A study led by researchers at the National Institutes of Health (NIH) suggests that hepatitis E virus (HEV) is common among wild rats in the United States.

Although hepatitis E disease is very rare among people in the United States, many have HEV antibodies in their blood -- evidence that they were once infected with the virus, even though it did not make them sick. The finding raises questions about whether there is any connection between rats and HEV infection in humans. A report of the study appears in the August 1999 issue of the American Journal of Tropical Medicine and Hygiene.

Scientists analyzed blood samples from 239 rats captured in alleyways in Baltimore, MD, along the Mississippi River levee in New Orleans, LA, and in urban and rural areas of Hawaii. Tests revealed that more than 80 percent of the rats had HEV antibodies in their blood, evidence of prior HEV infection. Yamina Kabrane-Lazizi, Ph.D., of the National Institute of Allergy and Infectious Diseases (NIAID) was lead author of the study. Her collaborators included scientists from the National Institute of Neurological Disorders and Stroke, the Johns Hopkins School of Public Health in Baltimore, and the John A. Burns School of Medicine in Honolulu, HI.

Hepatitis E disease generally affects young adults and usually is not life-threatening, except in pregnant women infected with the virus where fatality rates of 15 to 20 percent have been reported. According to the Centers for Disease Control and Prevention (CDC), virtually all cases of hepatitis E disease in the United States have occurred among travelers returning from developing countries, where the disease is endemic and spread through contaminated drinking water. Nevertheless, tests show that between 1 and 5 percent of healthy blood donors in the United States have HEV antibodies in their blood.

"Since hepatitis E is so rare in this country, it's puzzling that so many people have antibodies to the virus in their bloo
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Contact: John Bowersox
jbowersox@niaid.nih.gov
301-402-1663
NIH/National Institute of Allergy and Infectious Diseases
19-Aug-1999