Zika can keep growing in infant brains even after birth

Chubby babies on the decline

NEW YORK, Dec 14, (Agencies): US researchers have found evidence of the Zika virus replicating in fetal brains for up to seven months after the mother became infected with the virus, and they showed the virus can persist even after birth, according to a study published on Tuesday.

The findings confirm earlier observations from case studies suggesting that the mosquitoborne Zika virus can grow in fetal brains and women’s placentas.

“Our findings show that Zika virus can continue to replicate in infants’ brains even after birth, and that the virus can persist in placentas for months — much longer than we expected,” Julu Bhatnagar, lead of the molecular pathology team at CDC’s Infectious Diseases Pathology Branch and the study’s lead author, said in a statement.

The findings help explain how the virus causes devastating birth defects and pregnancy losses even if a woman had only a minor illness. Last month, the World Health Organization declared that Zika no longer constitutes an international emergency, but stressed the need for a long-term effort to address the virus, which has been linked to thousands of birth defects and neurological complications.

For the study, CDC researchers tested tissues from 52 patients with suspected Zika virus infection, including brain tissues from eight infants who had microcephaly and later died. They also tested placental tissues from 44 women — 22 of whom delivered apparently healthy babies and 22 whose pregnancies ended in miscarriage, abortion, stillbirth or who delivered babies with microcephaly. Zika has been shown to cause microcephaly, a rare birth defect in which infants are born with undersized heads and brains, which can cause life-long disability.

The researchers found Zika genetic material in fetal brain tissue and placentas more than seven months after the mothers contracted the virus. In one case, they also found evidence of the virus growing in an infant with microcephaly who died two months after birth.

Of the eight infants who had microcephaly and later died, all tested positive for Zika. The mothers of all eight of these infants contracted Zika during the first trimester of pregnancy, adding to prior evidence that Zika is most dangerous early in pregnancy.

“We don’t know how long the virus can persist, but its persistence could have implications for babies born with microcephaly and for apparently healthy infants whose mothers had Zika during their pregnancies,” said Bhatnagar, whose findings were published in CDC’s Emerging Infectious Diseases journal.

There are no treatments or vaccines for Zika, which previously had been seen causing only mild disease.

A decline in chubby babies and toddlers is providing a glimmer of good news in the fight against childhood obesity.

The trend was found in a study of children up to age 2 enrolled in a US nutrition assistance program for low-income women and children. Half of all US infants up to 12 months old are enrolled in the program.

The rate of youngsters at risk for obesity fell during the study, from almost 15 percent in 2010 to 12 percent overall in 2014, researchers from the federal Centers for Disease Control and Prevention reported Tuesday in the journal Pediatrics.

The rate declined in all ages studied. It was lowest — about 8 percent in 2014 — for the youngest infants, from 3 to 5 months, versus almost 15 percent among toddlers.

The results were unexpected, given rising rates earlier in the decade, said CDC researcher David Freedman, the lead author. “People are thrilled,” he said. Freedman said reasons are uncertain for the decline, but it came amid changes designed to improve nutrition and health in food packages, including more whole grains, fruits and vegetables. Also, breast-feeding among participating women increased in 2009 and that can protect against obesity.

The results echo a reported decline in older children in the program, referred to as WIC for women, infants and children. Also previous CDC data showed a similar decline in all US youngsters from 2 to 5 years old, from about 14 percent in 2004 to 9 percent in 2014, coinciding with national campaigns targeting childhood obesity. Obesity rates tend to be higher in children from low-income families including WIC participants.

Dr David Ludwig, director of obesity prevention at Boston Children’s Hospital, called the results encouraging but said, “It’s too soon to tell whether these new data represent a statistical fluke or evidence of real progress with the pediatric obesity epidemic. “The researchers analyzed WIC survey data from 2000 to 2014 involving almost 17 million infants and young children. Rates increased early on, then remained stable from 2004 to 2010 until the decline.

Doctors don’t usually describe babies as obese, but measure their risk using a weightfor-length ratio. Those with a high ratio, generally heavier than 95 percent of their peers, face an increased chance of becoming obese later on.

Whether the decline has continued is uncertain and the study didn’t track infants to see if they became overweight or obese later on.

According to the CDC, US obesity rates total almost 18 percent among all 6- to 11-year-olds and nearly 21 percent among 12- to 19-yearolds