West Nile Virus Still Active

West Nile Virus

The West Nile Virus is still active in the U.S., long after summer is technically over. Incidences of West Nile Virus have not advanced beyond the outbreak threshold this year, but the basic fact that we are seeing multiple cases in less than warm weather climate areas is cause for concern.

Numerous cases have been reported recently in California, Florida, Louisiana, and Texas, as well as in Nebraska. A California man died from West Nile Virus on Oct. 6 in San Diego County, the first case resulting in death in the county since 2007.

According to The Centers for Disease Control and Prevention (CDC) we have experienced an outbreak of West Nile Virus in the U.S. in 2014, and do so every year. This year’s outbreak has not reached epidemic proportions, but there have been epidemics in years past. So far this year, the CDC is indicating that incidences of the West Nile Virus have been reported in 47 states, with 1,585 cases reported overall in the U.S. Of this total, 917 cases were reported as Neuroinvasive Disease cases, with 668 cases reported as Non-Nueroinvasive. Of those 1,585 reported cases in the U.S., 54 people have died.

Active West Nile Virus cultures present themselves in two different categories, Neuroinvasive and Non-Nueroinvasive disease states. The Neuroinvasive disease state is the worse of the two, and can cause encephalitis and meningitis as a result. Typically only one percent of West Nile Virus sufferers contract this more virulent strain of the virus.

The Non-Nueroinvasive category of this disease is the normally the more common of the two, but in 2014, the more virulent strain of West Nile Virus has been reported in more than 60 percent of the cases. Upwards of 80 percent of those that contract the virus see no advancing symptomology, and generally these patients contract the less virulent strain of the disease.

People who contract the more virulent strain of West Nile Virus, the Neuroinvasive Disease state, can develop a more serious neurologic illness such as meningitis or encephalitis. Signs and symptoms include, but are not limited to fever and headache, with associated muscle pain and stiffness in the neck and back. More severe symptoms include coma, seizures and in rare cases, paralysis and even death as a result. There is no vaccine available to prevent West Nile Virus, and treatment options for the infection focus on relieving symptoms.

The virus is mainly transmitted to humans by mosquito bites, and the infected mosquitos receive the virus from the main carriers of the disease, birds. The CDC reports that more than 65 species of mosquitos carry and transmit the virus. There are several other, extremely rare ways to contract the West Nile Virus, through surgical and laboratory procedures and blood transfusions. Additionally, West Nile Virus has been known to cross the placenta, and can be transmitted from a pregnant mother to her unborn child.

The World Health Organization (WHO) indicates that outbreaks of the virus happen all over the world each year, and are generally the result of migratory bird routes. As these birds migrate north from their winter nesting spots along the equator and other warmer climates, they bring with them the disease. The virus only stays with them for several days, just long enough for the offending mosquitos to feed on the bird, and contract the virus themselves allowing them to pass it along to humans.

The West Nile Virus has been reported by the CDC to be still active in the U.S. this year, and as far north as Nebraska recently. According to the Southwest Nebraska Department of Public Health, there have been 114 reported cases of the virus in Nebraska this year, with two deaths.

By Jim Donahue

Sources:
CDC – FAQ’s
CDC – Disease by State
WHO
North Platte Telegraph
Image Source:
CDC – Image ID# 17713Creative Commons James Gathany

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