West Nile virus (WNV) is a potentially serious illness. Experts believe West Nile Virus is established as a seasonal epidemic in North America that flares up in the summer and continues into the fall. This fact sheet contains important information that can help you recognize and prevent West Nile virus. The rate of fatality is 3-15% among those who develop the disease. WNV encephalitis primarily affects persons over 50 years of age. Those with a compromised immune system may also be more susceptible to acquiring encephalitis. Currently no approved human vaccine is available for WNV.
There are two means to keep safe: get rid of mosquitoes and prevent them from biting you. The get rid of mosquitoes (or at least control them, scroll down this page. And for information about which repellent to use; what is most effective and safe mosquito repellent, is found on this other page.
There are about 200 different species of mosquitoes (often called "skeeters", "mossies", "mosskeeters" or misspelled "mosquitos", ) in the United States, all of which live in specific habitats, exhibit unique behaviors and bite different types of animals. Despite these differences, all mosquitoes share some common traits, such as a four-stage life cycle. After the female mosquito obtains a blood meal (male mosquitoes do not bite), she lays her eggs directly on the surface of stagnant water, in a depression, or on the edge of a container where rainwater may collect and flood the eggs. The eggs hatch and a mosquito larva or "wriggler" emerges. The larva lives in the water, feeds and develops into the third stage of the life cycle called a pupa or "tumbler". The pupa also lives in the water, but no longer feeds. Finally, the mosquito emerges from the pupal case and the water as a fully developed adult, ready to bite.
The type of standing water in which the mosquito chooses to lay her eggs depends upon the species. The presence of beneficial predators such as fish and dragonfly nymphs in permanent ponds, lakes and streams usually keep these bodies of water relatively free of mosquito larvae. However, portions of marshes, swamps, clogged ditches and temporary pools and puddles are all prolific mosquito breeding sites. Other sites in which some species lay their eggs include tree holes and containers such as old tires, buckets, toys, potted plant trays and saucers and plastic covers or tarpaulins. Some of the most annoying and potentially dangerous mosquito species, such as the Asian tiger mosquito, come from these sites.