Mosquitoes carrying the West Nile virus were collected in a residential section of Bowie last week by Maryland Department of Agriculture staff members, state officials said.
It is the first detection this year of a West Nile virus mosquito pool in Maryland.
Spraying to control adult mosquitoes in that section of Bowie occurred the night following trapping, department officials said in a prepared statement.
Maryland typically sees three or four reports a year of mosquitoes carrying the virus, said Jeannine Dorothy, a College Park-based entomologist for the Department of Agriculture.
"It's not that uncommon," Dorothy said. "We pick it up every year. I don't think we have human cases every year. This year there was just a lot of rain. June was insane with rain, so there were a lot of mosquitoes. We're picking up a lot more mosquitoes than usual."
Two years ago, the first detected case of a mosquito carrying the virus was found in a New Carrollton backyard.
The kinds of mosquitoes that typically carry the virus are more often found in urban and suburban areas, Dorothy said. In areas like Western Maryland and the Eastern Shore, mosquitoes carrying the virus are extremely rare.
The department typically sets up traps in places where it has received complaints about mosquitoes or in places where mosquitoes have been a problem in the past, she said.
"We know that West Nile virus may be present throughout Maryland. It typically appears at this time in the summer, so we are not surprised with this positive finding," Secretary of Agriculture Joe Bartenfelder said in a prepared statement. "The confirmation of virus-positive mosquitoes serves as a reminder to all residents to continue protecting themselves against mosquito bites and to conduct backyard mosquito control activities in addition to MDA's routine surveillance and spray activities."
The MDA Mosquito Control Office, in cooperation with Department of Health and Mental Hygiene, has been collecting and testing mosquitoes throughout the state for West Nile virus and several other mosquito-borne diseases. These diseases are endemic in Maryland and are transmitted through the bite of a mosquito.
About 20 percent of those infected with West Nile virus develop West Nile fever, which is typically characterized by fever, headache, and body aches which can last for just a few days or as long as several weeks. Less than one percent of people bitten by a mosquito carrying the West Nile virus will develop a more severe form of the disease. People most at risk for developing severe disease are those over 50 and those with already compromised immune systems.
While not all mosquitoes carry these diseases, MDA suggests that residents take precautions to minimize their exposure to mosquito bites. These measures include:
•Wear long, loose fitting, light colored clothing.
•Wear insect repellents according to product labels.
•Avoid mosquito infested areas during prime periods of activity (between dusk and dawn).
•Install, inspect, and repair window and door screens in homes and stables.
•Regularly clean bird baths and bowls for pet food and water.
•Remove or empty all water-holding containers.
Also, dog owners are also urged to have their pets checked for heartworms, the most common disease transmitted by mosquitoes in Maryland. Dogs in all Maryland jurisdictions should be placed on a heartworm preventive program. Pet owners should consult with their veterinarians.
The Department of Agriculture — rather than the city — conducts the annual insect spraying program in the city of Bowie, said George Stephanos, city director of public works.
"We participate in the state's program by signing up for it and providing some of the funding to it," he said. "What we do is collect (mosquito) complaints and relay the complaints to Department of Agriculture. What we have done (here) is push the information (about the mosquitoes carrying the virus) through typical channels to make sure the residents are aware locally."
Stephanos said his department took more than 100 calls about mosquitoes on Monday after residents learned of the state's findings.
"We're taking the calls and just providing the facts," he said.