In announcing a change today to the way it reports the number of pregnant women with Zika virus, namely, folding in those with lab-confirmed asymptomatic infections, the US Centers for Disease Control and Prevention (CDC) said it is currently monitoring 279 cases.
The number is up sharply from 112 reported the week before, when only women with Zika symptoms or pregnancy complications were included in the totals. Today's new total is current as of May 12 and includes 122 women in Puerto Rico and other US territories experiencing local Zika transmission and 157 from US states who were infected outside of the mainland.
At a media telebriefing today, Margaret Honein, MD, chief of the birth defects branch at the CDC's National Center for Birth Defects and Developmental Disabilities, said CDC numbers are pulled from two Zika pregnancy registries that began early this year, one that tracks affected women on the US mainland and the other in affected pregnant women in Puerto Rico. CDC described the new reporting system today in an early report in Morbidity and Mortality Weekly Report (MMWR).
Numbers align with monitoring efforts
Honein said the new reporting method aligns with CDC's recommendations to monitor pregnant women with Zika symptoms as well as those without them who may have been exposed to the virus. Also, Honein said the new reporting strategy reflects the scientific understanding of the virus, based on reports in the medical literature describing congenital abnormalities in babies of women who don't recall having Zika symptoms.
"The numbers from the registries provide a more complete picture of the effects on Zika on pregnant women," Honein said, adding that the more comprehensive picture will help health providers with counseling pregnant women and help states plan for resources to help families affected by Zika-related birth defects.
Most of the women are still pregnant, and less than a dozen birth defects and miscarriages have been reported, she said. When pressed for a specific number, Honein said privacy concerns and lack of complete details about all of the cases preclude the CDC from revealing a number. For now, the CDC isn't reporting the number of infections in pregnant women potentially linked to sexual transmission.
Honein said the CDC's total reflects infected women who are still pregnant as well as those who are no longer pregnant.
The CDC's goal is to be as transparent as possible about the number of affected pregnant women, she said, adding that it has taken time to verify all the cases with local health departments. She said it's not possible to gauge the risk of Zika-related birth defects from the CDC's numbers, which will be updated by about noon each Thursday, though they won't be real-time totals.
Honein said the CDC anticipates sharing information about pregnancy outcomes in the months ahead.
See also:
May 20 MMWR report
May 20 CDC press release
