Zika virus is the latest pandemic making its unwelcome appearance on the world stage. Transmitted primarily by the Aedes aegypti mosquito, a species of daytime-biting mosquitoes that flourishes in much of South America and the lower United States, the Zika virus has the potential to spread across much of the Americas. Since the Zika virus outbreak in Brazil was announced, reports have left many of us feeling confused and frightened about the reach, severity and potential effects of the outbreak – particularly what seems to be an increased risk of microcephaly, a rare but devastating birth defect, among babies born to mothers who were infected with the virus during pregnancy.
To help provide clarity, 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 the most important information Canadians should know about the Zika virus. Here’s what we learned.
1) For most people, the Zika virus has mild or no symptoms– and most who get it won’t even know they’ve had it. Eight in 10 people who contract the virus while travelling won’t experience symptoms and are unlikely to realize they’ve been infected. 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.
2) The greatest potential risk seems to be for pregnant women and their unborn babies or couples trying to conceive. Though it has not yet been scientifically validated, it appears that there may be a connection between Zika virus infection in pregnant women and the development of microcephaly in her unborn baby. 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 has been sexually transmitted on at least two occasions, a male partner who has been infected while travelling could potentially infect his partner. For this reason, 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 four to six weeks before attempting to conceive.
3) A Zika virus outbreak in Canada is extremely unlikely. The species of mosquito that transmits the virus cannot survive in Canada’s cool climate. As a result, the risk of new, active cases in Canada is very low.
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. As Dr. McGeer says, we rarely make rational decisions about risk. For example, travellers are much more likely to be injured in a road traffic accident than they are to contract Zika virus. And yet, for expectant mothers or women trying to conceive, the potential risks 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 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 its connection to what appears to be a rising incidence of microcephaly.
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 aware of the latest news and recommendations about the Zika virus. Very little is known for certain about the Zika virus, but information is likely to continue evolving rapidly as scientists and public health officials work feverishly to understand the virus and its effects. Stay informed by visiting the Centers for Disease Control or Public Health Canada for the latest updates, travel advisories and recommendations.