West Nile virus: How to know if you're infected

Touch of fever? Unexplained headache? These may be symptoms of the West Nile virus.

By

Melissa Breyer

Thu, Aug 23 2012 at 4:03 PM

Related Topics:

Viruses & Diseases

Photo: Dmitrijs Bindemanis/Shutterstock

The recent West Nile virus outbreak is the largest ever in the United States, according to the Centers for Disease Control and Prevention, with the highest recorded number of cases through August since the disease was first detected in the United States in 1999. As of this earlier this week, 38 states had reported human infections, with a total of 1,118 cases, including 41 deaths.

Would you know if you had it? Symptoms for the mosquito-borne infection come in three categories of severity, from no symptoms at all to stupor and paralysis. And while milder forms of infection don't need medical attention, the more serious cases generally require hospitalization, so knowing the symptoms is important. Here is the rundown:

No symptoms
About 80 percent of people who are infected with the virus will not show any symptoms.

Mild symptoms: West Nile fever

Roughly 20 percent of people who become infected with West Nile Virus will develop West Nile fever. The following symptoms can last anywhere from a few days to several weeks:

Fever
Headache
Body aches
Nausea
Vomiting
Swollen lymph glands
Skin rash on the chest, stomach and back

Serious symptoms: West Nile encephalitis, West Nile meningitis, West Nile poliomyelitis

Things start to look more grim for the one in 150 people infected with West Nile virus who develop a severe illness. These symptoms can last for several weeks, and neurological effects may be enduring. Serious illness can happen to people of any age, although people older than 50 and those with compromised immune systems are at the highest risk for getting seriously ill. The severe symptoms can include:

High fever
Headache
Neck stiffness
Stupor
Disorientation
Coma
Tremors
Convulsions
Muscle weakness
Vision loss
Numbness
Paralysis

There is no cure of specific treatment for West Nile infection. People with milder West Nile fever recover on their own, though symptoms can be helped with various treatments (like medication for headache and body aches). If you develop symptoms of severe illness, seek medical attention immediately.

Prevention

The best way to avoid West Nile virus is to avoid mosquitos. Use repellants, wear long sleeves and pants — especially at dusk and dawn (or consider staying indoors during these hours). Make sure your screens are in good shape. Make sure you are not inadvertently creating mosquito farms with standing water. Empty water from flower pots, buckets, barrels and any other receptacles. Replace bird bath water weekly. Drill holes in tire swings and other containers so that water drains out. Keep vessels like children's wading pools empty and stored properly when they aren't being used.

More West Nile stories from MNN and partners:

You might also like:

Join the conversation

Comments: 10

quantum999 Sep 28 2012 at 3:51 AM

Everybody Relax! There is a most natural way, right from Mother Nature to stay absolutely untouchable for them nasty critters - all sort of viruses... The spread, or number of West Nile virus carrying mosquitoes does not matter even in the least, because... Humanity Strikes Back! The Deadliest, The T-Rex Virus Killer has been discovered - The Immunizer - The Most Powerful Immunity Booster on Earth. Yes, The T-Rex Virus-Killing Power is inside your body, waiting for you to activate it. Action! The

.... More

Immunizer does the job of killing viruses - that is just a simple exercise, but is The Complete Colds/Flus/AIDS/West Nile/Yosemite/Cancers Prevention - normally done for a minute a day for kids and adults as the full prevention of the major plagues of civilization. No killer viruses on Earth got any chance against the tremendous power of the immunizer - they just die the moment they touch you... If done for 2 - 3 minutes a day, the immunizer guarantees a very fast recovery for those infected by Colds, Flus, AIDS, West Nile, Yosemite and any other known, or unknown killer viruses on Earth... Human body can be a fortress immune against viral attack... I offer my Dream Immunizer (The Deadliest Virus Killer on Earth) to the world for 2 trillion US Dollars [For the U.S., Britain, Canada, Australia and New Zealand I guess to pay me 200 Billion US Dollars (or BP) is an acceptable offer]. The sooner I am paid, the better for the Entire World... I will disclose the greatest discovery in human history (in more than 200,000 years of humankind on the planet) to everybody and all of us, kids and adults, will stay absolutely healthy all the time, all our lives, even if we are directly exposed to any possibly existing viruses on Earth - mutant, deadly and all the like... Iron Constitution for everybody on the planet is The Reality of The Future...

Log in or register to post comments
Report This Post

Enter your name Sep 17 2012 at 11:59 AM

idk if i have i have alot of mosquito bites on my legs an arms idk wat to do.oh btw im pregnet so plezzzzzzzz HELP

Log in or register to post comments
Report This Post

Tarrant Sep 17 2012 at 4:21 PM

Give your doctor a call. No one can make a guess or diagnose over the Internet.

Log in or register to post comments
Report This Post

evaivonne Sep 03 2012 at 11:01 AM

Does anyone know whether you can get it again if you've had it before? I had West Nile encephalitis once many years ago. For a very long time, I had major reactions to every mosquito bite. I don't react as bad now, unless there are several bites. Am I now immune or more vulnerable?

Log in or register to post comments
Report This Post

keyylliy Sep 02 2012 at 10:35 PM

Hi im very scared if i have west nile how can i tell because i have ringworm but i have a small headache and i kinda have this red line in my arm and a lump in the middle of it does it me i have west nile please HELP me!

Log in or register to post comments
Report This Post

drew p weiner Sep 02 2012 at 1:16 AM

don't get bit

Log in or register to post comments
Report This Post

rm Sep 01 2012 at 11:34 AM

Two people in my extended family got it recently, from mosquito bites from two different parts of the country. It knocked both of them out of commission for three and four weeks. The neurological pain was off the charts for one of them. It's not that rare, and as the article says, 80% of the people who get it don't know they have it. I've been on the phone for the past week with doctors, labs, state health departments, and the CDC, and there is very little information available about it, and

.... More

no lab that tests for it in my part of the country. It's a serious threat to your well being, and if you are around mosquitos at all, even just a few of them, it's best to watch out so that you don't have the possibility of being one of those 20% that know that they have it. It's a difficult disease, with no treatment at all, you just have to ride it out, and it is not pleasant, to say the least.

Log in or register to post comments
Report This Post

Guest Oct 10 2012 at 1:24 AM

I had it and just got over it. Well mostly over it. You are right there is little info. Most sites just use the same list. My doctor did not want to test me. I read the test is costly so they dont run them. My doc was super nice after she saw my positive test that I made her do. Homeopathic treatment was the only relief. I took "Belladonna 30 you can find it on amazon.com I did not get a mosquito bite. I work with wildlife for a living. I know the cdc says you cannot get it that way but I handled

.... More

a very sick wild bird and think I got it from the bird. Just saying I do not think we are being told everything.

Log in or register to post comments
Report This Post

Guest Sep 02 2012 at 10:16 PM

It does not say 80% of people infected don't know they have it. It says 80% of people infected don't have symptoms. So, they are asymptomatic, with no reason to even see a doctor.