OBJECTIVE: Zika virus infection during pregnancy is a cause of microcephaly and other fetal brain abnormalities. Reports indicate that the duration of detectable viral RNA in serum after symptom onset is brief. In a recent case report involving a severely affected fetus, Zika virus RNA was detected in maternal serum 10 weeks after symptom onset, longer than the duration of RNA detection in serum previously reported. This report summarizes the clinical and laboratory characteristics of pregnant women with prolonged detection of Zika virus RNA in serum that were reported to the U.S. Zika Pregnancy Registry.
METHODS: Data were obtained from the U.S. Zika Pregnancy Registry, an enhanced surveillance system of pregnant women with laboratory evidence of confirmed or possible Zika virus infection. For this case series, we defined prolonged detection of Zika virus RNA as Zika virus RNA detection in serum by real-time reverse transcription-polymerase chain reaction (RT-PCR) 14 or more days after symptom onset or, for women not reporting signs or symptoms consistent with Zika virus disease (asymptomatic), 21 or more days after last possible exposure to Zika virus.
RESULTS: Prolonged Zika virus RNA detection in serum was identified in four symptomatic pregnant women up to 46 days after symptom onset and in one asymptomatic pregnant woman 53 days postexposure. Among the five pregnancies, one pregnancy had evidence of fetal Zika virus infection confirmed by histopathologic examination of fetal tissue, three pregnancies resulted in live births of apparently healthy neonates with no reported abnormalities, and one pregnancy is ongoing.
CONCLUSION: Zika virus RNA was detected in the serum of five pregnant women beyond the previously estimated timeframe. Additional real-time RT-PCR testing of pregnant women might provide more data about prolonged detection of Zika virus RNA and the possible diagnostic, epidemiologic, and clinical implications for pregnant women.
In some pregnant women, Zika virus RNA can be detected for a prolonged period, which might have diagnostic, epidemiologic, and clinical implications.
Office of the Director, the Division of Vector-Borne Diseases, and the Infectious Diseases Pathology Branch, National Center for Emerging and Zoonotic Infectious Diseases, the Division of Reproductive Health, National Center for Chronic Disease Prevention and Health Promotion, the Epidemic Intelligence Service, the Division of Congenital and Developmental Disorders, National Center on Birth Defects and Developmental Disabilities, the National Center for Chronic Disease Prevention and Health Promotion, and the National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia; the Bureau of Communicable Disease Control, and the Laboratory of Viral Diseases and the Viral Encephalitis Laboratory - Viral Diseases, Wadsworth Center, New York State Department of Health, Albany, the Bureau of Communicable Disease, Division of Disease Control, and the Public Health Laboratory, New York City Department of Health and Mental Hygiene, and the New York State Department of Health and Mental Hygiene, New York, and the Suffolk County Department of Health Services, Great River, New York; and the Bureau of Epidemiology and the Division of Disease Control and Health Protection, Florida Department of Health, Tallahassee, Florida.
Corresponding author: Dana Meaney-Delman, MD, MPH, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, 1600 Clifton Rd., Mailstop C-12, Atlanta, GA 30333; e-mail: firstname.lastname@example.org.
Financial Disclosure The authors did not report any potential conflicts of interest.
* For a list of members of the U.S. Zika Pregnancy Registry Prolonged Viremia Working Group, see Appendix 1, available online at http://links.lww.com/AOG/A851.
The findings and conclusions in this report are those of the authors and do not necessarily represent the official position of the Centers for Disease Control and Prevention.