Laura Riley, MD, medical director of Labor and Delivery at Massachusetts General Hospital, and a specialist in pregnancy complications related to infectious diseases, answers frequently asked questions about the Zika virus.
What is Zika?
Zika is a mosquito-transmitted infection sharing biologic similarity to dengue, yellow fever and the West Nile virus – even though its clinical picture is generally more mild. It was first discovered in Uganda’s Zika Forest in 1947 and has always been common in places like Africa and Asia. It wasn’t until recently that we began to see widespread reports of the virus in the Western Hemisphere – first in Brazil and now throughout Central and South America and the Caribbean. In Brazil, the rise in Zika infection has been associated with an increase in babies born with microcephaly – a birth defect resulting in abnormally small heads and stunted brain development – although cause and effect between the two observations has not yet been proven.
How is it spread?
Zika is spread through the bite of an infected mosquito. Although transmission through mosquitoes is by far the most common route of transmission, there have now been at least three reported cases of Zika being transmitted sexually. Given these reports and the risks of Zika in pregnancy, the Centers for Disease Control and Prevention does now recommend men who may be at risk for Zika use condoms if their partners are pregnant (throughout the entire pregnancy) or abstain from sex altogether.
How is Zika virus detected – and is there a cure?
About 80 percent of people infected with Zika never develop any symptoms. Some people may experience a rash, fever, joint pain or red eyes. There is no vaccine to prevent Zika and no cure. Blood testing for evidence of infection is now recommended for all pregnant women who either live or have traveled to an area where Zika transmission has been reported. This testing is recommended whether or not a pregnant woman has had symptoms of the virus. Additional testing using ultrasound to detect microcephaly will be recommended in many of these women as well. Testing for people who are not pregnant is generally not recommended.
If you are pregnant or planning a pregnancy, your best bet is to again avoid areas where Zika transmission has been reported.
Who is most at risk?
Because of an association between Zika virus infections and birth defects, pregnant women or women who are trying to become pregnant should avoid areas where Zika transmission has been reported. Even women who are not planning to become pregnant should be cautious, as about half of all pregnancies are unintended. We advise strict use of birth control if you are planning to visit a Zika-affected country to ensure you don’t get pregnant while at risk for infection.
What is the best way to protect yourself?
If you are pregnant or planning a pregnancy, your best bet is to again avoid areas where Zika transmission has been reported. Those who do decide to travel to areas in which mosquitoes carry Zika can protect themselves by taking steps to prevent mosquito bites. Use insect repellent, wear long-sleeved shirts and pants and stay in places with air conditioning or with window and door screens. DEET is safe to use in pregnancy and pregnant women can choose this or another EPA-registered insect repellent and use it according to the product label.
This story first appeared in MGH Hotline.