It was only Monday that the exploding Zika outbreak was declared a global public health emergency by the World Health Organization (WHO), and now reports have surfaced of a rare case of sexual transmission of the virus in Texas. While there have been other cases in the country, this marks the first time that an infection has been contracted on mainland U.S., and only the second documented case of sexual transmission, the Guardian reports.
According to the BBC, the individual had not traveled to any Zika areas but became infected after their partner returned from a trip to Venezuela, a country accused of vastly underestimating cases of infection. As a known mosquito-borne disease, it’s likely that the partner became infected after being bitten and then passed on the virus through unprotected sex.
After developing flu-like symptoms, the individual sought medical advice and, upon learning the partner’s travel history, was sent for diagnostic tests. The Centers for Disease Control and Prevention (CDC) then confirmed that the patient was indeed infected with Zika. Prior to this, there had only been one possible case of sexual transmission reported, although the virus had also been found in the semen of one other infected man.
Since Zika is predominantly spread by the Aedes aegypti mosquito, which also transmits dengue, yellow fever, and chikungunya, as a precautionary measure officials screened the insects around the affected couple’s home but did not find this particular species.
If Zika is ultimately confirmed to be a sexually transmitted disease, then this could mean that the situation is worse than previously thought. While an international public health issue, it was at least limited to countries in which the Aedes aegypti mosquito is found. Although travelers can obviously bring the virus to other countries, it was thought unlikely to spread further in the absence of these vectors.
The CDC has yet to issue further advice on avoiding sexual transmission, but condoms are an effective way to prevent the spread of any sexually transmitted infections. In addition, people in affected areas should avoid mosquito bites by using insect repellant, wearing long clothing where possible, and sleeping under bed nets.
It’s important to note that while this does potentially suggest that Zika could spread faster and further than previously believed, for the vast majority of people infections are extremely mild and symptomless. Although there have been documented cases of a rare neurological condition being associated with infection, Guillain-Barré syndrome, the major concern is for those who are pregnant. Infection is strongly associated with a birth defect called microcephaly, in which babies are born with abnormally small heads, so pregnant women are advised against travel to infected areas.