West Nile virus is back in Maine. Four birds have tested positive for the potentially fatal virus in the last week and a half, the state Bureau of Health announced Monday. Between July 31 and Aug. 4, blue jays in Lewiston and Stonington and crows in Brunswick and York were found to be carrying the mosquito-borne virus that has sickened 182 people nationwide and caused five human deaths so far in 2003. Last year’s cases numbered 4,156 with 284 deaths.

Maine is one of a handful of states that has yet to report a human case of West Nile virus, but Bureau of Health director Dr. Dora Mills said Monday the state is “very likely” to see its first human case this year. “The peak season for West Nile virus is now through the middle of October,” said Mills.

The number and timing of the positive bird tests are “right on par” with last year, she said, and given the rate at which humans have been infected in other areas, Mainers’ chances of avoiding the disease for another season are slim. About ten people have been tested this year, Mills said, but none have had the virus.

Since June 15, health bureau officials have asked people who find dead ravens, crows and jays to contact them. Mills said that of 374 birds reported so far, 88 have been tested for West Nile virus, with just four testing positive. The decision to test a bird depends on its location, its condition and whether numbers of birds are reported in a given area.

Although the majority of the birds reported have come from coastal areas and population centers, Mills said, “We believe the human risk for contracting West Nile virus is statewide.” More-populated areas are just more likely to result in more reports.

West Nile virus affects many animals and is transmitted to humans by mosquitoes that have bitten infected animals. Birds are most likely to spread the disease from one area to another. They are also more likely than other species to die of the infection. Corvids – the bird family that includes ravens, crows and jays – are easily recognized and large enough to be seen, Mills said, which is why most states use them to monitor the spread of the virus.

Many people who contract the virus report no symptoms. Mild reactions include headache and a slight fever. In more serious cases, West Nile virus causes encephalitis – a swelling of the brain – and can be accompanied by high fever, severe headache, confusion, muscle aches, seizures and paralysis. Severe cases, most often seen in the elderly and immunologically impaired, may result in permanent brain damage, coma and death.

The disease was unknown in the United States until the summer of 1999, when four people in New York City died. As of last year, humans had been infected in 44 states. Out of the 182 human cases and five deaths reported this year in 17 states, Colorado alone accounts for 72 cases, followed by Texas with 34 and Louisiana with 15, according to the Centers for Disease Control and Prevention. Five people have died: two each in Alabama and Texas and one in Colorado. State officials in Colorado have reported 166 cases and five deaths, numbers not confirmed by the CDC, because it reports mild cases that some states do not. Still, Colorado’s higher incidence has not been adequately explained.

Mainers should take steps to prevent being bitten by mosquitoes, Mills said, including staying indoors at dusk and dawn, times when mosquitoes are active, and wearing long-sleeved shirts and long pants, shoes and socks when outside. They should consider using a DEET-containing repellent if they must be out when mosquitoes are present, she said.

Additionally, homeowners should get rid of standing water on their properties, especially in old tires, recycling containers, wading pools and gutters. The state also recommends removing brush and debris from family areas.

Mills said testing of birds will continue through October, and that some mosquito populations will be tested as well.

Anyone finding a dead crow, raven or blue jay is asked to call the state’s toll-free reporting line at (800) 697-5846. Although there’s no evidence that casual contact with an infected bird can spread the virus, Mills recommends the use of plastic or latex gloves when handling any dead animal, and careful hand-washing afterward.

More information on West Nile virus can be found at www.MainePublicHealth.org and www.cdc.gov.