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The National Academies: What You Need To Know About Infectious Disease

What You Need To Know About Infectious Disease

West Nile Virus

West Nile virus is an arthropod-borne virus, or arbovirus, most commonly spread by the bite of an infected mosquito that contracted the virus after feeding on infected birds. In a very small number of cases, West Nile virus also has been spread through blood transfusions, organ transplants, breastfeeding, and even during pregnancy, from mother to baby. West Nile virus is not, however, spread through casual person-to-person contact s or from handling live or infected birds, though proper safety precautions should be taken when working with infected animals.

West Nile virus has been documented in Europe, the Middle East, Africa, parts of India, and Australia. It arrived in North America—the continental United States and Canada—in 1999. According to preliminary data from 2016, there were 1,938 cases reported in the United States and 92 deaths.

Symptoms
Approximately 80 percent of people who are infected with West Nile virus will not show any symptoms at all. Up to 20 percent of the people who become infected have symptoms such as fever, headache, body aches, nausea, vomiting, and sometimes swollen lymph glands or a skin rash on the chest, stomach, and back. Most people who develop these symptoms recover completely, but fatigue and weakness can last for weeks or even months. Less than 1 percent of infected people will develop serious neurologic illnesses, such as encephalitis and meningitis. Symptoms of those illnesses include headache, high fever, neck stiffness, disorientation, coma, tremors, seizures, or paralysis.

Treatment
There is no specific treatment for West Nile virus. In cases with milder symptoms, such as fever and aches, people usually get better on their own, without treatment. In more severe cases, people usually need to go to the hospital, where they can receive supportive treatment, including intravenous fluids, help with breathing, and nursing care.

Sources:
http://www.cdc.gov/westnile/transmission/index.html
http://www.cdc.gov/westnile/faq/genquestions.html
http://www.cdc.gov/westnile/statsmaps/preliminarymapsdata/histatedate.html
http://www.cdc.gov/westnile/symptoms/index.html

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What do you know about infectious disease?

Which is the vector (animal that carries the pathogen) for West Nile virus?

  • Sorry, that’s incorrect.

    The mosquito is the vector for West Nile virus. The mosquito suffers no ill effects from the virus but transmits it to humans and other warm-blooded creatures (such as crows) when it takes a blood meal. 

  • Correct!

    The mosquito is the vector for West Nile virus. The mosquito suffers no ill effects from the virus but transmits it to humans and other warm-blooded creatures (such as crows) when it takes a blood meal. 

  • Sorry, that’s incorrect.

    The mosquito is the vector for West Nile virus. The mosquito suffers no ill effects from the virus but transmits it to humans and other warm-blooded creatures (such as crows) when it takes a blood meal. 

  • Sorry, that’s incorrect.

    The mosquito is the vector for West Nile virus. The mosquito suffers no ill effects from the virus but transmits it to humans and other warm-blooded creatures (such as crows) when it takes a blood meal. 

Infectious Disease Defined

Pandemic

An increase in the occurrence of a particular disease over a very large region, such as a continent or the entire globe, that is greater than what is expected over a given period of time.

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