A pool of mosquitoes in Linthicum Heights in Anne Arundel County tested positive for West Nile virus, according to the Maryland Department of Agriculture.
The result came several weeks after the state’s first confirmed case of West Nile virus this year as mosquito populations are thriving in Maryland’s wet conditions.
Brian Prendergast, program manager for mosquito control at the Maryland Department of Agriculture, said his department is stepping up efforts to combat flourishing mosquito colonies. His team puts out hundreds of traps each week across the state, including about 50 a week in Anne Arundel County. He said he was not surprised the trap in Linthicum Heights contained mosquitoes carrying West Nile.
“It’s not a brand-new occurrence,” he said. “It’s not shocking that we got a positive trap.”
The Maryland Department of Health partners with the agriculture department to test mosquitoes in traps for human pathogens. Several other mosquito colonies in Prince George’s County have tested positive for West Nile virus this year, Prendergast said.
The first case of West Nile virus in Maryland this year was confirmed July 23, when the state health department announced an adult in the Baltimore area contracted the virus.
Symptoms of West Nile virus — including fever, headache, skin rash and swollen lymph glands — can take two days to two weeks to appear.
Prendergast encouraged Maryland residents to protect against mosquito bites by wearing long, loose-fitting clothing and using repellents. He also suggested residents dump any containers on their property that contain rainwater to guard against breeding grounds for Asian tiger mosquitoes, which he said present the largest nuisance off all mosquito species in the state.
The mosquito population in Maryland this summer is about two to three times larger than usual, Prendergast said.
“It’s much higher than it’s ever been,” he said. “We’re getting a huge number of complaints. That makes sense — it’s because of all the rain we’ve gotten.”
Mosquito breeding in Maryland has been aided by record-setting rain this spring and summer. Many mosquitoes lay eggs in flood-prone areas, and flooding prompts their eggs to hatch.
Prendergast said the state has been stepping up its efforts to spray for the bugs and treat water where they lay eggs.
“It is very difficult to keep up with it,” he said.
Baltimore Sun reporter Andrea McDaniels contributed to this article.