Scientists warn drought raises West Nile risk

Scientists warn drought raises West Nile risk

Mosquito populations have dropped dramatically in parts of the United States this summer as a severe drought has reduced the amount of standing water needed for breeding. Some regions in the West and Midwest have reported declines of 50 to 70 percent, with states such as Minnesota, North Dakota and Colorado among the hardest hit.

Despite the decline in mosquitoes, scientists are warning that West Nile virus risk has not eased. The article explains that drought can concentrate mosquitoes and bird hosts around the remaining water sources, which may increase the chances of virus transmission even when total mosquito numbers are lower. It also points to a peer-reviewed study published in Proceedings of the Royal Society B that found drought can lower mosquito abundance while raising West Nile infection rates.

Key Events

  • Mosquito numbers dropped sharply across parts of the United States during a historic drought.
  • Some regions saw mosquito populations fall by as much as 50 to 70 percent.
  • The drought has affected areas across the West and Midwest, including Minnesota, North Dakota and Colorado.
  • West Nile virus cases have risen even as mosquito numbers declined.
  • Researchers say drought concentrates mosquitoes and birds around limited water sources, increasing transmission risk.
  • A peer-reviewed study in Proceedings of the Royal Society B found drought can reduce mosquito abundance while increasing West Nile infection rates.