Despite a series of early ultrasounds, Zika remained undetected for nearly half of a women's pregnancy, according to a new case study appearing in The New England Journal of Medicine and covered by the Washington Post.
The new report provides more troubling information on the malicious virus experts are still trying to better understand. Here five things to know about this case and the capability of the virus to infect a fetus and inflict devastating damage.
1. Background: The woman in the study was 33 years old and reportedly in the 11th week of gestation while traveling through Mexico, Guatemala and Belize. After arriving at her current residence in Washington D.C., the woman fell ill, experiencing symptoms of ocular pain, myalgia, mild fever and a rash. The woman and her husband both recalled being bitten by mosquitoes during their travels.
2. Closely monitored: One week after her symptoms dissipated, a series of ultrasounds began. Ultrasounds were conducted at 13, 16, and 17 weeks of gestation (one, four, and five weeks after the resolution of symptoms) and displayed no evidence of microcephaly. However, brain abnormalities began to appear at 19 weeks with ultrasounds showing the brain contained an unusual amount of liquid. At week 20, a fetal MRI exposed severe deterioration, especially in the front and top brain areas that are involved in decision-making, learning, vision, hearing, touch and taste. The woman decided to terminate her pregnancy at 21 weeks.
3. False hope: Rita Driggers, MD, one of the study's lead authors and medical director of Washington, D.C.-based Sibley Memorial Hospital's maternal-fetal medicine division, a physician involved in the patient's care and one of the lead authors of the study, said in the Washington Post article that the ultrasounds "only looked at the size of the head and looked for brain calcifications to make sure she didn't have microcephaly and reassured her that everything looks okay." Dr. Driggers said the takeaway from her patient's story is that clinicians should attempt to identify other brain changes beyond direct signs of microcephaly and intracranial calcifications to facilitate earlier detection of possible complications down the line.
4. Delayed diagnosis: Adre du Plessis, director of Children's National Health System's Fetal Medicine Institute and another study author, said in the Post that the ultrasound's inability to detect the abnormality not only gave the mother hollow reassurances, but this kind of delayed diagnosis could put women who would want to terminate a pregnancy "outside the legal limits" of an abortion. Fetal MRIs, the method that effectively diagnosed the abnormal condition, are expensive and not easily accessible in many of the nations that have been hit hardest by Zika.
5. A path for the future: The study did unlock new information about Zika's lifespan in the blood. Previous estimates have suggested that the virus is only extant in the blood for seven to 14 days. Conversely, for the woman in the study, the virus remained in her blood from the point of infection at approximately 11 weeks, up until the time of her abortion at 21 weeks. "That's a very novel finding and important for future study," Roberta DeBiasi, MD, Children's chief of infectious disease division and one of the study's authors, said in the Post.
More articles on the Zika virus:
5 things to know about Zika misperceptions in US
CDC updates guidance on Zika transmission prevention & pregnancy: 7 things to know
California's first sexually transmitted Zika case confirmed