Uniform multidrug therapy for leprosy patients in Brazil (U-MDT/CT-BR): Results of an open label, randomized and controlled clinical trial, among multibacillary patients

Late relapses in leprosy patients in Brazil: 10-year post-trial of uniform multidrug therapy (U-MDT/CT-BR)

BACKGROUND

Leprosy is a neglected dermato-neurologic, infectious disease caused by Mycobacterium leprae or M. lepromatosis. Leprosy is treatable and curable by multidrug therapy/MDT, consisting of 12 months rifampicin, dapsone and clofazimine for multibacillary/MB patients and for 6 months for paucibacillary/PB patients. The relapse rate is considered a crucial treatment outcome. A randomized Controlled Trial (U-MDT/CT-BR) conducted from 2007‒2012 compared clinical outcomes in MB patients after 12 months regular MDT/R-MDT and 6 months uniform MDT/U-MDT in two highly endemic Brazilian areas.

OBJECTIVES

To estimate the 10 years relapse rate of MB patients treated with 6 months U-MDT.

METHODS

The statistical analyses treated the data as a case-control study, sampled from the cohort generated for the randomized trial. Analyses estimated univariate odds ratio and applied logistic regression for multivariate analysis, controlling the confounding variables.

RESULTS

The overall relapse rate was 4.08 %: 4.95 % (16 out of 323) in the U-MDT group and 3.10 % (9 out of 290) in the regular/R-MDT group. The difference in relapse proportion between U-MDT and R-MDT groups was 1.85 %, not statistically significant (Odds Ratio = 1.63, 95 % CI 0.71 to 3.74). However, misdiagnosis of relapses, may have introduced bias, underestimating the force of the association represented by the odds ratio.

CONCLUSIONS

The relapse estimate of 10 years follow-up study of the first randomized, controlled study on U-MDT/CT-BR was similar to the R-MDT group supporting strong evidence that 6 months U-MDT for MB patients is an acceptable option to be adopted by leprosy endemic countries worldwide.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT00669643.

The role of CXCL10 as a biomarker for immunological response among patients with leprosy: a systematic literature review

Introduction

Involvement of a chemokine known as C-X-C motif chemokine ligand 10 or CXCL10 in the immunopathology of leprosy has emerged as a possible immunological marker for leprosy diagnosis and needed to be investigate further. The purpose of this systematic review is to assess CXCL10's potential utility as a leprosy diagnostic tool and evaluation of therapy.

Methods

This systematic review is based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020. A thorough search was carried out to find relevant studies only in English and limited in humans published up until September 2023 using PubMed, Scopus, Science Direct, and Wiley Online Library database with keywords based on medical subject headings (MeSH) and no exclusion criteria. The Newcastle-Ottawa Scale (NOS) was utilized for quality assessment, while the Risk of Bias Assessment tool for Non-randomized Studies (RoBANS) was utilized for assessing the risk of bias. Additionally, a narrative synthesis was conducted to provide a comprehensive review of the results.

Results

We collected a total of 115 studies using defined keywords and 82 studies were eliminated after titles and abstracts were screened. We assessed the eligibility of the remaining 26 reports in full text and excluded four studies due to inappropriate study design and two studies with incomplete outcome data. There were twenty included studies in total with total of 2.525 samples. The included studies received NOS quality evaluation scores ranging from 6 to 8. The majority of items in the risk bias assessment, using RoBANS, across all included studies yielded low scores. However, certain items related to the selection of participants and confounding variables showed variations. Most of studies indicate that CXCL10 may be a helpful immunological marker for leprosy diagnosis, particularly in leprosy reactions as stated in seven studies. The results are better when paired with other immunological markers. Its effectiveness in field-friendly diagnostic tools makes it one of the potential biomarkers used in diagnosing leprosy patients. Additionally, CXCL10 may be utilized to assess the efficacy of multidrug therapy (MDT) in leprosy patients as stated in three studies.

Conclusion

The results presented in this systematic review supports the importance of CXCL10 in leprosy diagnosis, particularly in leprosy responses and in tracking the efficacy of MDT therapy. Using CXCL10 in clinical settings might help with leprosy early diagnosis. Yet the findings are heterogenous, thus more investigation is required to determine the roles of CXCL10 in leprosy while taking into account for additional confounding variables.

Unmasking the Hidden Burden: A Delayed Diagnosis of Leprosy Patients With Grade 2 Disability and Its Effects on the Healthcare System in Bangladesh

Introduction Leprosy remains a significant cause of preventable disability worldwide. Early diagnosis and treatment of leprosy are critical not only to stop its spread but also to prevent physical and social complications and reduce the disease burden. Objectives The study aims to evaluate the factors that lead to a delayed leprosy diagnosis. Methods This study was conducted in the outpatient departments of Leprosy Control Institute and Hospital, Dhaka, Bangladesh, and at Medical College for Women and Hospital, Dhaka, Bangladesh, from March 2023 to June 2023. A total number of 252 male (148) and female (104) patients were selected with any sign of leprosy, including disability, age ranging from 15 to 74 years. Data was collected in a pre-designed structured questionnaire by the researchers. To assess the risk of independent exposures of Grade 2 leprosy disabilities, we used a logistic regression model. A chi-square test showed the association between significant effects and leprosy disabilities. A p-value of 0.05 was considered as significant. For statistical analysis, STATA version 15 (StataCorp LLC, College Station, Texas, USA) was used. Results The study participants exhibited a higher percentage of disability, with a rate of 25.8% for Grade 2 disabilities. In addition to this, males represented a more considerable proportion, 58.7%, than females among leprosy and disability patients across all levels of disability. In our study, lack of money and painless symptoms showed a significant association (p<0.001) with Grade 2 disability. Conclusion The study reveals that Grade 2 disabilities are more common in males and are particularly prevalent in lower socioeconomic groups.

Single-Dose Rifapentine in Household Contacts of Patients with Leprosy

BACKGROUND

Previous studies have suggested that a single dose of rifampin has protective effects against leprosy in close contacts of patients with the disease. Rifapentine was shown to have greater bactericidal activity against Mycobacterium leprae than rifampin in murine models of leprosy, but data regarding its effectiveness in preventing leprosy are lacking.

METHODS

We conducted a cluster-randomized, controlled trial to investigate whether single-dose rifapentine is effective in preventing leprosy in household contacts of patients with leprosy. The clusters (counties or districts in Southwest China) were assigned to one of three trial groups: single-dose rifapentine, single-dose rifampin, or control (no intervention). The primary outcome was the 4-year cumulative incidence of leprosy among household contacts.

RESULTS

A total of 207 clusters comprising 7450 household contacts underwent randomization; 68 clusters (2331 household contacts) were assigned to the rifapentine group, 71 (2760) to the rifampin group, and 68 (2359) to the control group. A total of 24 new cases of leprosy occurred over the 4-year follow-up, for a cumulative incidence of 0.09% (95% confidence interval [CI], 0.02 to 0.34) with rifapentine (2 cases), 0.33% (95% CI, 0.17 to 0.63) with rifampin (9 cases), and 0.55% (95% CI, 0.32 to 0.95) with no intervention (13 cases). In an intention-to-treat analysis, the cumulative incidence in the rifapentine group was 84% lower than that in the control group (cumulative incidence ratio, 0.16; multiplicity-adjusted 95% CI, 0.03 to 0.87; P = 0.02); the cumulative incidence did not differ significantly between the rifampin group and the control group (cumulative incidence ratio, 0.59; multiplicity-adjusted 95% CI, 0.22 to 1.57; P = 0.23). In a per-protocol analysis, the cumulative incidence was 0.05% with rifapentine, 0.19% with rifampin, and 0.63% with no intervention. No severe adverse events were observed.

CONCLUSIONS

The incidence of leprosy among household contacts over 4 years was lower with single-dose rifapentine than with no intervention. (Funded by the Ministry of Health of China and the Chinese Academy of Medical Sciences; Chinese Clinical Trial Registry number, ChiCTR-IPR-15007075.).

Effectiveness and safety of multidrug therapy containing clofazimine for paucibacillary leprosy and clarithromycin for rifampicin-resistant leprosy: a systematic review and meta-analysis

Introduction

The present study aimed to evaluate leprosy cure and relapse rates as primary outcomes related to two additional strategies for leprosy treatment: clofazimine for paucibacillary (PB) leprosy patients and clarithromycin for patients with rifampicin-resistant leprosy.

Methods

We conducted two systematic reviews (protocols CRD42022308272 and CRD42022308260). We searched the PubMed, EMBASE, Web of Science, Scopus, LILACS, Virtual Health Library and Cochrane Library databases, registers of clinical trial databases and gray literature. We included clinical trials evaluating the addition of clofazimine to PB leprosy treatment and the use of clarithromycin for treating patients with rifampicin-resistant leprosy. Risk of bias (RoB) in randomized clinical trials was assessed by the RoB 2 tool and that in non-randomized clinical trials was assessed by the ROBINS-I tool; and the certainty of the evidence was assessed by the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system. A meta-analysis of dichotomous outcomes was performed.

Results

For clofazimine, four studies were included. Cure and relapse rates were not different with the addition of clofazimine to PB leprosy treatment and demonstrated very low certainty of evidence. For clarithromycin, six studies were included. Considerable heterogeneity resulted from the difference between comparators, and studies showed no difference in the assessed outcomes with the addition of clarithromycin to rifampicin-resistant leprosy treatment. Mild adverse events were reported for both drugs but did not significantly impact treatment.

Discussion

The effectiveness of both drugs still needs to be determined. Adding clofazimine to PB leprosy treatment may reduce the repercussions of an incorrect operational classification with no apparent relevant side effects.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022308272; https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022308260, identifier: CRD42022308272; CRD42022308260.

Critical observation of WHO recommended multidrug therapy on the disease leprosy through mathematical study

Leprosy is a skin disease and it is characterized by a disorder of the peripheral nervous system which occurs due to the infection of Schwann cells. In this research article, we have formulated a four-dimensional ODE-based mathematical model which consists of the densities of healthy Schwann cells, infected Schwann cells, M. leprae bacteria, and the concentration of multidrug therapy (MDT). This work primarily aims on exploring the dynamical changes and interrelations of the system cell populations during the disease progression. Also, evaluating a critical value of the drug efficacy rate of MDT remains our key focus in this article so that a safe drug dose regimen for leprosy can be framed more effectively and realistically. We have examined the stability scenario of different equilibria and the occurrence of Hopf-bifurcation for the densities of our system cell populations with respect to the drug efficacy rate of MDT to gain insight on the precise impact of the efficiency rate on both the infected Schwann cell and the bacterial populations. Also, a necessary transversality condition for the occurrence of the bifurcation has been established. Our analytical and numerical investigations in this research work precisely explores that the process of demyelination, nerve regeneration, and infection of the healthy Schwann cells are the three most crucial factors in the leprosy pathogenesis and to control the M. leprae-induced infection of Schwann cells successfully, a more flexible version of MDT regime with efficacy rate varying in the range η∈(0.025,0.059) for 100-120 days in PB cases and 300 days in MB cases obtained in this research article should be applied. All of our analytical outcomes have been verified through numerical simulations and compared with some existing clinical findings.

Seventy years of evidence on the efficacy and safety of drugs for treating leprosy: a network meta-analysis

OBJECTIVE

The World Health Organization (WHO) recommends multidrug therapy (MDT) with rifampicin, dapsone, and clofazimine for treating leprosy, which is based on very low-quality evidence. Here, we performed a network meta-analysis (NMA) to produce quantitative evidence to strengthen current WHO recommendations.

METHOD

All studies were obtained from Embase and PubMed from the date of establishment to October 9, 2021. Data were synthesized with frequentist random-effects network meta-analyses. Outcomes were assessed using odds ratios (ORs), 95% confidence intervals (95% CIs), and P score.

RESULTS

Sixty controlled clinical trials and 9256 patients were included. MDT was effective (range of OR: 1.06-1255584.25) for treating leprosy and multibacillary leprosy. Six treatments (Range of OR: 1.199-4.50) were more effective than MDT. Clofazimine (P score=0.9141) and dapsone+rifampicin (P score=0.8785) were effective for treating type 2 leprosy reaction. There were no significant differences in the safety of any of the tested drug regimens.

CONCLUSIONS

The WHO MDT is effective for treating leprosy and multibacillary leprosy, but it may not be effective enough. Pefloxacin and ofloxacin may be good adjunct drugs for increasing MDT efficacy. Clofazimine and dapsone+rifampicin can be used in the treatment of a type 2 leprosy reaction. Single-drug regimens are not efficient enough to treat leprosy, multibacillary leprosy, or a type 2 leprosy reaction.

AVAILABILITY OF DATA AND MATERIALS

All data generated or analyzed during this study are included in this published article [and its supplementary information files].

Systematic Review of Survival Analysis in Leprosy Studies-Including the Following Outcomes: Relapse, Impairment of Nerve Function, Reactions and Physical Disability

Leprosy is a public health problem in South American, African and Oceanian countries. National programs need to be evaluated, and the survival analysis model can aid in the construction of new indicators. The aim of this study was to assess the period of time until the outcomes of interest for patients with or exposed to leprosy by means of survival analysis surveys. This review researched articles using the databases of PubMed, Science Direct, Scopus, Scielo and BVS published in English and Portuguese. Twenty-eight articles from Brazil, India, Bangladesh, the Philippines and Indonesia were included. The Kaplan-Meier method, which derives the log-rank test, and Cox's proportional hazards regression, which obtains the hazard ratio, were applied. The mean follow-up until the following outcomes were: (I) leprosy (2.3 years) in the population who were exposed to it, (II) relapse (5.9 years), (III) clinical manifestations before, during and after treatment-nerve function impairment (5.2 years), leprosy reactions (4.9 years) and physical disability (8.3 years) in the population of patients with leprosy. Therefore, the use of survival analysis will enable the evaluation of national leprosy programs and assist in the decision-making process to face public health problems.

Mycobacterium leprae induces Schwann cell proliferation and migration in a denervated milieu following intracutaneous excision axotomy in nine-banded armadillos

Nine-banded armadillos develop peripheral neuropathy after experimental Mycobacterium leprae infection that recapitulates human disease. We used an intracutaneous excision axotomy model to assess the effect of infection duration by M. leprae on axonal sprouting and Schwan cell density. 34 armadillos (17 naïve and 17 M. leprae-infected) underwent 3 mm skin biopsies to create an intracutaneous excision axotomy followed by a concentric 4-mm overlapping biopsy 3 and 12-months post M. leprae inoculation. A traditional distal leg biopsy was obtained at 15mo for intraepidermal nerve fiber (IENF) density. Serial skin sections were immunostained against a axons (PGP9.5, GAP43), and Schwann cells (p75, s100) to visualize regenerating nerves. Regenerative axons and proliferation of Schwann cells was measured and the rate of growth at each time point was assessed. Increasing anti-PGL antibody titers and intraneural M. leprae confirmed infection. 15mo following infection, there was evidence of axon loss with reduced distal leg IENF versus naïve armadillos, p < 0.05. This was associated with an increase in Schwann cell density (11,062 ± 2905 vs. 7561 ± 2715 cells/mm³, p < 0.01). Following excisional biopsy epidermal reinnervation increased monotonically at 30, 60 and 90 days; the regeneration rate was highest at 30 days, and decreased at 60 and 90 days. The reinnervation rate was highest among animals infected for 3mo vs those infected for 12mo or naïve animals (mean ± SD, 27.8 ± 7.2 vs.16.2 ± 5.8vs. 15.3 ± 6.5 mm/mm³, p < 0.05). The infected armadillos displayed a sustained Schwann cell proliferation across axotomy time points and duration of infection (3mo:182 ± 26, 12mo: 256 ± 126, naive: 139 ± 49 cells/day, p < 0.05). M. leprae infection is associated with sustained Schwann cell proliferation and distal limb nerve fiber loss. Rates of epidermal reinnervation were highest 3mo after infection and normalized by 12 mo of infection. We postulate that excess Schwann cell proliferation is the main pathogenic process and is deleterious to sensory axons. There is a compensatory initial increase in regeneration rates that may be an attempt to compensate for the injury, but it is not sustained and eventually followed by axon loss. Aberrant Schwann cell proliferation may be a novel therapeutic target to interrupt the pathogenic cascade of M. leprae.

[Factors associated with timing of lepra reactions in a cohort from 2008 to 2016 in Rondônia, Amazon Region, Brazil]

The clinical management of leprosy patients poses a specific challenge, namely lepra reactions. This non-concurrent cohort study aimed to analyze the timing of the first lepra reaction during and after polychemotherapy (PCT) and associated factors. A total of 1,621 patients were assessed (PB = 8.9% and MB = 91.1%) from 2008 to 2016, reported to the System of Reaction States in Leprosy (SisReação/RO) database. Reactions occurred predominantly during PCT (997; 61.5%) and less frequently only after PCT (624; 38.5%). Earliness of the reaction after diagnosis was analyzed with Kaplan-Meier survival curves, with comparison between the PB and MB groups using the Mantel-Cox log-rank test. Univariate and multivariate Cox regression models were constructed to identify factors associated with occurrence of lepra reactions (hazard ratio) and the corresponding 95%CI. The multivariate model included variables with p-values < 0.20 in the univariate analysis. PB patients developed reactions earlier than MB patients. Other characteristics were associated with earlier reactions: female gender and negative smear microscopy. In the aggregate period (during and after PCT), PB presented 24% higher risk of lepra reaction than MB patients, and negative smear microscopy increased this risk by 40% compared to positive smear microscopy. During and after PCT, PB presented 1.3 and 1.6 times the risk, respectively, of reactions when compared to MB patients. We thus recommend prioritizing surveillance of lepra reactions during and after PCT as measures to prevent physical disabilities and to improve quality of life for persons with leprosy.

A systematic review and meta-analysis of studies on the diagnostic accuracy and screening of tests to detect antimicrobial resistance in leprosy

Although multidrug therapy is considered an effective treatment for leprosy, antimicrobial resistance is a serious concern. We performed a systematic review of studies on the diagnostic accuracy and screening of tests for antimicrobial resistance in leprosy. This review was registered in PROSPERO (CRD42020177958). In April 2020, we searched for studies in the PubMed, EMBASE, Web of Science, Scopus, Scielo, and LILACS databases. A random effects regression model was used for the meta-analysis. We included 129 studies. Molecular tests for dapsone resistance had a sensitivity of 78.8% (95% confidence interval [CI] = 65.6-87.9) and a specificity of 97.0% (95% CI = 94.0-98.6). Molecular tests for rifampicin resistance had a sensitivity and specificity of 88.7% (95% CI = 80.0-93.9) and 97.3% (95% CI = 94.3-98.8), respectively. Molecular tests for ofloxacin resistance had a sensitivity and specificity of 80.9% (95% CI = 60.1-92.3) and 96.1% (95% CI = 90.2-98.5), respectively. In recent decades, no increase in the resistance proportion was detected. However, the growing number of resistant cases is still a clinical concern.

Chronic aspects of leprosy-neglected but important

The chronic aspects of leprosy are discussed here. They are a consequence of the peripheral nerve damage that affects many patients during their lifetime with leprosy. The peripheral nerve damage leaves people unable to feel and with weakness in their hands and feet. They are at risk of damaging their hands and feet, causing the disabilities and deformities that characterise late leprosy. More than 200 000 new leprosy patients are diagnosed globally each year. Better data are needed from cohort studies to estimate the number of patients developing nerve damage and modelling studies are needed to estimate the number of patients who develop disabilities. For some of them, this will be a lifelong disability. Nerve damage is caused by inflammation in leprosy-affected nerves. Patients with nerve damage of <6-mo duration need treatment with steroids. About 66% of multibacillary patients will develop nerve damage. Plastic graded monofilaments can be used to detect nerve damage in leprosy and diabetic clinics. Assessing nerve damage and treating patients with steroids in leprosy programmes needs to be strengthened. The World Health Organization has a successful programme for supplying antibiotics for treating leprosy infection to national leprosy programmes. They should take responsibility for providing steroids to national programmes since this is a core part of the treatment for >66% of multibacillary patients. Patients need to be asked about neuropathic pain symptoms and treated if necessary. Treated leprosy patients are at risk of developing ulcers in their feet. Treatment and prevention needs to be improved through health education, providing protective footwear and patient empowerment.

Clofazimine: an old drug for never-ending diseases

Clofazimine (CFZ), an old hydrophobic riminophenazine, has a wide range of antimycobacterial activity ranging from leprosy to nontuberculous mycobacterial diseases. CFZ has several advantages such as a favorable pharmacokinetic profile, dose-dependent side effects as well as low price. In this narrative review, we have assessed the clinical development of CFZ, starting from the potential in vitro mechanism of actions, to the spectrum of side effects and potential drug-drug interactions, highlighting its current place in therapy and future possible use in leprosy, nontuberculous mycobacterial diseases and drug-resistant tuberculosis.

Leprosy: Treatment and management of complications

In the second article in this continuing medical education series, we review the treatment of leprosy, its immunologic reactions, and important concepts, including disease relapse and drug resistance. A fundamental understanding of the treatment options and management of neuropathic sequelae are essential to reduce disease burden and improve patients' quality of life.

Human Genetic Susceptibility of Leprosy Recurrence

Host genetic susceptibility to leprosy has been intensively investigated over the last decades; however, there are no studies on the role of genetic variants in disease recurrence. A previous initiative identified three recurrent cases of leprosy for which none of the M. leprae strains, as obtained in the first and the second diagnosis, had any known genomic variants associated to resistance to Multidrug therapy; in addition, whole genome sequencing indicated that the same M. leprae was causing two out of the three recurrences. Thus, these individuals were suspected of being particularly susceptible to M. leprae infection, either as relapse or reinfection. To verify this hypothesis, 19 genetic markers distributed across 11 loci (14 genes) classically associated with leprosy were genotyped in the recurrent and in three matching non-recurrent leprosy cases. An enrichment of risk alleles was observed in the recurrent cases, suggesting the existence of a particularly high susceptibility genetic profile among leprosy patients predisposing to disease recurrence.

World Health Organization (WHO) antibiotic regimen against other regimens for the treatment of leprosy: a systematic review and meta-analysis

BACKGROUND

To evaluate the effectiveness and safety of the World Health Organization antibiotic regimen for the treatment of paucibacillary (PB) and multibacillary (MB) leprosy compared to other available regimens.

METHODS

We performed a search from 1982 to July 2018 without language restriction. We included randomized controlled trials, quasi-randomized trials, and comparative observational studies (cohorts and case-control studies) that enrolled patients of any age with PB or MB leprosy that were treated with any of the leprosy antibiotic regimens established by the WHO in 1982 and used any other antimicrobial regimen as a controller. Primary efficacy outcomes included: complete clinical cure, clinical improvement of the lesions, relapse rate, treatment failure. Data were pooled using a random effects model to estimate the treatment effects reported as relative risk (RR) with 95% confidence intervals (CI).

RESULTS

We found 25 eligible studies, 11 evaluated patients with paucibacillary leprosy, while 13 evaluated patients with MB leprosy and 1 evaluated patients of both groups. Diverse regimen treatments and outcomes were studied. Complete cure at 6 months of multidrug therapy (MDT) in comparison to rifampin-ofloxacin-minocycline (ROM) found RR of 1.06 (95% CI 0.88-1.27) in five studies. Whereas six studies compare the same outcome at different follow up periods between 6 months and 5 years, according to the analysis ROM was not better than MDT (RR of 1.01 (95% CI 0.78-1.31)) in PB leprosy.

CONCLUSION

Not better treatment than the implemented by the WHO was found. Diverse outcome and treatment regimens were studied, more statements to standardized the measurements of outcomes are needed.

Brickley E, C. Rodrigues L, Smeeth L, L. Barreto M, Martins Pereira S, Oliveira Penna G. Geographic and socioeconomic factors associated with leprosy treatment default: An analysis from the 100 Million Brazilian Cohort

Background

Although leprosy is largely curable with multidrug therapy, incomplete treatment limits therapeutic effectiveness and is an important obstacle to disease control. To inform efforts to improve treatment completion rates, we aimed to identify the geographic and socioeconomic factors associated with leprosy treatment default in Brazil.

Methodology/Principal findings

Using individual participant data collected in the Brazilian national registries for social programs and notifiable diseases and linked as part of the 100 Million Brazilian Cohort, we evaluated the odds of treatment default among 20,063 leprosy cases diagnosed and followed up between 2007 and 2014. We investigated geographic and socioeconomic risk factors using a multivariate hierarchical analysis and carried out additional stratified analyses by leprosy subtype and geographic region. Over the duration of follow-up, 1,011 (5.0%) leprosy cases were observed to default from treatment. Treatment default was markedly increased among leprosy cases residing in the North (OR = 1.57; 95%CI 1.25–1.97) and Northeast (OR = 1.44; 95%CI 1.17–1.78) regions of Brazil. The odds of default were also higher among cases with black ethnicity (OR = 1.29; 95%CI 1.01–1.69), no income (OR = 1.41; 95%CI 1.07–1.86), familial income ≤ 0.25 times Brazilian minimum wage (OR = 1.42; 95%CI 1.13–1.77), informal home lighting/no electricity supply (OR = 1.53; 95%CI 1.28–1.82), and household density of > 1 individual per room (OR = 1.35; 95%CI 1.10–1.66).

Conclusions

The findings of the study indicate that the frequency of leprosy treatment default varies regionally in Brazil and provide new evidence that adverse socioeconomic conditions may represent important barriers to leprosy treatment completion. These findings suggest that interventions to address socioeconomic deprivation, along with continued efforts to improve access to care, have the potential to improve leprosy treatment outcomes and disease control.

While the leprosy new case detection has been decreasing worldwide since the introduction of multidrug therapy (MDT) in the 1980s, treatment default remains an important risk factor for leprosy-associated disability and an obstacle to disease control and elimination. Treatment default occurs when an individual with leprosy does not take the prescribed number of doses required for treatment with MDT. We hypothesized that the frequency of defaulting may be influenced by geographic factors, especially as related to access to care, and socioeconomic factors, such as income, education, and household living conditions. To test this hypothesis, we investigated geographic and socioeconomic factors associated with leprosy treatment default among 20,063 new leprosy cases followed as part of the 100 Million Brazilian Cohort between 2007 and 2014. In total, 5.0% of the leprosy patients defaulted from MDT. Among the associated factors, we found that having residency in the North and Northeast of Brazil, black ethnicity, low familial income, lack of formal electricity, and a high household density were associated with higher odds of leprosy treatment default. Overall, these findings highlight the need for tailoring MDT strategies for vulnerable populations in high-burden communities and suggest that social policies aiming to alleviate poverty should be investigated as potential tools for improving leprosy treatment completion.

Mycobacterium leprae's evolution and environmental adaptation

Leprosy is an ancient disease caused by the acid-fast bacillus Mycobacterium leprae, also known as Hansen's bacillus. M. leprae is an obligate intracellular microorganism with a marked Schwann cell tropism and is the only human pathogen capable of invading the superficial peripheral nerves. The transmission mechanism of M. leprae is not fully understood; however, the nasal mucosa is accepted as main route of M. leprae entry to the human host. The complete sequencing and the comparative genome analysis show that M. leprae underwent a genome reductive evolution process, as result of lifestyle change and adaptation to different environments; some of lost genes are homologous to those of host cells. Thus, M. leprae reduced its genome size to 3.3 Mbp, contributing to obtain the lowest GC content (approximately 58%) among mycobacteria. The M. leprae genome contains 1614 open reading frames coding for functional proteins, and 1310 pseudogenes corresponding to 41% of the genome, approximately. Comparative analyses to different microorganisms showed that M. leprae possesses the highest content of pseudogenes among pathogenic and non-pathogenic bacteria and archaea. The pathogen adaptation into host cells, as the Schwann cells, brought about the reduction of the genome and induced multiple gene inactivation. The present review highlights the characteristics of genome's reductive evolution that M. leprae experiences in the genetic aspects compared with other pathogens. The possible mechanisms of pseudogenes formation are discussed.

Interventions for ulceration and other skin changes caused by nerve damage in leprosy

BACKGROUND

At the end of 2016, 145 countries reported to the World Health Organization (WHO) over 173,000 new cases of leprosy worldwide. In the past 20 years, over 16 million people have been treated for leprosy globally. The condition's main complications are injuries and ulceration caused by sensory loss from nerve damage. In this review we explored interventions to prevent or treat secondary damage to the skin in people affected by leprosy (Hansen's disease). This is an update of a Cochrane Review published in 2008.

OBJECTIVES

To assess the effects of education, information, self-care programmes, dressings, skin care, footwear and other measures for preventing and healing secondary damage to the skin in persons affected by leprosy.

SEARCH METHODS

We updated our searches of the following databases up to July 2018: the Cochrane Skin Group Specialised Register, CENTRAL, MEDLINE, Embase, AMED, LILACS, and CINAHL. We also searched five trial registers, three grey literature databases, and the reference lists of included studies for further references to relevant randomised controlled trials (RCTs).

SELECTION CRITERIA

RCTs or quasi-RCTs or randomised cross-over trials involving anyone with leprosy and potential damage to peripheral nerves who was treated with any intervention designed to prevent damage, heal existing ulcers, and prevent development of new ulcers. Eligible comparisons were usual care, no interventions, or other interventions (e.g. other types of dressings or footwear).

DATA COLLECTION AND ANALYSIS

We adhered to standard methodological procedures expected by Cochrane. Primary outcomes were prevention of ulcer(s), healing of existing ulcer(s) and adverse events. We used GRADE to assess the certainty of evidence for each outcome.

MAIN RESULTS

We included 14 trials (854 participants). Eleven studies reported on gender (men: 472, women: 157). Participant age varied from 18 to 74 years. Most participants had a single, mainly non-infected, wound on one foot, which had been there for less than a year. Only seven studies reported whole study duration (there was no follow-up post-treatment), which was on average six months (range: 1 to 12 months). The studies were conducted in Brazil, Ethiopia, Egypt, Indonesia, Mexico, South Korea, and India. Many 'Risk of bias' assessments were rated as unclear risk due to limited information. Six studies had high risk of bias in at least one domain, including selection and attrition bias.Thirteen studies evaluated different interventions for treating existing ulcers, one of them also evaluated prevention of new ulcers. One study aimed to prevent skin changes, such as cracking and fissures. Investigated interventions included: laser therapy, light-emitting diode (LED), zinc tape, intralesional pentoxifylline, pulsed magnetic fields, wax therapy, ketanserin, human amniotic membrane gel, phenytoin, plaster shoes, and footwear.We are uncertain about the following key results, as the certainty of evidence is very low. All time points were measured from baseline.Three studies compared zinc tape versus other interventions and reported results in favour of zinc tape. One study compared zinc tape versus magnesium sulphate: at one month the number of healed ulcers and reduction in mean ulcer area was higher with zinc tape (risk ratio (RR) 2.00, 95% confidence interval (CI) 0.43 to 9.21, and mean difference (MD) -14.30 mm², 95% CI -26.51 to -2.09, respectively, 28 participants). Another study compared zinc tape and povidone iodine and found that even though there was a greater reduction in ulcer area after six weeks of treatment with zinc tape, there was no clear difference due to the wide 95% CI (MD 128.00 mm², 95% CI -110.01 to 366.01; 38 participants). The third study (90 participants) compared adhesive zinc tape with gauze soaked in Eusol, and found the healing time for deep ulcers was less compared to zinc tape: 17 days (95% CI 12 to 20) versus 30 days (95% CI 21 to 63). Adverse events were only collected in the study comparing zinc tape with gauze soaked in Eusol: there were no signs of skin sensitisation in either group at two months.Two studies compared topical phenytoin versus saline dressing and reported results in favour of phenytoin. One study reported a greater mean percentage reduction of ulcer area after four weeks with phenytoin 2% (MD 39.30%, 95% CI 25.82 to 52.78; 23 participants), and the other study reported a greater mean percentage reduction of ulcer volume (16.60%) after four weeks with phenytoin (95% CI 8.46 to 24.74; 100 participants). No adverse events were observed with either treatment during the four-month treatment period (2 studies, 123 participants). Prevention of ulcers was not evaluated in these nor the zinc studies, as the interventions were not for preventative use.Two studies compared protective footwear (with or without self-care) with either 1) polyvinyl chloride (PVC) boots, or 2) pulsed magnetic fields plus self-care and protective footwear. In the study comparing canvas shoes versus PVC boots, none of the 72 participants with scars at the start of the study developed new ulcers over one-year follow-up. Healing of ulcers was assessed in 38 participants from this study, but we are unclear if there is a difference between groups. In the study comparing pulsed magnetic fields (in addition to self-care and protective footwear) to only self-care and footwear in 33 participants, we are uncertain if the mean volume of ulcers at four to five weeks' follow-up was different between groups; this study did not evaluate the prevention of ulcers. Information for adverse events was only reported in the study comparing canvas shoes with PVC boots; the authors stated that the PVC boots could become hot in strong sunlight and possibly burn the feet.

AUTHORS' CONCLUSIONS

Based on the available evidence, we could not draw firm conclusions about the effects of the included interventions. The main evidence limitations were high or unclear risk of bias, including selection, performance, detection, and attrition bias; imprecision due to few participants in the studies; and indirectness from poor outcome measurement and inapplicable interventions. Future research should clearly report important outcomes, such as adverse events, and assess widely available interventions, which should include treatments aimed at prevention. These trials should ensure allocation concealment, blinding, and an adequate sample size.

Diagnostic accuracy of tests for leprosy: a systematic review and meta-analysis

OBJECTIVES

Owing to difficulties in the clinical diagnosis of leprosy, several complementary tests have been developed and used. The aim was to systematically summarize the accuracy of diagnostic tests for leprosy.

METHODS

We searched for relevant articles in Embase, Medline, and Global Health databases, until June 2017. Studies evaluating the accuracy of any diagnostic techniques for differentiating between people with and without leprosy were included. Studies solely focusing on differentiating between the separate forms of leprosy were excluded. Our protocol was registered on PROSPERO (CRD42017071803). We assessed study quality using the QUADAS-2 checklist. A bivariate random effects regression model was used for the meta-analyses.

RESULTS

We included 78 studies, most of those evaluating the detection of IgM antibodies against phenolic glycolipid I using ELISA. Sensitivity of the 39 studies evaluating ELISA was 63.8% (95% CI 55.0-71.8); specificity 91.0% (95% CI 86.9-93.9). The lateral flow test (nine studies) and the agglutination test (five studies) had a slightly higher sensitivity and a slightly lower specificity. Sensitivity of qPCR was (five studies) 78.5% (95% CI 61.9-89.2) and specificity 89.3% (95% CI 61.4-97.8). Sensitivity of conventional PCR was (17 studies) 75.3% (95% CI 67.9-81.5) and specificity 94.5% (95% CI 91.4-96.5).

CONCLUSIONS

Although the test accuracy looks reasonable, the studies suffered from heterogeneity and low methodological quality.

Underlying mechanisms of leprosy recurrence in the Western Amazon: a retrospective cohort study

BACKGROUND

The multidrug therapy (MDT) for leprosy treatment adopted by Brazil in the 1990s was important for reducing leprosy in the country; however, recurrent cases remained problematic. Mechanisms involved in leprosy recurrence are heterogeneous and can be sorted into three groups: insufficient therapy, bacillary persistence and new infections. This study aimed to analyse the time interval of leprosy recurrence in relation to the therapeutic scheme in the state of Acre. The hypotheses were as follows: 1) treatments (a) rifampicin, ofloxacin and minocycline (ROM) and (b) dapsone (DDS) have a short leprosy recurrence time, 2) treatments based on MDT have a long leprosy recurrence time, 3) there is a dose-response relationship between MDT and the time interval between leprosy episodes.

METHODS

This retrospective cohort study included 201 patients with a second episode of clinical leprosy at the reference centers for leprosy control in the state of Acre. Exposure was the type of therapeutic scheme as follows: 1) ROM, 2) DDS, 3) MDT0-9 doses, 4) MDT10-19 doses, 5) MDT20-29 doses, and 6) MDT30+ doses. Outcome was the time interval between release from treatment and a diagnosis of a recurrent leprosy case. Incidence rate ratios and relative risk Poisson regressions adjusted by age and sex were calculated with 95% confidence intervals.

RESULTS

The 201 patients studied during this retrospective follow-up resulted in a total of 224 cases of recurrent leprosy. Incidence rate ratios within this therapeutic scheme were as follows: 3.3 (2.39, 4.2; ROM/MDT30+), 1.12 (0.33, 1.92; DDS/MDT30+), 2.17 (1.39, 2.94; MDT0-9/MDT30+), 1.94 (1.13, 2.75; MDT10-19/MDT30+) and 1.26 (0.47, 2.05; MDT20-29/MDT30+). Relative risk Poisson regressions showed a protective effect of MDT30+ in comparison with ROM (0.22; 0.07, 0.72), MDT0-9 (0.42; 0.21, 0.85), and MDT10-19 (0.44; 0.21, 0.92). No differences among MDT30+ and DDS (0.71; 0.36, 1.41) and MDT20-29 (0.76; 0.38, 1.49) were observed.

CONCLUSIONS

New infection is an important-yet neglected-mechanism in leprosy recurrence in the state of Acre and can challenge the leprosy elimination plan in Brazil. MDT with few doses might be associated with leprosy recurrence due to insufficient therapy or bacillary persistence.

The achievements of the SUS in tackling the communicable diseases

This article presents the development of the epidemiological situation of some of the major communicable diseases (CD) in Brazil, with emphasis on the interventions by the SUS and other social policies. The data and information were collected from Datasus, epidemiological newsletters from the Brazilian Ministry of Health, and scientific articles on the issue. The universalization, decentralization and expansion of the surveillance, control and prevention of CD has produced an impact on the morbidity and mortality of these diseases, mainly those which are vaccine-preventable. The emergence and re-emergence of three arboviruses, for which there are no effective control instruments, interrupted the downward trend in the morbidity profile of CD in Brazil. Other social and economic programs, which are geared to the needier sectors of the Brazilian population, have also contributed to the improvement of the analyzed health indicators. However, the universalization of access to healthcare services, as well as improvements in the scope of the surveillance of diseases and health risks, has played a key role in improving the health and quality of life of the population, as well as contributing to the process of the democratization of Brazil.

Mycobacterium leprae-Specific Antibodies in Multibacillary Leprosy Patients Decrease During and After Treatment With Either the Regular 12 Doses Multidrug Therapy (MDT) or the Uniform 6 Doses MDT

Leprosy serology reflects the bacillary load of patients and multidrug therapy (MDT) reduces Mycobacterium leprae-specific antibody titers of multibacillary (MB) patients. The Clinical Trial for Uniform Multidrug Therapy Regimen for Leprosy Patients in Brazil (U-MDT/CT-BR) compared outcomes of regular 12 doses MDT/R-MDT and the uniform 6 doses MDT/U-MDT for MB leprosy, both of regimens including rifampicin, clofazimine, and dapsone. This study investigated the impact of R-MDT and U-MDT and the kinetic of antibody responses to M. leprae-specific antigens in MB patients from the U-MDT/CT-BR. We tested 3,400 serum samples from 263 MB patients (R-MDT:121; U-MDT:142) recruited at two Brazilian reference centers (Dona Libânia, Fortaleza, Ceará; Alfredo da Matta Foundation, Manaus, Amazonas). Enzyme-linked immunosorbent assays with three M. leprae antigens [NT-P-BSA: trisaccharide-phenyl of phenollic glycolipid-I antigen (PGL-I); LID-1: Leprosy Infectious Disease Research Institute Diagnostic 1 di-fusion recombinant protein; and ND-O-LID: fusion complex of disaccharide-octyl of PGL-I and LID-1] were performed using around 13 samples per patient. Samples were collected at baseline/M0, during MDT (R-MDT:M1–M12 months, U-MDT:M1–M6 months) and after MDT discontinuation (first, second year). Statistical significance was assessed by the Mann–Whitney U test for comparison between groups (p values < 0.05). Mixed effect multilevel regression analyses were used to investigate intraindividual serological changes overtime. In R-MDT and U-MDT groups, males predominated, median age was 41 and 40.5 years, most patients were borderline lepromatous and lepromatous leprosy (R-MDT:88%, U-MDT: 90%). The bacilloscopic index at diagnosis was similar (medians: 3.6 in the R-MDT and 3.8 in the U-MDT group). In R-MDT and U-MDT groups, a significant decline in anti-PGL-I positivity was observed from M0 to M5 (p = 0.035, p = 0.04, respectively), from M6 to M12 and at the first and second year posttreatment (p < 0.05). Anti-LID-1 antibodies declined from M0 to M6 (p = 0.024), M7 to M12 in the R-MDT; from M0 to M4 (p = 0.003), M5 to M12 in the U-MDT and posttreatment in both groups (p > 0.0001). Anti-ND-O-LID antibodies decreased during and after treatment in both groups, similarly to anti-PGL-I antibodies. Intraindividual serology results in R-MDT and U-MDT patients showed that the difference in serology decay to all three antigens was dependent upon time only. Our serology findings in MB leprosy show that regardless of the duration of the U-MDT and R-MDT, both of them reduce M. leprae-specific antibodies during and after treatment. In leprosy, antibody levels are considered a surrogate marker of the bacillary load; therefore, our serological results suggest that shorter U-MDT is also effective in reducing the patients’ bacillary burden similarly to R-MDT.

Leprosy: current situation, clinical and laboratory aspects, treatment history and perspective of the uniform multidrug therapy for all patients

In this review, the most relevant and current epidemiological data, the main clinical, laboratory and therapeutical aspects of leprosy are presented. Detailed discussion of the main drugs used for leprosy treatment, their most relevant adverse effects, evolution of the therapeutic regimen, from dapsone as a monotherapy to the proposed polychemotherapy by World Health Organization (WHO) can be found in this CME. We specifically highlight the drug acceptability, reduction in treatment duration and the most recent proposal of a single therapeutic regimen, with a fixed six months duration, for all clinical presentations, regardless of their classification.