Another Reason to Hate Mosquitoes
May 24, 2000 (Los Angeles) -- Each year, 36,000 people in the U.S. contract the deadly hepatitis C virus, which infects the liver and is the leading cause of damage requiring a liver transplant. The virus goes on to kill up to 10,000 Americans each year. Now researchers in France have evidence suggesting that mosquitoes may spread hepatitis C and other viruses, such as West Nile virus. The scientists discussed their work at a microbiology meeting here this week.
The people at highest risk of getting hepatitis C are drug abusers, people who receive blood transfusions, patients who require kidney dialysis, and health care workers. However, approximately 20% of people with the disease have no risk factors for it at all.
Hepatitis C belongs to a family of viruses, such as the Dengue and yellow fever viruses, that are known to be spread by mosquitoes, says co-author Dominique Debriel, MD, PhD. But, he tells WebMD, "to my knowledge, no one has yet shown [that mosquitoes transmit hepatitis C]."
To determine whether hepatitis C could grow in mosquito cells, Debriel and his colleagues grew the virus in monkey cells, human cells, and mosquito cells. They found that the mosquito cells were uniquely designed to connect with hepatitis C, suggesting that these insects could indeed carry and transmit the virus.
Debriel, a staff physician at the HÃ´pital Pasteur in Colmar, France, warns that much more research must be done before it can be definitely concluded that mosquitoes actually spread the disease.
However, this is no mere laboratory experiment. The havoc wreaked by a mosquito-borne virus hit close to home last summer, when New York City was swept by an outbreak of West Nile virus, another relative of hepatitis C. Sixty-two cases of encephalitis, or inflammation of the brain, and seven deaths occurred during that outbreak -- all thanks to the West Nile virus carried by mosquitoes.
According to the CDC, this was the first report of a West Nile virus outbreak in the U.S. As its name implies, the virus is most commonly found in Africa, West Asia, and the Middle East. Its fatality rate can range from 3% to 15% and is highest in the elderly.