Descriptive study of suspected congenital Zika syndrome cases during the 2015-2016 epidemic in Brazil

Clinical and epidemiological data on suspected congenital Zika syndrome (CZS) cases from southern Mato Grosso (MT) in Brazil during the Zika virus (ZIKV) outbreak in 2015-2016 were evaluated.

This is a descriptive case series study of newborns whose mothers were suspected cases of ZIKV infections during their pregnancies. The medical records of all the suspected CZS cases (mothers and newborns) treated by the specialized ambulatory service from June 2015 to August 2016 were analyzed.

Twenty suspected CZS cases were included in these analyses. They were categorized into four groups based on the clinical and laboratory findings: confirmed cases (n=1), highly probable cases (n=13), moderately probable cases (n=5), and somewhat probable cases (n=1). The mothers tested negative for STORCH (syphilis, toxoplasmosis, other infections, rubella, cytomegalovirus infection, and herpes simplex) and other important congenital infections; however, specific ZIKV tests were not performed during the study period. Microcephaly was observed in the majority of these newborns, and all the patients showed altered cranial computed tomography image findings. Extracranial abnormalities such as arthrogryposis, and otological and ophthalmological manifestations were also observed.

Although ZIKV was not confirmed to cause the congenital malformations, this study demonstrated that the clinical and epidemiological findings associated with a STORCH exclusion strengthened the CZS diagnosis. The suspected cases in MT occurred simultaneously with the first CZS cases reported in Brazil, suggesting ZIKV circulation in the study region during the same period.