York High School is changing its sports schedules to start all outdoor home night games two hours earlier than usual to mitigate the threat of Eastern equine encephalitis.

According to Athletic Director Ted Welch, the school’s soccer and football schedule will be adjusted to minimize exposure of students and fans to the virus, which has been discovered in two mosquito test pools in town in the past month. Home games usually start at 6 p.m. but now will begin at 4 p.m., well before dusk, when disease-transmitting mosquitoes are likely to become more active and the possibility of being bitten increases.

The decision to move up the starting times of night games was made Monday after high school officials consulted with Superintendent Debra Dunn, as well as other district and municipal officials, Welch said. Some York Middle School events will also be rescheduled.

State officials first found the virus in mosquitoes collected in a pool in Alfred on July 16. The Maine Principals’ Association and the state Department of Education issued a joint advisory on Aug. 22 to all member schools. It said that if additional infected mosquitoes were found, officials within affected districts were being advised by the Maine Center for Disease Control and Prevention to consider scheduling earlier starting times for night events, according to Mike Burnham, assistant executive director of the association. The second positive test for the virus in York was reported last Friday.

“We are taking precautionary steps,” Dunn said. The district has already sprayed a pesticide along tree lines on the edges of all athletic fields and playgrounds.

The pesticide used was LESCO CrossCheck Plus Multi-Insecticide, a pyrethroid with the active ingredient bifenthrin. It was applied by Municipal Pest Management Services of Portsmouth, N.H., Dunn said. The pesticide, designed to kill several insects, also is listed as highly toxic to fish and other aquatic organisms.

The first contest affected by the earlier playing time is a girls’ varsity soccer game, which is now set for 4 p.m. Friday. The change applies only to home games, Welch said.

This is the second time in district history that York schools have changed their athletic schedules to avoid holding events in the evening, he said.

“I don’t want to be an alarmist,” said Welch, emphasizing that no human cases of Eastern equine encephalitis have been reported anywhere in Maine this year. However, because of the second positive test from a mosquito pool last week on Bog Road, about two miles from the high school, officials felt it was prudent to adjust outdoor activity schedules.

“People being cautious is a good idea,” said Burnham.

Because of the risk posed by the virus, he said people should take steps to protect themselves from being bitten by mosquitoes and use good sense about being outdoors at night. But it is not a cause for panic, he said.

Eastern equine encephalitis is a viral disease transmitted to humans by mosquitoes. The mosquitoes get infected by biting a bird that carries the disease. The virus can cause serious neurological damage or even death and is considered more serious than West Nile virus, which is also a mosquito-borne disease.

Many people infected with the virus, for which there is no specific treatment, exhibit no obvious symptoms, according to the Maine Center for Disease Control and Prevention. Infection is most effectively prevented by avoiding exposure to mosquitoes, particularly between dusk and dawn. State health officials also recommend that those heading outdoors in the evening wear long-sleeved shirts and full-length pants and use insect repellent.

Eastern equine encephalitis has never been reported in a Maine resident, according to the Maine CDC. However, the July 16 collection in Alfred that yielded the first positive test was the earliest in the season on record. In 2008, a fatal case of the disease was diagnosed in a Massachusetts resident who may have been infected while vacationing in Maine’s Cumberland County.

The virus was found in a flock of pheasants in Lebanon in 2012, and the state experienced a spike in virus reports in 2009, when multiple animals and mosquito pools tested positive.

Mosquito pools in New Hampshire, Vermont and Massachusetts also have tested positive for the virus this year, and in the Bay State two horses also tested positive.

The risk ends when the first hard frost kills the mosquito population, usually between Oct. 1 and 15.

According to the National Weather Service, the average date of the first hard frost in York is Oct. 1, Welch said. If no frost has occurred by that date, the district will consider extending the rescheduling of home games, he said.

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