The Board of Health has been notified by the state that a mosquito trapped in town tested positive for West Nile virus. Health officials say the mosquito was collected from a testing pool in the south part of town on Aug. 14. Officials will continue to monitor the risk level in Wayland and adjacent communities. Mosquito populations are abundant and any areas of standing water in people’s yards should be drained, officials said. The Board of Health recommends that residents also cover up exposed skin when outdoors, and make sure that window and door screens are adequate. The highest risk of contracting a mosquito-borne disease is between now and the first hard frost of fall.