Hepatitis A.

Hepatitis A is a common viral illness worldwide, although the incidence in the United States has diminished in recent years as a result of extended immunization practices. Hepatitis A virus is transmitted through fecal-oral contamination, and there are occasional outbreaks through food sources. Young children are usually asymptomatic, although the likelihood of symptoms tends to increase with age. Most patients recover within two months of infection, although 10 to 15 percent of patients will experience a relapse in the first six months. Hepatitis A virus does not usually result in chronic infection or chronic liver disease. Supportive care is the mainstay of treatment. The Centers for Disease Control and Prevention and the American Academy of Pediatrics recommend routine vaccination of all children 12 to 23 months of age, as well as certain vulnerable populations. Hepatitis A vaccine is also recommended for most cases of postexposure prophylaxis, although immunoglobulin is an acceptable alternative in some situations.