Evaluation of Mothers and Infants with Presumed Exposure to Zika Virus: A Look into the Lehigh Valley Experience

Abstract

Background. Zika virus (ZIKV) is a flavivirus known to cause a self-limited infection with some outbreaks associated with neurological effects. Recently it has become an emerging public health threat due to the presumed correlation between in-utero ZIKV infection and rising rates of microcephaly and other neurodevelopmental abnormalities in exposed infants. Infected travelers from affected areas aid in the spread of ZIKV. This is particularly significant in the Lehigh Valley, where 47% of the city's population of Allentown, Pennsylvania is Hispanic or Latino with frequent travel to ZIKV endemic areas. Methods. A retrospective review was performed of data collected on mothers and infants with suspected ZIKV exposure between June 2016 and May 2017 at Lehigh Valley Health Network, Allentown, Pennsylvania. Results. A total of 16 pregnant women with 15 completed pregnancies and 1 fetal demise were included. Seven women were exposed in the first trimester, 4 in the second, and 5 over multiple trimesters. Six pregnant women reported symptoms, including fever, rash, arthritis, conjunctivitis, and diarrhea. Two mothers were tested during the first trimester, 5 during the second, and 6 during the third. Timing of testing did not always correlate with time of exposure. Of the 6 mothers that reported symptoms, only one was positive for ZIKV by serum PCR. Five mothers had a positive ZIKV plaque reduction neutralization test (PRNT). Pathological findings of the placental tissue for the fetal demise were consistent with ZIKV infection. One infant had equivocal ZIKV IgM antibodies and positive PRNT, with positive ZIKV IgM antibodies found in the mother. Although 2 infants had prenatal ultrasounds concerning for microcephaly, no neurological abnormalities, microcephaly or developmental delays were reported at birth or during available follow up. Conclusion. No anatomic or neurological abnormalities have been noted in infants born in our region after in-utero ZIKV exposure. Timing of testing might play an important role in identifying pregnant women at risk of delivering infants with ZIKV related anomalies. Further research is needed to determine the usefulness of serology testing as an indicator of ZIKV in-utero infection.