Understanding Mosquito-Borne Viruses: EEE, West Nile, and Jamestown Canyon Virus

As concerns over mosquito-borne viruses grow, particularly in states like New Hampshire, awareness about diseases such as Eastern Equine Encephalitis (EEE), West Nile Virus (WNV), and Jamestown Canyon Virus (JCV) is becoming increasingly important. These viruses can cause serious health complications, including viral encephalitis, and protecting yourself from mosquito bites is essential in minimizing risk.

In this blog, we’ll discuss the common mosquito-borne viruses, the symptoms of EEE, WNV, and POWV, and how to protect yourself from these potentially dangerous infections.

Mosquito-Borne Viruses: A Growing Public Health Threat

Mosquitoes are more than just a summer nuisance; they are carriers of numerous viruses that can lead to severe health issues. In New Hampshire, for example, there have been increasing reports of EEE, West Nile Virus, and Jamestown Canyon Virus, all spread by infected mosquitoes​(NH Health & Human Services). These viruses pose significant risks to both public health and individuals, with symptoms ranging from mild flu-like illness to severe neurological complications like viral encephalitis.

Eastern Equine Encephalitis (EEE)

Eastern Equine Encephalitis (EEE) is one of the most severe mosquito-borne viruses in the United States, though it’s relatively rare. The virus is primarily transmitted through the bite of infected mosquitoes and can cause inflammation of the brain (encephalitis) in both humans and animals. Symptoms of EEE virus typically develop 4-10 days after being bitten and may include high fever, severe headaches, muscle pain, seizures, and disorientation​(NH Health & Human Services). Unfortunately, EEE has a high fatality rate, particularly among those who develop encephalitis.

In 2024, New Hampshire reported an increase in mosquito batches testing positive for EEE, raising concerns for both residents and health officials​(NH Health & Human Services). While human cases remain rare, the high mortality rate associated with EEE makes prevention essential.

West Nile Virus (WNV)

West Nile Virus (WNV) is another mosquito-borne virus that has become prevalent in the U.S., particularly in warm, humid climates. Like EEE, WNV is transmitted through mosquito bites, though most people infected with WNV experience mild or no symptoms. However, for a small percentage of individuals, especially the elderly and those with weakened immune systems, WNV can lead to serious complications, including viral encephalitis​(NH Health & Human Services,InDepthNH.org).

Common symptoms of West Nile Virus include fever, headaches, body aches, and sometimes swollen lymph nodes or a skin rash. In severe cases, WNV can cause inflammation of the brain or spinal cord, leading to long-term neurological damage or death.

Jamestown Canyon Virus (JCV)

Although less well-known than EEE and WNV, Jamestown Canyon Virus (JCV) is an emerging threat in states like New Hampshire. Spread by infected mosquitoes, JCV often causes flu-like symptoms such as fever, fatigue, muscle aches, and headaches. In rare cases, it can progress to more severe conditions, such as meningitis or encephalitis​(NH Health & Human Services).

New Hampshire has seen an increase in JCV cases in recent years, and the virus is becoming a significant concern for public health officials. While there are no specific treatments for JCV, the best way to protect yourself is to avoid mosquito bites during peak mosquito season, which typically lasts from late spring to early fall​(InDepthNH.org).

Symptoms of EEE, West Nile Virus, and Powassan Virus (POWV)

While EEE, West Nile Virus, and Powassan Virus (POWV) have distinct characteristics, they share similar symptoms. These viruses can start with flu-like symptoms but have the potential to develop into severe and life-threatening conditions. Let’s break down the symptoms of EEE virus, WNV, and POWV, so you can recognize the warning signs:

1. Flu-Like Symptoms: Common to all three viruses are initial symptoms like fever, muscle aches, headaches, and fatigue.
2. Neurological Symptoms: In more severe cases, especially with EEE and POWV, the infection can spread to the brain and central nervous system, causing confusion, seizures, and viral encephalitis​(NH Health & Human Services).
3. Long-Term Effects: Individuals who recover from severe infections may suffer from long-term neurological damage, including memory loss, muscle weakness, and cognitive impairments​(InDepthNH.org,NH Health & Human Services).

Due to the serious nature of these infections, it’s critical to seek medical attention if you or someone you know exhibits any of these symptoms after being bitten by a mosquito.

Mosquito-Borne Illness Prevention: Protect Yourself from Mosquito Bites

Given the risks associated with mosquito-borne viruses, taking preventive measures is crucial to reducing your chances of infection. Here are some practical steps you can take to avoid mosquito bites and lower your risk of contracting EEE, WNV, JCV, or POWV.

1. Use Insect Repellents: One of the most effective ways to prevent mosquito bites is by using insect repellents containing DEET or Picaridin. For those looking for natural options, oil of lemon eucalyptus can also provide protection​(NH Health & Human Services).
2. Wear Protective Clothing: When spending time outdoors, especially during the evening and early morning when mosquitoes are most active, wear long sleeves, long pants, and socks. Light-colored clothing is also less attractive to mosquitoes​(NH Health & Human Services).
3. Eliminate Standing Water: Mosquitoes breed in standing water, so it’s essential to eliminate any potential breeding sites around your home. This includes emptying flowerpots, birdbaths, and gutters​(NH Health & Human Services).
4. Install Screens on Windows and Doors: Ensure your home is well-protected by installing screens on windows and doors to keep mosquitoes from entering​(InDepthNH.org).
5. Limit Outdoor Activities During Peak Mosquito Times: Avoid spending time outdoors during dawn and dusk, when mosquito activity is at its highest​(NH Health & Human Services).

Viral Encephalitis and the Dangers of Mosquito Bites

Mosquito bites aren’t just an inconvenience; they can lead to serious health issues, such as viral encephalitis. As we’ve discussed, both EEE and WNV can cause inflammation of the brain, resulting in potentially fatal complications​(InDepthNH.org). Powassan Virus (POWV), though transmitted by ticks rather than mosquitoes, also carries the risk of severe encephalitis​(NH Health & Human Services).

The dangers of mosquito bites should not be underestimated. While not everyone who is bitten by an infected mosquito will experience severe symptoms, the possibility of contracting a life-threatening illness like EEE or WNV makes prevention essential.

Stay Vigilant and Protect Yourself from Mosquito-Borne Viruses

As the spread of mosquito-borne viruses like EEE, West Nile Virus, and Jamestown Canyon Virus increases, so does the importance of taking precautions to avoid mosquito bites. These viruses can cause severe illness, including viral encephalitis, and protecting yourself is key to minimizing risk.

Remember to use insect repellents, wear protective clothing, and eliminate standing water around your home to reduce your exposure to mosquitoes. By following these preventive measures, you can help protect yourself and your loved ones from the dangers of EEE, WNV, and JCV.

For more information on protecting yourself from mosquito-borne illnesses, visit the Regent Studies website for valuable resources. For the latest updates on these viruses, check out the CDC’s mosquito-borne illness page.

Stay safe, stay informed, and protect yourself this mosquito season!