Kateryna Kon/ShutterstockThe Zika virus, first identified in Uganda in the late 1940s, started out as a mosquito-borne illness that caused minimal and short-lived symptoms in its sufferers. (Here are other mosquito-born diseases you need to know about ASAP.) The virus took its sweet time spreading around the world, mutating along the way. Now it comes to American shores with a nasty new trick: It can be transmitted through sexual contact.
“Scientists are just gobsmacked by the virus’ sexual transmission,” New York Times reporter Donald G. McNeil Jr. told NPR, soon after the World Health Organization predicted that the United States was about to be hit hard by Zika. “Viruses mutate like crazy, but one thing they don’t normally change is how they’re transmitted. You don’t expect a mosquito-borne virus to become something that can be transmitted through an act of unprotected sex. But this one is.”
In people carrying the virus, Zika turns up in multiple bodily fluids—including semen and vaginal secretions, says Aileen M. Marty, MD, FCAP. Dr. Marty is the director of the Florida International University Health Travel Medicine Program and professor of Infectious Diseases at the Herbert Wertheim College of Medicine. “Sexual transmission is primarily via semen,” she explained, “but it’s been transmitted from women to men as well when a woman with Zika virus was undergoing her menstrual period. In addition, the Zika virus can be found in vaginal secretions, so it is also theoretically possible to transmit Zika from women to men in this way.”
Further, Dr. Marty points out that it is “well-documented that persons who were totally unaware of their Zika infections have transmitted Zika to others sexually.” In fact, only one in every five patients who contracts the virus even exhibits symptoms, says Gary Mazer, MD, director of emergency management and employee health services at New York City’s CityMD. And even those who exhibit symptoms—fever, joint pain, red eyes, and rash—may either ignore those symptoms or misattribute them to flu.
Accordingly, Zika has the potential to spread widely. In fact, as of today, Zika has been reported in every state in the U.S. except for one, according to Edward McCabe, MD, former Chief Medical Officer of the March of Dimes. This is of particular concern to Dr. McCabe and the March of Dimes because although Zika virus does not usually cause serious or long-lasting symptoms in its sufferers, it is associated with serious and life-threatening birth defects in babies born to pregnant women infected by the virus, including microcephaly (in which the baby is born with an abnormally tiny head) and may be linked to Guillain-Barré syndrome, a neurological syndrome that can cause paralysis.
Given the silent but insidious nature of Zika, couples of child-bearing age should adhere to safe sex practices even if they do not believe they are experiencing symptoms. This means, according to Dr. Mazer, either “abstaining from sex or consistently using latex condoms, from start to finish, every time they engage in vaginal, oral or anal intercourse.” In addition, Dr. Mazer advises that men and women who have traveled to a Zika endemic area should avoid pregnancy for eight weeks upon returning home if they are asymptomatic and for six months if they are symptomatic. Dr. Marty also advises the use of dental dams and avoiding sharing sex toys.
Something we need to stress, says Dr. McCabe, is that “Zika is not going away, and much more needs to be done to protect women and their babies from the devastating birth defects caused by the Zika virus. The March of Dimes hopes to see vaccine development, public health education and the provision of services to affected children and their families and is working to to pass legislation to do so.”