The Massachusetts Department of Public Health (DPH) has confirmed the first case of West Nile virus (WNV) in an animal this year. A goat from Lunenburg in Worcester County tested positive for the virus, prompting public health officials to raise the risk level to moderate in the surrounding towns of Lunenburg, Leominster, Shirley, and Fitchburg. This update comes with a warning of heightened mosquito activity due to the current weather conditions—a combo of elevated temperatures and high humidity—is creating the perfect storm to ramp up the buzzing pests' bite.
During a statement issued by the DPH, Public Health Commissioner Robbie Goldstein, MD, PhD said on Mass.gov, "With this evidence of an animal infected with West Nile virus, we know that there are the right conditions and enough disease circulating to result in a human infection." He urged the public to adopt simple preventative measures like applying mosquito repellent outdoors and staying vigilant during peak mosquito hours. As of the June 17 announcement, there have been 10 positive mosquito samples identified with WNV for this year, though no human cases have been reported. By contrast, there were 19 human cases of WNV last year, underscoring the need to start to take protective actions against mosquitoes now.
People over 50 years old are particularly at risk for severe disease from WNV, which typically manifests with no symptoms but can cause fever and flu-like illness. In extreme cases, it can lead to more severe complications. Dr. Catherine M. Brown, State Epidemiologist, highlighted on Mass.gov that "animals that live outdoors are at somewhat higher risk from arboviruses than humans who spend more time indoors." However, she cautioned that the current summer weather might lead to a busy season for WNV, emphasizing the importance of proactive measures against mosquito bites.
Moreover, the DPH is advocating for personal and household strategies to reduce exposure to mosquitos, such as using insect repellents that contain EPA-registered ingredients, being cognizant of peak mosquito hours, and dressing in protective clothing while outdoors. Homeowners are also advised to eliminate standing water around their property and ensure that windows and doors are fitted with tightly fitting screens to keep mosquitos out. For animal owners, particularly those with horses, the DPH suggests keeping animals in indoor stalls at night and consulting with a veterinarian about appropriate mosquito repellents and vaccinations to prevent WNV and EEE. Should an animal be suspected of having WNV or EEE, it's mandatory for owners to report this to the Department of Agricultural Resources, Division of Animal Health, as well as the Department of Public Health.
Detailed information on WNV and Eastern Equine Encephalitis (EEE) is available on the Arbovirus Surveillance Information web page, which is updated daily. For additional guidance, the DPH Division of Epidemiology can also be reached by calling 617-983-6800.
