The first case of Zika virus contracted in the continental U.S. was reported earlier this week, not through mosquito contact, but through sexual contact. After returning to Texas from Venezuela, an infected person apparently transmitted Zika to a partner through sex. The CDC has since issued recommendations for preventing sexual transmission, whether or not pregnancy is involved. Meanwhile, a research team in Brazil has announced that it has detected active Zika virus in both saliva and urine. It’s unclear whether the disease is actually contagious through these routes, but some experts have suggested that pregnant women in affected regions avoid kissing people other than their partners. Whether this is actually necessary remains to be seen.
But the CDC has issued strong recommendations that men with any potential exposure to the virus wear condoms if their partners are pregnant, throughout the course of the pregnancy, or abstain from sex completely. They stress that this includes all kinds of "insertive sex," vaginal, oral or anal. Though the first trimester appears to be the most vulnerable, researchers stress that there's no time during pregnancy that's without cause for concern when it comes to Zika.
"Until we know more, if your male sexual partner has traveled to or lives in an area with active Zika virus transmission, you should abstain from sex or use condoms the right way every time you have vaginal, anal and oral sex for the duration of the pregnancy," warns the CDC.
The virus appears to stay in the blood for about a week, although some estimates suggest it may be longer. After a person has developed antibodies, he or she is apparently immune to the disease going forward, and mosquitoes cannot pick it up from a person who has developed immunity. The best strategy for reducing risk for Zika is to protect yourself from mosquito bites with clothing, screen doors and windows and using an effective mosquito repellent.
For adults, symptoms tend to be mild or even absent, but the virus is thought to be linked to increased risk for microcephaly in the babies of infected mothers. In microcephaly, the baby’s head is smaller than normal because the brain is underdeveloped, which can lead to serious sensory and cognitive problems throughout life.
Also linked to Zika virus in adults has been an increased risk of Guillain-Barré syndrome, which can lead to paralysis. Though this connection is also not well understood, increased instances of Guillain-Barré have been reported in affected areas in El Salvador, Brazil, and French Polynesia. Colombia has just reported three deaths from Zika-related Guillain-Barré syndrome.
The WHO has declared Zika a global emergency, and will funnel research efforts to developing a vaccine and testing for the disease, as well as understanding how the virus spreads and how it is linked to microcephaly and Guillain-Barré. In the meantime, the agencies are recommending people take all precautions when traveling to or from affected countries.
And yesterday, a research team in Brazil has reported that the active virus appears in both urine and saliva, prompting concerns about whether even kissing or sharing cutlery might spread the virus.
Paulo Gadelha, president of the Fiocruz research institute, recommended that pregnant women avoid kissing people other than their partners, and sharing silverware, glasses and plates with anyone who has symptoms. But Gadelha added, "This is not a generalized public health measure, for the love of God.”
Though it's not clear whether the virus can spread from one person to another through saliva or urine, it's raised some concerns, particularly since Carnival has just begun in Brazil, in which kissing strangers is common.
But Thomas Frieden, director of the CDC, stressed in a press conference that the organization simply hasn't issued guidelines on the kissing matter. When pressed about the potential risk of contraction through saliva and urine, he said, "We just have no data to inform that, and we try to stick to the science here at CDC."
The central mode of transmission remains mosquito bites, so protecting oneself from those in affected regions is still key. And though the risk from kissing is much less clear, sexual transmission of Zika now seems possible as well. The science is at least there for that.
For more information on how the virus spreads and the effected regions see the CDC's Zika page, or the WHO's.
