Leprosy in Brazil and its association with characteristics of municipalities: ecological study, 2009-2011

Potential drivers of leprosy infection: A case–control study of parasitic coinfection and water, sanitation, and hygiene in North Gondar, Ethiopia

Background

Despite extensive control measures and a declining number of human reservoirs, the incidence of leprosy in excess of 200,000 new cases each year suggests that alternative pathways of transmission may play a role in continued endemicity. Parasitic coinfection and limited water, sanitation, and hygiene (WASH) have been suggested to predispose individuals to Mycobacterium leprae infection and were further explored in this study.

Methods

Leprosy cases and uninfected controls were recruited from areas around North Gondar, Ethiopia throughout 2019. Participants completed dietary and WASH surveys in addition to providing stool for helminth microscopic diagnosis and urine for Schistosoma mansoni Point-of-care circulating cathodic antigen (POC-CCA)™ rapid diagnostic testing. A similar methodology was employed for a case–control study of leprosy previously conducted by our research team in North Gondar from May to October of 2018. To more comprehensively evaluate associations between the above exposures and leprosy, data from the present 2019 study and the previous 2018 study were combined in select multivariate logistic regression analyses.

Results

A total of 47 men (59%) and 33 women (41%) participated in this study with an average age of 40 (SD 15.0 years). Most leprosy cases were multibacillary (93%). There was a high prevalence of parasitic coinfection among both cases (71%) and controls (60%). WASH insecurities were also widespread. On multivariate analysis, lack of soap for handwashing [aOR= 2.53, 95% CI (1.17, 5.47)] and the lack of toilet facilities [Adjusted odds ratio (aOR)= 2.32, 95% CI (1.05, 5.12)] were significantly associated with leprosy. Positive directionality was identified for a number of other inputs, including helminth infection [aOR= 3.23, 95% CI (0.85, 12.35)].

Conclusions

Taken together, these findings strengthen previous research conducted in 2018 implicating poor WASH conditions as a driver of leprosy infection. Leprosy remains the leading infectious cause of disability in the world. As such, future research should explore the above susceptibilities in more depth to curtail the global burden of disease.

The effect of conditional cash transfers on the control of neglected tropical disease: a systematic review

BACKGROUND

Neglected tropical diseases (NTDs) are diseases of poverty and affect 1·5 billion people globally. Conditional cash transfer (CCTs) programmes alleviate poverty in many countries, potentially contributing to improved NTD outcomes. This systematic review examines the relationship between CCTs and screening, incidence, or treatment outcomes of NTDs.

METHODS

In this systematic review we searched MEDLINE, Embase, Lilacs, EconLit, Global Health, and grey literature websites on Sept 17, 2020, with no date or language restrictions. Controlled quantitative studies including randomised controlled trials (RCTs) and observational studies evaluating CCT interventions in low-income and middle-income countries were included. Any outcome measures related to WHO's 20 diseases classified as NTDs were included. Studies from high-income countries were excluded. Two authors (AA and TH) extracted data from published studies and appraised risk of biases using the Risk of Bias in Non-Randomised Studies of Interventions and Risk of Bias 2 tools. Results were analysed narratively. This study is registered with PROSPERO, CRD42020202480.

FINDINGS

From the search, 5165 records were identified; of these, 11 studies were eligible for inclusion covering four CCTs in Brazil, the Philippines, Mexico, and Zambia. Most studies were either RCTs or quasi-experimental studies and ten were assessed to be of moderate quality. Seven studies reported improved NTD outcomes associated with CCTs, in particular, reduced incidence of leprosy and increased uptake of deworming treatments. There was some evidence of greater benefit of CCTS in lower socioeconomic groups but subgroup analysis was scarce. Methodological weaknesses include self-reported outcomes, missing data, improper randomisation, and differences between CCT and comparator populations in observational studies. The available evidence is currently limited, covering a small proportion of CCTs and NTDs.

INTERPRETATION

CCTs can be associated with improved NTD outcomes, and could be driven by both improvements in living standards from cash benefits and direct health effects from conditionalities related to health-care use. This evidence adds to the knowledge of health-improving effects from CCTs in poor and vulnerable populations.

FUNDING

None.

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.

Time trend, social vulnerability, and identification of risk areas for tuberculosis in Brazil: An ecological study

Introduction

Tuberculosis is one of the ten leading causes of death and the leading infectious cause worldwide. The disease represents a challenge to health systems around the world. In 2018, it is estimated that 10 million people were affected by tuberculosis, and approximately 1.5 million people died due to the disease worldwide, including 251,000 patients coinfected with HIV. In Brazil, the disease caused 4,490 deaths, with rate of 2.2 deaths per 100,000 inhabitants. The objective of this study was to analyze the time behavior, spatial, spatial-temporal distribution, and the effects of social vulnerability on the incidence of TB in Brazil during the period from 2001 to 2017.

Materials and methods

A spatial-temporal ecological study was conducted, including all new cases of tuberculosis registered in Brazil during the period from 2001 to 2017. The following variables were analyzed: incidence rate of tuberculosis, the Social Vulnerability Index, its subindices, its 16 indicators, and an additional 14 variables available on the Atlas of Social Vulnerability. The statistical treatment of the data consisted of the following three stages: a) time trend analysis with a joinpoint regression model; b) spatial analysis and identification of risk areas based on smoothing of the incidence rate by local empirical Bayesian model, application of global and local Moran statistics, and, finally, spatial-temporal scan statistics; and c) analysis of association between the incidence rate and the indicators of social vulnerability.

Results

Brazil reduced the incidence of tuberculosis from 42.8 per 100,000 to 35.2 per 100,000 between 2001 and 2017. Only the state of Minas Gerais showed an increasing trend, whereas nine other states showed a stationary trend. A total of 326 Brazilian municipalities were classified as high priority, and 22 high-risk spatial-temporal clusters were identified. The overall Social Vulnerability Index and the subindices of Human Capital and Income and Work were associated with the incidence of tuberculosis. It was also observed that the incidence rates were greater in municipalities with greater social vulnerability.

Conclusions

This study identified clusters with high risk of TB in Brazil. A significant association was observed between the incidence rate of TB and the indices of social vulnerability.

Evolução temporal e distribuição espacial da hanseníase em município de baixa endemicidade no estado de São Paulo

Resumo Objetivo Analisar a distribuição espacial e temporal da hanseníase em cenário de baixa endemicidade no estado de São Paulo, Brasil. Métodos Estudo ecológico, sobre casos de hanseníase notificados no município de Ribeirão Preto, entre 2006 e 2016. A tendência temporal da taxa de detecção de hanseníase foi verificada mediante decomposição de séries temporais, e identificadas as áreas de alta e de baixa ocorrência da doença utilizando-se a técnica Getis-Ord Gi*. Resultados Foram registrados 890 casos, e a taxa de detecção apresentou uma tendência crescente no período analisado, com crescimento médio de 1% ao mês. Identificaram-se áreas de alta ocorrência da doença na região norte do município (99% e 95% de confiança). Conclusão A taxa de detecção de hanseníase apresentou tendência temporal crescente, e a análise espacial permitiu visualizar que a região do município com maior ocorrência da doença se caracteriza por apresentar as maiores desigualdades sociais.

Factors associated with the development of leprosy in Brazilian contacts: a systematic review

People who interact with leprosy patients in their environment, neighborhood, family, or social relationships are at risk to develop the disease. This systematic review investigated the risk and protective factors associated with the development of leprosy in Brazilian contacts. The studies were found in Cochrane Library, PubMed (MEDLINE), Embase, Virtual Health Library, grey literature and hand search until July 2021. The study selection, data extraction and quality assessment were independently performed by two investigators. The quality assessment was performed using the Newcastle-Ottawa Scale (NOS). This review was registered in PROSPERO (CRD42020160680). Seventeen articles fulfilled the inclusion criteria (n=544). The immunological and molecular factors, such as Anti-phenolic Glycolipid Antibodies (Anti-PGL-1) seropositivity, negative Mitsuda test, absence of Bacillus Calmette-Guérin (BCG) scar, positive Polymerase Chain Reaction (PCR) in blood; age and race; conviviality, education, contact time and type of contact, as well as elements related to the index case (bacilloscopic index; genetic conditions, family relationships), and some combined factors were shown to be relevant risk factors associated with the development of the disease in Brazilian leprosy contacts. The protective factors reported were the presence of one or more BCG scars, positive Mitsuda test, and education level. All selected studies were considered of high quality according to NOS. The knowledge of disease-related risk and protective factors provides the scientific basis for decision-making in the management of the disease in leprosy contacts.

Detection of Mycobacterium leprae infection in family clusters from six leprosy-endemic regions in Colombia

BACKGROUND

Leprosy is a chronic infectious disease caused by Mycobacterium leprae, which continues to be endemic in tropical countries, making it necessary to implement strategies for its elimination. The objective of the current article was to detect M. leprae infection and associated factors through serological and epidemiological evaluation in family clusters of leprosy patients.

METHODS

Mycobacterium leprae infection was determined in 50 family clusters of leprosy patients from the departments of Bolívar, Atlántico, Santander, Boyacá, Chocó and Antioquia through the detection of antibodies (protein A, IgM, IgG) against anti-natural octyl disacharide-leprosy IDRI diagnostic (NDO-LID).

RESULTS

Higher seroconversion and elevated titers of these antibodies against NDO-LID were observed in the population of Chocó and Atlántico (p<0.05). Additionally, a higher frequency of infection was observed in large family groups that consumed armadillo meat and belonged to a low socioeconomic stratum (p<0.05). Multivariate analysis established that the main associated factors for a family cluster experiencing this infection were belonging to a vulnerable economic stratum and a large family group.

CONCLUSIONS

This study found that the set of social and demographic variables (i.e. armadillo consumption, geographic area, low socioeconomic status and belonging to a large family cluster) are related to the promotion of seropositivity in family clusters.

High-risk transmission clusters of leprosy in an endemic area in the Northeastern Brazil: A retrospective spatiotemporal modelling (2001-2019)

OBJECTIVES

To analyse and map the leprosy risk areas in the state of Alagoas, an endemic region in the Northeastern Brazil, between 2001 and 2019.

METHODS

Ecological and time series study, using spatial analysis techniques. First, we analyse the epidemiological aspects of leprosy cases, using the data available in the Notifiable Diseases Information System; then, we used the segmented log-linear regression model to assess time trends. Spatial distribution was analysed by the Local Empirical Bayesian Estimator and by calculating the Global and Local Moran Index. Finally, spatiotemporal clusters were identified through scanning statistics, using the Kulldorf method of retrospective analysis.

RESULTS

We observed that Alagoas showed an average new case detection rate of 14.43/100,000 inhabitants between 2001 and 2019, being classified as highly endemic. The area of highest risk was the 9th health region (state hinterland), with increasing time trend (Annual Percentage Change/APC = 7.2; p-value < 0.05). Several clusters of high risk of leprosy transmission were verified in Alagoas, including the state capital and hinterland municipalities.

CONCLUSIONS

Our data indicate that active M. leprae transmission persists in Alagoas; that diagnosis is delayed and that there are high-risk areas, especially in inland municipalities.

Social inequalities and their association with the leprosy burden in a Brazilian city of low endemicity: An ecological study

OBJECTIVE

To analyse the association between social inequalities and the leprosy burden in a low endemicity scenario in the state of São Paulo, Brazil.

METHODS

This ecological study was carried out in the city of Ribeirão Preto, state of São Paulo, Brazil, considering leprosy cases notified from 2006 to 2016. Regarding social inequalities, dimensions related to high household density, literacy, home occupation conditions, health conditions, household income, ethnicity and age were considered. The generalised additive model for location, scale and shape (GAMLSS) was used to verify the association between the social inequalities and leprosy burden.

RESULTS

The increase in men and women with no education and people with an income of 1 to 2 minimum wages was associated with a relative increase in the number of leprosy cases (7.37%, 7.10% and 2.44%, respectively). Regarding the ethnicity variables, the increase in the proportion of men (black) and women (mixed race) with no schooling was associated with a relative increase in the number of cases of the disease (10.77% and 4.02%, respectively). Finally, for people of mixed race or ethnicity, the increase in the proportion of households with 1/2 to 1 minimum wage was related to a relative decrease in the total number of cases (-4.90%).

CONCLUSION

The results show that the determinants associated with the increase in leprosy cases are similar to those in Brazilian hyperendemic regions, and that even in cities with low endemicity, social inequality is one of the main determinants of the disease.

Physical disabilities caused by leprosy in 100 million cohort in Brazil

BACKGROUND

Leprosy continues to be an important cause of physical disability in endemic countries such as Brazil. Knowledge of determinants of these events may lead to better control measures and targeted interventions to mitigate its impact on affected individuals. This study investigated such factors among the most vulnerable portion of the Brazilian population.

METHODS

A large cohort was built from secondary data originated from a national registry of applicants to social benefit programs, covering the period 2001-2015, including over 114 million individuals. Data were linked to the leprosy notification system utilizing data from 2007 until 2014. Descriptive and bivariate analyses lead to a multivariate analysis using a multinomial logistic regression model with cluster-robust standard errors. Associations were reported as Odds Ratios with their respective 95% confidence intervals.

RESULTS

Among the original cohort members 21,565 new leprosy cases were identified between 2007 and 2014. Most of the cases (63.1%) had grade zero disability. Grades 1 and 2 represented 21 and 6%, respectively. Factors associated with increasing odds of grades 1 and 2 disability were age over 15 years old (ORs 2.39 and 1.95, respectively), less schooling (with a clear dose response effect) and being a multibacillary patient (ORs 3.5 and 8.22). Protective factors for both grades were being female (ORs 0.81 and 0.61) and living in a high incidence municipality (ORs 0.85 and 0.67).

CONCLUSIONS

The findings suggest that the developing of physical disabilities remains a public health problem which increases the burden of leprosy, mainly for those with severe clinical features and worse socioeconomic conditions. Early diagnosis is paramount to decrease the incidence of leprosy-related disability and our study points to the need for strengthening control actions in non-endemic areas in Brazil, where cases may be missed when presented at early stages in disease. Both actions are needed, to benefit patients and to achieve the WHO goal in reducing physical disabilities among new cases of leprosy.

[Epidemiological characteristics of leprosy in elderly Brazilians and comparison with other age groups (2016-2018)]

The article aimed to describe epidemiological indicators and characteristics of new cases of leprosy in elderly Brazilians in 2016-2018, compared to other age groups. A descriptive cross-sectional cohort study was conducted with data from the Information System on Diseases of Notification (SINAN). New leprosy cases were categorized by age groups: 60 or more, 40-59, 15-39, and 15 years of age. Pearson's chi-square test was used to verify differences between groups. A total of 81,205 new leprosy cases were reported in Brazil. Of these, 24.1% were elderly, 37.7% from 40-59 years, 31.9% from 15-39 years, and 6.3% in individuals under 15 years of age. The elderly showed higher proportions (p < 0.001) of cases in males (60.1%), with multibacillary classification (81.3%), and with physical disability grade 2 (PDG2) (11.4%) when compared to the other groups. However, the proportion of new cases detected in the elderly based on contact testing (4.9%) was the lowest among all the age brackets (p < 0.001). The mean detection rate and rate of new cases with PDG2 at diagnosis were higher among the elderly (25.1/100,000 and 28.6/million inhabitants, respectively) compared to other age groups in Brazil as a whole and in the regions and states. Important differences were seen in the epidemiological and clinical profile of leprosy in the elderly compared to other age brackets, especially higher proportions of multibacillary cases, new cases with PDG2, and low detection by contact testing. The findings highlighted the need for leprosy control in this age group, aimed at contributing to interruption of transmission of the disease.

Modelagem espacial da hanseníase no estado da Bahia, Brasil, (2001-2015) e determinantes sociais da saúde

Resumo O trabalho analisa a distribuição espacial da hanseníase na Bahia e os determinantes sociais relacionados. Estudo ecológico com dados de hanseníase do período 2001-2015. Três indicadores epidemiológicos foram selecionados: coeficiente de detecção na população geral e em menores de 15 anos e a taxa de casos novos com grau II de incapacidade. Os indicadores foram suavizados pelo Modelo Bayesiano Empírico Local e aplicou-se estatística de Moran Global e Local. As variáveis independentes foram selecionadas a partir do Censo IBGE-2010. Regressões multivariadas foram empregadas, seguidas de regressão espacial. Observou-se distribuição heterogênea no estado, com concentração no eixo norte-oeste e região sul. Para o coeficiente de detecção geral, cinco variáveis compuseram o modelo: densidade demográfica, proporção da população urbana, renda per capita, proporção de extremamente pobres e domicílios com mais de três pessoas por dormitório. A proporção de analfabetismo compôs o modelo final para a taxa de grau II de incapacidade física. Não foram identificados determinantes da ocorrência da doença em menores de 15 anos. A modelagem utilizada contribuiu para demonstrar a heterogeneidade espacial e os determinantes sociais da doença na Bahia, colocando em evidência a complexidade do problema.

Temporal trend of leprosy among the elderly in Brazil, 2001 - 2018

Objective.

To describe the temporal trends of leprosy indicators among the elderly in Brazil in 2001 – 2018.

Methods.

This was an ecological time-series study of new leprosy cases in the elderly reported to the Notifiable Diseases Information System. Prais-Winsten generalized linear regression was used to estimate temporal variations.

Results.

There were 687 317 new leprosy cases in Brazil from 2001 – 2018, of which 129 214 (18.8%) were among elderly people. Overall detection rates in the elderly and of new cases with grade-2 disability showed a falling trend, with an annual percent change of -4.6% (95%CI = -5.1 to -4.0) and -3.9% (95%CI = -4.6 to -3.2). New case and new multibacillary case proportions showed an increasing trend, with an annual percent change of 2.9% (95%CI = 2.6 to 3.3) and 1.4% (95%CI = 1.0 to 1.7), respectively. Detection rates for new leprosy cases in elderly people in Brazil are decreasing, but the proportion of new cases and multibacillary cases are trending upwards.

Conclusions.

New cases are shifting to older age groups, and demographic transition and immunosenescence are an influence. Inadequate reduction of grade-2 disability indicates a high risk of physical disability persists. Improved contact tracing and more effective action are needed in this age group.

Leprosy in urban space, areas of risk for disability and worsening of this health condition in Foz Do Iguaçu, the border region between Brazil, Paraguay and Argentina

BACKGROUND

Leprosy is a public health problem and a challenge for endemic countries, especially in their border regions where there are intense migration flows. The study aimed to analyse the dynamics of leprosy, in order to identify areas of risk for the occurrence of the disease and disability and places where this health condition is worsening.

METHOD

This ecological study considered the new cases of leprosy reported in the municipality of Foz do Iguaçu from 2003 to 2015. Spatial and spatial-temporal scan statistics were used to identify the risk areas for the occurrence of leprosy, as well as the Getis-Ord Gi and Getis-Ord Gi* methods. Areas of risk for disabilities were identified by the scan statistic and kernel density estimation.

RESULTS

A total of 840 cases were reported, of which 179 (21.3%) presented Grade 1 or 2 disabilities at the time of diagnosis. Leprosy risk areas were concentrated in the Southern, Eastern and Northeastern Health Districts of the municipality. The cases of Grade 2 disability were observed with higher intensity in regions characterized by high population density and poverty.

CONCLUSION

The results of the study have revealed changes in the pattern of areas at risk of leprosy according to the investigated periods. In addition, it was possible to verify disabilities as a condition present in the investigated cases, or that may be related to the late diagnosis of the disease. In the areas of risk identified, patients have reported worse physical disability after diagnostic confirmation, or indicate inadequate clinical examination, reinforcing the need for structuring leprosy control services in a qualified manner.

Hanseníase e carência social: definição de áreas prioritárias em estado endêmico do Nordeste brasileiro

RESUMO: Introdução: A hanseníase é uma doença que guarda estreita relação com as condições sociais e econômicas. O Brasil é o único país que ainda não alcançou a meta de eliminação da doença como problema de saúde pública. Objetivo: Este trabalho teve como objetivo analisar a associação entre a carência social dos municípios baianos e a detecção de casos novos de hanseníase na população, como instrumento para a definição de áreas prioritárias para intervenção. Metodologia: Trata-se de um estudo ecológico realizado no estado da Bahia, no período de 2001 a 2015. Variáveis analisadas: coeficiente de detecção casos novos, índice de carência social (ICS) e hanseníase em menores de 15 anos. O ICS foi construído com base em quatro variáveis: índice de performance socioeconômica, renda per capita, proporção de extremamente pobres e densidade domiciliar. Na análise espacial, foram utilizadas modelagem bayesiana empírica local e estatística de Moran global e local. Na análise estatística, foram empregados regressão multivariada, espacial e logística, cálculo do odds ratio e análise de variância. Resultados: A hanseníase apresentou distribuição heterogênea no estado, com concentração no eixo norte-oeste e sul. Dos municípios, 60,4% (n = 252) apresentaram muito baixa condição de vida. Observou-se associação entre as condições de vida e a detecção da hanseníase, com maiores coeficientes no grupo de município com melhor condição de vida (p < 0,001). Conclusão: As piores condições atuaram como um impeditivo ao diagnóstico, ao mesmo tempo que ampliaram o risco de adoecimento. As boas condições possuem efeito inverso.

Socioeconomic factors related to leprosy: an integrative literature review

ABSTRACT Objective: To investigate in the literature the relation of socioeconomic factors in the incidence of the disease and other outcomes related to leprosy. Method: Integrative review conducted in Lilacs, Medline, Scopus databases and SciELO online library with studies from 2000 to 2016. Results: 32 studies were included. Only studies that analyzed statistical associations of socioeconomic factors and outcomes related to leprosy were selected. Conclusion: Leprosy is greatly affected by the social context in which the patient is inserted, the chances of exposure to illness are the result of a set of not only individual aspects, but also of contexts or collective conditions. It is imperative for Nursing, as an essential part of the multiprofessional team entrusted with the care and surveillance of the disease, to recognize these factors to predict unfavorable outcomes and to develop new practices capable of reducing inequities.

Spatial clustering, social vulnerability and risk of leprosy in an endemic area in Northeast Brazil: an ecological study

BACKGROUND

Despite the global decline in the detection of leprosy cases, its incidence has remained unchanged in certain settings and requires the determination of the factors linked to its persistence. We examined the spatial and space-time distribution of leprosy and the influence of social vulnerability on the occurrence of the disease in an endemic area of Northeast Brazil.

METHODS

We performed an ecological study of all leprosy cases reported by Sergipe state, Northeast Brazil from 2001 to 2015, to examine the association of the Social Vulnerability Index and the prevalence and persistence of leprosy among the State's municipalities. Socio-economic and leprosy surveillance information was collected from the Brazilian information systems, and a Bayesian empirical local model was used to identify fluctuations of the indicators. Spatial and space-time clusters were identified using scan spatial statistic tests and to measure the municipalities' relative risk of leprosy.

RESULTS

Leprosy clusters and burden of disease had a strong statistical association with the municipalities' Social Vulnerability Index. Municipalities with a high social vulnerability had higher leprosy incidence, multibacillary leprosy and newly diagnosed cases with grade 2 disability than areas with low social vulnerability.

CONCLUSION

Social vulnerability is strongly associated with leprosy transmission and maintenance of disease incidence. Leprosy control programmes should be targeted to the populations with high social vulnerability.

Factors Associated with Multibacillary Leprosy in a Priority Region for Disease Control in Northeastern Brazil: A Retrospective Observational Study

Background

Leprosy is an infectious disease that can lead to physical disabilities and stigmatization. It remains an important public health problem, especially in Brazil.

Objective

To analyse sociodemographic and clinical factors associated with multibacillary leprosy in a hyperendemic region of the disease in northeastern Brazil.

Method

This is a retrospective observational study with secondary data acquired from 2012 to 2015, from a group of leprosy cases reported in a reference outpatient clinic for the treatment and followup of leprosy in the city of Imperatriz, Maranhao, in northeastern Brazil.

Results

From 905 new cases of leprosy studied, 656 (72.5%) were classified as multibacillary leprosy and 249 (27.5%) as paucibacillary leprosy. We observed that men were more likely to present 5 to 15 skin lesions (OR: 1.32; 95% CI: 1.18-1.49; p <0.0001) and >15 skin lesions (OR: 1.26; 95% CI: 1.09 -1.45; p = 0.005) and a lower chance of having <5 skin lesions (OR: 0.67; 95% CI: 0.59-0.76; p <0.0001). Women were more likely to have no affected nerves compared to men (OR: 1.46; 95% CI: 1.20-1.77; p <0.0001). The age range of 16 to 60 years showed a greater chance of having <5 skin lesions (OR: 1.01; 95% CI: 1.007-1.20; p = 0.03) and a lower chance of having 5 to 15 skin lesions (OR: 1.12, 95% CI: 1.03-1.23; p= 0.008) and a lower chance of being a grade I disability ( CI= 0.73-0.94; p=0.83) and II (OR: 0.82; 95% CI: 0.77-0.98; p=000.1).

Conclusion

Cases of multibacillary leprosy were associated with male gender, low educational level, and clinical variables such as number of skin lesions and grade I or II disability.

Spatial modeling of leprosy in the state of Bahia and its social determinants: a study of health inequities

BACKGROUND

Leprosy is a neglected disease caused by Mycobacterium leprae. Brazil has the second largest number of cases in the world.

OBJECTIVES

To analyze the spatial distribution of leprosy in the state of BAHIA, Brazil, and the association between his occurrence and the synthetic indicators of municipal socioeconomic performance, social vulnerability and income inequality.

METHODS

An ecological study with secondary data obtained from the National System of Notifiable Diseases. Dependent variables: coefficient of detection in the general population and in the population under 15 years old and the rate of grade II of physical disability. Independent variables: Synthetic indicators of socioeconomic performance, social vulnerability and income inequality.

RESULTS

The highest coefficients of detection of new cases in the general population and in children under 15 years old are concentrated in the north-west axis and in the southern region of the state. On the other hand, the highest rates of degree II of physical incapacity are concentrated in the north, northeast and south regions. Only the Index of Social and Economic Performance(IPESE)-Economy and Finance composed the final regression model of the general detection coefficients and in children under 15 years old. The municipalities with the highest indexes had the highest detection coefficients, reflecting the capacity to diagnose new cases.

STUDY LIMITATIONS

The use of synthetic indicators is a limitation of the study.

CONCLUSIONS

Leprosy presents a heterogeneous spatial pattern in the state of BAHIA, and the IPESE-Economics and Finance indicator is the only one with explanatory potential of the disease.

Analysis of the epidemiological situation of leprosy in an endemic area in Brazil: spatial distribution in the periods 2001 - 2003 and 2010 - 2012

INTRODUCTION

In Brazil, the spatial distribution of leprosy is heterogeneous. Areas with high transmission of the disease remain in the North, Center-west and Northeast. Areas with high transmission of the disease remain in the Northern, Central-Western and Northeastern regions of the country.

OBJECTIVE

to describe the spatial distribution of leprosy in municipalities with high risk of transmission, in the periods from 2001 - 2003 and 2010 - 2012.

METHODS

This was an ecological study using data from the Notifiable Diseases Information System (SINAN). They included all municipalities in the states of Mato Grosso, Tocantins, Rondônia, Pará and Maranhão. The following leprosy indicators were calculated per 100,000 inhabitants: incidence rate of leprosy, incidence rate in children aged less than 15 years and rate of new cases with grade 2 disabilities. The spatial scan statistic was used to detect significant clusters (p ≤ 0.05) in the study area.

RESULTS

In the period 2001 - 2003, the scan spatial statistics identified 44 significant clusters for the leprosy incidence rate, and 42 significant clusters in the period 2010 - 2012. In the period 2001 - 2003, it was possible to identify 20 significant clusters to the incidence rate in children aged less than 15, and 14 significant clusters in the period 2010 - 2012. For the rate of new cases with grade 2 disability, the scan statistics identified 19 significant clusters in the period 2001 - 2003, and 14 significant clusters in the period 2010 - 2012.

CONCLUSIONS

Despite the reduction in the detection of leprosy cases, there is a need intensify disease control actions, especially in the clusters identified.

Epidemiological and geographical characterization of leprosy in a Brazilian hyperendemic municipality

Abstract: This study aimed to identify the distribution pattern of leprosy in a hyperendemic municipality in Brazil and determine its relationship with the clinico-epidemiological situation over 11 years. The geographic information system, MapInfo, spatial scan statistics and the Moran I index were used to analyze new cases. The digital cartographic base was used to map clusters of new paucibacillary and multibacillary cases and cases in minors under 15 years old. Socioeconomic indicators are shown using the choropleth mapping technique. A reduction in the detection coefficient, increases in high-risk spatial clusters, marked changes in the distribution of high-risk and low-risk clusters, and high-risk clusters of minors under 15 years old were observed from 2006 to 2010, showing recent illness, the presence of active foci, and overlapping of high-risk clusters of multibacillary infection in minors under 15 years old. Leprosy remains a public health problem in Rondonópolis, Mato Grosso State; the high-risk areas require an intensification of control measures and active search strategies to detect new cases.

Grade 2 disabilities in leprosy patients from Brazil: Need for follow-up after completion of multidrug therapy

Background

Leprosy continues to be a public health problem in many countries. Difficulties faced by health services include late diagnosis, under-reporting of new cases, adequate monitoring of disabilities and treatment. Furthermore, systematic follow-up after completion of treatment is important, when new disabilities may occur, or existing disabilities may get worse. The objective of the present study was to determine the prevalence of leprosy-associated grade 2 disabilities (G2D) after completion of multidrug therapy (MDT) and to identify factors associated with G2D.

Methods

We performed a cross-sectional study of 222 leprosy cases registered in Vitória da Conquista, Bahia state, Brazil from 2001–2014. We performed a clinical examination of the study participants and collected socio-economic and clinical information by interview. We identified factors associated with grade 2 disability (G2D) using logis tic regression.

Results

In total, 38 (17.1%) participants were diagnosed with G2D, and 106 (47.7%) with grade 1 disabilities (G1D). The following independent factors were significantly associated with G2D: occurrence of leprosy reaction (adjusted OR = 2.5; 95%CI = 1.09–5.77), thickening and/or tenderness of one or more nerve trunks (adjusted OR = 3.0; CI = 1.13–8.01) and unemployment (adjusted OR = 7.17; CI = 2.44–21.07).

Conclusions

This study shows that physical disabilities remain after completion of MDT and frequently occur in an endemic area in Brazil. Finding new ways to reduce the burden of disability are urgently needed, and may include systematic follow-up of patients after treatment completion combined with evidence-based preventative measures.

Leprosy is a Neglected Tropical Disease that is still common in many countries. Patients who have had leprosy often suffer long-term physical disabilities. For some patients, disabilities occur after finishing treatment or existing disabilities may get worse. We contacted 222 leprosy patients who had previously completed multidrug therapy (MDT) in a typical endemic area in Brazil and assessed leprosy-associated disabilities, and the associated clinical or sociodemographic factors. We found that 17.1% of the participants had severe (grade 2) disabilities. Disabilities were more common among patients who had had a leprosy reaction, thickening and/or tenderness of one or more nerve trunks and were unemployed. The findings are important because we show that physical disabilities occur frequently after treatment completion in this area, and that patients need long-term follow-up by the health system. Integrated measures that consider clinical and socio-economic aspects are also needed to reduce leprosy burden after completion of treatment, such as devising of public policies, implementation of clinical monitoring and the development of evidence-based guidelines for follow-up after release from MDT.

Assessing epidemiology of leprosy and socio-economic distribution of cases

Leprosy still represents a serious health problem in a number of countries, including Brazil. Although leprosy has been associated with poverty for a long time, it is still difficult to accurately define this relationship. Here, we evaluated in an endemic municipality the progress from 1995 to 2015 of epidemiological indicators to establish if there were any strong associations between social indicators and the occurrence of leprosy. An ecological study was conducted using the SINAN database (Brazilian leprosy-national notifiable diseases information system) in combination with georeferencing of leprosy cases. The georeferencing used the ArcGis programme and occurrence of cases was evaluated in relation to the Health Vulnerability Index (HVI), an indicator that categorises socio-economic and sanitation factors. The data identified a marked decrease in the overall prevalence of leprosy, a reduction in the new case-detection rate and a reduction in the number of cases with grade 2 disabilities (albeit with transient peaks in 2007 and 2015). Logistic regression analysis showed association of detection rates with elevated HVI. Thus, while the epidemiological indicators point to the elimination of leprosy, there is evidence of hidden cases and an association between higher rates of leprosy detection and greater social vulnerability remain.

Socioeconomic risk markers of leprosy in high-burden countries: A systematic review and meta-analysis

Over 200,000 new cases of leprosy are detected each year, of which approximately 7% are associated with grade-2 disabilities (G2Ds). For achieving leprosy elimination, one of the main challenges will be targeting higher risk groups within endemic communities. Nevertheless, the socioeconomic risk markers of leprosy remain poorly understood. To address this gap we systematically reviewed MEDLINE/PubMed, Embase, LILACS and Web of Science for original articles investigating the social determinants of leprosy in countries with > 1000 cases/year in at least five years between 2006 and 2016. Cohort, case-control, cross-sectional, and ecological studies were eligible for inclusion; qualitative studies, case reports, and reviews were excluded. Out of 1,534 non-duplicate records, 96 full-text articles were reviewed, and 39 met inclusion criteria. 17 were included in random-effects meta-analyses for sex, occupation, food shortage, household contact, crowding, and lack of clean (i.e., treated) water. The majority of studies were conducted in Brazil, India, or Bangladesh while none were undertaken in low-income countries. Descriptive synthesis indicated that increased age, poor sanitary and socioeconomic conditions, lower level of education, and food-insecurity are risk markers for leprosy. Additionally, in pooled estimates, leprosy was associated with being male (RR = 1.33, 95% CI = 1.06-1.67), performing manual labor (RR = 2.15, 95% CI = 0.97-4.74), suffering from food shortage in the past (RR = 1.39, 95% CI = 1.05-1.85), being a household contact of a leprosy patient (RR = 3.40, 95% CI = 2.24-5.18), and living in a crowded household (≥5 per household) (RR = 1.38, 95% CI = 1.14-1.67). Lack of clean water did not appear to be a risk marker of leprosy (RR = 0.94, 95% CI = 0.65-1.35). Additionally, ecological studies provided evidence that lower inequality, better human development, increased healthcare coverage, and cash transfer programs are linked with lower leprosy risks. These findings point to a consistent relationship between leprosy and unfavorable economic circumstances and, thereby, underscore the pressing need of leprosy control policies to target socially vulnerable groups in high-burden countries.

Tendências e padrões espaço-temporais da mortalidade relacionada à hanseníase no Estado da Bahia, Nordeste do Brasil, 1999-2014

Resumo Introdução A hanseníase é uma condição negligenciada, com alta carga de morbimortalidade, especialmente em áreas mais desfavoráveis. O objetivo deste estudo foi analisar as tendências e os padrões espaço-temporais da mortalidade relacionada à hanseníase no estado da Bahia, 1999-2014. Objetivo Analisar tendências e padrões espaço-temporais da mortalidade relacionada à hanseníase no Estado da Bahia de 1999 a 2014. Método Estudo de base populacional com dados secundários de mortalidade. Incluíram-se todos os óbitos em que a hanseníase foi mencionada como causa de morte. Resultados Foram registrados 1.152.262 óbitos, dos quais a hanseníase foi identificada em 481 (0,04%) casos, resultando em coeficiente bruto médio anual de mortalidade de 0,21 óbito/100 mil habitantes (intervalo de confiança [IC] de 95%: 0,13-0,29). Hanseníase não especificada (87,73%, ou 422/481) e complicações da hanseníase (6,44%, ou 31/481) foram as formas clínicas mais comumente mencionadas. O risco de óbito relacionado à hanseníase foi maior entre os homens (risco relativo [RR]: 2,38; IC 95%: 0,19-0,46), em idosos (RR: 74,79; IC 95%: 9,57-582,20) e na região oeste do Estado (RR: 4,08; IC 95%: 2,33-7,15). A mortalidade apresentou tendência temporal de aumento significativo no período ( Average Annual Percentual Change [AAPC] 7,3; IC 95%: 4,5 a 10,3), assim como a mortalidade proporcional (AAPC 5,3; IC 95%: 2,2 a 8,3). Conclusões A hanseníase representa uma causa negligenciada de óbito no Estado da Bahia. Apresenta tendências espaço-temporais desiguais nas regiões de saúde, com riscos associados, principalmente, à população masculina e idosa.

Social determinants, their relationship with leprosy risk and temporal trends in a tri-border region in Latin America

BACKGROUND

Brazil is the only country in Latin America that has adopted a national health system. This causes differences in access to health among Latin American countries and induces noticeable migration to Brazilian regions to seek healthcare. This phenomenon has led to difficulties in the control and elimination of diseases related to poverty, such as leprosy. The aim of this study was to evaluate social determinants and their relationship with the risk of leprosy, as well as to examine the temporal trend of its occurrence in a Brazilian municipality located on the tri-border area between Brazil, Paraguay and Argentina.

METHODS

This ecological study investigated newly-diagnosed cases of leprosy between 2003 and 2015. Exploratory analysis of the data was performed through descriptive statistics. For spatial analysis, geocoding of the data was performed using spatial scan statistic techniques to obtain the Relative Risk (RR) for each census tract, with their respective 95% confidence intervals calculated. The Bivariate Moran I test, Ordinary Least Squares (OLS) and Geographically Weighted Regression (GWR) models were applied to analyze the spatial relationships of social determinants and leprosy risk. The temporal trend of the annual coefficient of new cases was obtained through the Prais-Winsten regression. A standard error of 5% was considered statistically significant (p < 0.05).

RESULTS

Of the 840 new cases identified in the study, there was a predominance of females (n = 427, 50.8%), of white race/color (n = 685, 81.6%), age range 15 to 59 years (n = 624, 74.3%), and incomplete elementary education (n = 504, 60.0%). The results obtained from multivariate analysis revealed that the proportion of households with monthly nominal household income per capita greater than 1 minimum wage (β = 0.025, p = 0.036) and people of brown race (β = -0.101, p = 0.024) were statistically-significantly associated with risk of illness due to leprosy. These results also confirmed that social determinants and risk of leprosy were significantly spatially non-stationary. Regarding the temporal trend, a decrease of 4% (95% CI [-0.053, -0.033], p = 0.000) per year was observed in the rate of detection of new cases of leprosy.

CONCLUSION

The social determinants income and race/color were associated with the risk of leprosy. The study's highlighting of these social determinants can contribute to the development of public policies directed toward the elimination of leprosy in the border region.

Spatial distribution of leprosy in Brazil: a literature review

Leprosy remains a public health problem in developing countries. Among communicable diseases, it is one of the leading causes of permanent disability. Brazil had not reached the goal of reducing cases to less than 1 per 10,000 population. This study aimed to analyze the spatial distribution of leprosy cases in Brazil, using a literature review. The search strategy included the LILACS and MEDLINE databases with no language or period restriction. Ecological studies with spatial data analysis were considered as a criterion for the inclusion. We found 38 studies for review after the selection criteria. Among the epidemiological indicators of the disease, the most common was the new case detection rate. Several articles have explored the association between spatial distribution of leprosy and socioeconomic, demographic, and environmental factors. The most common unit of analysis was the municipality. The spatial distribution methods mostly used were: empirical Bayesian method, autocorrelation (Moran's I index) and Kernel estimates. The distribution of leprosy was very heterogeneous, independent of the unit of analysis. There was a decrease in the rate of detection and among under-15-year-olds, but some regions maintained high endemicity during the study period. The distribution and risk of illness were directly related to living conditions of the population. Improved access to health services was associated with increased detection rate in some regions. Spatial analysis seems to be a very useful tool to study leprosy and to guide interventions and surveillance.

Social determinants of leprosy in a hyperendemic State in North Brazil

OBJECTIVE

To identify the socioeconomic, demographic, operational, and health service-related factors associated with the occurrence of leprosy in a hyperendemic State in North Brazil.

METHODS

This is an ecological study based on secondary data from the Sistema de Informações de Agravos de Notificação in municipalities of the State of Tocantins from 2001 to 2012. Units of analysis were the 139 municipalities of the State. Negative binomial log linear regression models were used to estimate incidence rate ratios.

RESULTS

In bivariate analysis, the incidence rate ratios were significantly higher for municipalities with higher income ratio of the poorest 20.0% (1.47; 95%CI 1.19-1.81) and better Municipal Human Development Index (1.53; 95%CI 1.14-2.06). In multivariate analysis, the incidence rate ratios were significantly higher in municipalities with higher proportion of immigrants (1.31; 95%CI 1.11-1.55) and higher proportion of households with waste collection (1.37; 95%CI 1.11-1.69). There was a significant reduction in the incidence rate ratio with increased coverage of the Bolsa Família Program (0.98; 95%CI 0.96-0.99).

CONCLUSIONS

Control programs need to focus on activities in municipalities of greater social vulnerability with intersectoral investment for the improvement of the living conditions of the population.

OBJETIVO

Identificar fatores socioeconômicos, demográficos, operacionais e de serviços de saúde associados à ocorrência da hanseníase em um estado hiperendêmico do norte do Brasil.

MÉTODOS

Estudo ecológico com dados secundários do Sistema de Informações de Agravos de Notificação em municípios do estado do Tocantins de 2001 a 2012. As unidades de análise foram os 139 municípios do estado. Modelos de regressão log linear binomial negativa foram utilizados para estimar as razões de taxas de incidência.

RESULTADOS

Na análise bivariada, a razão de taxa de incidência foi significativamente maior para os municípios com maior razão de renda dos 20,0% mais pobres (1,47; IC95% 1,19-1,81) e melhor Índice de Desenvolvimento Humano Municipal (1,53; IC95% 1,14-2,06). Na múltipla, a razão de taxa de incidência foi significativamente superior em municípios com maior concentração de imigrantes (1,31; IC95% 1,11-1,55) e proporção de domicílios com coleta de lixo (1,37; IC95% 1,11-1,69). Houve redução significativa da razão de taxa de incidência com o aumento da cobertura do programa bolsa família (0,98; IC95% 0,96-0,99).

CONCLUSÕES

Os programas de controle precisam focar as atividades em municípios de maior vulnerabilidade social com investimentos intersetoriais para a melhoria das condições de vida da população.

Análise da distribuição geográfica dos casos de hanseníase. Rio de Janeiro, 2001 a 2012

Resumo Trabalhos demonstraram que a distribuição geográfica da hanseníase está relacionada a diferentes fatores socioeconômicos. O objetivo deste artigo é estudar a distribuição geográfica da hanseníase no estado do Rio de Janeiro. Os casos de hanseníase notificados no período 2001-2012 foram mapeados segundo município. Foram calculados indicadores epidemiológicos e socioeconômicos. Utilizou-se o programa ArcMap para a construção dos mapas e o Terra View para o cálculo de taxa bayesiana. Observou-se que a hanseníase apresenta-se em níveis hiperendêmicos, especialmente na região metropolitana. No entanto, observa-se também uma redução do coeficiente de detecção no período mais recente do estudo. Em municípios da região metropolitana e da região noroeste a detecção em menores de 15 anos é elevada, indicando situação de transmissão ativa. Em municípios da região centro-sul e especialmente na baixada litorânea, observou-se elevada proporção de casos diagnosticados com grau II de incapacidade, refletindo alto índice de diagnóstico tardio. Não foi observada correlação linear entre os indicadores socioeconômicos e a detecção da hanseníase. Esses resultados contribuem para a análise da distribuição geográfica da hanseníase, importante para a identificação de áreas para alocação de recursos, visando controle e eliminação da doença.

A tale of two neglected tropical infections: using GIS to assess the spatial and temporal overlap of schistosomiasis and leprosy in a region of Minas Gerais, Brazil

BACKGROUND

Despite public health efforts to reduce the global burden of leprosy, gaps remain in the knowledge surrounding transmission of infection. Helminth co-infections have been associated with a shift towards the lepromatous end of the disease spectrum, potentially increasing transmission in co-endemic areas.

OBJECTIVES

Using this biologically plausible association, we conducted a geographic information systems (GIS) study to investigate the spatial associations of schistosomiasis and leprosy in an endemic area of Minas Gerais (MG), Brazil.

METHODS

Data on new cases of Mycobacterium leprae and Schistosoma mansoni infections from 2007-2014 were retrieved from the Brazilian national notifiable diseases information system for seven municipalities in and surrounding Vespasiano, MG. A total of 139 cases of leprosy and 200 cases of schistosomiasis were mapped to a municipality level. For one municipality, cases were mapped to a neighborhood level and a stratified analysis was conducted to identify spatial associations.

FINDINGS

A relative risk of 6.80 [95% confidence interval (CI) 1.46 - 31.64] of leprosy was found in neighborhoods with schistosomiasis. Incidence rates of leprosy increased with corresponding incidence rates of schistosomiasis, and the temporal trends of both infections were similar.

CONCLUSIONS

The associations found in this project support the hypothesis that helminth infections may influence the transmission of leprosy in co-endemic areas.

Trends of main indicators of leprosy in Brazilian municipalities with high risk of leprosy transmission, 2001-2012

Background

Leprosy incidence has reduced in recent years in Brazil, although the disease still persists as a public health problem in some regions. To investigate the trends of selected leprosy indicators in Brazilian municipalities with high risk of transmission is essential to provide effective control of the disease, yet this area has not been investigated.

Methods

This is an ecological time-series study with multiple groups using Notifiable Diseases Information System (SINAN) data. All 692 municipalities of the states of Mato Grosso, Tocantins, Rondônia, Pará and Maranhão were included. The incidence rates of leprosy were calculated, as well as incidence rates in children under 15 years per 100,000 inhabitants and rates of new cases presenting grade-2 disabilities per 100,000 inhabitants. Joinpoint Regression was used to analyse the time trends of the different indicators studied. The spatial distribution of temporal variations of the indicators in the period was presented.

Results

Between 2001 and 2012, 176,929 leprosy cases were notified in the area studied, this being equivalent to 34.6 % of total cases in Brazil. In the aggregate of municipalities, there was a reduction in incidence rate of leprosy from 89.10 to 56.98 new cases per 100,000 inhabitants between 2001 and 2012, with a significant reduction between 2003 and 2012 (APC: − 6.2 %, 95 % CI: −7.2 % to −5.2 %). The incidence rate in <15 years also reduced significantly between 2003 and 2012 (APC: −5.6 %; 95 % CI: −7.2 % to −4.1 %). The rate of new cases with grade 2 disability remained stable between 2001 and 2012 (APC: −1.3 %; 95 % CI: −2.6 % to 0.1 %).

Conclusion

Despite the reduction in the leprosy incidence rate, strategies for controlling this disease need to be enhanced to enable early case detection, especially in hyperendemic municipalities, in order to prevent disability.

Langerhans cells (CD1a and CD207), dermal dendrocytes (FXIIIa) and plasmacytoid dendritic cells (CD123) in skin lesions of leprosy patients

The clinical course of infection with Mycobacterium leprae varies widely and depends on the pattern of the host immune response. Dendritic cells play an important role in the activation of the innate and adaptive immune system and seem to be essential for the development of the disease. To analyze the presence of epidermal dendritic cells (CD1a and CD207), plasmacytoid dendritic cells (CD123) and dermal dendrocytes (factor XIIIa) in lesion fragments of leprosy patients, skin samples from 30 patients were studied. These samples were submitted to immunohistochemistry against CD1a, CD207, FXIIIa, and CD123. The results showed a larger number of Langerhans cells, detected with the CD1a or CD207 marker, dermal dendrocytes and plasmacytoid dendritic cells in patients with the tuberculoid form. A positive correlation was observed between the Langerhans cell markers CD1a and CD207 in both the tuberculoid and lepromatous forms, and between Langerhans cells and dermal dendrocytes in samples with the tuberculoid form. The present results indicate the existence of a larger number of dendritic cells in patients at the resistant pole of the disease (tuberculoid) and suggest that the different dendritic cells studied play a role, favoring an efficient immune response against infection with M. leprae.

In Vitro Protective Effect and Antioxidant Mechanism of Resveratrol Induced by Dapsone Hydroxylamine in Human Cells

Dapsone (DDS) hydroxylamine metabolites cause oxidative stress- linked adverse effects in patients, such as methemoglobin formation and DNA damage. This study evaluated the ameliorating effect of the antioxidant resveratrol (RSV) on DDS hydroxylamine (DDS-NHOH) mediated toxicity in vitro using human erythrocytes and lymphocytes. The antioxidant mechanism was also studied using in-silico methods. In addition, RSV provided intracellular protection by inhibiting DNA damage in human lymphocytes induced by DDS-NHOH. However, whilst pretreatment with RSV (10–1000 μM significantly attenuated DDS-NHOH-induced methemoglobinemia, but it was not only significantly less effective than methylene blue (MET), but also post-treatment with RSV did not reverse methemoglobin formation, contrarily to that observed with MET. DDS-NHOH inhibited catalase (CAT) activity and reactive oxygen species (ROS) generation, but did not alter superoxide dismutase (SOD) activity in erythrocytes. Pretreatment with RSV did not alter these antioxidant enzymes activities in erythrocytes treated with DDS-NHOH. Theoretical calculations using density functional theory methods showed that DDS-NHOH has a pro-oxidant effect, whereas RSV and MET have antioxidant effect on ROS. The effect on methemoglobinemia reversion for MET was significantly higher than that of RSV. These data suggest that the pretreatment with resveratrol may decrease heme-iron oxidation and DNA damage through reduction of ROS generated in cells during DDS therapy.