Zika Sexual Transmission Jolts Public Health Message

February 3rd, 2016

By Gary Evans, Senior Staff Writer

It was not entirely unexpected that emerging Zika virus could transmit sexually -- as it has now done in the first case acquired in the U.S. – but it jolts a public health narrative that was primarily focused on mosquitoes, pregnancy and birth defects.

The case was reported Feb. 2 in Dallas, as a person who apparently acquired the virus in Venezuela transmitted it to a sex partner upon return to the U.S. The partner reported illness despite not having left the country and residing in an area where mosquito transmission has not been reported. On the same day the Dallas County Health and Human Services (DCHHS) department received confirmation from the Centers for Disease Control and Prevention of a second Zika virus case, “an ill individual” who had “recently traveled to Venezuela and was diagnosed with the virus upon returning to Dallas County.” Citing medical confidentiality, health officials gave no other details.

Playing catch-up in a manner similar to the first case of Ebola transmission in the U.S. – which bizarrely also occurred in Dallas – the CDC is now reportedly emphasizing condom use while working on more detailed guidelines to prevent sexual transmission. A CDC statement reported by CNN said, “Sexual partners can protect each other by using condoms to prevent spreading sexually transmitted infections. People who have Zika virus infection can protect others by preventing additional mosquito bites."

Prior to the Dallas case, Anne Schuchat, MD, principal deputy director of the CDC, said at a Jan. 28 press conference, “There is one reported case of Zika virus through possible sexual transmission. In another case, Zika virus was found in semen two weeks after a man had Zika virus infection. That gives you the plausibility of spread, but the science is clear to date that Zika virus is primarily transmitted to people through the bite of an infected mosquito.”

Zika virus is thought to clear from the blood within about a week of infection, but how long it can survive in semen is currently unknown and under study. As a practical matter, that means it is unclear how long men returning from Zika epidemic sites south of the U.S. border should practice safe sex. Presumably some time range or testing protocol will be forthcoming in updated CDC guidelines. As of this posting on Feb. 3, the CDC frequently-asked-questions Zika website did not list sex as an answer on how the virus is transmitted.

On the other hand, the UK National Health Service listed specific advice on Zika sexual transmission before the U.S. case occurred, recommending these answers to the following questions.

I am trying to get pregnant and have visited a country where there is an ongoing Zika virus outbreak. What should I do?

If you have experienced Zika symptoms either during or within two weeks of returning home it is recommended that you wait at least six months after full recovery before you try to conceive. Even if you have not been unwell, it is recommended that you wait at least 28 days after you return home from a country where there is an ongoing Zika virus outbreak before you try to conceive.

My partner has visited a country where there is an ongoing Zika virus outbreak. What should I do?

Sexual transmission of Zika virus has occurred in a small number of cases, but the risk of sexual transmission of Zika virus is thought to be very low. If your partner has travelled to a country where there is an ongoing Zika virus outbreak, condom use is advised:

• for 28 days after his return home if he had no Zika symptoms
• for six months following recovery if he experienced Zika symptoms or a Zika virus infection has been confirmed by a doctor.

AHC Media is dedicated to covering developments in this ongoing story. In addition to breaking news on our homepage, the cover story of April ED Management outlines what hospitals need to do to prepare for a potential outbreak. The March issue of Hospital Infection Control & Prevention contains a trio of stories examining the latest Zika developments, including combating the spread of the virus via sexual transmission. Additionally, the March issue of Hospital Employee Health contains a story about protecting pregnant healthcare workers from contracting the virus.