State officials increased mosquito control efforts on the lower Eastern Shore this week, after a spike in the mosquito population and the report of a probable case of West Nile virus in Worcester County.

Mosquito populations, which were lower than normal due to the drought, have risen to slightly above normal in recent weeks, said Cy Lesser, chief of mosquito control for the Maryland Department of Agriculture.

High tides in early August flooded marsh areas that had been dry, creating breeding habitat for mosquitoes. The lower Eastern Shore and Southern Maryland, both areas with extensive marshland, have the highest mosquito populations, Lesser said

Those factors, combined with the report of a likely case of West Nile Virus in Worcester County this month, led to the decision to increase spraying.

“Mosquito control remains especially important to decrease the risk of infection with all mosquito-borne diseases,” said Agriculture Secretary Roger Richardson in a prepared statement.

The West Nile case still had not been confirmed by Friday, but initial tests indicated that infection was probable, said Kim Mitchell, chief of rabies and vector-borne disease with the Maryland Department of Health and Mental Hygiene.

She said the unidentified patient first showed symptoms on Aug. 6, but it was not reported as a possible West Nile case until about two weeks later.

Last year there were 11 reported cases of the virus in the state, with most cases occurring in August and September, said Amy Bergmann, epidemiologist with the state health department.

Symptoms include fever, headache and body ache and occasionally a skin rash and swollen lymph glands. People showing symptoms should see their doctor, who can recommend testing for the virus, Bergmann said.

Less than 1 percent of those infected with West Nile develop severe symptoms and many have no reaction to the virus. Those over 50 are more likely to show symptoms.

The threat of the virus led to the state’s beefed-up mosquito control efforts on the Lower Shore.

Maryland uses an integrated mosquito management program that includes field surveys, biological controls like mosquito-eating fish, and insecticide applied to larvae or adult mosquitoes by hand, truck and airplane.

Pesticides used in mosquito spraying must go through a lengthy approval process by the EPA and when used according to directions pose virtually no risk to people, said Joe Conlon, adviser for the American Mosquito Control Association.

“We’ve got no interest in poisoning the areas we live in,” Conlon said.

Maryland does make accommodations for people who do not want their property to be sprayed, leaving a 300-foot buffer around their property. Residents can contact their local mosquito control office to make a request

All Maryland counties and Baltimore City have communities participating in the mosquito control program. Residents can check if their community takes part in the program by checking the Maryland Department of Agriculture’s website.

The best defense against mosquitoes and mosquito-borne diseases is t