West Nile Virus Classification
The official West Nile virus classification is that the species is a member the Flaviviridae family and belongs in the RNA virus Group 4 order. Within the Flaviviridae family, West Nile Virus, or WNV, is part of the viral Japanese encephalitis complex. The structure of the virus is similar to that of dengue fever and both are classified into the same system. The RNA structure is between 11,000 and 12,000 nucleotides and the virus appears with a smooth protein surface and a length of 45-50 nanometers. The genes of WNV include three structural proteins and seven non-structural proteins. Primarily, the virus is known to attack birds, but has also been found in the following animals: horses, cats, chipmunks, squirrels, rabbits, dogs, bats, and skunks. In addition, WNV has infected humans by way of mosquito bites.
In human cases, the WNV can take on three distinct and separate effects. An infection without symptoms may commonly be present, but a rare version of the infection manifests itself as a neuroinvasive disease named West Nile encephalitis or meningitis. The third possible appearance of West Nile virus symptoms is in the form of West Nile Fever, a mild febrile syndrome. It is this form of WNV that is most known. After contact has occurred, the virus incubates between two and eight days and then symptoms begin to appear. The experienced adverse reactions are similar to influenza and include the following complications: fever, chills, swollen lymph nodes, aching joints, headaches, pronounced sweating, weakness, and drowsiness. Some patients may also have gastrointestinal reactions such as nausea, vomiting, diarrhea, a loss of appetite, or the development of a rash in the torso region of the body. For the majority of sufferers, symptoms disappear after 7-10 days, but patients who experience lymph node problems may have problems for up to two months. The neuroinvasive version is much more dangerous and a person who contracts this infection may fall into a state similar to a coma where consciousness is severely impaired. WNV is not thought to be particularly threatening, but deaths have occurred from the virus. In the United States, mortality rate is estimated at 1%, but this figure may be inaccurate as nearly 80% of all cases have no symptoms and are not reported.
West Nile virus is currently a treatable and manageable infection. In addition, prevention by using mosquito repellent is an effective way for people to avoid contracting the infection. For cases in horses and other animals, a vaccine has been developed that successfully produces antibodies within the host’s body, thus creating an immunity to WNV. West Nile virus classification is relatively limited as the virus has not shown a considerable amount of mutation.