Maternal infection with Zika virus and prevalence of congenital disorders in infants: systematic review and meta-analysis.

OBJECTIVE: Zika virus (ZIKV) infection is a vector-borne disease that can be transmitted sexually and vertically. The vertical transmission of the virus may lead to congenital Zika syndrome in infants. The aim of this study is to conduct a systematic review and meta-analysis of published reports documenting the prevalence of congenital Zika-related disorders in infants of mothers infected with ZIKV during pregnancy. METHODS: We conducted a comprehensive search in Ovid MEDLINE, Ovid MEDLINE (R) Epub ahead of print, Embase, Embase Classic and Web of Science databases to identify human studies reporting prevalence of congenital disorders in infants of ZIKV-infected mothers. RESULTS: We identified 25 reports selected for inclusion in the current study (n = 4683 subjects). The majority of the studies were from South American high-risk countries. Only one third of the identified studies were conducted in the United States. Clinical maternal symptoms included maculopapular rash (76.9%), arthralgia (46.4%), fever (45.5%) and headache (31.8%) with myalgia and conjunctivitis only presented in 25% of the cases. The most prevalent congenital disorder in the newborns was brain calcifications (42.6; 95% CI, 30.8-54.4), followed by ventriculomegaly (21.8; 95% CI, 15.2-28.4), joint abnormalities (13.2; 95% CI, 9.4-18.2), ocular abnormalities (4.2; 95% CI, 1.0-7.5) and microcephaly (3.9; 95% CI, 2.4-5.4). CONCLUSION: The current study highlights the high prevalence of a range of congenital disorders in newborns of mothers infected with ZIKV. It warrants developing studies to further clarify the mechanisms by which each of these disorders occurs in response to the viral infection during pregnancy and its vertical transmission to the infants.