(Boston Orange編譯)麻州公共衛生廳（Department of Public Health, DPH） 9 月 18 日宣佈，麻州出現今年第 8 起人類確診西尼羅病毒（West Nile virus, WNV）案例，一名密德薩克斯郡（Middlesex County）30 多歲女性證實感染。
麻州公衛廳指出，這 8 起病例，有高達 7 例集中於密德薩克斯郡與薩福克郡（Suffolk County）。目前共有 11 個地區被列為高風險區，包括波士頓（Boston）、布魯克萊恩（Brookline）、劍橋（Cambridge）、雀喜（Chelsea）、埃弗里特（Everett）、摩頓（Malden）、牛頓（Newton）、里維爾（Revere）、尚莫維爾（Somerville）、水城（Watertown）及溫斯羅普（Winthrop），麻州其餘多數地區則處於中度風險。
自 6 月 16 日首度檢出帶毒蚊子以來，麻州全部 13 個郡累計已有 327 個蚊子樣本對 WNV 呈陽性反應，所幸目前尚無動物感染報告。此外，當地蚊群中亦驗出 21 個東部馬腦炎（Eastern equine encephalitis, EEE）陽性樣本，但尚未出現人類或動物病例。
麻州當局提醒民眾，黃昏至黎明為蚊子叮咬高峰期，戶外活動應使用含 DEET 或派卡瑞丁（Picaridin）等成分的防蚊液，並穿著長袖衣物。居家環境應定期清空花盆、鳥浴室等積水容器以阻斷幼蟲滋生，並修復門窗紗網。飼主則應定期清洗水槽、避免讓馬匹夜間滯留室外，並諮詢獸醫施打疫苗。
State Health Officials Announce Season’s Eighth Human Case of West Nile Virus in Massachusetts
WNV risk levels remain moderate in most of the state
BOSTON (September 18, 2026) – The Massachusetts Department of Public Health (DPH) today announced the eighth human case of West Nile virus (WNV) this year. A woman in her 30s was exposed to WNV in an area of Middlesex County where other exposures have occurred this season.
Seven of the eight cases have been exposed in areas of Middlesex and Suffolk counties that are at high risk for WNV. Risk levels for WNV are currently high in Boston, Brookline, Cambridge, Chelsea, Everett, Malden, Newton, Revere, Somerville, Watertown, and Winthrop. Most of the rest of the state is at moderate risk.
DPH announced the state’s first WNV-positive mosquitoes this year on June 16. Since then, a total of 327 mosquito samples has tested positive for WNV so far this season from Barnstable, Berkshire, Bristol, Dukes, Essex, Franklin, Hampden, Hampshire, Middlesex, Norfolk, Plymouth, Suffolk, and Worcester counties. There have been no animal cases of WNV reported this year.
Eastern equine encephalitis (EEE) continues to be detected in mosquitoes in Massachusetts this year. There have been 21 EEE-positive mosquito samples and no human or animal cases so far this year.
Surveillance information, including case updates, is updated daily and posted online at the Massachusetts Arbovirus Update web page. DPH encourages everyone to use this online resource regularly to stay informed on risk levels in their community and around the state.
People have an important role to play in protecting themselves and their loved ones from illnesses caused by mosquitoes.
Avoid Mosquito Bites
Apply Insect Repellent when Outdoors. Use a repellent with an EPA-registered ingredient, such as DEET (N,N-diethyl-m-toluamide), permethrin, picaridin (KBR 3023), or oil of lemon eucalyptus (p-menthane-3,8-diol (PMD) or IR3535) according to the instructions on the product label. DEET products should not be used on infants under two months of age and should be used in concentrations of 30 percent or less on older children. Oil of lemon eucalyptus should not be used on children under three years of age.
Be Aware of Peak Mosquito Hours. The hours from dusk to dawn are peak biting times for many mosquitoes. Consider rescheduling outdoor activities that occur during evening or early morning in areas of high risk.
Clothing Can Help Reduce Mosquito Bites. Wearing long sleeves, long pants and socks when outdoors will help keep mosquitoes away from your skin.
Mosquito-Proof Your Home
Drain Standing Water. Mosquitoes lay their eggs in standing water. Limit the number of places around your home for mosquitoes to breed by draining or discarding items that hold water. Check rain gutters and drains. Empty unused flowerpots and wading pools and change the water in birdbaths frequently.
Install or Repair Screens. Keep mosquitoes outside by having tightly fitting screens on all windows and doors.
Protect Your Animals
Animal owners should reduce potential mosquito breeding sites on their property by eliminating standing water from containers such as buckets, tires, and wading pools – especially after heavy rains. Water troughs provide excellent mosquito breeding habitats and should be flushed out at least once a week to reduce mosquitoes near paddock areas. Horse owners should keep horses in indoor stalls at night to reduce their risk of exposure to mosquitoes. Owners should also speak with their veterinarian about mosquito repellents approved for use in animals and vaccinations to prevent West Nile virus (WNV) and EEE. If an animal is suspected of having WNV or EEE, owners are required to report to the Department of Agricultural Resources, Division of Animal Health by calling 617-626-1795, and to the Department of Public Health by calling 617-983-6800.
More information, including all WNV and EEE positive results, is available on the Arbovirus Surveillance Information web page, which is updated daily, or by calling the DPH Division of Epidemiology at 617-983-6800.
