Hepatitis A (HAV) is a virus that infects the liver and causes hepatitis A, an illness with an abrupt onset that can include fever, malaise, nausea, abdominal discomfort, dark urine and jaundice after a prolonged incubation period (for example, more than two months). In children less than six years old, most infections (70 percent) are asymptomatic, but in older children and adults, infection is usually symptomatic, with jaundice occurring in more than 70 percent of patients. Signs and symptoms of Hepatitis A usually last more than two months, but there are no chronic consequences. About 130,000 infections with HAV and 100 deaths occur every year in the U.S..
The primary mode of transmission for HAV is person-to-person by the fecal-oral route. (Preparing food with unwashed hands after using the toilet or changing diapers, is a typical faecal-oral route) Recognized foodborne Hepatitis A outbreaks account for only 2 to 5 percent of Hepatitis A cases reported in the U.S. every year, most of which are caused by an infected food handler.
Outbreaks caused by foods contaminated before preparation have been associated with widely distributed products such as shellfish, lettuce, frozen raspberries and frozen strawberries. Hepatitis A can be prevented by good personal hygiene and safe food-handling practices.