A research team from Brazil has reported preliminary results of a case-control study investigating the association between microcephaly and Zika virus infection during pregnancy. The study, conducted in eight public hospitals in Recife, Brazil, included 32 neonates with microcephaly (cases) and 62 neonates without microcephaly (controls) between January and May 2016. According to the data, 80% of 30 mothers of cases had Zika virus infection, compared with 64% of 61 mothers of controls. Additionally, 41% of 32 cases and none of 62 controls had laboratory-confirmed Zika virus infection. The estimated crude overall odds ratio was 55.5 for seven cases with brain abnormalities and 24.7 for four cases without brain abnormalities. The researchers concluded, "This preliminary analysis shows a strong association between microcephaly and laboratory confirmation of Zika virus infection by RT-PCR or Zika virus-specific IgM in cerebrospinal fluid or serum of neonates. The risk was high in cases with brain abnormalities detected by imaging, but was also present in cases without brain abnormalities." The research was funded by the Brazilian Ministry of Health, Pan American Health Organization, and Enhancing Research Activity in Epidemic Situations.