Roughly 1 in 12 infants born to mothers with confirmed Zika virus infection are born with a related birth defect, a Centers for Disease Control and Prevalence (CDC) analysis has concluded.
The sobering findings
were published in the Morbidity and Mortality Weekly Report
) for June 16, 2017.
Of course, research
conducted since the first outbreak of the mosquito-borne virus was reported in Brazil in 2014 has linked the disease with birth defects such as microcephaly and various neurological deficits during early infancy. The problems are particularly acute among infants born to mothers infected with Zika during the first trimester of pregnancy.
For the CDC study, researchers at the agency abstracted data from its Zika pregnancy and infant registries collected between January 1, 2016 and April 25, 2017. They focused on completed pregnancies involving mothers with laboratory evidence of recent possible Zika virus infection and a subset with positive nucleic acid tests (NAT) confirming Zika virus infection (NAT-confirmed).
The authors analyzed the registries and identified fetuses and/or infants with birth defects meeting the CDC Zika surveillance criteria and classified them into 2 distinct categories: with one encompassing those with “brain abnormalities and/or microcephaly and the other including those with neural tube defects, eye abnormalities, or consequences of central nervous system dysfunction among fetuses or infants without evidence of other brain abnormalities or microcephaly.”
In all, 3930 pregnancies in US territories with laboratory evidence of recent possible Zika infection were reported to the registries during the study period. These pregnancies resulted in 2464 “live-born” infants and 85 pregnancy losses. A total of 61% of the women with completed pregnancies had signs or symptoms compatible with Zika virus infection during pregnancy. Maternal symptoms or positive laboratory test results were recorded in the first, second, and third trimesters for 21%, 43%, and 34% of the women included in the analysis, respectively.