Recent studies from Brazil and Colombia have found that women appear significantly more likely to be infected by the Zika virus than men — a disparity that some scientists believe indicates that sexual transmission of the disease is far more common than previously thought. A study of men and women in Rio de Janeiro, released in May, found that women were 60 percent more likely to be infected with Zika — a figure that led Vargas Foundation biostatistician Flavio C. Coelho, the lead author of the study, to conclude that sexual transmission “was the most probable cause.”
Scientists such as Donald A. Berry, lead biostatistician at the University of Texas M.D. Anderson Cancer Center, have disputed those results, arguing that women’s fear of the disease means that many more women are asking to be tested for Zika than men. But another study from Columbia, published last month in The New England Journal of Medicine, found that although young boys and girls contract Zika at roughly the same rates, rates in girls rose significantly after age 15. And while women ages 25 to 29 were more than three times as likely as men to contract Zika, in men and women over the age of 65 infection rates were once again balanced.
The “most intriguing difference” in the study’s results, according to Margaret A. Honein, an author of the Columbia study and chief of the Centers for Disease Control and Prevention’s birth defects branch, was that women aged 45 to 64 were still nearly twice as likely as men to be infected. These women, Honein suggested, would likely not be worried about pregnancy or fetal damage and so would have no special reason to seek out Zika testing.
Read the full story at The New York Times.