The Olympic Games in Rio de Janeiro, Brazil, have begun amid an ongoing Zika virus pandemic. Now, local cases of the virus have also been identified in Florida, the first such cases in the continental U.S. In the months since the world first learned about Zika virus and the increased risk of microcephaly, a rare but devastating birth defect, among babies born to mothers infected with the virus during pregnancy, the scientific community has been racing to learn more about the virus, and to help protect people, especially women who are pregnant or trying to conceive, from infection.
While a Zika virus outbreak in Canada is extremely unlikely, neither species of mosquito that transmits the virus can survive in Canada’s cool climate. We asked Dr. Allison McGeer, Director of Infection Control at Mount Sinai Hospital, and Dr. Kellie Murphy, a maternal-fetal medicine specialist at Mount Sinai, to share an update on the latest information about the Zika virus. Here’s what they told us.
1) Zika virus is transmitted primarily by the Aedes species of mosquito including the earliest- known culprit, the Aedes aegypti, and the Aedes albopictus, which has been confirmed more recently. Primarily daytime-biting mosquitos, the Aedes species of mosquito flourish in much of South and Central America and the lower United States, as well as other tropical and subtropical areas. They prefer to bite humans, and typically lay their eggs in and near standing water in things like buckets, bowls, animal dishes, flower pots and vases.
2) Eight in 10 people who contract the Zika virus have mild or no symptoms and most who get it won’t even know they’ve had it. For those who do experience symptoms, the effects of the virus are mild and may include fever, joint pain, rash, red eyes and muscle weakness.
3) The greatest potential risk seems to be for pregnant women and their unborn babies or couples trying to conceive because Zika virus infection in pregnant women can result in the development of microcephaly, and possibly other birth defects, in their unborn babies. Microcephaly is a rare but potentially severe birth defect that results in a baby’s head being demonstrably smaller than average, often restricting proper brain development and leading to long-term disabilities. Because the virus can be sexually transmitted, the Centers for Disease Control encourage partners who have traveled to Zika-affected areas to use condoms or abstain from sex for the remainder of the pregnancy or to wait at least eight weeks before attempting to conceive.
4) If you are pregnant or trying to conceive, avoid traveling to an affected region or at least carefully weigh the risks of travel against the benefits. For expectant mothers or couples trying to conceive, the potential consequences of infection are great. A baby born with severe microcephaly who survives past infancy may be severely disabled, requiring intense and costly care for the rest of its life. For this reason, women who are pregnant or couples trying to conceive are highly encouraged to refrain from travel to affected areas at least until researchers and public health officials have had more time to learn about the virus and the risk of birth defects after infection during pregnancy.
5) If you must travel to an affected region, take every precaution to prevent mosquito bites. Use DEET bug repellant at all times of day, wear long sleeves and long pants in light colours and stay indoors in air conditioned environments or in spaces with well-maintained screens on all windows and doors.
6) If you return from an affected area and have active symptoms consistent with Zika infection, see your doctor immediately. Unfortunately, we currently do not have an accurate blood test to determine whether an individual has been exposed to the Zika virus in the past. However, those with active symptoms can be given a PCR test to confirm whether the infection is in fact the Zika virus. While it is also possible to test amniotic fluid with the PCR test, Drs. Murphy and McGeer discourage women from pursuing this testing because of the risk the amniocentesis poses to the baby. Instead, doctors are currently recommending that the baby should be carefully monitored via ultrasound every 4 weeks to ensure its head is developing in proper proportion to the rest of its body.
7) Stay informed by visiting the Centers for Disease Control or Public Health Canada for the latest updates, travel advisories and recommendations. Information continues to evolve rapidly as scientists and public health officials work feverishly to understand the virus and its effects.