Maryland Department of Health Confirms First Human Case of West Nile virus for 2025

The Maryland Department of Health has confirmed the first human case of West Nile virus in the state this year. An adult in Central Maryland is now recovering.

West Nile virus primarily spreads to humans via mosquitoes that have fed on infected birds. Rare transmission can occur through organ donation, blood transfusion, breastfeeding, or from a pregnant mother to her fetus. While the disease affects the nervous system, about 80% of those infected are asymptomatic. However, individuals with underlying health conditions may experience severe illness.

Deputy Secretary for Public Health Services Dr. Meg Sullivan reminds everyone that we are currently in the season for West Nile and other mosquito-borne viruses in Maryland. She advises vigilance and preventive measures, such as eliminating standing water, where mosquitoes breed.

West Nile virus was first detected in the U.S. in 1999. In 2024, 18 Maryland residents tested positive. Symptoms, if they appear, are usually mild and include fever, headache, body aches, and sometimes a skin rash or swollen lymph nodes. These symptoms can last for days to weeks. Individuals over 50 or with compromised immune systems face a higher risk of serious illness.

To protect yourself from mosquito bites, cover exposed skin and use an EPA-registered insect repellent. Residents should also regularly check their yards for standing water, as even small amounts can support mosquito breeding.

The Department launched a campaign in May to help Marylanders protect themselves and their homes from mosquitoes, including a social media toolkit.

While birds are not routinely tested for West Nile virus in Maryland, sick or injured birds can be reported to a local wildlife rehabilitator by calling 1-877-463-6497 or by visiting the Maryland Department of Natural Resources Wildlife website.

For more information on West Nile virus, including data and educational materials, please visit the Center for Zoonotic and Vectorborne Diseases and the Centers for Disease Control and Prevention websites.