an accompanying editorial. “Paradoxically, then, as hepatitis A becomes less common, the burden of new infections shifts from children to adults, and the frequency of clinically severe acute hepatitis A increases — an unintended consequence of progress,” the editorialists wrote. The outbreak was brought to the attention of Pennsylvania health authorities by an alert clinician on Nov. 1, 2003. Although there had been only one case of hepatitis A among residents of Beaver County, Pa., over the previous year, the authorities were suddenly confronted with infections in six county residents, all of whom had eaten at the same restaurant. The same day, an inspector from the state’s Department of Agriculture inspected the restaurant and found no sanitary violations, but heard that some food workers at the restaurant were ill. The restaurant closed voluntarily, and by Nov. 7, the number of cases had climbed to 11. Eventually, 601 restaurant patrons and 13 employees would be diagnosed with hepatitis A. The investigators conducted a case-control study, focusing on a group of 240 Pennsylvania residents who had dined at the restaurant between October 3 and October 6, and who ate there only once during the two- to six-week incubation period. Controls were either their meal companions who were not infected, or other patrons who dined at the restaurant during the same period, as identified by credit card receipts. They found that 218 of the 240 infected people (91%) had eaten mild salsa, compared with 45 of 130 controls (35%) for whom data were available. The odds ratio for the difference was 19.6; 95% confidence interval, 11.0 to 34.9. In all, 98% of patients but only 58% of controls recalled having eaten a menu item containing green onions (odds ratio, 33.3; 95% CI, 12.8 to 86.2). All the restaurant workers were tested, but none could be identified as the source of the outbreak. The investigators also found that nucleic acid sequences from the virus were identical in all 170 patients they tested, indicating that the infections came from the same source. After narrowing the list of possible contamination sources to five menu items, the researchers were eventually able to pin it on the green onions contained in the mild salsa served to all patrons by the restaurant. “Contamination of green onions could occur by contact with workers (or workers’ children) who are infected with hepatitis A virus during harvesting and preparation or by contact with contaminated water during irrigation, rinsing, processing, cooling, and icing,” Dr, Wheeler and colleagues wrote. “In addition, viral particles or feces are especially difficult to wash off complex plant surfaces.” They recommend that food-service facilities consider the possibility that contaminated produce could cross contaminate other produce or food preparations surfaces and utensils. The editorialists added, “Potentially, universal childhood vaccination against hepatitis A could eliminate the risk of new infections. Moreover, now that combination hepatitis A and hepatitis B vaccines are available and the infrastructure is in place to immunize children routinely against hepatitis B during well-child visits, a policy of universal hepatitis A vaccination in childhood would be facilitated.” Further, they wrote that “several assessments indicate the cost-effectiveness of childhood hepatitis A vaccination to prevent infection in adolescents and adults.” Related article: Hepatitis A Vaccinations Yield Dramatic Decline in Infections Primary source: New England Journal of Medicine Source reference: N Engl J Med 2005;353:890-7 Additional source: ,New England Journal of Medicine Source reference: N Engl J Med 2005;353:944-6 ### Other Hepatitis A Lawsuits [La Serranita Concha Negra Frozen Clam Hepatitis A Outbreak Lawsuits](https://marlerclark.com/la-serranita-concha-negra-frozen-clam-hepatitis-a-outbreak-lawsuits) [Washington and California Hepatitis A Outbreak linked to Imported Strawberries](https://marlerclark.com/washington-hepatitis-a-outbreak-linked-to-imported-strawberries) [Hepatitis A outbreak - Strawberries sicken 27 in Canada and United States](https://marlerclark.com/hepatitis-a-outbreak-strawberries-sicken-27-in-canada-and-united-states) [Gino's Ristorante & Pizzeria linked to Hepatitis A Outbreak](https://marlerclark.com/ginos-ristorante-pizzeria-linked-to-hepatitis-a-outbreak) [Famous Anthony's Hepatitis A Outbreak; 52 sick, 36 hospitalized and 4 deaths](https://marlerclark.com/hepatitis-a-outbreak-linked-to-roanoke-famous-anthonys-restaurants) [Los Angelos Hepatitis A Outbreak linked to 555 East American Steakhouse](https://marlerclark.com/los-angelos-hepatitis-a-outbreak-linked-to-555-east-american-steakhouse) [Marler Clark retained in Hepatitis A cases linked to Fresh Thyme or Woodman’s blackberries](https://marlerclark.com/marler-clark-retained-in-nebraska-hepatitis-a-case-linked-to-fresh-thyme-farmers-market-blackberries) [Mendham Golf & Tennis Club Hepatitis A Outbreak](https://marlerclark.com/mendham-golf-tennis-club-hepatitis-a-outbreak) [Hawaii Hepatitis A Outbreak Linked to Genki Sushi Restaurants](https://marlerclark.com/oahu-hepatitis-a-outbreak-investigation) [New Hawaii Sea Restaurant Hepatitis A Outbreak](https://marlerclark.com/new-hawaii-sea-restaurant-hepatitis-a-outbreak) [Townsend Farms organic frozen berries from Costco and Harris Teeter linked to hepatitis A outbreak](https://marlerclark.com/townsend-farms-organic-frozen-berries-from-costco-linked-to-hepatitis-a-out) [A Tom's Gyro Restaurant Employee Tests Positive for Hepatitis A in Idaho](https://marlerclark.com/a-toms-gyro-restaurant-employee-tests-positive-for-hepatitis-a-in-idaho) ### Lawsuit updates about foodborne illnesses [Reactive Arthritis Lawsuit Updates](/news_events/case-news?illness=reactive-arthritis&year=all) [E. coli Lawsuit Updates](/news_events/case-news?illness=e-coli&year=all) [Guillain-Barre Syndrome Lawsuit Updates](/news_events/case-news?illness=guillain-barre-syndrome&year=all) [Salmonella Lawsuit Updates](/news_events/case-news?illness=salmonella&year=all) [Hemolytic Uremic Syndrome Lawsuit Updates](/news_events/case-news?illness=hemolytic-uremic-syndrome&year=all) [Listeria Lawsuit Updates](/news_events/case-news?illness=listeria&year=all) [Irritable Bowel Syndrome Lawsuit Updates](/news_events/case-news?illness=irritable-bowel-syndrome&year=all) [Hepatitis A Lawsuit Updates](/news_events/case-news?illness=hepatitis-a&year=all) [Norovirus Lawsuit Updates](/news_events/case-news?illness=norovirus&year=all) [Botulism Lawsuit Updates](/news_events/case-news?illness=botulism&year=all) [Campylobacter Lawsuit Updates](/news_events/case-news?illness=campylobacter&year=all) [Shigella Lawsuit Updates](/news_events/case-news?illness=shigella&year=all) [Cyclospora Lawsuit Updates](/news_events/case-news?illness=cyclospora&year=all) ### Lawsuits updates by year [Foodborne Illness Lawsuits in 1998](https://marlerclark.com/news_events/case-news?illness=all&year=1998) [Foodborne Illness Lawsuits in 1999](https://marlerclark.com/news_events/case-news?illness=all&year=1999) [Foodborne Illness Lawsuits in 2000](https://marlerclark.com/news_events/case-news?illness=all&year=2000) [Foodborne Illness Lawsuits in 2001](https://marlerclark.com/news_events/case-news?illness=all&year=2001) [Foodborne Illness Lawsuits in 2002](https://marlerclark.com/news_events/case-news?illness=all&year=2002) [Foodborne Illness Lawsuits in 2003](https://marlerclark.com/news_events/case-news?illness=all&year=2003) [Foodborne Illness Lawsuits in 2004](https://marlerclark.com/news_events/case-news?illness=all&year=2004) [Foodborne Illness Lawsuits in 2005](https://marlerclark.com/news_events/case-news?illness=all&year=2005) [Foodborne Illness Lawsuits in 2006](https://marlerclark.com/news_events/case-news?illness=all&year=2006) [Foodborne Illness Lawsuits in 2007](https://marlerclark.com/news_events/case-news?illness=all&year=2007) [Foodborne Illness Lawsuits in 2008](https://marlerclark.com/news_events/case-news?illness=all&year=2008) [Foodborne Illness Lawsuits in 2009](https://marlerclark.com/news_events/case-news?illness=all&year=2009) [Foodborne Illness Lawsuits in 2010](https://marlerclark.com/news_events/case-news?illness=all&year=2010) [Foodborne Illness Lawsuits in 2011](https://marlerclark.com/news_events/case-news?illness=all&year=2011) [Foodborne Illness Lawsuits in 2012](https://marlerclark.com/news_events/case-news?illness=all&year=2012) [Foodborne Illness Lawsuits in 2013](https://marlerclark.com/news_events/case-news?illness=all&year=2013) [Foodborne Illness Lawsuits in 2014](https://marlerclark.com/news_events/case-news?illness=all&year=2014) [Foodborne Illness Lawsuits in 2015](https://marlerclark.com/news_events/case-news?illness=all&year=2015) [Foodborne Illness Lawsuits in 2016](https://marlerclark.com/news_events/case-news?illness=all&year=2016) [Foodborne Illness Lawsuits in 2017](https://marlerclark.com/news_events/case-news?illness=all&year=2017) [Foodborne Illness Lawsuits in 2018](https://marlerclark.com/news_events/case-news?illness=all&year=2018) [Foodborne Illness Lawsuits in 2019](https://marlerclark.com/news_events/case-news?illness=all&year=2019) [Foodborne Illness Lawsuits in 2020](https://marlerclark.com/news_events/case-news?illness=all&year=2020) [Foodborne Illness Lawsuits in 2021](https://marlerclark.com/news_events/case-news?illness=all&year=2021) [Foodborne Illness Lawsuits in 2022](https://marlerclark.com/news_events/case-news?illness=all&year=2022) [Foodborne Illness Lawsuits in 2023](https://marlerclark.com/news_events/case-news?illness=all&year=2023) [Foodborne Illness Lawsuits in 2024](https://marlerclark.com/news_events/case-news?illness=all&year=2024) [Foodborne Illness Lawsuits in 2025](https://marlerclark.com/news_events/case-news?illness=all&year=2025) [Foodborne Illness Lawsuits in 2026](https://marlerclark.com/news_events/case-news?illness=all&year=2026) ##### Get Help #### Affected by an outbreak or recall? The team at Marler Clark is here to answer all your questions. Find out if you’re eligible for a lawsuit, what questions to ask your doctor, and more. [ Get a free consultation ](https://marlerclark.com/contact) ##### Related Resources ###### [Hepatitis A Food Poisoning](https://marlerclark.com/foodborne-illnesses/hepatitis-a/about-hepatitis) An Introduction to Hepatitis A Viral hepatitis is a major global public health problem affecting hundreds of millions of people and is associated with significant morbidity and mortality. Five biologically... ###### [The Incidence of Hepatitis A Infection](https://marlerclark.com/foodborne-illnesses/hepatitis-a/how-common-is-hepatitis-a-infection) How common is Hepatitis A infection? Hepatitis A incidence varies between regions and is much more common in countries with underdeveloped sanitation systems; thus, contracting hepatitis A is a risk... ###### [Transmission of Hepatitis A](https://marlerclark.com/foodborne-illnesses/hepatitis-a/how-does-hepatitis-a-spread) How does Hepatitis A spread? Hepatitis A is a communicable (or contagious) disease that is acquired primarily by the fecal oral route either from person to person or through contaminated... ###### [Symptoms of Hepatitis A Infection](https://marlerclark.com/foodborne-illnesses/hepatitis-a/hepatitis-symptoms-risks) What are the symptoms of Hepatitis A infection? Hepatitis A may cause no symptoms at all when it is contracted, especially in children. Asymptomatic individuals may only know they were... ###### [Complications of Hepatitis A Infection](https://marlerclark.com/foodborne-illnesses/hepatitis-a/hepatitis-complications) Fulminant hepatitis A, or acute liver failure, can be a complication of hepatitis A infection. Fulminant hepatitis A is a rare but devastating complication of HAV infection. As many as... ##### Outbreak Database #### Looking for a comprehensive list of outbreaks? The team at Marler Clark is here to answer all your questions. Find out if you’re eligible for a lawsuit, what questions to ask your doctor, and more. [ View Outbreak Database ](https://outbreakdatabase.com)