West Nile Virus
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West Nile Virus: Facts You Need To Know

 The Aedes albopictus mosquito, which is also called Asian tiger mosquito, is found to be an agent of West Nile Virus. The virus spreads through mosquito bites. The virus does not multiply as fast in animals as in humans. It was in Uganda that the first sign of the disease was identified in West Nile district in 1937. Bird acts as hosts as it develops enough viral levels in transmitting the infection to biting mosquitoes, which in turn infect other birds as well as humans.

Cause of West Nile Virus Disease

West Nile Virus spreads through mosquito bites and can infect man and animals alike. The mosquito species that is infected differs according to the geographical area of the world. There are three different effects seen on humans with West Nile virus. The first is called an asymptomatic infection while the second is a mild febrile syndrome, which is known as West Nile Fever. The third effect seen is called West Nile meningitis or encephalitis and is a neuro-invasive disease. The ratio of appearance among the three states is around 110:30:1.

In the second state, the incubation period of the febrile stage is around 3 to 8 days after which the person has fever, headache, diaphoresis, lymphadenopathy, chills, weakness and drowsiness. The person sometimes have truncal rash for short durations while some other have gastrointestinal symptoms like nausea, loss of appetite, diarrhea or vomiting. All the symptoms disappear in 10 days time, except fatigue, which can go for some more weeks, and lymphadenopathy takes around two months to disappear.

The severe encephalitis also makes the consciousness of the person to decrease, which sometimes can reach near coma. The deep tendon reflexes become hyperactive at the beginning, but later it diminishes. There is also incidence of extra pyramidal disorders of the patient. The recovery from this condition is long and the patient feels week.

In recent study of the disease with West Nile Virus, it has been found that the spinal cord gets infected along with frontal myelitis. It may or may not accompany encephalitis. There are cases of West Nile virus linked to Guillain-Barré syndrome. Some rarer effects of having the disease are multifocal chorioretinitis, hepatitis, nephritis, splenomegaly, myocarditis and pancreatitis.

West Nile Virus Disease Symptoms

The person affected by the virus shows no apparent symptoms of illness. If any, the symptoms include flu like illness along with fever, muscle aches and headache. In a region with the virus, around 1 in 150 people are found to develop severe illness like encephalitis or meningitis.

Treatment for West Nile Virus Disease

There is no definitive treatment for West Nile virus. If any person becomes ill with the virus, he or she needs supportive treatment, requiring intravenous fluids. West Nile virus is controlled by controlling mosquito bites. This incorporates eliminating mosquito breeding sites and also use of mosquito repellents. One should use bug repellent having DEET. People should spend less amount of time outdoors and also wear clothes with long sleeves and trousers. All windows and doors should have net covering to stop mosquitoes from entering the house. Till date, there is no vaccination found for humans. One vaccine has been found for horses. The vaccination is widely used in zoos around the world.


If you are traveling to regions where there is prevalence of virus transmission to humans, you should take necessary protection against mosquito bites. One should use mosquito repellent, mosquito nets and should wear long sleeves and trousers. People who are over the age of 50 years are more at risk of incurring severe illness. This is also true of people who have other illness. The virus is mostly seen in Africa , the Middle East and West Asia . IN regions of temperate climate, like Russia and the northern part of America , there are cases of its occurrence during late summer as well as early autumn. But in tropical climate, the transmission of the virus can take place the year round.

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