Mosquitoes infected with malaria are found in Md.

Insects trapped on island in Montgomery mark first instance in 30 years

October 08, 2002|By Dennis O'Brien | Dennis O'Brien,SUN STAFF

For the first time in at least 30 years, researchers have found malaria-infected mosquitoes in Maryland, trapping them on an uninhabited Montgomery County island in the Potomac River.

Dr. Carol Garvey, Montgomery County's health director, said that a decision is likely in the next 48 hours on whether to spray insecticide in areas where malaria-infected mosquitoes may be breeding.

Montgomery County Executive Douglas M. Duncan plans to seek advice from health and environmental officials before making a decision, according to county officials.

Spraying sometimes prompts complaints from environmentalists about the effects of insecticides.

"Right now, he's awaiting recommendations from the state and from the Centers for Disease Control [and Prevention]," said Donna Bigler, a Duncan spokeswoman.

The infected mosquitoes were found in traps set on Selden Island by federal researchers last week after malaria was diagnosed in two teen-agers in nearby Virginia and pools of infected mosquitoes were found in the Virginia suburbs.

Garvey said that two of the 10 traps contained mosquitoes with the same type of malaria parasite that sickened the Virginia teen-agers. It is less lethal than the parasite that kills more than 1 million people worldwide each year, she said.

Both teen-agers have recovered, health officials said.

Garvey said the risks of malaria could be minimized with the same precautions used to avoid West Nile disease.

They include using insect repellent with DEET, wearing long-sleeve shirts and avoiding outdoor activities at dusk and dawn.

She said that malaria symptoms - including fever, chills, sweats and a headache - usually occur in seven to 30 days.

Although about 1,200 cases of malaria are reported in the United State's each year, almost all of the victims are infected while overseas, experts said.

No vaccines exist for malaria, a parasite that is transmitted by mosquito from the blood of one human to another.

State health officials said yesterday that they are considering setting up facilities next spring to test mosquitoes for malaria, along with tests now performed on mosquitoes for West Nile.

Selden Island is a crescent-shaped slice of Maryland that lies on what is predominantly the Virginia side of the Potomac.

The island is about 2 miles long, is accessible only by a small highway bridge and is used as a turf farm.

Although the island is uninhabited, the infected mosquitoes were found about a quarter-mile from homes in Virginia, said Don Roberts, who led the mosquito research team from the Bethesda-based Uniformed Services University of the Health Sciences.

The infected insects were found in standard mosquito light traps set out Wednesday near the bridge leading to Virginia. The results were confimed after a series of DNA tests completed yesterday, Roberts said.

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