West Nile Virus (WNV) and Eastern Equine Encephalitis Virus (EEEV) are two of the more common illnesses transmitted to humans through bites of infected mosquitoes. These mosquito-transmitted viruses may cause no symptoms at all, minor symptoms, or serious symptoms including inflammation of the brain.
West Nile Virus
West Nile Virus is not contagious, meaning it is not spread by humans, and is rarely spread through blood transfusions. WNV has been detected in all lower 48 states and occurs usually in June through September.
Most people who become infected with WNV have no symptoms. Those who develop symptoms can have head and body aches, joint pains, vomiting, diarrhea, fatigue, and weakness. More severe symptoms, like inflammation of the brain, high fever, disorientation, seizures, coma, tremors, or paralysis are rare.
Eastern Equine Encephalitis Virus
Eastern Equine Encephalitis is a rare illness in humans also caused by the bite of an infected mosquito. Most cases occur in the Atlantic and Gulf Coast states. The EEEV is not contagious. Those infected with EEEV have no apparent illness, unless it is severe infection.
Symptoms of severe EEEV cases often begin with the sudden onset of a headache, high fever, chills, and vomiting. Infections sometimes progress, developing more serious, potentially life-threatening symptoms involving inflammation of the brain such as disorientation, seizures, or coma.
There are no vaccines to prevent WNV or EEEV infections. Avoiding mosquito bites provides the best protection against developing WNV and EEEV infections. Here are some helpful tips for preventing or limiting mosquito bites:
- Use Mosquito repellent with DEET, Picaridin, IR3535, or Oil of lemon eucalyptus. Examples of Mosquito repellent with some of these active ingredients are Cutter Advanced, Skin So Soft Bug Guard Plus, Repel, and Off! Botanicals. Products containing higher percentages of DEET provide protection for longer periods of time.
- Cover exposed skin. Wear hats, long-sleeved shirts, long pants, and socks.
- Stay and sleep in screened-in or air-conditioned rooms. Make sure the screens are secure with no holes.
- Use a bed net if you are sleeping in an area exposed to the outdoors.
- Eliminate mosquito breeding sites. Empty standing water from flower pots, buckets, barrels, or other containers.
- Limit time outdoors during dusk and dawn. This is the time when infected mosquitoes are usually out.
- Avoid scratching the bites, as they can become infected.
- Apply over the counter hydrocortisone cream or calamine lotion to reduce itching.
- Seek immediate medical attention if you exhibit any unusual symptoms.
There are no specific treatments for WNV or EEEV, as antibiotics are not effective against viral infections. Over-the-counter medication can be used to reduce fever and relieve minor symptoms, including pain.
Care for more severe cases is typically based on the symptoms presented in each patient. Patients with severe symptoms are often hospitalized to receive respiratory support, IV fluids, and additional supportive care to manage their symptoms.
Tracking WNV and EEEV Where You Live
For the summer season of 2013, no human cases of West Nile or Eastern Equine Encephalitis have been reported in the state of Connecticut thus far. However, mosquitoes collected at various trapping stations have tested positive for virus. Specifically, The Connecticut Agricultural Experiment Station in New Haven has found mosquitoes infected with either WNV or EEEV in many towns in Connecticut. These statistics change weekly. Click on the link below to review the latest details of their findings:
Fast Fact: “Station scientists found that the American robin is a favorite host for some mosquitoes and is an important carrier of the virus.” – Source: The Connecticut Agricultural Experiment Station, New Haven, CT.
For those interested in tracking mosquito activity in areas outside Connecticut, the following links provide helpful information: