Tiny Mosquito



Mosquito Diseases - West Nile Virus

What is West Nile Virus?
West Nile virus is a mosquito-borne virus contracted by mosquitoes that feed on the blood of infected birds. The infected mosquito then passes the virus to a human host.

Originating in Uganda, the first recorded North American outbreak of West Nile virus was in 1999. In 2002, more than 4,000 North Americans became ill after being infected with the virus.

What are the symptoms?
Many infected people do not experience illness. However, when infection does cause illness, symptoms will usually appear within two to fifteen days.

In mild cases of the West Nile virus, flu-like symptoms such as fever and headache may appear. For those with weaker immune systems, more serious health complications may follow infection. Such complications include headache, high fever, nausea, vomiting, difficulty swallowing, drowsiness, muscle weakness and paralysis and such fatal illnesses as meningitis and encephalitis.

Who is at risk?
While people of any age can contract West Nile virus, severe health risks are more likely to occur in older people and in those with weaker immune systems. This includes people with chronic diseases and those who are undergoing forms of medical treatment that weaken the immune system (i.e. chemotherapy).

However, it is important to remember that anyone exposed to mosquitoes in an area where West Nile virus has been detected is at some degree of risk for infection.

What are the long-term effects?
Just like the symptoms of the virus, the long-term effects vary from person to person. Some people with serious health complications recover completely while others experience prolonged health problems such as:


See our article about The History of West Nile Virus.

Learn more about West Nile Virus.



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