The hepatitis A virus (HAV) is shed in the stool (feces) of infected individuals. Secondary cases, or people who become infected with hepatitis A and have an epidemiologic link to exposure by a person who has laboratory-confirmed hepatitis A (e.g., household or sexual contact with an infected person during the 15–50 days before the onset of symptoms) are common in outbreak-situations. Some individuals with hepatitis A infection are asymptomatic, or do not display symptoms of infection. Children often have asymptomatic or unrecognized hepatitis A infections and can pass the virus through ordinary play.

A person who has become infected with hepatitis A can shed the virus in their stool for several weeks before showing symptoms of hepatitis A infection and is infectious until HAV can no longer be isolated from their stool – usually a week or so after jaundice sets in. Proper hand washing reduces the risk of transmission from person-to-person, and is essential for anyone recovering from hepatitis A infection, as well as for people caring for individuals with HAV and those changing the diapers of infected children.

In 2004, a hepatitis A outbreak was traced to the Maple Lawn Dairy Family Restaurant in Elmira, New York. At least four people were confirmed ill with hepatitis A, including one man who developed fulminant hepatitis and died. Individuals who had eaten at the restaurant and had been exposed to the hepatitis A virus were encouraged to receive immune globulin injections to prevent infection. The Chemung County Health Department investigated the hepatitis A outbreak, and determined that a food worker was the source of the outbreak. The worker, who handled food items while infectious, was diagnosed with hepatitis A several weeks before the outbreak was announced. See Maple Lawn Dairy Hepatitis A Outbreak Litigation.

In 2001, the Massachusetts Department of Public Health (MDPH) investigated a hepatitis a outbreak among customers of two D’Angelo’s restaurants. The restaurant’s corporate office notified MDPH that a D’Angelo’s employee had been working while infectious with hepatitis A, and while MDPH and the Swansea Board of Health monitored the restaurant, they learned that seven individuals had become ill with hepatitis A infection several weeks after eating at the restaurant during the time period when the infected employee worked there. The investigation yielded a total of 53 cases meeting the outbreak case definition. An epidemiological analysis of the case interviews revealed an association between the hepatitis A illness and the consumption of food from D’Angelo’s. MDPH concluded, “This large outbreak of HAV was most likely caused by improper foodhandling while an ill employee was shedding hepatitis-A virus in his stool.” Two confirmed cases were food workers employed at Rudy’s Country Store. Both employees had eaten at the Swansea D’Angelo’s three to four weeks prior to the onset of their HAV infections. Accordingly, patrons of Rudy’s received immune globulin injections to prevent infection with hepatitis A. Over 1,600 people received the injections. See D’Angelo’s Hepatitis A Outbreak Litigation.