Worst-Ever West Nile Epidemic: What Happened?
Stopping West Nile: Lessons Learned
There's no vaccine against West Nile virus. There's no treatment. The best advice for avoiding infection is CDC's "Fight the Bite" campaign. This means wearing protective clothing and insect repellent, avoiding the outdoors at dawn and dusk, and ridding your home of places mosquitoes breed.
One controversial measure has been the use of aerial spraying of insecticide to kill adult mosquitoes. While such spraying is considered safe, it's not totally without risk. And there have been questions about whether it works.
There's still no definitive answer to those questions. However, data strongly supporting aerial spraying comes from Texas, which saw some 30% of the nation's severe cases this year.
"In areas of Texas subjected to aerial spraying, the spray reduced the number of vector mosquitoes by more than 90%. Areas not sprayed had an increase in mosquitoes," Petersen says. "Once we analyze all the data, we expect that these control measures were effective -- probably highly effective -- in stopping the outbreak in those areas."