Hepatitis E virus (HEV)

The disease caused by HEV is called hepatitis E, or enterically transmitted non-A non-B hepatitis (ET-NANBH). Other names include fecal-oral non-A non-B hepatitis,and A-like non-A non-B hepatitis. Note: This disease should not be confused with hepatitis C, also called parenterally transmitted non-A non-B hepatitis (PT-NANBH), or B-like non-A non-B hepatitis, which is a common cause of hepatitis in the U.S.

What are the symptoms of hepatitis caused by HEV?

Hepatitis caused by HEV is clinically indistinguishable from hepatitis A disease. Symptoms include malaise, anorexia, abdominal pain, arthralgia, and fever. The infective dose is not known.

How is HEV diagnosed?

Diagnosis of HEV is based on characteristics of the outbreak and by exclusion of hepatitis A and B viruses by blood tests. Confirmation requires identification of the virus-like particles by immune electron microscopy in feces of acutely ill patients.

How is HEV transmitted?

HEV is transmitted by the fecal-oral route. Waterborne and person-to-person spread have been documented. The potential exists for foodborne transmission.

How common is hepatitis associated with HEV?

Hepatitis E occurs in both epidemic and sporadic-endemic forms, usually associated with contaminated drinking water. Major waterborne epidemics have occurred in Asia and North and East Africa. To date no US outbreaks have been reported.

What is the course of the disease and what are the complications?

The incubation period for hepatitis E varies from 2 to 9 weeks. The disease usually is mild and resolves in 2 weeks, leaving no sequelae. The fatality rate is 0.1-1% except in pregnant women. This group is reported to have a fatality rate approaching 20%.

Who is most susceptible to HEV?

The disease is most often seen in young to middle aged adults (15-40 years old). Pregnant women appear to be exceptionally susceptible to severe disease, and excessive mortality has been reported in this group.

How is HEV detected in food?

HEV has not been isolated from foods. No method is currently available for routine analysis of foods.