Case Fatality Rate Related to Microcephaly Congenital Zika Syndrome and Associated Factors: A Nationwide Retrospective Study in Brazil †.

BACKGROUND: The clinical manifestations of microcephaly/congenital Zika syndrome (microcephaly/CZS) have harmful consequences on the child's health, increasing vulnerability to childhood morbidity and mortality. This study analyzes the case fatality rate and child-maternal characteristics of cases and deaths related to microcephaly/CZS in Brazil, 2015-2017. METHODS: Population-based study developed by linkage of three information systems. We estimate frequencies of cases, deaths, case fatality rate related to microcephaly/CZS according to child and maternal characteristics and causes of death. Multivariate logistic regression models were applied. RESULTS: The microcephaly/CZS case fatality rate was 10% (95% CI 9.2-10.7). Death related to microcephaly/CZS was associated to moderate (OR = 2.15; 95% CI 1.63-2.83), and very low birth weight (OR = 3.77; 95% CI 2.20-6.46); late preterm births (OR = 1.65; 95% CI 1.21-2.23), Apgar < 7 at 1st (OR = 5.98; 95% CI 4.46-8.02) and 5th minutes (OR = 4.13; 95% CI 2.78-6.13), among others. CONCLUSIONS: A high microcephaly/CZS case fatality rate and important factors associated with deaths related to this syndrome were observed. These results can alert health teams to these problems and increase awareness about the factors that may be associated with worse outcomes.

Cross-sectional study of the anthropometric characteristics of children with congenital Zika syndrome up to 12 months of life.

BACKGROUND: Little is known about physical development of children with Congenital Zika Syndrome (CZS). This study aims to evaluate the anthropometric characteristics of children with CZS up to 12 months. METHODS: This is a cross-sectional study developed with 46 children with CZS living in Bahia. We used the Public Health Events Register, Live Births Information System and Childcare Records of Primary Health Care Services. Descriptive analysis was performed by distributing absolute and relative frequencies and median and interquartile range. The Weight/Age (W/A), Length/Age (L/A), Weight/Length (W/L) and Head Circumference/Age (HC/A) indexes were calculated for each month and expressed in z-score values, and the results were evaluated individually and by group average. Values between ≥ - 2 and ≤ 2 standard deviations were used as reference. T-Student and Spearman's Correlation Tests were applied to verify the existence of any relationship between maternal and children's variables with the anthropometric indexes weight/age and height/age at birth and at 3, 6 and 12 months of age. RESULTS: The studied children had high proportions of low birth weight (23.9%), dysphagia (56.8%) and seizures (53.5%). The mean z-score for the HC/A index at birth was - 3.20 and remained below - 3 z-scores throughout the assessed period. The analysis of the indices equivalent to every single child's anthropometric measurement showed a deficit in 20.4% of the W/A, 39.1% of the L/A, 9.2% of the W/L and 85.7% of the HC/A measurements. Distribution of the mean values of these anthropometric indices revealed a risk of delayed stature growth (L/A < -1 z-score). There was a statistically significant association between L/A at 12 months and dysphagia (p = 0.0148) and a positive correlation between breastfeeding time and W/A. No statistically significant correlation was found between any other tested variables. CONCLUSIONS: We observed a deficit in the HC/A index, which is a common feature in CZS, but also a high proportion of W/A and L/A deficit. The average group z-score highlighted the risk of delay in stature growth for age, which calls attention to the need for health interventions, as this condition exposes them to a higher risk of morbidity and mortality.