Spatio-temporal analysis of leprosy risks in a municipality in the state of Mato Grosso-Brazilian Amazon: results from the leprosy post-exposure prophylaxis program in Brazil.

BACKGROUND: Leprosy post-exposure prophylaxis (LPEP) with single dose rifampicin (SDR) can be integrated into different leprosy control program set-ups once contact tracing has been established. We analyzed the spatio-temporal changes in the distribution of index cases (IC) and co-prevalent cases among contacts of leprosy patients (CP) over the course of the LPEP program in one of the four study areas in Brazil, namely the municipality of Alta Floresta, state of Mato Grosso, in the Brazilian Amazon basin. METHODS: Leprosy cases were mapped, and socioeconomic indicators were evaluated to explain the leprosy distribution of all leprosy cases diagnosed in the period 2016-2018. Data were obtained on new leprosy cases [Notifiable diseases information system (Sinan)], contacts traced by the LPEP program, and socioeconomic variables [Brazilian Institute of Geography and Statistics (IBGE)]. Kernel, SCAN, factor analysis and spatial regression were applied to analyze changes. RESULTS: Overall, the new case detection rate (NCDR) was 20/10 000 inhabitants or 304 new cases, of which 55 were CP cases among the 2076 examined contacts. Changes over time were observed in the geographic distribution of cases. The highest concentration of cases was observed in the northeast of the study area, including one significant cluster (Relative risk = 2.24; population 27 427, P-value < 0.001) in an area characterized by different indicators associated with poverty as identified through spatial regression (Coefficient 3.34, P-value = 0.01). CONCLUSIONS: The disease distribution was partly explained by poverty indicators. LPEP influences the spatial dynamic of the disease and results highlighted the relevance of systematic contact surveillance for leprosy elimination.

Social school contacts of multibacillary leprosy cases in children living in the hyperendemic region of the Midwest of Brazil.

OBJECTIVE: To analyze the prevalence of Mycobacterium leprae detection and the associated factors among social contacts in the school environment of multibacillary cases living in a hyperendemic municipality of the state of Mato Grosso. METHODS: Cross-sectional study with 236 social contacts of multibacillary leprosy from public schools and residents in Cuiabá (Mato Grosso) in 2018. The sources of information were interviews and nasal swab tests for molecular analysis by polymerase chain reaction - PCR. For the prevalence ratio estimates, crude and adjusted analyses were performed using robust Poisson regression and their respective confidence intervals (95% CI). The ArcGIS 9.1 software was used for the geographic distribution analyses. RESULTS: The prevalence of detection of M. leprae in social contacts was 14%. A total of 63.6% of the schools surveyed had 5.1% to 50% of the social contacts of leprosy with positive PCR. The analysis of the geographic distribution in the neighborhoods showed a high prevalence of infection, being higher than 50% in some localities. The highest proportion of positive results occurred in the northern region of the city and from a precarious socioeconomic class. CONCLUSION: The results showed a high prevalence of detection of M. leprae among social contacts in areas with poor socioeconomic conditions. In these regions, there is a greater risk of infection and of getting sick.

[Migration and Hansen's disease in Mato Grosso]. / Migração e hanseníase em Mato Grosso.

Studies on medical geography about leprosy discuss the role of the detailed report of the occupation of the territories as a basis of the permanence of leprosy focus. In Brazil, the states that present the highest rates of detection historically are in the Amazon region, which shows an uneven regional evolution of the disease. This paper analyzes the evolution of leprosy contextualizing the migratory processes that occurred in the State of Mato Grosso since the second half of the 20th century. The economic dynamism that occurred in the State in the 1970s, 1980s and 1990s caused population growth rates higher than the national average. The data analyzed permitted an association between the evolution of leprosy and the process of occupation of the mato-grossense territory. However, the permanence of leprosy in the municipalities of the Baixada Cuiabana, as well as in other municipalities that lost population, seem to point to the existence of geographic contexts of different vulnerability to the social production of the disease in the tate. The migration would explain the appearance and evolution of leprosy. However, we consider that the maintenance of the endemic can be associated to contextual factors related to environment.