Tuesday, 18 December, 2018

Zika birth defects have increased twenty-fold — CDC

Melissa Porter | 03 March, 2017, 02:19

Pregnancies of women in the United States infected with the Zika virus are about 20 times more likely to result in babies with certain birth defects compared with the prevalence of these birth defects before the Zika epidemic swept through the Americas, according to a report released Thursday.

A year ago the World Health Organization declared a Public Health Emergency of International Concern because of the rapid pace with which the virus was spreading and the alarming number of cases of microcephaly seen in Brazil where large numbers of women had been infected.

"This study shows the importance of keeping a birth defect registry", says Dr. Peggy Honein, Epidemiologist at the National Center on Birth Defects and Developmental Disabilities, CDC. The finding strengthens the evidence that a mother's Zika infection during pregnancy raises her baby's risk of microcephaly and other brain malformations. The rate for the pre-Zika period is for live births while the rate for 2016 represents completed pregnancies. According to the report, three of 1,000 infants born in 2013 to 2014-before Zika hit US shores-were found to have brain abnormalities, microcephaly, neural tube defects or other complications of the central nervous system and the eyes. In Washington, D.C., the District's public-health lab has produced erroneous or inconclusive results for nine, and perhaps more, pregnant women who were tested for Zika between July and December of a year ago.

They compared this with published rates of infants from a 2016 U.S. Zika registry and found the rates of these same birth defects were 20 times higher, occurring in almost 60 of every 1,000 completed pregnancies with Zika infections.

"You'll see there's over 1,500 pregnant women in the 50 USA states and D.C. with lab evidence of possible Zika virus infection and more than 50 fetuses and infants that have had one of these Zika-related birth defects", she said.

On the heels of a new study from the Centers for Disease Control and Prevention showing that Zika has increased the rate of birth defects in the United States, Florida health officials on Thursday reported three more cases of the virus that were locally acquired in Miami-Dade - two infections dating to October 2016 and the first one of 2017. Brain abnormalities, including microcephaly, were the most common conditions reported. Maternal age was similar across birth defect categories.

She said pregnant women should not travel to areas where Zika virus transmission and they should also avoid sexual contact with partners who have traveled to areas with Zika virus transmission.

Dr. Janet Cragan, a medical officer in the birth defects branch of the CDC, noted that in this report the investigators only looked at the physical abnormalities present at birth.