By Wallace Ransom, MD
If it were not for an unexplained spike in birth defects in Brazil, there’s a good chance that you would never have heard about the Zika virus. Or, if you did, it would from a small article buried deep in your local newspaper or at the bottom of your Internet news feed.
Zika is one a dozen or more viruses carried by Aedes Aegypti mosquito, and one of five considered harmful to humans. Of those five, including Yellow Fever, Malaria, Dengue, and Chikungunya, Zika has, until recently, been considered the least serious. It is the only one of the five with no recorded fatalities. It is also the least painful to the victim.
Even more significant, only about one in five victims of the Zika virus actually suffers any effects at all.
Late last year, however, all of this changed dramatically when scientists in Brazil reported a possible link between microcephaly, a condition that restricts brain development in infants, and Zika. Suddenly, pregnant women were in the cross-hairs not only of Zika, but of the medical establishment and the world media as well.
Brazilian authorities first reported that there were more than 4,000 cases of microcephaly linked to Zika, well above the number of cases reported in most years. On further examination, however, they now say that in many of those cases, the link to Zika was inaccurate. Microcephaly is most often caused by genetic disorders but can also be the result of drug and alcohol abuse on the part of the mother.
The World Health Organization, acting on the information from Brazil, has issued a worldwide warning for the Zika virus, saying, essentially that it is erring on the side of extreme caution.
In Africa, where Zika originated, and in some parts of Southeast Asia, where the virus appeared several years ago, no credible link to microcephaly has been established. Much more telling is that in Colombia, where as many of 25,000 cases of Zika have been reported, there has been no linkage between the virus and microcephaly.
Today, it is almost impossible to avoid the scary news about Zika. Several countries, including Ecuador, have suggested that women postpone pregnancies. The U.S. and European countries are suggesting that pregnant women not travel in Latin America, where the virus is spreading most rapidly. Many headlines suggest all travelers, pregnant or not, delay travel to countries where Zika virus is present. Other headlines scream that Latin America faces a health crisis of gargantuan proportions. Within the past two weeks, scientists in the U.S. and Brazil report that the virus is showing up in the urine, blood and semen of those infected.
In the uproar, common sense is thrown out the window. By late April or May, Zika will appear in the southeastern U.S. and the travel alert for Latin America will seem almost beside the point (will there be a travel ban in the U.S.?). Many viruses, including ones that are relatively benign, show up in bodily fluids, but there is no reporting of this fact. And most important of all, the fact that Zika is not a serious threat to anyone who is not pregnant is hardly mentioned at all. Neither is the fact that, worldwide, fewer than two percent of international travelers are pregnant women.
I do not dismiss the possibility of a link between Zika and microcephaly but, unfortunately, it could be many months, maybe years, before the issue can be definitively decided. Women who are pregnant should take precautions against the virus. Postponing a vacation to areas with large numbers of cases of Zika makes sense.
On the other hand, the prudent, non-pregnant traveler, should not change his or her plans. The world poses many dangers and for most people Zika is a relatively minor one.
Dr. Wallace Ransom is an epidemiologist currently conducting research in Quito. He has worked for the U.S. Centers for Disease Control and Doctors Without Borders