BOSTON (CBS) – State public health officials are warning of a high risk for West Nile virus in some Massachusetts communities after a fourth person has tested positive for mosquito-borne illness.
An investigation found that at least two of the four cases were exposed in the greater Boston area, leading public health officials to raise the risk level from moderate to high for 11 communities in the area.
The high-risk communities are Arlington, Boston, Belmont, Brookline, Cambridge, Chelsea, Everett, Medford, Newton, Somerville, and Watertown.
“Several individuals from the same area have developed West Nile virus,” said Massachusetts Public Health Commissioner Monica Bharel. “That means that there is an increased risk in this specific area and that additional people could become infected.”
Health officials are especially concerned for people over 50 and people with compromised immune systems, as they are most likely to develop the disease.
On Aug. 21, the DPH raised the risk level for West Nile virus from low to moderate statewide.
People at high risk for severe illness are encouraged to consider avoiding outdoor activity at dusk and dawn.
“It is extremely important for people to take steps to avoid mosquito bites, including using repellents, wearing clothing to reduce exposed skin, dumping standing water, and moving indoors when you notice mosquitoes biting you,’’ said DPH State Epidemiologist Dr. Catherine Brown.
West Nile virus symptoms may include fever and flu-like illness, but most people infected with the disease have no symptoms.
State health officials are also urging pet owners to eliminate standing water on their property to protect animals from getting the illness.
In 2017, there were 6 human cases of West Nile virus infection in Massachusetts.