Hepatitis A is a communicable (or contagious) disease that spreads from person to person. It is transmitted by the “fecal – oral route,” generally from person-to-person, or via contaminated food or water. Food-related outbreaks are usually associated with contamination of food during preparation by an HAV-infected food handler (CDC, 2009c). The food handler is generally not ill: the peak time of infectivity (that is, when the most virus is present in the stool of an infectious individual) occurs during the 2 weeks before illness begins. Fresh produce contaminated during cultivation, harvesting, processing, and distribution has also been a source of hepatitis A (Fiore, 2004). In 1997, frozen strawberries were determined to be the source of a hepatitis A outbreak in five states (Hutin, et al., 1999), and in 2003, fresh green onions were identified as the source of a hepatitis A outbreak traced to consumption of food at a Pennsylvania restaurant (Wheeler, et al., 2005). Other produce, such as blueberries and lettuce, has been associated with hepatitis A outbreaks in the U.S. as well as other developed countries (Butot et al., 2008; Calder et al., 2003).
HAV is relatively stable and can survive for several hours on fingertips and hands and up to two months on dry surfaces, but can be inactivated by heating to 185°F (85°C) or higher for one minute or disinfecting surfaces with a 1:100 dilution of sodium hypochlorite (household bleach) in tap water (Advisory Committee on Immunization Practices [ACIP], 2006; CDC, 2009c; Todd et al., 2009). However, HAV can still be spread from cooked food if it is contaminated after cooking.
Although ingestion of contaminated food is a common means of spread for hepatitis A, it may also be spread by household contact among families or roommates, sexual contact, by the ingestion of contaminated water or shellfish (like oysters), and by direct inoculation from persons sharing illicit drugs. Children often have asymptomatic or unrecognized infections and can pass the virus through ordinary play, unknown to their parents, who may later become infected from contact with their children.