Spatial Distribution of Mycobacterium leprae Infection and Association with Unsafe Water and Sanitation in Eastern Minas Gerais, Brazil Restricted; Files Only
Mastrud, Nikki (Spring 2024)
Published
Abstract
Background: The mode of transmission of M. leprae, the causative agent of Hansen’s Disease (HD), remains uncertain due to the long incubation period of HD and the inability to culture M. leprae in the lab. Our research investigates the role of household-level water, sanitation, and hygiene (WASH) factors on HD transmission.
Methods: We conducted a cross-sectional study of 1,315 participants living in four municipalities of a HD-endemic area of Minas Gerais, Brazil. Individuals were tested for M. leprae infection determined via antibody testing against LID-1, a recombinant M. leprae protein. Data were collected on participants’ household WASH factors and demographics through questionnaires. We created smooth relative risk surfaces to estimate the spatial distribution of relative risk of anti-LID-1 positivity and used logistic regressions to estimate associations between sets of exposures and anti-LID-1 positivity.
Results: Among the study population, the highest anti-LID-1 positivity rates were found in the municipality of Mantena (12.26%). These results are consistent with patterns of reported HD cases, indicating that reported HD cases may act as reasonable representations of underlying M. leprae distribution. Analyzed household-level WASH factors of piped household drinking water (aOR = 2.06, 95% CI 0.86, 5.64), piped water for toilet (aOR = 0.60, 95% CI 0.30, 1.29), and shared household toilet facility (aOR = 0.56, 95% CI 0.29, 1.03) did not have a significant association with anti-LID-1 positivity on adjusted analysis. Residence in rural regions (cOR = 2.53, 95% CI 1.45, 4.28) and residence in Mantena (cOR = 2.77, 95% CI 1.59, 4.76) were found to be significantly associated with anti-LID-1 positivity in univariate analysis. In adjusted analysis, the estimated association with rural residence was mitigated (aOR = 1.68, 95% CI 0.73, 4.10).
Conclusions: Disease mapping of anti-LID-1 positivity showed that there is heterogeneity of M. leprae infection in the eastern region of Minas Gerais. Our analyses of residence in rural regions as an exposure indicates that there may be additional environmental or structural characteristics at the municipality level that are not inherently related to rural living that affect the risk of anti-LID-1 positivity.
Table of Contents
CHAPTER I: LITERATURE REVIEW ................................................................................................ 1
Literature Review ................................................................................................................................... 1
CHAPTER II: MANUSCRUPT .............................................................................................................. 6
Introduction............................................................................................................................................. 6
Methods.................................................................................................................................................. 8
Results .................................................................................................................................................. 14
Discussion............................................................................................................................................. 18
References............................................................................................................................................. 22
Tables ................................................................................................................................................... 26
Figures.................................................................................................................................................. 31
CHAPTER III: CONCLUSIONS.......................................................................................................... 40
Summary............................................................................................................................................... 40
Public Health Implications.................................................................................................................... 41
Future Directions .................................................................................................................................. 42
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File download under embargo until 20 May 2025 | 2024-04-25 22:27:02 -0400 | File download under embargo until 20 May 2025 |
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