Abstract
Congenital microcephaly is the result of a disturbance in early brain development and can have multiple etiologies. Establishing background prevalence of microcephaly in Zika virus (ZIKV)-affected areas is important for improving identification of ZIKV-affected newborns. However, to date, there is limited consistent guidance for the accurate identification of microcephaly in infants of unknown gestational age, a common concern in low- and middle-income countries. Occipital frontal head circumference (OFC) obtained from infants (0-13 days) of unknown gestational age at enrollment in a pregnancy registry in rural Guatemala from August 2014 to March 2016 were retrospectively reviewed. Trained community health nurses recorded anthropometry in an online database. In April 2015, ZIKV was identified in this population. Gestational age was approximated in 2 ways: presumed term and estimated using z-score of zero for height on modified Fenton growth curves. After which, z-scores for OFC and weight were obtained. Microcephaly and microcephaly background prevalence were estimated using 7 established microcephaly case definitions from national and international organizations and 3 proposed definitions using Fenton growth curves. Independent associations with microcephaly and OFC, including relationship with date of birth, were assessed with prevalence ratios and linear regression. For 296 infants, the mean OFC was 33.1 cm (range, 29.5 to 37 cm) and the mean OFC z-score was -0.68. Depending on case definition, 13 to 125 infants were classified as having microcephaly (background prevalence 439 to 4,223 per 10,000 live births), and 1 to 9 infants were classified as having severe microcephaly (<-3 standard deviation [SD]) (34 to 304 per 10,000 live births). Five (1.7%) infants met all the microcephaly case definitions. Weight ≤-1 SD (prevalence rate [PR], 3.77; 95% confidence interval [CI]: 1.6 to 8.8; P=.002) and small for gestational age (PR, 4.68; 95% CI, 1.8 to 12.3; P=.002) were associated with microcephaly. Date of birth was not associated with OFC z-score or OFC after adjusting for gestational age and gender. Estimated background microcephaly is high in rural Guatemala compared with reported rates in Latin America prior to ZIKV epidemic, which has important implications for neonatal screening programs for congenital ZIKV infection. Fenton growth curves offer a standardized approach to the identification of microcephaly in infants of unknown gestational age.
Highlights
Congenital microcephaly is the result of a disturbance in early brain development leading to an abnormally small head circumference and structural abnormalities of the brain, and can have multiple etiologies.[1]
The case definitions were applied to our dataset to identify suspected cases of microcephaly in this population and estimate microcephaly background prevalence prior to the Zika virus (ZIKV) epidemic
When the case definition required a gestational age, the estimated gestational age was derived from the Fenton growth curves
Summary
Congenital microcephaly is the result of a disturbance in early brain development leading to an abnormally small head circumference and structural abnormalities of the brain, and can have multiple etiologies.[1] Prior to the Zika virus (ZIKV) epidemic, the estimated prevalence of microcephaly in Latin America was 3.30 per Congenital Microcephaly in Rural Guatemala and Zika Screening www.ghspjournal.org. To date, there is limited consistent guidance for the accurate identification of microcephaly in infants of unknown gestational age, a common concern in low- and middle-income countries
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
