As foresters, woodland owners and tree and wildlife enthusiasts, we hear the word safety and immediately think about making sure our hard hat is packed, our gas tank is full, our cell phone is charged and we have a buddy to call in case of an emergency. How many of us think about diseases? Who thinks about West Nile Virus (WNV) or Eastern Equine Encephalitis (EEE)? For those of us that take our pets into the field, WNV and EEE are very real threats. West Nile Virus originated in Africa but spread quickly throughout the United States after an outbreak in New York in 1999. By 2003, 46 states had been infected, and nearly 10,000 people had fallen ill.
Although not contagious by contact with an infected person or animal, a protective layer is recommended when handling potential infected subjects. Most infected humans show no symptoms while a minority exhibit fevers, headaches, skin rashes, meningitis or encephalitis. Very few people die from WNV (< 1:1,000), but precautions should always be taken to prevent exposure. A total of 156 cases of WNV have been reported in Indiana this year with one sample being human. Other cases have been found in bordering states with 741 cases (mosquito) in Illinois, two mosquito and four human cases in Michigan, 64 mosquito cases in Ohio and zero cases of any kind in Kentucky as of August 20, 2013.
Eastern Equine Encephalitis is a rare viral disease that can be transmitted from host mosquitoes to a number of other animal species. Historical accounts of the disease show that in Midwestern states, EEE is most often found in southwestern Michigan; however, infected horses in Indiana have been found. EEE infects nearly all game birds, amphibians and reptiles, and last year in Michigan, an 8-week-old puppy.
Humans are not immune to EEE. Nearly 30% of people that develop the disease die, and approximately 50% of survivors have permanent neurological complications. Symptoms of infection may or may not occur and will often take between three and 10 days to be realized. EEE symptoms in humans range from fever, headache and nausea to abdominal pain, paralysis, seizures and fainting. An elderly woman in New England died on August 21, 2013, and was the first human casualty of the disease this year. A vaccine has been developed to prevent EEE in horses; however, no vaccine or treatment is available to protect humans or other animals from EEE or WNV. Elimination of standing water is our only defense against potential EEE and WNV threats.
As the summer is in full swing and more and more of us head out to the field, please do not forget to protect yourself and your pets from potential exposure to mosquitoes.
Beasley, D.W.C. et al. (2013) Resurgence of West Nile neurologic disease in the United States in 2012: What happened? What needs to be done? Antiviral Research 99:1–5.
Wendell, L.C. et al. (2013) Successful Management of Severe Neuroinvasive Eastern Equine Encephalitis. Neurocrit Care 19:111–115.
USGS Disease Maps
Van Buren County Horse Dies of Eastern Equine Encephalitis, Horse Owners Urged to Vaccinate Animals, MLIVE Media Group
Weymouth Officials Urge Caution After EEE Death, The Patriot Ledger
Mosquitoes, Purdue Extension Entomology
Shaneka Lawson, Plant Physiologist
Hardwood Tree Improvement and Regeneration Center (HTIRC)
Department of Forestry and Natural Resources, Purdue University