State public health officials are continuing to monitor the dangerous mosquito-borne disease Eastern equine encephalitis after confirming Friday that a second person in Massachusetts had contracted the virus.
The Department of Public Health says scores of communities in the state are currently considered at risk — and more could be added to the list.
“Changes to [EEE] risk assessments (at the high or critical level) happen whenever data are received that indicate that the risk level has increased,” said Omar Cabrera, a spokesman for DPH, via e-mail on Monday. “Because those data come from many different sources, it is not possible to plan for their occurrence.”
Cabrera added that the risk “from mosquito-borne disease will persist until the first hard frost which kills off any remaining mosquitoes. The risk levels are maintained until that time to serve as a reminder for residents to take precautions against mosquito bites.”
The DPH said Friday that “across Massachusetts, there are 19 communities now at critical risk, 18 at high risk, and 24 at moderate risk for the EEE virus as determined by DPH.” By Monday, the tally stood at 19 critical, 18 high, and 37 at moderate risk, Cabrera said.
Communities at critical risk include Hopkinton, Grafton, Northbridge, Shrewsbury, Southborough, Upton, Westborough, Easton, Norton and Raynham, according to DPH. High-risk communities include Framingham, Marlborough, Millbury, Northborough, and Sutton, DPH said Friday.
Public health officials in Boston, meanwhile, have scheduled spraying for Monday and Wednesday nights in parts of Hyde Park and West Roxbury.
“Spraying is scheduled for Hyde Park neighborhoods located between Hyde Park Avenue and the Stony Brook Reservation,” the Boston Public Health Commission said in a statement. “Spraying is also scheduled for West Roxbury neighborhoods in the vicinity of Eagle Street, Cowing Street, Pine Lodge Road, and Centre Terrace.”
More spraying will occur in East Boston on Tuesday and Thursday evenings.
“Spraying is scheduled for neighborhoods located near Orient Heights, including streets in the vicinity of Orient Avenue, Boardman Street, Andrew Road, and Horace Street in East Boston,” the Boston Public Health Commission said in a follow-up statement Monday.
The DPH statement Friday urged residents in the all affected areas to stay safe.
“All residents are reminded that they should continue to use mosquito repellent and those in high and critical risk communities should consider staying indoors during the dusk to dawn hours to reduce exposure to mosquitoes,” DPH said in Friday’s statement. “Last week DPH and the Massachusetts Department of Agricultural Resources (MDAR) conducted aerial spraying in specific areas of Bristol and Plymouth counties to reduce the mosquito population and public health risk. Aerial spraying began August 8 and was completed the night of August 11. A second round is being planned” for later this week.
The two people who recently contacted EEE are a man between the ages of 19 and 30 in eastern Worcester County, and another man in southern Plymouth County, according to officials.
EEE is a serious and potentially fatal disease that can be spread from mosquitoes to other animals and humans. People under the age of 15 are particularly at risk, according to DPH.
The state Department of Conservation and Recreation has also canceled evening programming at a number of state parks, including Berkley State Forest, Borderland State Park, Dighton Rock State Park, Freetown-Fall River State Forest, Fort Phoenix State, Reservation, Kingston State Forest, Massasoit State Park, Myles Standish State Forest, Nasketucket Bay State Reservation, Rehoboth State Forest, Borderland State Park, Callahan State Park, Cochituate State Park, Hopkinton State Park, Purgatory Chasm State Reservation, Sudbury Reservoir, and Upton State Forest.
The evening programming will be halted “until the EEE virus risk levels have decreased,” DCR said in a weekend statement.
The DPH urges the public to take several precautions to guard against mosquito bites, including applying insect repellent when outdoors, being aware of peak mosquito hours from dusk to dawn, wearing long sleeves, pants and socks, draining standing water and installing or repairing screens.
Globe Correspondent Maria Lovato contributed to this report. Travis Andersen can be reached at travis.andersen@globe.com. Follow him on Twitter @TAGlobe.