No doubt you’ve heard plenty about the Zika virus in the news this year. In 2015, Brazil simultaneously experienced an increase in Zika infections and an in the births of babies with microcephaly, a condition in which a baby’s head and brain are smaller than normal. In September 2016, scientists confirmed suspicions that the virus is, in fact, a cause of microcephaly and other birth defects, and the World Health Organization (WHO) declared the virus’ spread and its complications in babies a global health emergency. (Somewhat controversially, the WHO announced that the emergency ended in November.)
Zika virus initially infected non-human primates in Central Africa and was transmitted to humans, by way of mosquitos, in the middle of the 20th century. It was later learned that Zika can also be spread between humans via sexual transmission. Zika’s history mirrors that of human immunodeficiency virus (HIV), which also initially infected only non-human primates in Central Africa and then transmitted to humans in the early part of the 20th century. In the early 1980s, HIV began to rapidly spread among the humans across the world primarily via sexual transmission (though new research has traced its arrival in the United States to even earlier than previously assumed).
Among U.S. states and territories, Puerto Rico has been most affected by Zika. As of November 23, 2016, the total case count in Puerto Rico is now at 31,944 (almost all of which were locally acquired). Florida is thus far the only state in which Zika cases have been acquired locally (i.e., not travel-related, but from local mosquitoes). There have been 950 reported travel-related cases and 232 locally-contracted cases statewide, as of November 22, 2016. To combat the spread of the virus in the region, Florida conducted massive ground and aerial insecticide efforts, albeit amid local protests.
Insecticide does not prevent the spread of disease between humans, though. If the HIV epidemic taught us anything, it’s that there can be dire consequences if we fail to acknowledge and proactively address the sexual transmission of a dangerous illness. “SILENCE = DEATH” was a powerful motto used by the gay community in the mid-1980s and ‘90s to draw attention to the HIV crisis ravaging so many Americans and people around the world. While Zika is not a life-threatening illness for those who contract it, it does have huge implications for pregnancy, childbearing, and infected newborns’ long-term health. A November 22 report from the Centers for Disease Control and Prevention (CDC), for instance, indicated that even Zika-infected babies with normal-sized heads at birth can still exhibit a slowing in head and brain growth and the onset of microcephaly after their delivery.
The first documented sexually transmitted case of Zika in the United States occurred in July 2016 in New York City: a woman who had traveled to a Zika-infected area returned and transmitted the virus to a male partner via condom-less vaginal intercourse. The very next month, an infected but asymptomatic man transmitted the virus to a female partner in Maryland. This case indicated that not all infected individuals may even know they have the virus, and it demonstrated the risks of such a lack of awareness. To date, the CDC has recorded a total of 34 sexually transmitted Zika cases in the United States. (Sexually transmitted cases are not reported for U.S. territories, because it is not possible to determine whether locally transmitted infections occurred from mosquito-borne or sexual transmission.)
Nevertheless, the federal response to this disease has largely focused on preventing infection in pregnant people (and those attempting to become pregnant) rather than in the general public.
The CDC is advising people of reproductive age who are, or hope to become, pregnant soon (as well as their partners) to avoid regions in which there have been mosquito-acquired Zika cases, and individuals who have traveled to these regions and risked exposure are advised to practice safe sex with their partners for 8 weeks following their return. But this guidance is only helpful for citizens who are intentionally planning their pregnancies, and 45 percent of all pregnancies in the United States are unplanned. Given the preponderance of unplanned pregnancies, and our general lack of knowledge about the long-term effects of Zika on babies, it makes sense to spread a message of infection prevention for all people, regardless of their reproductive plans.
William Smith, former executive director of the National Coalition of STD Directors, said he is “frustrated by the lack of focus on Zika as an STD.” CDC-sponsored signs at airports, he pointed out, refer to avoiding bites and wearing mosquito repellent, but don’t show or mention condoms. The implementation of proven public health practices (e.g., safer-sex education and campaigns, increased condom availability) will be critical in curbing sexual transmission of the Zika virus. These practices conveniently align with effective family planning approaches as well, which will be imperative in preventing future cases of microcephaly and other Zika-related birth defects.
Maryjo Oster, PhD, Research Scientist