Leprosy transmission in Bahia, 2001-2015: modeling based on Joinpoint regression and spatial scan statistics^*

Abstract

Objective:

to describe the trend and the spatial distribution of leprosy in the state of Bahia, Brazil, 2001-2015.

Methods:

this was a mixed ecological study of epidemiological indicators of leprosy; Joinpoint regression was used for the temporal analysis, while spatial scan statistics were used to identify clusters of the disease; the trend was classified as stationary, increasing or decreasing; we calculated the annual percent change (APC) and average annual percent change (AAPC).

Results:

there was a reduction in prevalence (AAPC = -5.6; p<0,001), treatment dropout (AAPC = -13.7; p<0.001), and females with leprosy (AAPC = -0.6; p<0.001); the new grade II case coefficient (AAPC = 2.7; p<0.001) and the proportion of multibacillary cases (AAPC = 2,2; p<0.001) showed a growing trend; spatial distribution was heterogeneous and concentrated in three regions in particular (north, west and south of the state), with variation between the indicators.

Conclusion:

persisting leprosy transmission in the state, late diagnosis and high hidden prevalence is suggested.

Keywords:
Leprosy; Spatial Analysis; Neglected Diseases; Time Series Studies; Ecological Studies