Why men need to worry about Zika virus

Story highlights

  • Zika virus lives in semen for an unknown period of time
  • A man infected with Zika could potentially infect his sexual partner
  • And he could put unborn baby at risk for a birth defect, experts say

(CNN)Watching the news, Dr. William Schaffner wanted to reach into his television set and give soccer player Hope Solo this message: "You have it all backward!"

He heard last week that Solo said she wouldn't compete at the 2016 Olympics in Brazil if the games were held today because she worried she might contract the Zika virus and, at some point, give birth to a child with health problems.
    "I do not accept being forced into making the decision between competing for my country and sacrificing the potential health of a child, or staying home and giving up my dreams and goals as an athlete," Solo told Sports Illustrated.
    Ex-NFL player Jerramy Stevens congratulates his wife, soccer star Hope Solo, last year.
    The mosquito-borne virus has prompted worldwide concern because of a link to a birth defect and its rapid spread, including in South America.
    "I wanted to tell her she's looking at the wrong side of the coin," said Schaffner, a professor at the Vanderbilt University Medical Center and a member of an advisory panel for the Centers for Disease Control and Prevention. "It's not yourself you should be so worried about -- it's your husband!"
    He explained that as long as Solo isn't pregnant when she's in Brazil, or doesn't get pregnant shortly afterward, she doesn't run the risk of a mosquito bite leading to Zika in a baby.
    But Zika has been found in the semen of infected men -- and it's unknown how long it stays there and over what period of time a man can transmit the virus through sex.
    Other infectious disease experts agree: Reproductively speaking, men -- not women -- have the most reason for concern after visiting a country with a large Zika outbreak.

    Zika and future dads

    If a man were to get Zika through a mosquito bite, he could potentially infect his sexual partner and put their unborn baby at risk for microcephaly, a devastating neurological birth defect linked to the virus.
    And since it's unclear how long Zika lasts in semen, and there's no commercial test available, it's not known how long a man needs to worry about possibly infecting his partner -- and his baby.
    "The fellas clearly have an ongoing problem," Schaffner said.
    Tom Skinner, a CDC spokesman, said the agency hopes to start a study as soon as possible to figure out how long Zika lasts in sperm.
    In the meantime, the CDC advises men who've returned from a Zika-affected area that they might consider abstaining from sex or using condoms for an unspecified period of time.
    Such guidance is hardly conducive to starting a family.
    Schaffner said if Solo, 34, intends to get pregnant soon after the Olympics, she might want to tell her husband, former NFL player Jerramy Stevens, to stay home, no matter how much he might want to be in Brazil to support her.
    "If starting a family is a very high priority for a female athlete -- she's done all this training and now her biological clock is ticking -- then I think given the CDC's recommendations, her husband shouldn't be exposing himself to Zika," Schaffner said.

    Zika and future moms

    A woman only has to worry about transmitting Zika for a finite period of time, experts say.
    She can spread the virus to her unborn baby through her bloodstream, and Zika doesn't last long in blood.
    "We've measured the virus in the blood of people who've been infected, and it usually clears the bloodstream in five to seven days, or 10 days at the most," said Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases.
    The American Congress of Gynecologists and Obstetricians says that "there currently is no evidence that prior Zika virus infection poses a risk of birth defects in future pregnancies."
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    "You clear the infection completely," said Mark Wilson, an epidemiologist at the University of Michigan School of Public Health.
    Wilson noted that contracting Zika while traveling also will help keep the infection away if a woman does get pregnant in the future.
    "Getting infected would give extremely long-lasting immunity," he said. "Since there's no vaccine, this would be the best way to be protected."
    Fauci, Schaffner and Wilson all said they wouldn't hesitate to let their daughters compete in the Olympics -- as long as they didn't get pregnant between now and the games, during the games or for about a month after returning home from Brazil.
    But Schaffner said if his son were competing there in August, he would advise him not to get his wife pregnant afterward until more is known about how long Zika lasts in semen.
    "I'd tell him to be patient until science works out this question," he said.