A Worcester man has died of West Nile virus, the first fatal case in Massachusetts during a year in which there has been an unprecedented level of infection across the United States.
The state announced three other human cases of West Nile Friday and raised the risk level for mosquito-borne illnesses for all Massachusetts communities to at least moderate.
“We are really considering this a generalized risk across the Commonwealth,” said Kevin Cranston, director of the state Bureau of Infectious Disease. “This is unique.”
The last West Nile death in Massachusetts was in 2005. Public health officials have been monitoring a record-high number of West Nile infections nationally. Massachusetts’ mild winter and hot, dry summer may have fueled the spread of infected mosquitoes, Cranston said. Federal officials have suggested the virus may be adapting in ways that have led to the higher number of cases.
While about 80 percent of people who contract the disease never experience symptoms, West Nile virus is particularly dangerous for older people and those with other illnesses.
The Worcester man, who was in his 60s, had “underlying conditions that would potentially interfere with an immune response to a severe infection like this,” said Dr. Michael Hirsh, acting commissioner of the Worcester Division of Public Health.
The death was announced one day after state officials said that a Westborough man had died of Eastern equine encephalitis — the state’s first EEE death this year. Former research scientist and US Army veteran Benjamin Duce was infected with EEE in early August and died several days later, according to his family.
The 79-year-old had worked for Astra Pharmaceutical (now AstraZeneca) for more than 20 years and was an avid gardener, said his wife of 56 years, Diane Duce. “He loved talking to people and everybody loved him back,” she said.
The state has raised the threat level for EEE in Westborough to critical. The level for nearby towns of Grafton, Hopkinton, Northborough, Shrewsbury, Southborough, and Upton has been raised to high. Mattapoisett also has been listed as high-risk after mosquitoes there tested positive for EEE.
The state urges communities listed at high or critical risk for EEE to forgo outdoor evening events until the first frost, though those decisions are made locally.
The state announced three other West Nile infections Friday, bringing the total of confirmed human cases to 13.
A woman in her 50s has been treated and released from the hospital after becoming the first Boston resident this year confirmed to have West Nile virus. The woman, who lives in Beacon Hill, had been traveling just before she became ill, so it was not clear where she was infected, a statement from the Boston Public Health Commission said. The city’s risk level for mosquito-borne illnesses is listed by the state as high.
A woman in Greater Boston in her 70s and a Middlesex County woman in her 60s also are recovering from the West Nile virus, the state reported.
“People often think that since Labor Day is the unofficial end of summer, there’s no need to worry about mosquitoes until next year, but that’s not the reality,” said Dr. Anita Barry, director of the city’s Infectious Disease Bureau. “Temperatures are still warm, and that means that mosquitoes will continue to be an issue until the first hard frost.”
Mosquitoes infected with West Nile virus have been found in Dorchester, Hyde Park, West Roxbury, Roslindale, East Boston, and Jamaica Plain. They have been detected in 106 towns and cities and nine counties so far this year.
Public health officials urged people to repair screens on windows and doors, remove standing water from around their homes, and wear protective clothing and insect repellent when outside.
Suffolk County Mosquito Control and city officials have spread larvicide in catch basins to control the mosquito population.
Residents of Worcester can call the city at 508-929-1300 if they need help removing larger pools of water, which can serve as breeding grounds.