In the letter world of hepatitis, B and C are most well-known as causing severe and potentially fatal liver injury. But what about hepatitis A virus (HAV)? HAV is one of the world’s most common viral infections, and even though a vaccine given to school age children helps to limit the occurrence of the disease, it is still the cause of over half of the reported cases of viral hepatitis in the United States, and has significant morbidity.
Hepatitis A is an RNA viral infection shed in the stool and is usually spread by food contaminated with fecal matter. It can also be contracted from contaminated water, personal contact with others infected with the disease, spread in daycare centers from child to child, and even sexual contact. Since hepatitis A has a very long incubation period (approximately 28 days from exposure to the onset of symptoms), it is often hard to trace back to a particular source. In more than half the cases a specific identifiable risk factor is never found.
Onset of the disease is quite intense, with fever, nausea, vomiting, diarrhea, and jaundice (yellow skin). Headache, weight loss, dark urine, and abdominal pain develop as the liver is affected. Symptoms generally increase with age, and younger children are generally less affected than older individuals. Hepatitis A is most contagious in the two weeks before, and the first week after symptoms begin, and recurrences are common.
It is typically not possible to differentiate the different types of hepatitis from their clinical presentation alone. Even viral infections, drugs, toxins, and bacterial and parasitic infections may present with similar pictures. Diagnosis is made by the detection of serum immunoglobulin M (IgM) anti HAV antibodies. This test is available in most clinical laboratories.
Thankfully hepatitis A is a self-limiting infection and in most cases complications are generally most severe after the age of 50. One in six affected people may have a relapse, but unlike other forms of hepatitis, like B and C, there is no chronic state. Inflammation of blood vessels, anemia, kidney failure, and pancreatitis can occur during the acute phase. There’s no treatment except supportive care for the virus, and almost all cases subside, even those with relapses. Older individuals should be watched more carefully for complications, and children should not return to school until fever and jaundice have subsided.
The CDC has authorized a vaccine where children can get a series of immunizations between the age of one and two. Those traveling into areas where hepatitis A is common should receive the vaccine as well. An immunoglobulin that gives passive immunity for up to three months may also be co-administered in adults. Vaccinations have been an essential part in cutting the occurrence of the disease by almost 90% in the U.S. Always check with your doctor before traveling to an endemic area for hepatitis A to see what is needed in terms of vaccination or medication. Likewise if you have been exposed to someone with hepatitis A, the disease can be short circuited or made milder in course if the vaccine is administered within the first two weeks of exposure.
Authored by Dr. Bob Goldstone, M.D.
The information contained on this page is not intended to provide medical advice, which should be obtained directly from your physician.