What is Zika virus?
Zika is a virus, which was first discovered in the Zika Forest of Uganda in 1947. There have been outbreaks over the years in Africa, Southeast Asia, and the Pacific Islands. In January of 2016, it was recognized that more outbreaks were occurring in the Americas. There was also an associated increase in birth defects and Guillain-Barre syndrome.
Many people infected with the virus will not have symptoms. In those who do show symptoms they are often mild, and are symptoms which can be caused by many other diseases. These symptoms include fever, rash, joint pain, conjunctivitis (or red eyes), muscle pain, and headache. Symptoms can last several days up to a week. Most people do not have to go to the hospital, and people rarely die from the virus. Once someone has been infected, he or she is likely protected from future infections.
How is Zika virus spread?
The virus is spread mostly by the bite of an infected mosquito (Aedes aegypti and Aedes albopictusI). It can also be spread through sex in the semen of an infected man, and from a pregnant woman to her fetus. It is possible that the virus can also be spread through a blood transfusion or laboratory exposure. An infected person can pass the virus to a mosquito that can then spread the virus to other people.
Testing and Diagnosis
Testing is done with blood and urine samples. It is performed at the CDC Arbovirus Diagnostic Laboratory, most state health departments, and some commercial laboratories.
Who should be tested:
- Men and women who had potential Zika virus exposure and who have symptoms consistent with Zika virus
- Pregnant women with Zika virus exposure regardless of symptom status. Exposure can be from travel or a partner who has traveled to an affected area
Who should NOT be tested:
- Men and non-pregnant women with Zika exposure but no symptoms
Treat the symptoms of Zika virus by resting, drinking plenty of fluid, and taking tylenol to reduce fever and pain. You should avoid aspirin and ibuprofen as these can be dangerous if you have a similar mosquito borne infection called Dengue fever.
Zika virus during pregnancy can cause microcephaly (when a baby’s head is smaller than expected often with a smaller brain) and other birth defects. These include eye defects, hearing loss, impaired growth. Pregnant women are advised to avoid travel to areas with Zika, and to protect themselves from getting Zika virus during sex if a partner may have been infected. You can find the most up to date information on the CDC website, but at the time of this posting, active transmission of Zika virus has been reported in many countries in the Americas, the Pacific Islands, Cape Verde in Africa, and Singapore in Asia.
There is currently not enough information to know how likely it is that a Zika virus infection will affect a pregnancy, or if a baby will have birth defects when the mother is infected while pregnant.
Transmission of Zika virus through breast milk has not been documented. Benefits of breastfeeding outweigh the possible risk.
Pregnant women should postpone non-essential travel to areas with active Zika virus outbreaks.
In the US these areas include :
- Specific areas in Florida (Wynwood neighborhood in Miami, and a section of Miami Beach, Miami-Dade County)
- Puerto Rico
There are many other countries with active Zika virus transmission including areas of:
- The Americas and Carribbean
- Oceania/Pacific Islands
- Cape Verde in Africa
- Singapore in Asia
Southeast Asia is an area of special consideration as Zika virus has been present for many years with small outbreaks in the past. Many local residents are immune but US travelers may not be immune and can become infected. The level of risk of Zika virus to pregnant women is unknown but likely lower than in areas where Zika virus is newly introduced and spreading widely. Dengue and Japanese encephalitis viruses also circulate widely in Southeast Asia and may give false positive blood test results. Pregnant women without symptoms should not be tested but pregnant women with symptoms of Zika should be offered testing after travelling to these countries.
Click here for the CDC travel guidelines. Below is the updated map, as of November 8, 2016.
Unfortunately there is not yet a vaccine to protect us from the virus. The best way to protect yourself is to prevent mosquito bites.
If you live in area or travel to an area with active Zika virus transmission, follow these recommendations:
- Wear long-sleeved shirts and long pants
- Spray clothing and gear with permethrin.
- Use insect repellent and follow product label instructions. Recommended formulations are DEET (30-35%) and picardin (>20%)
- Stay in locations with air conditioning and screens or mosquito nets
- Protect your home from mosquitos by using water treatment tabs in standing water
- Use condoms or abstain from sex to prevent sexual transmission with an infected male partner
Zika virus in a woman who is not pregnant should not pose a risk for future pregnancies once the virus has cleared. In fact, once a woman is infected with the virus, she is likely protected from a future Zika infection.
The rate of sexual transmission of Zika virus is unknown but it has been reported through male-to-female and female-to-male transmission. The longest reported period between symptom onset and sexual contact that may have transmitted the Zika virus was 32-41 days, though the Zika virus has been deteted in semen up to 69 days after symptom onset.
Attempting pregnancy: These recommendations are based on limited data. Some couples may wish to wait longer or shorter than the recommended period to attempt pregnancy depending on details of exposure, risk tolerance, age, and fertility.
- Men with possible Zika virus exposure who are considering pregnancy should wait at least 6 months after symptom onset or last possible Zika virus exposure.
- Women who have had possible Zika virus exposure and do not have ongoing risks of exposure should wait at least 2 months (8 weeks) from symptom onset or last possible exposure.
- Couples living in or frequently traveling to an area with active Zika virus:
- Men or women who experience symptoms should be tested for Zika virus.
- Men with positive results should wait at least 6 months from symptom onset to attempt pregnancy.
- Women with positive results should wait at least 2 months (8 weeks) from symptom onset to attempt pregnancy.
1. Center for Disease Control. (2016, November). Zika Virus. Retrieved from <https://www.cdc.gov/zika/>
2. American Congress of Obstetricians and Gynecologists. (2016, October). Practice Advisory on Zika Virus. Retrieved from <http://www.acog.org/About-ACOG/News-Room/Practice-Advisories/Practice-Advisory-Interim-Guidance-for-Care-of-Obstetric-Patients-During-a-Zika-Virus-Outbreak>
By Loriana Newman, M.D.
Loriana Newman, MD is an Assistant Professor for the General Division of the Department of Obstetrics and Gynecology at The Ohio State University. She completed her undergraduate degree at Duke University in North Carolina. She received her Medical Degree at the Ohio State University College of Medicine and also completed her Obstetrics and Gynecology residency at Ohio State. Dr. Newman's clinical interests include in office procedures, contraception, well woman care, and prenatal care.