Hepatitis, Viral – Type A

Infectious agent:  Hepatitis A virus (HAV)

Description of illness: Hepatitis A is a vaccine-preventable, acute, self-limited illness characterized by fever, malaise, jaundice, anorexia, and nausea. It is transmitted person-to-person through the fecal-oral route or through exposure to contaminated food or water.  Only 30% of infected children younger than 6 years of age will become symptomatic, and few will have jaundice.  Among older children and adults, infection usually is symptomatic and typically lasts several weeks, with jaundice occurring in ≥70%.  Ten to fifteen percent of symptomatic people have prolonged or relapsing disease lasting as long as 6 months.  Fulminant hepatitis and death is rare and is more common in people with underlying liver disease.  Chronic infection does not occur. Serologic testing for HAV IgM in the absence of acute illness compatible with hepatitis A is not recommended due to the possibility false positive results, especially in older adults.