BackgroundLeprosy control is based on early diagnosis and multidrug therapy. For treatment purposes, leprosy patients can be classified as paucibacillary (PB) or multibacillary (MB), according to the number of skin lesions. Studies regarding a uniform treatment regimen (U-MDT) for all leprosy patients have been encouraged by the WHO, rendering disease classification unnecessary.Methodology and findingsAn independent, randomized, controlled clinical trial conducted from 2007 to 2015 in Brazil, compared main outcomes (frequency of reactions, bacilloscopic index trend, disability progression and relapse rates) among MB patients treated with a uniform regimen/U-MDT (dapsone+rifampicin+clofazimine for six months) versus WHO regular-MDT/R-MDT (dapsone+rifampicin+clofazimine for 12 months). A total of 613 newly diagnosed, untreated MB patients with high bacterial load were included. There was no statistically significant difference in Kaplan-Meyer survival function regarding reaction or disability progression among patients in the U-MDT and R-MDT groups, with more than 25% disability progression in both groups. The full mixed effects model adjusted for the bacilloscopic index average trend in time showed no statistically significant difference for the regression coefficient in both groups and for interaction variables that included treatment group.During active follow up, four patients in U-MDT group relapsed representing a relapse rate of 2.6 per 1000 patients per year of active follow up (95% CI [0·81, 6·2] per 1000). During passive follow up three patients relapsed in U-MDT and one in R-MTD. As this period corresponds to passive follow up, sensitivity analysis estimated the relapse rate for the entire follow up period between 2·9- and 4·5 per 1000 people per year.ConclusionOur results on the first randomized and controlled study on U-MDT together with the results from three previous studies performed in China, India and Bangladesh, support the hypothesis that UMDT is an acceptable option to be adopted in endemic countries to treat leprosy patients in the field worldwide.Trial registrationClinicalTrials.gov: NCT00669643
FUNDAMENTOS: A hanseníase permanece sério problema de saúde pública mundial. O conhecimento das características epidemiológicas da doença é importante ferramenta para o controle da endemia. OBJETIVO: Descrever as características clínicas e epidemiológicas dos pacientes diagnosticados com hanseníase no ano de 2004 em um centro de referência da Região Nordeste do Brasil. MÉTODO: Foram avaliados prontuários de pacientes que deram entrada no registro ativo do Centro de Dermatologia Dona Libânia, em Fortaleza, Ceará, no período de janeiro a dezembro de 2004. RESULTADOS: dos 967 casos que deram entrada nesse Centro naquele ano, 909 foram casos novos. Cerca de 7,7% eram pacientes entre zero e 14 anos de idade, e a distribuição por gênero foi de 483 (49,95%) homens e 484 (50,05%) mulheres. A maioria apresentava a forma clínica dimorfa (54,6%), sendo 82,2% dos pacientes provenientes de Fortaleza, CE. Foi realizada a avaliação do grau de incapacidades no diagnóstico em 94,2% dos pacientes, com 21,7% apresentando grau diferente de zero no diagnóstico. CONCLUSÃO: Com base nos resultados obtidos, constatou-se a presença de elevado percentual (7,7%) de casos detectados em menores de 15 anos, associado a baixo percentual (5,8%) de pacientes diagnosticados na forma indeterminada e elevado percentual (21,7%) de casos com incapacidade ao diagnóstico.
h Skin biopsy samples from 145 relapse leprosy cases and from five different regions in Brazil were submitted for sequence analysis of part of the genes associated with Mycobacterium leprae drug resistance. Single nucleotide polymorphisms (SNPs) in these genes were observed in M. leprae from 4 out of 92 cases with positive amplification (4.3%) and included a case with a mutation in rpoB only, another sample with SNPs in both folP1 and rpoB, and two cases showing mutations in folP1, rpoB, and gyrA, suggesting the existence of multidrug resistance (MDR). The nature of the mutations was as reported in earlier studies, being CCC to CGC in codon 55 in folP (Pro to Arg), while in the case of rpoB, all mutations occurred at codon 531, with two being a transition of TCG to ATG (Ser to Met), one TCG to TTC (Ser to Phe), and one TCG to TTG (Ser to Leu). The two cases with mutations in gyrA changed from GCA to GTA (Ala to Val) in codon 91. The median time from cure to relapse diagnosis was 9.45 years but was significantly shorter in patients with mutations (3.26 years; P ؍ 0.0038). More than 70% of the relapses were multibacillary, including three of the mutation-carrying cases; one MDR relapse patient was paucibacillary. There is no doubt about the efficiency of the currently used multidrug therapy (MDT) scheme for treatment of leprosy, as demonstrated by the strong decrease in disease prevalence since its implementation and the low number of reported relapse cases (18). However, there has been a scarcity of in-depth studies of relapse occurrences in recent decades (27). As is known, differentiating diagnosis of relapse and reactional states poses some difficulties in the field, being responsible for under-or overdiagnosis of both disease stages. This is important because undiagnosed relapse cases could contribute to continuing disease transmission. In addition, hardly any data on the contribution of emergence of drug-resistant strains of Mycobacterium leprae to leprosy relapses exist.Diaminodiphenylsulfone (DDS), also called dapsone, was the first drug to be effective against leprosy worldwide, and the first cases of resistance to dapsone were detected in 1964 and involved two single nucleotide polymorphisms (SNPs) in the gene folP1, located in codons 53 and 55 (8, 9, 14, 29). Rifampin is the key component of the standard multidrug regimen used for treatment of leprosy, and it has been shown that PCR-based DNA sequence analysis of the rpoB gene of M. leprae was in full concordance with rifampin susceptibility testing in the mouse footpad system (17, 30). In addition to dapsone and rifampin, ofloxacin is also used for leprosy treatment and is a quinolone with an action mechanism based on interaction with DNA gyrase (2); SNPs in gyrA and gyrB confer resistance or hypersensitivity to quinolones (15). Although there is not yet an official definition of multidrug resistance (MDR) in leprosy, in parallel with tuberculosis, we adopt this terminology when we encounter resistance to rifampin and one other drug of the standard M...
BackgroundSince leprosy is both treated and controlled by multidrug therapy (MDT) it is important to monitor recurrent cases for drug resistance and to distinguish between relapse and reinfection as a means of assessing therapeutic efficacy. All three objectives can be reached with single nucleotide resolution using next generation sequencing and bioinformatics analysis of Mycobacterium leprae DNA present in human skin.MethodologyDNA was isolated by means of optimized extraction and enrichment methods from samples from three recurrent cases in leprosy patients participating in an open-label, randomized, controlled clinical trial of uniform MDT in Brazil (U-MDT/CT-BR). Genome-wide sequencing of M. leprae was performed and the resultant sequence assemblies analyzed in silico.Principal findingsIn all three cases, no mutations responsible for resistance to rifampicin, dapsone and ofloxacin were found, thus eliminating drug resistance as a possible cause of disease recurrence. However, sequence differences were detected between the strains from the first and second disease episodes in all three patients. In one case, clear evidence was obtained for reinfection with an unrelated strain whereas in the other two cases, relapse appeared more probable.Conclusions/SignificanceThis is the first report of using M. leprae whole genome sequencing to reveal that treated and cured leprosy patients who remain in endemic areas can be reinfected by another strain. Next generation sequencing can be applied reliably to M. leprae DNA extracted from biopsies to discriminate between cases of relapse and reinfection, thereby providing a powerful tool for evaluating different outcomes of therapeutic regimens and for following disease transmission.
During recent years, comparative genomic analysis has allowed the identification of Mycobacterium leprae-specific genes with potential application for the diagnosis of leprosy. In a previous study, 58 synthetic peptides derived from these sequences were tested for their ability to induce production of IFN-γ in PBMC from endemic controls (EC) with unknown exposure to M. leprae, household contacts of leprosy patients and patients, indicating the potential of these synthetic peptides for the diagnosis of sub- or preclinical forms of leprosy. In the present study, the patterns of IFN-γ release of the individuals exposed or non-exposed to M. leprae were compared using an Artificial Neural Network algorithm, and the most promising M. leprae peptides for the identification of exposed people were selected. This subset of M. leprae-specific peptides allowed the differentiation of groups of individuals from sites hyperendemic for leprosy versus those from areas with lower level detection rates. A progressive reduction in the IFN-γ levels in response to the peptides was seen when contacts of multibacillary (MB) patients were compared to other less exposed groups, suggesting a down modulation of IFN-γ production with an increase in bacillary load or exposure to M. leprae. The data generated indicate that an IFN-γ assay based on these peptides applied individually or as a pool can be used as a new tool for predicting the magnitude of M. leprae transmission in a given population.
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