West Nile virus

Neurons that have been infected with West Nile Virus.The cold winter is over, and spring rains and warmer weather mean that mosquito season is coming. Since 1999, summer mosquitoes have meant a risk for West Nile Virus. No one knows what 2004 will bring, but the season seems to have started early. The Centers for Disease Control and Prevention (CDC) already is reporting the presence of the virus in mosquitoes, birds and other animals in nine states. There even is confirmation of a human case in Ohio. Infectious diseases specialists at Washington University School of Medicine in St. Louis remind that the people at greatest risk are those 50 and older and those with weakened immune systems. Younger people also can acquire the infection, but their risk is significantly lower.

Courtesy photoSculpture by Wesley Anderegg, Lompoc, CASo you think you know mosquitoes? Consider the venerable law that rainy weather is the cause of increased mosquito populations. An ecologist at Washington University in St. Louis says if you believe that, you’re all wet.

*Culex pipiens*, a breed of mosquito known to carry the West Nile VirusIt was a cold winter in much of the country. That’s bad news for mosquitoes, but a wet spring in much of the United States will be a benefit to the buzzing bugs. Vector control specialists have plans in place to eradicate as many mosquitoes as possible, in part to prevent another summer of the West Nile Virus. In 2002, there were more than 4,000 cases reported in the United States, and almost 300 people died. The virus also decimated bird populations. This summer Michael Diamond, M.D., Ph.D., an infectious disease specialist at Washington University School of Medicine in St. Louis, believes the situation could worsen if the virus continues to be carried by mosquitoes that bite humans more than birds. Most cases in the United States still involve livestock, and a vaccine for animals recently was approved, but no vaccine exists for humans.