# BCG vaccination decline and pediatric tuberculosis rise in Brazil: spatial-temporal study

## TL;DR

This study shows that declining BCG vaccination rates in Brazil correlate with rising pediatric tuberculosis cases, especially in regions with high incidence.

## Contribution

The study provides a spatial-temporal analysis linking BCG vaccination coverage decline to increased pediatric TB cases in Brazil.

## Key findings

- Pediatric tuberculosis cases rose in 2020, with a 26.64% annual percent change.
- High-high clusters of TB cases were identified in Amazonas, Mato Grosso, and Rio de Janeiro.
- BCG vaccination coverage dropped below 90% in 2020, especially in the Northeast region.

## Abstract

To explore the spatial distribution of bacille Calmette-Guerin (BCG) vaccination coverage and tuberculosis cases in Brazilian children under the age of ten in the last two decades.

This is a population-based ecological study using data from the Sistema de Informação de Agravos de Notificação (SINAN – Information System for Notifiable Diseases) from January 2001 to December 2022. We investigated tuberculosis incidence and vaccination coverage in all Brazilian municipalities. Spatial dependence was analyzed by the Global Moran Index and Local Indicators of Spatial Association (LISA). Joinpoint regression was used to assess trends in tuberculosis and BCG rates over time.

The results indicated 39,840 pediatric tuberculosis cases, with 60.65% in children under the age of five. The highest incidence rates were in the states of Amazonas, Mato Grosso, and Rio de Janeiro. Spatial analysis showed significant positive spatial autocorrelation in pediatric tuberculosis cases, with high-high clusters in several states and municipalities. Tuberculosis cases in children under five have been declining since 2000 but rose in 2020 (APC = 26.64; p-value = 0.032). An earlier increase was observed in children up to ten years old, starting six years prior.

The study highlights the decline in BCG vaccination coverage below 90%, with the most significant drop in 2020, particularly in the Northeast. The findings underscore the need for high maintain vaccination coverage and robust public health policies to mitigate tuberculosis in children. Addressing these issues requires targeted public health interventions, especially in regions with higher tuberculosis burdens.