Mosquitoes in Pocomoke City have tested positive for the West Nile virus, marking Maryland's first confirmed case of the disease in an insect pool this year.
And while the Lower Shore has seen an increase in the pests this year -- the most in the past decade -- the appearance of the virus seems to be on schedule.
"This is right in line with when we normally start to see it," said Julie Olberg, a spokeswoman for the Maryland Department of Agriculture.
In 2008, the first annual case was confirmed Aug. 8 in Montgomery County.
West Nile is transmitted through mosquitoes that have bitten birds that carry the virus. The disease, which originated in North Africa, was first found in North America in New York City in 1999. Since then, the virus has spread across the United States, and has become a seasonal epidemic in the late summer and fall. While it can cause serious illness in humans, Katherine Feldman, the Maryland state public health veterinarian, said that about 80 percent of people who are infected will not have any symptoms.
"The remaining 20 percent will develop a relatively mild illness called West Nile fever; fever, headache and fatigue are the most common symptoms," Feldman said.
Only about one in 150 people infected will develop a severe illness that affects the nervous system -- either West Nile encephalitis or West Nile meningitis. People older than 50 tend to be more susceptible to the virus. There is no cure or vaccine presently available.
Cases in Maryland peaked in 2003, when 73 people became ill with the disease. Eight were fatal. Last year there were only 14 West Nile infections in the state, and all recovered. There is no way to know how many cases there will be this year, Feldman said.
"We can't gauge it yet," she said. "Any of these diseases that have an ecological component -- that involve nature and the environment, ticks, mosquitoes -- we pay particular attention to. But we can't actually predict what will happen, so we will wait and see."
While the state does spray some Lower Shore communities to reduce the mosquito population, there are certain things people can do to protect themselves from being bitten by the pests, Olberg said. The MDA recommends staying inside at dusk and dawn, the times of day when the insects are most active; wear bug repellent when outside; cover up when in mosquito-infested areas; maintain window and door screens to prevent holes; and prevent standing water from building up.
"Mosquitoes need water to breed," Feldman said. "So if you can ensure there is no standing water, that will go a long way."