The HAV is a small single strand RNA picornavirus.5 It is transmitted primarily by the fecal-oral route, either from person-to-person, i.e., close personal contact with an infected household member or sex partner; or by consumption of contaminated food or water. The HAV has an incubation period of about 28 days (range: 15–50 days). IgG antibodies to HAV, which appear early in the course of infection, provide lifelong protection against the disease.
The majority of children infected with the HAV are asymptomatic. Among adults the infection is typically symptomatic with jaundice occurring in more than 80% of infected persons. Other signs and symptoms include fever, fatigue, anorexia, nausea, vomiting, abdominal pain, dark urine, clay-colored bowel movements, and joint pain. HAV infection is self-limiting and does not result in chronic liver disease.
Infection with the HAV is vaccine-preventable. There are two single-antigen inactivated hepatitis A whole-virus vaccines (Vaqta, Havrix) and a combination hepatitis A and B vaccine (Twinrix) available. Twinrix contains the same hepatitis A component as Havrix, but half the dose. Vaccination is recommended for adults with chronic liver disease, illicit drug users, and those at risk of healthcare-associated exposure.
There are no special treatments for hepatitis A viral infections. Symptoms usually last less than 2 months, although 10%–15% of symptomatic persons have prolonged or relapsing disease for up to 6 months. During this time, medical management includes rest, and adequate nutrition and fluid intake. Alcohol should be avoided. Some infected individuals will require hospitalization.