Dr Rachel: How Mosquitoes Kill

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It is that time of year again: time to worry about mosquitoes and West Nile virus.

Let’s look at how West Nile virus gets into mosquitoes, then into us.

The virus actually interacts with mosquitos and birds. Some birds develop high levels of the virus in their bloodstream. A mosquito bites that bird and becomes infected with the West Nile virus. After about a week, the infected mosquito can pass the virus to more birds and mammals.

Mosquitoes infected with West Nile virus bite us and we can become infected.

West Nile virus can also be spread through blood transfusions, organ transplants, and from mom to baby during pregnancy, delivery, or breastfeeding–but these are not common.

The usual time from bite to symptoms is two to six days but can range from two to 14 days and can be several weeks in immunosuppressed people.

About 70-80% of people who become infected with West Nile virus do not develop any symptoms.

One in five people will develop symptoms such as fever, headache, weakness, and body aches.  Some people get nausea, vomiting, diarrhea, or rash. Most people with West Nile virus disease recover completely.  But, fatigue and weakness can last for weeks or months.

In less than one percent of people, the virus can cause a serious neurological infection. Signs and symptoms include:  high fever, severe headache, stiff neck, disorientation or confusion, tremors or muscle jerking, seizures, or coma. Some people can also get sudden paralysis.

About 10 percent of people who develop a neurologic infection from West Nile virus will die.

There is no treatment for West Nile disease, so wear your mosquito repellent and do what you need to do to avoid being bitten by those little buggers!