Lettuce, green onions, and strawberries have all been implicated as the source of hepatitis A outbreaks, and other fresh produce items that are not typically cooked before being served share the potential to become contaminated with hepatitis A while in the field or during processing. Fresh produce exposed to flood waters that carry hepatitis A can become contaminated pre-harvest; runoff water that could potentially carry HAV should be diverted from fields growing fresh produce and should not be used for irrigation. In addition, ill field workers should be excluded from working until they cease exhibiting symptoms of infection. Proper toilet and hand-washing facilities in fields and processing facilities should be available to workers to prevent the spread of hepatitis A.

In 2005, Los Angeles County Department of Health Services (LACDHS) officials learned that cast and crew members from the movie set of “The Good German” were confirmed ill with acute hepatitis A infection. Interviews conducted by LACDHS and an epidemiologic investigation revealed that a salad served on location by Silver Grill Location Catering Inc. was the source of infection. In all, 18 individuals became ill with hepatitis A after eating salad provided by Silver Grill Location Catering; one person was hospitalized. LACDHS determined that since all Silver Grill Catering food-handlers tested negative for acute hepatitis A, contamination by an ill food handler did not occur. LACDHS Environmental Health staff and the California Department of Health Services’ Food and Drug Branch conducted a traceback and identified lettuce distributed by Soleil Produce as the source of the hepatitis A outbreak. See Silver Grill Hepatitis A Outbreak Litigation.

In November 2003, public health officials from the Pennsylvania Department of Health (PDOH), Centers for Disease Control and Prevention (CDC), Food and Drug Administration (FDA), and other state and local public health agencies joined to investigate a hepatitis A outbreak among patrons of a Chi-Chi’s restaurant in Monaca, Pennsylvania. Over 600 people became ill with hepatitis A infection during the outbreak; 124 were hospitalized, and four developed fulminant hepatitis A. Three of the four outbreak victims with fulminant hepatitis A died; one received a liver transplant and survived. All restaurant workers were tested, but none were identified who could have been the source of the outbreak. Investigators determined that green onions were the source of the hepatitis A outbreak and that they were contaminated before arrival at the restaurant. Investigators concluded that the inclusion of contaminated onions in large batches of salsa served to all customers contributed to the size of the outbreak. A trace-back of the green onions led to the conclusion that the implicated green onions were contaminated with hepatitis A virus before or during packing into shipping boxes on farms in northern Mexico. See Chi-Chi’s Hepatitis A Outbreak Litigation.

In 2000, the Florida Department of Health and Lake County Health Department (LCHD) investigated a hepatitis A outbreak among patrons of the Fruitland Park Taco Bell restaurant. While the Lake County investigation was ongoing, the LCHD learned from the CDC that hepatitis A outbreak investigations were also underway in Russell County, Kentucky and Clark County, Nevada. Epidemiologic and environmental investigations and laboratory analysis implicated green onions served at Taco Bell locations in three states as the source of the hepatitis A outbreak. LCHD concluded, “[a]lthough most foodborne outbreaks of hepatitis A are due to food contaminated by an infected food preparer, we believe the ingredients were contaminated prior to arrival at the outlet in this outbreak. . . . The most likely contaminated ingredient is green onion.” See Taco Bell Hepatitis A Legal Cases.

In 1997, public health officials in Michigan investigated 213 cases of hepatitis A among students and teachers at 23 schools across the state. A cohort study among students and staff from different school districts established an association between hepatitis A infection and consumption of food items containing frozen strawberries that were served at the schools. A subsequent case-control study conducted by public health officials from several other states led to the identification of 29 hepatitis A cases from 13 schools in Maine, 5 patients in Wisconsin, and 7 patients in Arizona, all of whom attended schools where frozen strawberries from the same processor had been served. Two cases in Louisiana, both of whom had consumed commercially prepared products containing frozen strawberries from the same processor, also tested positive for hepatitis A.