Methodology of Maternal and Child Health Populational Surveys: A Statewide Cross-sectional Time Series Carried Out in Ceará, Brazil, from 1987 to 2017, with Pooled Data Analysis for Child Stunting.

BACKGROUND: Cross-sectional studies are fundamental studies in the practice of epidemiological science. This article aims to present in detail the methodology for conducting a series of cross-sectional studies, as well as the analysis of data through pooled data. METHODS: The series of studies are population cross-sectional studies, with statewide coverage, searching for representative sample of reproductive aged women and pre-school children in Ceará, Brazil. The sampling plan followed simple random, stratified, systematic and by conglomerates, in sequence. About 300 variables were collected. For each of the individual studies, multivariate data analysis was used to verify associations between dependent variables. For all the studies together, techniques used were trend chi-squared and pooled data analysis using linear mixed modeling procedures. RESULTS: There were 6 studies in sequence, for 30 years. Among other findings, the variables income, maternal education and breastfeeding time proved to be associated with the reduction of malnutrition in children considering all the period (p values 0.013, 0.033 and 0.037, respectively). CONCLUSIONS: Cross-sectional studies can be replicated at regular time series following the methodology exposed in this, even for locations with limited resources, ensuring adequate management of decisions of using federal funding aimed at achieving targeted programs to maximize the results obtained with the public resource available.

Zika Virus Infection and Microcephaly: A Case-Control Study in Brazil.

BACKGROUND: Brazil presented an alarming number of newborns with microcephaly in the years 2015 and 2016. The investigation of the cases raised the suspicion of the association of these cases with maternal infections by the zika virus. Also, in 2015, there was an epidemic of zika virus infection in Brazil, reinforcing this hypothesis. OBJECTIVE: The objective of this study was to identify factors associated with the diagnosis of microcephaly in newborns, including zika virus infection. METHODS: We conducted a case-control study. The cases were defined as children who received clinical and imaging diagnosis of microcephaly, born after October 2015 in Ceará, Brazil, which recorded the highest number of microcephaly cases in Brazil during the outbreak. The cases were identified in medical records of public and private maternity hospitals and in child development stimulation clinics tracked until June 2017. Epidemiological, clinical, and socioeconomic variables were collected, visiting their homes and confirming data from their medical records. Controls were children without microcephaly identified in the vicinity of the residence of each case. Logistic regression models were used to control confounding. FINDINGS: We evaluated 58 cases and 116 controls. The odds of having a baby with microcephaly was 14 times higher among mothers who had zika virus infection (p < 0.001), after multivariate analysis. Arboviruses infections symptoms, as fever (p = 0.220), skin change (p < 0.001), and joint pain (p = 0.002) also demonstrated an association with microcephaly. CONCLUSIONS: Maternal infection zika virus was associated with a diagnosis of microcephaly. Our study contributes to the investigation of the epidemiological factors associated with the diagnosis of microcephaly.