By: Dr. Jonathan WoodArbovirus infections in Maine?(A mosquito-borne virus is called an “arbovirus”)This week, the Maine CDC released an alert about finding the Eastern Equine Encephalitis virus (EEE) in one of their “mosquito pools” in mid-July. This is the earliest in the season that such a virus has been isolated in Maine. West Nile Virus (WNV) and EEE are two important causes of seasonal mosquito-borne viral encephalitis in the northeast. These viruses which infect humans through mosquitos are called “arboviruses” and are worthy of our attention.In 2012, there were over 5600 proven cases of WNV in the US, about 50% of which affected the nervous system. 60% of “neuroinvasive” cases were hospitalized and 1% died. There was one case of neuroinvasive disease in Maine, which suggests that there were 30-70 non-neuroinvasive cases that were not diagnosed.EEE is much less common, with only 15 proven cases nationally in 2012. However, all of these affect the brain and 9 of 15 occurred in New England. This is a very serious disease with a death rate of 36-70%. Vermont, New Hampshire, and Massachusetts have already isolated arboviruses in 2013. These were mostly isolated from mosquitos, but also from horses and, in the case of New Hampshire, from humans. Again, these viruses can cause severe brain and nervous system disease. Since there is no specific treatment for these viruses, preventing transmission is very important. The Maine CDC suggests the following for preventive measures to protect against WNV, EEE, and other arbovirus infections:• Use an EPA approved repellent when outdoors, especially around dawn and dusk – always follow the instructions on the product’s label • Wear protective clothing when outdoors, including long-sleeved shirts, pants, and socks • Use screens on your windows and doors to keep mosquitoes out of your home • Avoid being outdoors at dawn and dusk when many species of mosquitoes are most active • Drain artificial (non-natural) sources of standing water It has been a bad year for rain and mosquitos, as any walk in the woods or visit to camp will attest. Keep safe and keep the mosquitos away! Be smart!More Information: More information on arboviral illness is available at Maine CDC’s Vector-Borne Disease website at http://www.maine.gov/dhhs/mecdc/infectious-disease/epi/vector-borne/index.shtml. Information on pesticides and repellents is available at the Maine Board of Pesticides Control website at http://www.maine.gov/agriculture/pesticides/public/index.htm#mosquito.