Abstract
This cohort profile aims to describe the ongoing follow-up of children in the Microcephaly Epidemic Research Group Paediatric Cohort (MERG–PC). The profile details the context and aims of the study, study population, methodology including assessments, and key results and publications to date. The children that make up MERG–PC were born in Recife or within 120 km of the city, in Pernambuco/Brazil, the epicentre of the microcephaly epidemic. MERG–PC includes children from four groups recruited at different stages of the ZIKV microcephaly epidemic in Pernambuco, i.e., the Outpatient Group (OG/n = 195), the Microcephaly Case–Control Study (MCCS/n = 80), the MERG Pregnant Women Cohort (MERG-PWC/n = 336), and the Control Group (CG/n = 100). We developed a comprehensive array of clinical, laboratory, and imaging assessments that were undertaken by a ‘task force’ of clinical specialists in a single day at 3, 6, 12, 18 months of age, and annually from 24 months. Children from MCCS and CG had their baseline assessment at birth and children from the other groups, at the first evaluation by the task force. The baseline cohort includes 711 children born between February 2015 and February 2019. Children’s characteristics at baseline, excluding CG, were as follows: 32.6% (184/565) had microcephaly, 47% (263/559) had at least one physical abnormality, 29.5% (160/543) had at least one neurological abnormality, and 46.2% (257/556) had at least one ophthalmological abnormality. This ongoing cohort has contributed to the understanding of the congenital Zika syndrome (CZS) spectrum. The cohort has provided descriptions of paediatric neurodevelopment and early epilepsy, including EEG patterns and treatment response, and information on the frequency and characteristics of oropharyngeal dysphagia; cryptorchidism and its surgical findings; endocrine dysfunction; and adenoid hypertrophy in children with Zika-related microcephaly. The study protocols and questionnaires were shared across Brazilian states to enable harmonization across the different studies investigating microcephaly and CZS, providing the opportunity for the Zika Brazilian Cohorts Consortium to be formed, uniting all the ZIKV clinical cohorts in Brazil.
Highlights
The Microcephaly Epidemic Research Group Paediatric Cohort (MERG–PC) is a geographically defined longitudinal cohort of children with confirmed or suspected prenatal exposure to Zika virus (ZIKV), born during the 2015–2017 ZIKV epidemic in PernambucoState, Brazil
Infection during pregnancy; (ii) Presumably exposed children with other potentially Zika-related abnormalities born during the period of the microcephaly epidemic but without laboratory confirmation of maternal ZIKV infection during pregnancy; (iii) Confirmed or presumably exposed children with or without apparent congenital abnormalities born during the period of the microcephaly epidemic with laboratory evidence of maternal ZIKV infection during pregnancy; (iv) Unexposed children born during the period of the microcephaly epidemic with clinical and laboratory evidence against maternal ZIKV infection during pregnancy or without laboratory evidence of ZIKV infection
Assessments were conducted at the University Hospital (Oswaldo Cruz) for children of the Outpatient Group (OG), at the maternity ward where the child was recruited for the Microcephaly Case–Control Study (MCCS) children, and at Barão de Lucena for the children of the MERG–PWC
Summary
The Microcephaly Epidemic Research Group Paediatric Cohort (MERG–PC) is a geographically defined longitudinal cohort of children with confirmed or suspected prenatal exposure to Zika virus (ZIKV), born during the 2015–2017 ZIKV epidemic in Pernambuco. The cluster of microcephaly cases reported between August and October 2015 led the Brazilian Ministry of Health to declare a Public Health Emergency of National Importance in November 2015 [1]. In the midst of the unfolding public health emergency, the MERG initiated the first large-scale case–control study [4,5] investigating the hypothesis linking prenatal ZIKV infection and microcephaly (Figure 1). PC study population includes children recruited from four MERG studies at different stages of the ZIKV microcephaly epidemic in Pernambuco. This cohort profile aims to describe the ongoing follow-up of children in the MERG–. The profile details the context and specific aims of the study, the study population, the methodology including clinical assessments and diagnostic testing, and key results and publications to date
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