Association between microcephaly, Zika virus infection, and other risk factors in Brazil: final report of a case-control study.

Background: A Zika virus epidemic emerged in northeast Brazil in 2015 and was followed by a striking increase in congenital microcephaly cases, triggering a declaration of an international public health emergency. This is the final report of the first case-control study evaluating the potential causes of microcephaly: congenital Zika virus infection, vaccines, and larvicides. The published preliminary report suggested a strong association between microcephaly and congenital Zika virus infection.

Association between Zika virus infection and microcephaly in Brazil, January to May, 2016: preliminary report of a case-control study.

Background: The microcephaly epidemic, which started in Brazil in 2015, was declared a Public Health Emergency of International Concern by WHO in 2016. We report the preliminary results of a case-control study investigating the association between microcephaly and Zika virus infection during pregnancy.

Methods: We did this case-control study in eight public hospitals in Recife, Brazil.