Spatial analysis of congenital syphilis in a federative unit in northeastern Brazil

Abstract

Background Congenital syphilis is an infectious disease that affects 1 million children a year worldwide. Methods The objective of this study was to describe a spatial analysis of the epidemiological characteristics of congenital syphilis in the state of Maranhão, Brazil from 2007 to 2018. This was an ecological study using data obtained in May 2020 from three Brazilian information systems. The spatial correlation was analyzed according to local and global Moran indexes. Results During the 12-y period, 1 426 177 children were born. Of these children, 3684 acquired congenital syphilis (0.26%; mean annual rate of 2.62/1000 live births) and 70 died (1.90%; mean annual rate 0.05). The clusters were statistically significant according to the global Moran index of 0.40 (p=0.01). Spearman's correlation coefficient between the rate of detection of syphilis in pregnant women and family health strategy teams was strong, positive and significant (ρ=0.73; p<0.00). Most of the variables studied showed a trend of annual increase (p<0.05). Conclusions The use of spatial analysis tools have made it possible to detect areas with both a greater and a lesser need for intervention, and to more effectively improve and monitor those areas to change the epidemiological profile of the disease.