Estimated Microcephaly Cases and Microcephaly Background Prevalence Using Established and Proposed Microcephaly Case Definitions in Neonates Born Between August 1, 2014, to March 31, 2016, in Rural Guatemala

Origin of Case DefinitionMicrocephaly No. (%)Microcephaly Background Prevalence per 10,000 Live Births
Brazil MOH 1125 (42.2)a4,223
Brazil MOH 248 (16.2)a1,622
WHO 243 (14.5)b1,453
WHO 136 (12.2)b1,216
PAHO 220 (6.8)a676
Fenton 220 (6.8)a676
PAHO 115 (5.1)a507
Fenton 113 (4.4)a439
WHO 39 (3.0)b304
Fenton 31 (0.3)a34
  • Abbreviations: MOH, Ministry of Health; PAHO, Pan American Health Organization; WHO, World Health Organization.

  • a Based on infant's estimated GA using z-score of zero for length on Fenton growth curve adjusted for gender. Term if estimated GA ≥37 weeks; preterm if estimated GA <37 weeks.

  • b Assumes term (≥37 weeks) GA for all infants.