11/15/2012 12:27 pm ET

West Nile Virus: 'Survivor' Star Lisa Whelchel Announces Diagnosis, What Is It?

Lisa Whelchel, the "Facts of Life" actress who is now a contestant on "Survivor: Philippines," has been diagnosed with West Nile virus, according to news reports.

Whelchel tweeted about her diagnosis:

It's not clear whether the 49-year-old contracted the mosquito-borne illness while filming "Survivor" in the Philippines or if it was something she contracted here in the U.S., People magazine reported, but this year has been a particularly bad one for West Nile in the states. So far, this has been the second-worst year on record for West Nile, with more than 4,500 cases of the virus so far this year and 183 deaths, Reuters reported.

Many people with West Nile virus won't even know they have the virus, according to the Mayo Clinic. About one in five cases of the virus are mild -- with just headache, fever or body aches -- and symptoms go away on their own.

But in fewer than 1 percent of cases, symptoms are more severe and can even require the person to be hospitalized. That's because inflammation of the brain (encephalitis), surrounding membranes or spinal cord (meningitis) can occur. When a case is serious, symptoms usually include having convulsions or tremors, confusion, terrible headache, high fever, paralysis of part of the body, and even coma, according to the Mayo Clinic.

The CDC added that in these severe cases, symptoms can last weeks, and some of the effects may never go away.

Symptoms usually show up between three and 14 days after the mosquito has transmitted the virus to a person, the CDC reported. There is no set treatment for the virus, though for serious cases, treatments usually involve hospitalization where they will receive IV fluids and assistance with breathing.



Natural Ways To Prevent Mosquito Bites