Screening for Zika virus infection in 1057 potentially exposed pregnant women, Catalonia (northeastern Spain)

Abstract

Dear editor: A recent editorial in Travel Medicine and Infectious Diseases highlighted the lack of studies about Zika virus (ZIKV) in pregnancy and its implications in many countries [1]. Zika virus infection can induce congenital defects in the newborn such as microcephaly and miscarriage when mothers are infected during pregnancy [2]. However, relevant questions remain to be completely understood, such as the risk of infection for pregnant women and of subsequent congenital defects, and the ratio between symptomatic and asymptomatic ZIKV infections in the general population and in pregnant women. Here, we describe the results of a ZIKV screening of pregnant women in Catalonia, northeastern Spain. Testing for ZIKV was recommended for all pregnant women with history of travel to ZIKV endemic areas during pregnancy or in the 8 weeks before conception [3]. Symptomatic patients were screened by serological methods from day four after the onset of symptoms and by molecular methods within the first week (serum) and two weeks (urine) after illness. Asymptomatic patients were tested by serological methods. Seroneutralization assay for ZIKV was perfomed in samples positive for antibodies. Commercial diagnostic assays were used (RT-PCR, Altona Diagnostics and IIFT, Euroimmun). Neutralization titers ≥1/32 were considered indicative of the presence of ZIKV neutralizing antibodies. Follow up at two designated reference obstetrical departments for early detection of microcephaly or other malformations was offered to pregnant women with laboratory evidence of ZIKV infection. When available, amniotic fluid and placental tissue samples were tested for ZIKV by RT-PCR in cases of microcephaly or miscarriage, respectively.