A New Hampshire man has tested positive for three mosquito-borne viruses, including eastern equine encephalitis. Another man in the state contracted EEEV and died last month.

Joe Casey, 54, of Kensington came down with the viruses last month.

“He’s my brother. It’s very difficult, especially because it’s from a mosquito. He was positive for EEEV, for West Nile, and St. Louis encephalitis, but the [Centers for Disease Control and Prevention,] the infectious disease doctors, they don’t know which one is making him this sick,” Mr. Casey’s sister-in-law Angela Barker told Boston CBS affiliate WBZ-TV.

All three diseases can cause neurological conditions like encephalitis, the inflammation of the brain, and meningitis, the inflammation of membranes located around the brain and spinal cord.

The CDC data on EEEV doesn’t include Mr. Casey’s infection or the infection and Aug. 19 death of Steven Perry, 41, of Hampstead, announced by the New Hampshire Department of Health and Human Services on Aug. 27.

New Hampshire health officials haven’t officially announced the second human case of EEEV, but did note the virus was found in one horse and seven tested batches of mosquitoes. One of the mosquito batches that tested positive for EEEV was in Kensington.

The viruses vary in spread and in how fatal they are. 

Some survivors of West Nile and EEEV develop permanent symptoms even after recovery. In the case of EEEV, survivors can be left with mild to severe intellectual disability, seizures, paralysis, personality disorders and cranial nerve dysfunction, per the CDC website.

“My brother-in-law is not a small man, and to see someone that you love be as sick as he is and not be able to talk, to move, to communicate for over three weeks is terrifying and gut-wrenching,” Ms. Barker told WBZ-TV.

• Brad Matthews can be reached at bmatthews@washingtontimes.com.