topheader - FINAL.png

September 13, 2023

Media Contact:

Chase Cook, Acting Director, Office of Communications, 410-767-8649

Maryland Department of Health announces first human case of West Nile virus for 2023 

Maryland residents reminded to take basic steps to reduce risk of infection from mosquitoes

Baltimore, MD – The Maryland Department of Health today announced that an adult living in the Eastern Shore region has tested positive for West Nile virus – the first confirmed human case of the virus in Maryland this year.  The patient is recovering from the infection.


West Nile is transmitted to humans via mosquitoes infected by feeding on birds that have the virus. In rare instances, the virus may be spread from person to person through organ donation, blood transfusion, breastfeeding or from pregnant mother to fetus.


The disease affects the nervous system, and up to 80% of people who are infected will not display any signs of illness. However, those who have underlying health conditions could become seriously ill. 


“We are in the season when the West Nile virus can spread in Maryland,” said Deputy Secretary for Public Health Services Dr. Nilesh Kalyanaraman. “We urge people to be vigilant and take steps to avoid infection and eliminate standing pools of water where mosquitoes can breed. Our teams are continuing to monitor mosquito activity across the state."


West Nile virus was detected in the United States for the first time in 1999. In 2020, a single confirmed case was identified, four were identified in 2021, and a single infection was identified in 2022. 


While most people do not develop symptoms from this virus, some people who develop illness may experience mild symptoms such as fever, headache and body aches; occasionally, a skin rash and swollen lymph glands may be noticed. These symptoms may last a few days or as long as several weeks. People who are older than 50 or have immunocompromised conditions can become seriously ill.


People who are concerned about mosquitoes should cover up exposed skin and use an EPA-registered insect repellent. Residents are also urged to monitor their own yards and gardens for areas of high mosquito activity, especially standing water that can serve as a breeding ground. Even small amounts of water in a discarded can or container can support dozens of mosquitoes, as can clogged rain gutters or drain pipes.


Although birds are not routinely tested for West Nile virus in Maryland, sick or injured birds can be reported to an appropriate local wildlife rehabilitator. Residents can call 1-877-463-6497 for a list of licensed rehabilitators or visit the Maryland Department of Natural Resources Wildlife website


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



The Maryland Department of Health is dedicated to protecting and improving the health and safety of all Marylanders through disease prevention, access to care, quality management and community engagement. 

Follow us at and at