As summer temperatures rise, health departments across the U.S. are reporting a surge in West Nile virus activity. Cases and positive mosquito samples are emerging in various states, prompting officials to issue warnings and implement preventative measures.

Iowa's Department of Health and Human Services recently confirmed the state's first case of West Nile virus infection this year. The infected individual, an older adult between 61 and 80 years old from Plymouth County, tested positive at the State Hygienic Lab. Increased outdoor activity during warmer months raises the risk of mosquito bites, the primary transmission route for the virus.

Nebraska also reported its first human case earlier in June, while the Centers for Disease Control and Prevention (CDC) documented 13 cases nationwide as of June 13. These cases were spread across several states, including Oregon, Arizona, Wyoming, Nebraska, Illinois, Louisiana, Georgia, South Carolina, and Pennsylvania, with Arizona reporting the highest number of cases.

In Texas, the Harris County Public Health Mosquito Vector Control Division confirmed a positive mosquito sample, triggering evening spray operations in the affected area and surrounding regions. Dr. Maximea Vigilant, the Division Director, emphasized the importance of their surveillance program in identifying the virus and guiding control efforts. She reminded residents to take precautions against mosquito bites while enjoying outdoor activities.

Southern Nevada also detected its first virus-positive mosquitoes this season. While no human cases have been reported in Clark County yet, the Southern Nevada Health District stressed the need for vigilance in eliminating mosquito breeding grounds and protecting against bites. The health district noted minimal West Nile virus activity in the past three years, but 2019 saw unprecedented levels, including one fatality.

West Nile virus cases typically occur during mosquito season, spanning from summer through fall. There are currently no vaccines or specific medications to treat the virus. The CDC states that most infected individuals remain asymptomatic, while approximately 20% develop fever and other symptoms. A small percentage, about 1 in 150, develop severe and potentially fatal illness.