World War II Hepatitis Outbreak Was Biggest in History
BOSTON (AP) _ The hepatitis B virus was responsible for an outbreak of jaundice that struck 50,000 soldiers after they received yellow fever vaccines during World War II, a report today concludes.
The virus was long suspected to be the cause of the illness, but this was not confirmed until doctors sampled the blood of veterans two years ago. They estimate that as many as 330,000 soldiers may have been infected with hepatitis B spread by tainted vaccines, making it the biggest such outbreak ever recorded.
The researchers were surprised to find that few of those exposed to the virus still carried it in their bodies, even though there was evidence of prior infection.
The study was conducted to learn the long-term consequences of a hepatitis infection in otherwise healthy men. The research was directed by Dr. Leonard B. Seeff of the Veterans Administration Medical Center in Washington and published in today’s New England Journal of Medicine.
The outbreak was blamed on yellow fever vaccine that was made with human blood serum. Some of the blood serum was contaminated with hepatitis B.
The researchers estimate that 427,000 doses were drawn from the contaminated lots of vaccine. Perhaps 330,000 men were infected with or exposed to the hepatitis B virus over a six-month period in 1941 and 1942, and about 1 in 7 of them became sick.
Ordinarily experts expect that about 5 to 10 percent of those infected will continue to carry the virus in their bodies throughout their lives. However, of those tested in the follow-up study, only about one-quarter of 1 percent still had the virus.
They are not sure why this was so low. But they said it might have been because the men were healthy and only exposed once to the virus. The men also were white; studies have found whites are less likely than Asians and blacks to be carriers of the virus.
In the follow-up, conducted in 1985, doctors tested the blood of 597 veterans who had been in the Army in 1942.