Two dead crows found a few miles from each other last week in Baltimore and Howard counties were infected with West Nile virus, the first appearances of the disease in Maryland this year, state officials said yesterday.
In response, the state Department of Agriculture announced it would spray for mosquitoes, which are thought to carry the virus, between 7 p.m. today and 6 a.m. tomorrow in the area where the dead birds were found.
The insecticide Permethrin will be sprayed from trucks traveling local streets within two miles of the intersection of U.S. 29 and Route 32 in Columbia and the U.S. 1 and Interstate 95 corridor in portions of Baltimore and Howard counties. Although the insecticide is not harmful to humans, animals or the environment, department officials recommend that those who object to the spraying stay inside or leave the area during the spraying.
Gov. Parris N. Glendening said the state would step up monitoring the areas where the dead birds were found.
The virus, which first appeared in North America in August last year, is carried by infected birds and passed along to other birds and to people by infected mosquitoes. It killed seven New Yorkers last year and has sickened at least three this year.
The risk for most people is not great, Dr. Georges C. Benjamin, state health secretary, said. "Those most at risk "are at the extremes of age - the elderly and infants - and those whose immune systems have been compromised," he said.
The first crow was found Sept. 13 in the 1700 block of Magnolia Ave. in Relay. The second was found Sept. 15 in the 7400 block of First League Drive in Columbia. Tests for West Nile virus performed at a state laboratory between Sept. 14 and Wednesday were positive and confirmed yesterday by a lab in Fort Collins, Colo.
There are no reports of Maryland residents testing positive for the virus, which causes flu-like symptoms. In extreme cases, the virus can cause inflammation of the brain (encephalitis) or of the tissues that surround the brain (viral meningitis).