Zika Virus


Zika is primarily spread mostly by the bite of an infected Aedes species mosquito (Ae. Aegypti and Ae.alopictus). Many areas in the lower half of the United States have these types of mosquitoes. Montana does not have mosquitos that carry the Zika virus. These mosquitoes are aggressive daytime biters and can also bite at night. Insect repellant and covering your skin with clothing reduces the risk of getting Zika when traveling to an area with Zika. These Zika infected mosquitos are currently located throughout in central and south America, the Caribbean Islands, Africa, and the Pacific Islands. Check here to see current information regarding the location of Zika infected Aedes mosquitos throughout the world and in the United States.

Unfortunately, there is no vaccine or medicine for Zika.  About 80% of infected people have no symptoms while the remainder usually have a combination of rash, red eyes, a fever, and arthralgia. 

Zika can be also passed through sex from a person who has had a Zika infection to his or her sex partners. Additionally, Zika can be passed from a pregnant woman to her fetus. Zika infection during pregnancy can cause a serious birth defect called microcephaly that is a sign of incomplete brain development. Doctors have also found other birth defects among fetuses and infants infected with Zika virus. It is for this reason that pregnant women are advised not to travel to areas with Zika, at all.

If you were exposed to Zika through travel or sex and are of reproductive age, it is very important for you to avoid transmission of the virus to a pregnant partner and wait to become pregnant. Visit the CDC website for specific information about how to prevent pregnancy or for women and their partners trying to become pregnant.

If you were exposed to Zika virus you may wish to ask your healthcare provider about testing for Zika virus infection. Testing is recommended for symptomatic persons who have traveled to a country with a current Zika outbreak or for symptomatic pregnant women who traveled to an area with risk of Zika outside of the U.S. and its territories. Because of the changing epidemiology of Zika and dengue, CDC does not currently recommend conducting routine Zika testing for symptomatic persons. CDC also does not recommend routine Zika virus testing for asymptomatic pregnant women living or traveling in the U.S. and its territories. Talk with your healthcare provider if you have questions or concerns about Zika testing.

Montana’s local and state public health officials are monitoring developments regarding Zika closely. At this time only Montana residents who traveled to areas with ongoing Zika transmission have contracted Zika virus. No pregnant women from Montana have tested positive for Zika. See the surveillance section below for the current number of Zika tests (positive and negative) performed by the MT Public Health Laboratory.

Pregnant or planning on becoming pregnant? Visit CDC's website for pregnant women and for women trying to get pregnant.

Zika confirmed cases (current)

County Cases
Flathead 2
Gallatin 3
Glacier 1
Lewis and Clark 1
Mineral 1
Missoula 2

2017 Zika cases

Zero pregnant women have tested positive. 
*Zika testing can be performed at the Montana Public Health Laboratory or CDC. 
This map is current and will be updated as cases are confirmed. 

Zika Resourcesfor Travelers