Zika Virus

What is Zika Virus?

Zika is a virus transmitted by mosquitoes. The list of countries with Zika outbreaks is constantly changing, and the most current list of countries can be found here. In general, the virus is currently in the Caribbean, Central America, Mexico, Oceania/Pacific Islands, South America, Singapore, and certain countries in Africa. Local mosquito-borne Zika virus transmission has been reported in the continental United States and also in some US territories.

How is Zika Virus spread?

Zika virus is transmitted by the bite of Aedes mosquitoes, which are usually daytime pests. Less commonly, these mosquitoes may also bite at night. There are 4 ways that Zika is transmitted:

1. Zika mainly is spread when infected mosquitoes bite a human, who then becomes infected and acquires virus in their bloodstream. A mosquito then becomes infected by biting the infected human.
2. Zika can be transmitted from a pregnant woman to her unborn baby in utero.
3. Zika can be spread through sexual contact. A man/woman can transmit Zika to their sexual partners. This transmission can occur before a person has symptoms, and even if the infected source individual never develops symptoms. Zika is transmitted through semen for at least 6 months after a person has become infected.
4. Zika virus can be spread via blood transfusion. This type of transmission has not yet been seen in the US, but Zika-endemic countries have multiple reports of blood transfusion transmission.

What are the symptoms?

Zika disease is a mild illness, and only 1 in 5 people infected with Zika become symptomatic. Symptoms begin 2-7 days after being bitten by an infected mosquito and may include fever, rash, joint pain and red eyes, which can last several days to a week. These symptoms can mirror other mosquito-borne illness such as dengue or chikungunya. In extreme cases, Zika disease causes a rare complication called Guillain Barre Syndrome (GBS), which is a neurological condition that causes temporary paralysis or weakness.

If you are traveling overseas on a short-term trip, you may not present with symptoms until you return to the US. If you have a fever, rash, or joint pain, please visit SHS or an urgent care clinic. Please remind the medical provider that you have traveled internationally.

Who is at risk? 

Anyone traveling where this virus has been identified can become infected. Pregnant women are at greater risk as this virus can be transmitted to their unborn child. Individuals having unprotected sex (vaginal, oral, anal) within 6 months of return from a high-risk area may experience the Zika disease, as well as pass it on to their sexual partners.

Can Zika disease be treated?

There is currently no antiviral treatment for Zika disease. Focus on managing symptoms, which typically resolve on their own within a week. Get plenty of rest, stay hydrated, and use acetaminophen (Tylenol) for any fever or pain.

Can Zika disease be prevented?

There are no preventive vaccines or pharmaceuticals, so the WHO and CDC recommend that pregnant women avoid travel to Zika-affected areas. All travelers going to affected areas should take preventive measures to protect themselves, such as:

• Wear long-sleeved shirts and long pants.
• Live in lodging with screens on the windows and doors.
• Use effective insect repellent (controlled-release, 30% DEET, Picaridin). However, Skin-So-Soft and eucalyptus products have not been found effective. Apply sunscreen 30 minutes before application of insect repellent, if applicable.
• Spray your clothing with Permethrin before departing to your overseas destination.
• Sleep under mosquito nets.
• If you have been to a Zika-affected country, it is recommended to use a condom or abstain from sex for 6 months (whether or not you have symptoms).
• Upon returning to continental United States from a Zika-affected area, continue to use daily mosquito repellent for 3 weeks.
• Upon return from an endemic area, pregnancy should be avoided for at least 6 months. Men with pregnant partners should use condoms during intercourse and abstain from oral sex for the duration of the pregnancy (even if the man does not show Zika symptoms).

Travel with the mindset that everyone is at risk. Don’t rely on the fact that you “never get bitten” or “we never see any mosquitoes where I’m headed." Even if you are traveling to a high-altitude area (over 6500 meters above sea level) where Aedes mosquitoes don’t survive, you will almost always be arriving at an airport in a lower altitude area where there is a Zika risk. Take appropriate precautions.

More information

To learn more, please visit the CDC website: https://www.cdc.gov/zika/