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West Nile-infected mosquitoes detected in Rock County

Mosquitoes in Rock County have been determined to carry the West Nile virus, according to health officials' recent announcement.

Mosquitoes in Rock County detected carrying West Nile virus
Mosquitoes in Rock County detected carrying West Nile virus

West Nile-infected mosquitoes detected in Rock County

West Nile Virus Activity Remains Average in Wisconsin, With No Reported Cases in Rock County

As summer progresses, West Nile virus activity in Wisconsin is confirmed but currently at average levels. The first human case of West Nile virus in 2025 was reported in a resident of Barron County, with additional cases reported in Sheboygan County. Mosquitoes testing positive for the virus have been found in Milwaukee and Lafayette counties, indicating local virus circulation [1][2][3][4][5].

However, West Nile virus activity in Rock County has not resulted in reported cases in people this year. This is the first time mosquitoes have tested positive for the virus since Rock County started mosquito surveillance in early July [1].

The Wisconsin Department of Health Services notes that West Nile virus is transmitted through the bite of infected mosquitoes, primarily of the Culex species that feed on infected birds. The virus is not spread directly between humans or animals [3][4].

To prevent West Nile virus infection, health officials recommend these measures:

  1. Use insect repellents containing DEET or other EPA-approved ingredients when outdoors.
  2. Wear long-sleeved shirts and long pants, especially during mosquito-active times around dawn and dusk.
  3. Limit outdoor activities during peak mosquito hours when possible.
  4. Remove or drain standing water from containers like buckets and pools around homes to reduce mosquito breeding areas.
  5. Be especially cautious if you are over 50 years old or have a weakened immune system, as these groups are at higher risk of severe illness [1][2][5].

West Nile virus infection often causes no symptoms in most people; about 1 in 5 develops mild fever-like symptoms, while severe neurological illness is rare, occurring in about 1 in 150 infected individuals [1][2].

Public health officials are urging Wisconsinites to protect themselves against West Nile virus. By taking simple precautions, such as reducing exposure to mosquitoes, using insect repellent, wearing long-sleeved clothing, and pants outdoors, individuals can help protect themselves and their families from this potentially serious virus.

[1] Wisconsin Department of Health Services [2] Centers for Disease Control and Prevention [3] World Health Organization [4] American Mosquito Control Association [5] Mayo Clinic

  1. While the West Nile virus activity in Wisconsin remains average, there have been no reported cases of medical-conditions related to the virus in Rock County.
  2. Despite the high instances of West Nile virus cases in other counties, individuals are encouraged to prioritize health-and-wellness by taking preventive measures, as the virus can cause severe neurological disorders, particularly in those over 50 or with weakened immune systems.

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