A dead crow found in Mason earlier this month tested positive for the West Nile virus, the Ingham County Health Department said.

The virus, which is transmitted to humans, birds, horses and other animals by infected mosquitoes, can cause a flu-like illness. For older people and those with weak immune systems, it can cause deadly encephalitis, or inflammation of the brain.

The bird is the second dead crow found in the Lansing area in the last year. In August, a dead crow was found near U.S. Highway 127 and Lake Lansing Road.

Officials said finding a bird infected with the disease this early in the year could indicate an increase in West Nile virus activity this year.

West Nile first appeared in North America in 1999, when seven people died of the virus.

During the past several years, the virus has gradually traveled west from the East Coast. It reached Michigan in 2001.

Symptoms of the virus may include fever, headache and body aches.

People can protect themselves from infected mosquitoes by using insect repellent with DEET, keeping windows and doors screened or closed, and wearing pants and long-sleeved shirts when outdoors. Standing pools of water, such as flower pots, rain gutters, swimming pool covers and bird baths should be regularly drained to reduce mosquito breeding sites.

The most sensitive indicator of West Nile virus is the presence of dead crows. Health departments across the state often send dead birds to MSU’s Animal Health Diagnostic Laboratory for testing.

The lab receives and tests hundreds of birds each year for West Nile virus. There haven’t been any human cases of the virus in Michigan, but 65 of the 244 birds tested last year were found to have West Nile. A dead crow found in the Livonia this year also was found with the virus.