National surveillance of severe microcephaly in Australia

Abstract

Microcephaly is a rare condition usually manifested during fetal development or infancy. 1 It became a public health concern in 2016, following an outbreak of Zika virus infection associated with microcephaly in the Americas. 2 In response to the international emergency declared by the World Health Organization, some members of the International Network of Paediatric Surveillance Units (INOPSU), including Canada, the United Kingdom (UK) and New Zealand, initiated surveillance for severe microcephaly, defined as an occipitofrontal circumference (OFC) ≥3 standard deviations (SDs) below the mean for age and sex. [1][2][3] Given the paucity of epidemiological information on this condition in Australia, the Australian Paediatric Surveillance Unit (APSU) undertook surveillance for microcephaly using a similar surveillance method, but using a cut-off for microcephaly at an OFC of ≥2 SDs below the mean.Recent publications of national data on severe microcephaly from the Canadian Paediatric Surveillance Program (CPSP) 1 and the British Paediatric Surveillance Unit (BPSU) 3 reported that children with severe microcephaly endure substantial morbidity and neurodisability. 1,3 In this report, we describe clinical, epidemiological and aetiological features of severe microcephaly in Australian infants and compare findings to those reported by the CPSP and BPSU.