Zika virus: How concerned should we be?


February 2, 2016

Pregnant women should be cautious about travel plans. But there’s no reason to fear Zika virus.


The Ebola fear of 2014 is an important point to remember as we monitor the global public health threat of the Zika virus, which is spreading in South and Central America and prompting international advisories.

“We don’t want to create a Zika scare, an anxiety epidemic, the way there was an Ebola anxiety epidemic,” said William Schaffner, M.D., professor of Preventive Medicine at Vanderbilt University Medical Center.

On Monday, the World Health Organization declared the Zika virus a “public health emergency of international concern.” Transmitted mostly by Aedes aegypti mosquitoes, the virus causes mild, relatively fleeting illness in most people who are infected. But it has been associated with birth defects, particularly microcephaly (abnormal smallness of the head), in newborns of pregnant women who have the virus. The pattern is so strong that travel advisories have been issued and some Latin American counties have advised women to delay getting pregnant.

Schaffner does not anticipate widespread transmissions in the United States, but said we should expect bursts or clusters of “introductions,” meaning reported cases in the United States as people travel, are infected elsewhere and become sick after entering the U.S.

Until this week, there had been no cases contracted in the continental United States, only cases involving travelers who acquired the virus elsewhere becoming sick here. But on Tuesday, the Dallas County Health and Human Services in Texas released a statement that the U.S. Centers for Disease Control and Prevention had confirmed the first Zika virus case acquired through sexual transmission in Dallas County in 2016. Previous discussion among public health officials of sexual transmission of the illness turned to confirmation as a Texas patient was infected after having sexual contact with a someone who was ill and had just returned from a country with a Zika outbreak.

The Zika virus is mostly transmitted through mosquito bites. It can also be spread, rarely, from mother to child, and its transmission has also been reported through infected blood and sexual contact, as cited by the CDC.

Back home in the Southern U.S., we should keep the following in mind, Schaffner said:

  • If you are pregnant or considering becoming pregnant, weigh your travel plans carefully. As of Wednesday, the CDC has mapped 28 countries and territories with active transmission. The United States is not among them. Pregnant women are advised to avoid travel to active transmission areas. If they must travel to one, the CDC recommends talking with their physicians first and following the CDC’s steps for avoiding mosquito bites. Another change pregnant women will see here at home: The CDC is working closely with the American College of Obstetricians and Gynecologists, Schaffner said, to educate physicians about the Zika virus and what to ask patients.
  • Educate yourself with credible news reports about the Zika virus, but not in a passive way. Read actively and understand the nuances of the reports. Issues can be subtle and information will change quickly as public health officials adjust to new cases in new areas. The New York Times is a daily must-read for Schaffner, an often-quoted infectious disease specialist. The Centers for Disease Control and Prevention website is a good source, Schaffner said.
  • Understand that U.S. living conditions and our public health system are more developed than the countries where the virus is spreading. That makes us less vulnerable. “We spend a lot of time indoors in air conditioning, away from mosquitoes,” Schaffner said. “Most of us live in homes that are enclosed and have windows.” That is not the case for some of the countries where the virus is spreading. The world is too small for us to expect perfection, Schaffner said, but “When it comes to communicable disease control, we really have the best program in the world. None of us are perfect but it’s a really very skilled system in the United States. We can do a good job with this. That’s what I anticipate.”

The CDC cautions that imported cases could result in local spreading of the virus in some areas of the U.S. But Schaffner expects the public health system to do a reasonably good job of detecting people who come into the country with the virus and keeping those infected away from domestic mosquitoes during the time when the virus could be transmitted.

Meanwhile, researchers are working on a vaccine, as public health officials work to track and contain the spread. As for the public, “We should be interested, we should follow the news, we should become informed, but I don’t think we have to become anxious,” Schaffner said.