Q: What is the Zika virus?
A: Zika virus is a mosquito-borne virus that is a member of the Flavivirus group. This group includes several other viruses that cause serious, sometimes life-threatening diseases such as yellow fever, dengue fever, West Nile and Japanese encephalitis.
Zika virus has been known for decades to circulate in Africa, and Asia and more recently in the Pacific Islands, but very few cases of human disease were documented before 2007. In May of 2015, the first infections were confirmed in Brazil. Since then, the Brazilian government estimates that more than 1 million people have been infected with Zika virus. Zika is now confirmed to be circulating in more than 40 countries and territories in the Americas, including Mexico and now the U.S.
Q: What are the symptoms of Zika virus?
A: In children and adults, Zika virus infection is generally mild - some develop flu-like symptoms, joint pain, eye inflammation and red rashes, while other people may not have any symptoms. In some cases, infection is associated with serious complications, including Guillain-Barre syndrome, a disorder where the immune system attacks the peripheral nerves and eventually causes paralysis. There is currently no vaccine to prevent Zika disease nor are there any treatments to resolve disease symptoms.
Q: Where in the Americas has Zika virus been identified?
A: According to the Centers for Disease Control and Prevention, active Zika virus transmission has been reported in more than 50 countries in the Americas and the Pacific Islands. In the mainland United States, locally acquired cases have been reported in Florida and Texas (as of Jan. 2017); locally acquired cases have also been reported in the territories of American Samoa, Puerto Rico and the U.S. Virgin Islands.
For the latest information, visit the CDC reporting page at http://www.cdc.gov/zika/geo/united-states.html.
It is likely that more cases of Zika virus disease will occur locally in regions of the U.S. inhabited by the mosquito believed to be responsible for spreading the virus in most parts of Latin America and the Caribbean, Aedes aegypti . The southern U.S. is infested with this mosquito and therefore is at risk for local transmission of Zika in a manner similar to dengue and chikungunya viruses. Aedes albopictus has also been implicated in Zika virus transmission in Africa and occurs further north in the eastern U.S.
Q: What is the link between Zika and microcephaly?
A: Microcephaly is a neurological condition where a baby is born with an abnormally small head because his or her brain did not develop correctly. Children born with microcephaly after congenital Zika virus infection will likely have lifelong mental retardation and other impairments. Although many infected fetuses die during pregnancy, many first babies affected by congenital Zika virus infection have now survived for nearly
one year after birth.
There have been reports in Brazil and other countries of microcephaly and other brain abnormalities in babies of mothers who had been exposed to the Zika virus, and Zika virus has been detected in the amniotic fluid and tissues of several fetuses. Although the link between Zika virus and microcephaly is very strong, the exact risk of microcephaly is not certain; estimates that a fetus infected during pregnancy will develop fetal microcephaly range from 1-19% depending on the time of infection and other factors. The CDC suggests that pregnant women in any trimester should consider postponing travel to regions where the Zika virus is active, including the region of Miami where local mosquito-borne infections have been detected. And women trying to become pregnant should consult with their doctor or health care provider before travel to those regions.
You can find CDC guidance for pregnant women at http://www.cdc.gov/zika/pregnancy/index.html
Q: What is recommended for pregnant women at risk of Zika?
A: Women who are pregnant or are considering becoming pregnant should talk to their obstetrician and make sure they are familiar with the latest guidance from the CDC. This is particularly important if there has been recent travel to countries or areas affected by Zika virus, or for woman living in areas where Zika is present. Keep in mind that the virus is spreading rapidly so the list of countries affected may not reflect the current distribution due to the inherent lag in diagnostic testing and reporting. CDC’s current information on travel to affected countries and areas can be found at http://www.cdc.gov/zika/geo/index.html. Infected men can transmit to women through sexual contact so the safest approach is for pregnant women with a potentially exposed partner to abstain from intercourse during pregnancy. If abstinence is not an option, then the use of condoms is recommended. Although we do not know for sure with Zika virus due to our lack of experience with this infection, condom use probably nearly eliminates the risk of sexual transmission. If you are pregnant or may have sex with a pregnant woman you should consult your health care provider and follow the latest CDC guidance (http://www.cdc.gov/zika/transmission/sexual-transmission.html), which may include diagnostic testing and using protection or abstaining from sex.
Q: What can people do to minimize their risk of becoming infected with Zika virus?
A: Currently no vaccine exists to prevent Zika virus disease. The best prevention is avoiding mosquito bites. If you or someone you know plans on traveling to countries or areas where Zika virus (see map at http://www.cdc.gov/zika/geo/index.html) or other viruses spread by mosquitoes are found, take the following steps:
- When used as directed, insect repellents are safe and effective for everyone, including pregnant and nursing women.
- Most insect repellents can be used on children in proper concentrations. Do not use products containing oil of lemon eucalyptus in children under the age of three years.
- Repellents containing DEET, picaridin, IR3535, and some oil of lemon eucalyptus and para-menthane-diol products provide long lasting protection.
- If you use both sunscreen and insect repellent, apply the sunscreen first and then the repellent.
- Do not spray insect repellent on the skin under your clothing.
- Treat clothing with permethrin or purchase permethrin-impregnated clothing.
- Always follow the label instructions when using insect repellent or sunscreen and especially note recommendations for use on children.
- When weather permits, wear long-sleeved shirts and long pants.
- Use air conditioning or window/door screens to keep mosquitoes out of your home, hotel room or place of work. Remember that the mosquitoes believed to transmit Zika virus bite during the daytime as well as early morning and evening.
- Help reduce the number of mosquitoes inside and outside your home or hotel room by emptying standing water from containers such as flowerpots or buckets.
- If you live in areas inhabited by A. aegypti or A. albopictus, eliminate sources of standing water near your home to reduce populations of these mosquitoes and lower the risk of local Zika virus circulation if you or another traveler returns infected.
Q: What should I do if I was bitten by a mosquito?
A: As of now, the risk of being infected by a mosquito bite in the U.S. is still relatively low. However, the detection of mosquito transmission in new regions may not occur for several weeks after it begins due to lags in diagnostics and surveillance. If disease surveillance points to local transmission, or if you were bitten by a mosquito in a region of the U.S., Latin America or the Caribbean where Zika virus is circulating, you should watch for signs and symptoms of infection.
Q: What should I do if I have symptoms consistent with Zika virus infection (fever, joint pains, rash, red eyes etc.)?
A: You should seek care and advice from your health care provider, and be sure to tell them if you live in or have traveled to a region where Zika virus is known to be circulating. But remember that many other infections can cause indistinguishable signs and symptoms, so do not panic, especially if you have not traveled to an endemic area and are not in a high-risk group (pregnant women or men who could have sex with a pregnant woman). For all other groups, Zika virus causes a mild disease that usually resolves within a few weeks with no known long-term consequences.
Q: What should I do if my sexual partner lives in or just returned from an affected area or had Zika infection?
A: The CDC has issued guidance for these persons (http://www.cdc.gov/zika/transmission/sexual-transmission.html). The rate of virus presence in the semen of infected men is unknown and how long the virus persists in the semen is also not known, so the risks for sexual transmission cannot be estimated. Following is the specific guidance for symptomatic and asymptomatic persons.
Symptomatic patients: For women and men who have been diagnosed with Zika virus or who have symptoms of Zika including fever, rash, joint pain or red eyes after possible exposure to Zika virus, the following is advised:
- Women wait at least 8 weeks after their symptoms first appeared before trying to get pregnant.
- Men wait at least 6 months after their symptoms first appeared to have unprotected sex.
Asymptomatic patients: For men and women who have possible exposure (travel or sexual contact) but no symptoms, wait at least 8 weeks after possible exposure before trying to get pregnant, the following is advised:
- Couples with men who have confirmed Zika or symptoms of Zika should consider using condoms or abstaining from sex for at least 6 months after symptoms begin. This includes men who live in and men who traveled to areas with Zika virus transmission.
- Couples with men who traveled to an area with Zika virus transmission but who did not develop symptoms of Zika should consider using condoms or abstaining from sex for at least 8 weeks after their return in order to minimize risk.
Q: Why does UTMB have special Zika expertise?
A: UTMB Health is uniquely positioned to help understand and address this disease. It serves as home to The World Reference Center for Emerging Viruses and Arboviruses, a collection of more than 6,000 virus strains that accepts any virus suspected of being transmitted by animals or insects for identification and characterization. Most of the existing samples of Zika virus globally are housed in this Reference Center.
UTMB is also home to the Institute for Human Infections and Immunity, where more than 120 faculty are actively engaged in research. The university’s premiere research facility is the Galveston National Laboratory, which includes the largest fully operational Biosafety Level Four laboratory on an academic campus in the U.S. UTMB is also home to the Sealy Center for Vaccine Development, one of the most comprehensive vaccine development centers in the world, whose researchers are investigating new ways to treat infectious diseases of every type, from new strains of influenza to emerging diseases from every corner of the globe (including Zika). UTMB is also a designated World Health Organization Collaborating Center for Vaccine Research, only the second in the Western Hemisphere.
Complementing its considerable research strengths, UTMB features an extensive network of primary and specialty care clinics serving patients near what could be an important zone for the emergence of Zika in North America. Physicians and others health workers in these clinics are already screening patients, have protocols in place aligned with CDC recommendations, and understand as much as is known about the illness. If you have questions or concerns, contact a UTMB physician.