First Human Case of West Nile Virus Detected in Boston

BOSTON – August 25, 2022—The Boston Public Health Commission today announced that a case of West Nile Virus (WNV) has been detected in a Boston resident. The case was confirmed earlier today by the State Department of Public Health. Although mosquito pools have tested positive for WNV in Boston, it is unknown if the patient in question was exposed to the virus in Boston. It is the first case detected in Boston in 2022.  

WNV is a rare, but potentially serious disease that is spread to humans through mosquito bites. Mosquitoes carrying the virus appear in Boston, as well as the rest of state, during the summer and fall months. In addition to spreading through mosquito bites, WNV can spread through blood transfusions, organ transplants, and from mother to child during pregnancy and breastfeeding.  

Anyone who is outside from July through November, especially at dawn and dusk when mosquitoes are most active, is at risk for contracting WNV, however, the risk of contracting it is quite low. Individuals over 50-years old and those with compromised immune systems are more likely to experience severe illness if infected.  

“The Boston Public Health Commission is working closely with our partners at the State Department of Public Health to monitor mosquito pools and investigate this infection,” said Dr. Bisola Ojikutu, Commissioner of Public Health and Executive Director of the Boston Public Health Commission. “During this time of the year and into the fall, it’s very important for residents to take proper precautions. Use bug spray, avoid being outside at dusk and dawn for prolonged periods of time, and wear long clothing to avoid becoming infected.”  

Most people who are infected with WNV do not experience any signs or symptoms of illness. In some cases, people will experience a headache, fever, nausea, vomiting, and body aches which can last for a few days or several weeks. In most cases, individuals with mild symptoms recover on their own. If you believe you have WNV, contact your health care provider immediately.  

More serious symptoms, which can result in hospitalization, include:  

• high fever 
• severe headache 
• confusion 
• lack of coordination 
• permanent muscle weakness/paralysis 

Seek emergency medical care if you or someone you know is experiencing severe WNV symptoms.

• The best way to avoid contracting WNV is to avoid getting bug bites. The Boston Public Health Commission encourages residents to use and reapply FDA-approved mosquito repellant when outdoors; wear protective clothing (long sleeve shirts, long pants, and socks); limit time outdoors at dawn and dusk when mosquitoes are most active; and make sure windows and screens don’t have holes or gaps that can allow mosquitoes to enter your homes; and reduce the mosquito population by eliminating standing water around your home, which is where mosquitoes breed. 

More information about West Nile Virus is available on the Boston Public Health Commission’s website.  

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