Maryland residents reminded to take basic steps to reduce risk.
Baltimore, Md (July 23, 2018) – The Maryland Department of Health (MDH) recently announced the first confirmed and locally acquired case of West Nile Virus (WNV) in Maryland this year. The infected individual is an adult who lives in the Baltimore Metro region. MDH routinely tracks and responds to mosquito-borne infections, including Zika virus, and no other locally acquired arboviral infections have been identified this year.
The number of human WNV cases in Maryland has varied over time. The peak years of human activity occurred in 2003 and 2012, with 73 and 47 WNV cases reported statewide, respectively. In 2015, there were 46 human cases of WNV infection in Maryland, nearly reaching the 2012 peak.
Marylanders are reminded that they can take simple steps to reduce the risk of getting infected. Those protective measures include:
- Avoiding areas of high mosquito activity
- Wearing long pants, long-sleeved shirts, and hats, when concerned about mosquitoes
- Using an Environmental Protection Agency (EPA)-registered insect repellent according to package directions
Most individuals infected with WNV will not have any symptoms. Those who do develop illness usually will 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. Fewer than one percent of individuals 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. Individuals older than 60 have the greatest risk of developing severe disease. Individuals with compromised immune systems also may be at high risk of WNV infection.
Marylanders are urged to monitor their own yards and gardens for standing water that can serve as a breeding ground for mosquitoes. Small amounts of water in a discarded can or container will support dozens of mosquitoes. To eliminate mosquito-breeding areas:
- Clean rain gutters to allow water to flow freely
- Empty or screen corrugated drain pipes
- Remove old tires or drill drainage holes in tires used as playground equipment
- Turn over wading pools, wheelbarrows, wagons, and carts when not in use
- Flush water from the bottom of plant holders twice a week
- Replace water in birdbaths at least twice a week
- Turn garbage can lids upside down and make sure trash receptacles are empty of water
- Fix dripping faucets
- Aerate ornamental pools and water gardens or stock with fish and use a circulating filter system
The Maryland Department of Agriculture (MDA) will conduct larvicidal and spraying activities within a three-quarter mile radius of where the individual resides. Routine spray operations will continue in all other participating communities throughout the state.
Although birds are not routinely tested for WNV 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 website at http://dnr.maryland.gov/wildlife/Pages/plants_wildlife/rehabilitators.aspx. Detailed instructions on what to do when you find a sick or dead bird can be found at http://dnr.maryland.gov/Wildlife/Pages/plants_wildlife/wildlifeproblems.aspx.
MDH provides weekly updates of WNV detected in humans, mosquitoes, and horses in Maryland on its website. For each case, MDH indicates whether the infected individual is a child or an adult, and the region of the state where the individual resides. The reports are updated every Wednesday and can be found at https://phpa.health.maryland.gov/OIDEOR/CZVBD/pages/Data-and-Statistics.aspx.