Microcephaly in northeastern Brazil: a review of 16 208 births between 2012 and 2015

Abstract

A recent outbreak of microcephaly has been reported from Northeast Brazil. Neither its aetiology, nor its clinical significance has yet been fully established. A complication from an intrauterine infection with the Zika virus (ZIKV) is, thus far, the most explored hypothesis. In Paraíba, one of the nine States within the epicentre of the epidemic, 21 medical centres collaborate, via telemedicine since 2012, in a paediatric cardiology network. The Network’s database currently stores information on more than 100,000 neonates. To support the microcephaly research, from December 1st to 31st, 2015, the Network ran a task force and rescued the head circumference from 16,208 neonates. A much higher than expected incidence of microcephaly was observed, varying from 2% to 8% according to the utilized classification criteria. These findings raise questions about the condition’ s diagnosis and its notification. An observed presentation’ s seasonality might reflect that of infections carried on by the Aedis aegypti vector. However, the temporal fluctuation was documented since late 2012, before the allegedly entry of the ZIKV in Brazil, in mid-2014. Further questions are raised on both the epidemiological surveillance of the Aedis aegypti infections, as well as on different aetiological possibilities for the outbreak. At this stage, follow-up studies in the children diagnosed with microcephaly are mandatory prior to concluding what problem we are facing; how it came about and which consequences it may, or not, bring to the Brazilian population in years to come.