Health official discusses NH’s mosquito risk
Marco Notarangelo is the Vectorborne Disease Surveillance Coordinator at the Department of Health and Human Services (DHHS) in New Hampshire. He spoke to the Hippo about Eastern Equine Encephalitis Virus (EEEV), what it is and what people in the Granite State can do to stay safe. Visit dhhs.nh.gov for more information.
What is EEEV and how did this virus come about?
Triple E, also known as Eastern Equine Encephalitis, is an alpha virus that is transmitted by mosquitoes … primarily found in swamps and certain species of birds. It’s not necessarily native to the Northeast but we know it’s been circulating within the Northeast for a couple hundred years. It’s notorious for causing disease in ‘equine’ and perhaps that can lead to some confusion that the pathogen is maintained in horses but that’s not really the case. This is a very rare disease here in the Northeast. Most years we won’t even have detections. In fact, if you look at the data here in New Hampshire for the last 10 full years, only in 2023 do you have a couple of mosquito detections, really toward the end of the mosquito season,
How concerned should people be about EEEV with the recent news? What’s the probability or likelihood that someone would contract this infection?
Triple E is a very rare disease and you might recall in the United States there’s less than 15 cases that are typically reported nationwide. … [A]nd it’s thought that only 1 in 20 infections are actually going to result in individuals developing symptoms. However, what’s particularly concerning about this pathogen is severity. … it’s really thought that a large portion of infections that result in symptoms will result in individuals developing what is called Central Nervous System infections. Some examples of this are inflammation of the brain or inflammation of the membrane surrounding the spinal cord, which can be very severe. … about 30 percent of the individuals that develop this severe form of illness unfortunately do not make it. That’s not really the end of it, it’s also 50 percent of the survivors that have long-term if not lifelong complications and lifelong debilitation resulting from the illness. Although it’s very rare, it’s something that should be kept in mind because it can be a life-altering condition.
Why is EEEV an issue again now?
There is some uncertainty here, but … the current scientific thought on it is that Triple E is not really a pathogen that remains, or the strains of Triple E, surviving in the Northeast over extended periods of time. They may survive over winters for a couple years and then go locally extinct. It’s through their reintroduction from migratory birds that it comes back into the Northeast and causes novel outbreaks. We tend to see cycles with Triple E.
What areas of New Hampshire are most at risk for EEEV infection?
Historically, based on the last about 20 years’ worth of data we have, which is when Triple E has really resurged within our part of the United States, we see that the eastern part of the state, particularly the southeastern part of the state, is the area that most often has Triple E detections, human cases and equine detections. … We have had detections in other parts of the state. On the western side and then we’ve done surveys of deer populations, collecting their blood during the hunting season, and we’ve detected Triple E even in the far north part of the state, so around Coos County. …
What steps can people take to prevent mosquito bites?
The primary concern also lies when we spend time outside in greater mosquito habitats … So we want individuals to take steps such as wearing repellent, wearing protective clothing that makes it more difficult for mosquitoes to bite us, and being cognizant of where mosquitoes are most likely to be and when they’re most likely to be active. For Triple E we are primarily talking about swamp-dwelling mosquito species and unfortunately New Hampshire is very rich in swamp, especially in the southern part of the state. … it is a pathogen that’s more likely to cause severe illness in younger individuals, particularly those under the age of 15, so it’s very important for residents to consider not only their own personal care but also making sure their children are well aware of what they should do to prevent mosquito bites.
What repellants should people use?
Typically, EPA-registered repellents are the ones we are going to recommend, DEET being one of the more common ones. Oil of lemon eucalyptus and of course picaridin being additional options. … You always want to be reading the labels on the actual repellents to make sure that it works and … and is safe for different age groups….
—Zachary Lewis
Featured image: Courtesy photo.