There is nothing peskier than the buzz and bloodsucking bite of a mosquito except the buzz and bloodsucking bite of a mosquito infected with West Nile virus.

While no human infections have been reported this year, the Alexandria Health Department announced Wednesday that it has retrieved a collection of mosquitoes with the virus that can cause symptoms ranging from minor headaches and fatigue to decreased consciousness and a coma-like state.

The mosquitoes were collected on July 9 at Daingerfield Island Park, but the positive test results were just established and released.

West Nile Virus is a mosquito-borne disease that is endemic in this region, said Alexandria Health Director Dr. Lisa Kaplowitz. There are ways of preventing the spread of diseases like West Nile virus. Residents can play an important role in this effort by getting rid of mosquito-breeding areas around their homes. We urge city residents to be proactive in their efforts to eliminate mosquito breeding habitats.

Health Department officials cite standing water as the most obvious breeding ground for the 15 to 20 different species of mosquitoes found in Alexandria. There are about 44 to 60 different species in the state, according Holly Feltner, supervisor of the Vector-borne Illness Prevention Program.

It just takes a little bit of standing water, Feltner said. We collect them in every site location that we have. They tend to be attracted to stagnant water, ditches, little ponds. We cant go into everyones backyard and empty standing water, but thats the most effective thing to do.

The Health Department has mosquito traps, monitored daily, in every square mile of the city. Various types of traps are used, but the one used at Daingerfield Island was a gravid trap aimed at capturing egg-carrying mosquitoes the only gender that bites with odiferous water.

The vampiric pests are most aggressive during the daytime hours mainly at dusk and dawn, especially the tiger mosquitoes; theyll lay their eggs in pretty much anything, Feltner said.

The black and white tiger mosquitoes commonly associated with West Nile are easily identifiable, but there is no way of knowing which mosquitoes are infected with the virus just by looking at them. Elderly people and young children are most susceptible to it, while stronger immune systems can resist the virus without a person even knowing.

People get bitten all the time, and most of us have probably been bitten by a mosquito with West Nile, Feltner said. Its possible.

We might just get knocked back with a headache or slight fever, but its the older and younger people that were worried about.

The infected mosquitoes are not rare for the area. There are typically about 30 infected pools found in the city during the season, according to Feltner, and both Arlington and Fairfax County found their first West Nile-positive mosquitoes within days of Alexandrias discovery.