Study: Risk of Zika infection through sex may last only 1 month

NEW YORK — Signs of Zika infection can be seen in semen for as long as nine months, but the risk of sexual transmission appears to end in one month, according to a study published Wednesday.

The study suggests health officials have been overly cautious in advising couples to abstain from sex or to use condoms for at least six months after a male partner comes down with Zika.

The study’s lead author, Dr. Paul Mead of the U.S. Centers for Disease Control and Prevention, said the results are spurring work on new and better recommendations. But he said the study itself is not enough to change current guidelines yet.

The study was published online Wednesday by the New England Journal of Medicine.

Zika infections swept across Latin America and the Caribbean in 2015 and 2016, with a few very small outbreaks in the southern United States. The virus is mainly spread by tropical mosquitoes. But during the epidemic, scientists discovered some infections were spread through sex — in most cases by men infecting their partners.

In the U.S., 52 reported Zika cases have been attributed to sexual transmission, according to the CDC.

Most people infected with Zika don’t get sick, while some suffer a mild illness with fever, rash and joint pain.

But infection during pregnancy can cause devastating birth defects, including microcephaly, in which a baby’s skull is much smaller than expected because the brain hasn’t developed properly.

In the new study, health officials looked at semen and urine samples from about 180 U.S. men who were infected with Zika and developed symptoms.