The Maryland Department of Health and Mental Hygiene (DHMH) Thursday announced the first confirmed case of West Nile Virus (WNV) in Maryland this year. The infected individual is an adult who lives in the National Capital Region. In addition, WNV has also been detected in a horse, also in the National Capital Region, and in mosquito pools collected in Harford, Montgomery, Prince George’s and Talbot Counties. A mosquito pool is a group of mosquitoes collected at one of several trap sites across the State.
“A case of WNV is not unexpected,” said DHMH Secretary Dr. Joshua M. Sharfstein. “Marylanders are reminded that they can take basic steps to reduce the risk of getting infected.”
Measures people can take to protect themselves include avoiding areas of high mosquito activity, avoiding unnecessary outdoor activities at dawn and dusk when mosquitoes are most active, wearing long pants, long-sleeved shirts and hats when concerned about mosquito exposure and using an EPA-registered insect repellent according to package directions.
Most individuals infected with WNV will not have any symptoms. People that do develop illness will usually have any combination of fever, headache, body aches, skin rash and swollen lymph glands. These symptoms generally appear two to 14 days following the bite of an infected mosquito. Less than one percent of persons exposed to the virus will develop more severe infections, with symptoms such as headache, high fever, neck stiffness, stupor, disorientation, coma, tremors, convulsions, muscle weakness and paralysis. In rare instances, WNV can be fatal. Persons over 50 years of age have the highest risk of developing more severe disease. People who are immunocompromised may also be at high risk of WNV infection.
The number of human WNV cases in Maryland has varied over the years. The peak years of human activity occurred in 2003 and 2012, with 73 and 47 WNV cases reported statewide, respectively. In 2013, there were 16 reported cases of WNV infection in Maryland.