Clinicians Warn That Zika Virus May Still Be an Area of Concern for Travelers

Infectious disease experts from Emory University School of Medicine recommend that patients contemplating travel to Zika-affected areas consult with their care providers regarding travel plans and potential Zika virus testing.

In spite of the public’s willingness to disregard the threat posed by Zika virus, the Centers for Disease Control and Prevention, as well as Daniel S. Graciaa, MD, MPH, from Emory University School of Medicine, Atlanta, Georgia, and his team of vaccination specialists, still advise against pregnant women traveling to Zika-affected areas. They also advise against attempted conception within 2 months or 6 months of traveling to Zika regions for women and men, respectively, according to an opinion article published in the Annals of Internal Medicine.

The clinicians acknowledge that recent data suggest men may be clear of the disease before reaching the 6-month threshold. The trouble, Dr Graciaa says, is that these moratoria may be unrealistic for many travelers. There are, as the current opinion article recognizes, many couples who have time-sensitive considerations with regard to family planning and so, in the absence of disease symptoms, are not dissuaded from conception. There are also people for whom the necessity of regular travel means that they are never outside of Zika-affected regions for more than 6 months (or 2 months for women).

Because of the prevalence of travel to affected areas and the fact that up to 80% of people infected by the virus never show symptoms, the researchers believe testing and surveillance efforts are of paramount importance.

Caution in testing, however, has been shown. The Centers for Disease Control and Prevention eliminated the routine testing of asymptomatic pregnant women because of the decrease in the disease’s prevalence and an increased likelihood of false-positive test results. Even with this removal of testing recommendations for pregnant women, Dr Graciaa and colleagues report that his practice “receives frequent requests for pre-conception Zika testing from asymptomatic nonpregnant travelers.” None of the assays developed for Zika have been validated in cases in which patients show no disease symptoms, making such testing not only useless but also unnecessarily distressing for patients showing what could be a false-positive.

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“Until the risk for Zika can be further mitigated by vaccination or improved vector control, enhanced surveillance and diagnostic test validation must underpin the tools used in shared decision making with travelers to Zika-affected areas while incidence is decreasing yet unpredictable,” Dr Graciaa and colleagues stated.


Graciaa DS, Collins MH, Wu HM. Zika in 2018: Advising travelers amid changing incidence [published online July 16, 2018]. Ann Intern Med. doi: 10.7326/M18-1112