Zika infection in children is typically mild, CDC report finds

Early evidence suggests Zika infection in children typically triggers only mild disease, the Centers for Disease Control and Prevention said Friday.

CDC scientists reported on 158 infections among children in the United States between January 2015 and July of this year; all had contracted the virus during travels outside the country. It’s the biggest study of Zika-infected children in the medical literature.

None of the children died and none developed Guillain-Barré syndrome, a type of progressive paralysis that is generally temporary. There were also no reports of encephalitis or meningitis — inflammation of the brain or the membranes covering it.

Still, doctors should be on the lookout for brain-related side effects, the authors said.

“Although Zika virus disease in children is typically mild, health care providers should be aware of the possibility of serious complications, such as neurologic manifestations, and should report all cases of Zika virus disease to their state or local health department,” they wrote.

The children in the CDC study, published the journal Morbidity and Mortality Weekly Report, ranged from infancy to age 17, though the majority were preteens and teens. Five were pregnant teenagers. The article did not disclose what happened to those pregnancies.

Most of the children had rashes and a little over half had a fever. Conjunctivitis, also known as pink eye, and joint pain occurred in about 30 percent of the cases.

Two young children, ages 1 and 4, were hospitalized, one overnight and one for three days.

Though the data are reassuring, the authors point out some caveats. For one thing, they note the database to which these cases were reported often has missing information. If there were longer-term neurological complications, they would not systematically get reported there, the authors said.

There have been concerns about infection in very young infants, whose brains are still developing. They only make up a small portion of the 158 children the CDC studied: The group included just 16 babies and toddlers aged zero to four years.

In other Zika related news, the CDC announced Friday it is changing its recommendations on preventing sexual transmission of the virus, and specifically sexual transmission in pregnancy.

The agency is advising men who have traveled to a place where Zika is transmitted to wait six months after they return home to try to conceive a child.

Previously the CDC had only recommended the six-month wait for men who had been diagnosed with or had symptoms of  Zika infection.

The recommendation for women is unchanged: Regardless if they were infected or just potentially exposed, they are advised to wait eight weeks before trying to get pregnant.

The differing advice relates to the fact that Zika virus can get into the testicles and linger there. There have been a few reports of men emitting infectious Zika virus in their semen more than three months after recovering from infection, and a test that looks for viral RNA found pieces of the virus in semen from a man 188 days after he got sick.

The World Health Organization’s recommendation is more conservative than the CDC. The organization says both men and women who have been exposed to Zika should wait six months before trying to conceive.