The first documented case of female-to-male sexual transmission of the Zika virus was reported simultaneously Friday by health officials in New York City and scientists at the Centers for Disease Control and Prevention.
The new details add another dimension to the expanding catalog of data on the emerging Zika virus, an infectious agent that was barely known in this country a year ago. The woman’s case was announced during a news conference in Manhattan by officials with the New York City health department and in the current issue of the Morbidity and Mortality Weekly Report, a CDC publication.
Federal medical investigators collaborated with city health officials to confirm the mode of viral transmission, and their resulting scientific report reads almost like a daily diary covering the woman’s own Zika viral illness; its effect on her menstrual cycle; her sexual encounter, and the eventual Zika infection of her male partner.
The report emphasized that the case “represents the first reported occurrence of female-to-male transmission” and suggests that sex may be a more frequent mode of spread than previously thought.
“The timing and sequence of events support female-to-male Zika virus transmission,” the infectious disease experts wrote in their collaborative report. The woman was identified only as nonpregnant, in her 20s and having engaged in unprotected sex shortly after returning from a region of the world where the virus is flourishing.
Basing their report on interviews with the woman, public health investigators were able to learn that she was experiencing a range of classic Zika symptoms immediately after returning home: fever, fatigue, rash, joint pains and numbness in her hands and feet. She also told public health investigators that her menstrual cycle had just begun and that it was heavier than usual. Three days after returning to New York, the woman sought professional medical care and tests revealed the presence of viral genetic material in her blood and urine.
The woman’s sex partner developed a Zika viral infection about a week later.
Sen. Chuck Schumer said New York’s first female-to-male case of Zika virus transmission added another reason why federal funding was needed. Even though Congress recessed earlier this week, Schumer said lawmakers should return to Washington because the new report suggested broader modes of transmission. He wants Congress to pass a $1.9 billion Zika emergency funding measure to combat the virus.
Dr. Sunil Sood, an expert in infectious diseases at Northwell Health’s Southside Hospital in Bay Shore, said there was no question that Zika could be viewed as a sexually transmitted disease.
“We already knew it was transmitted male-to-female, so it was biologically plausible that it could be transmitted female-to-male,” said Sood, a professor of pediatrics and family medicine at Hofstra School of Medicine.
Though the case is not surprising from a medical standpoint, he said, it does bolster the public’s understanding of the virus and viral transmission beyond mosquitoes.
“Anytime when there is more blood involved, the risk of infection increases,” Sood said, referring to the woman’s menses.