Zika Virus

What Is Zika?

Zika is a virus that spreads to people mostly through the bite of certain kinds of mosquitoes (from the genus Aedes). Unlike some other types of mosquitoes, these bite any time of day or night. Aedes mosquitoes are not native to Montana.

Zika virus can also be spread during sex and from a pregnant woman to her baby.

Zika outbreaks are occurring in many parts of the Western Hemisphere, including Mexico and Central and South America. Because Aedes mosquitoes inhabit parts of the United States, health officials believe the disease could occur in this country, too. Travelers to places already experiencing Zika outbreaks also may become infected.

The map at left shows countries experiencing Zika outbreaks as of late July 2016. This map is subject to change as the disease spreads or outbreaks end.

Click here for an up-to-date list of places where Zika outbreaks are occurring.

Zika in Lewis and Clark County

Lewis and Clark Public Health reported the first confirmed case of Zika virus infection in Lewis and Clark County on July 22. The infected person, a woman who was not pregnant, had recently traveled to another country with an active Zika outbreak. She became ill shortly after returning home but recovered.

The case was only the third reported in Montana since the virus turned up in the Western Hemisphere in May 2015. Two travel-related cases were found in Missoula, one in February 2016 and the other in July.

Click here for up-to-date numbers of Zika cases in Lewis and Clark County and Montana.

Symptoms of Zika

Many people who become infected with the Zika virus have mild symptoms or no symptoms at all. The most common symptoms are:

  • Rash

  • Fever

  • Joint pain

  • Red, itchy eyes

These symptoms can last for several days to a week. Deaths due to the Zika virus are rare. 

Click here for more about symptoms, treatment, and testing.

Special Risks of Zika

Although illness caused by the Zika virus is usually mild, there are some cases in which the virus presents significant risks.

Zika infection during pregnancy has been found to cause birth defects in some babies. For this reason, the U.S. Centers for Disease Control and Prevention (CDC) recommends that pregnant women avoid traveling to areas with Zika outbreaks. If you're pregnant and have a sex partner who lives in or travels to an area with Zika, use condoms or avoid sex during pregnancy. If you're trying to become pregnant, take steps to avoid mosquito bites. Talk to your medical provider if you have concerns about Zika.

The Zika virus also has been associated with increased reports of Guillain-Barre syndrome, an uncommon condition of the nervous system.

Click here for more information about Zika and pregnancy. 

Preventing Zika Infection

So far, there is no vaccine to prevent infection by the Zika virus. Researchers are working hard to develop one.

There's also no treatment for Zika virus once a person has become infected.

The most effective way to prevent infection with Zika is to prevent mosquito bites. Since mosquitoes carry other diseases, like West Nile virus, this is always a good idea. Here are some ways to do so, especially when traveling in countries with active Zika outbreaks:

  • Use an EPA-registered insect repellent as directed. (Do not use insect repellents on babies under 2 months old; their skin is too sensitive.)

  • Treat your clothing and gear with permethrin, or buy pre-treated items.

  • Wear long-sleeved shirts and long pants.

  • Stay in places with air conditioning and window and door screens.

  • Sleep under mosquito netting.

  • Use mosquito netting to cover babies under 2 months old when in strollers, cribs, etc.

Click here for more about preventing Zika infection.

Zika Virus Resources

Zika Virus Brochure: This brochure, produced by Lewis and Clark Public Health, is available free for download and printing. It contains much of the information available on this web page.

U.S. Centers for Disease Control and Prevention

World Health Organization

Got Questions about Zika?

If you have questions about testing for Zika virus or how the disease might affect you, contact your medical provider. Be sure to share your travel history.

You can submit general questions to us at publichealth(at)lccountymt.gov We'll do our best to answer.