Leprosy: treatment, prevention, immune response and gene function.

Since the leprosy cases have fallen dramatically, the incidence of leprosy has remained stable over the past years, indicating that multidrug therapy seems unable to eradicate leprosy. More seriously, the emergence of rifampicin-resistant strains also affects the effectiveness of treatment. Immunoprophylaxis was mainly carried out through vaccination with the BCG but also included vaccines such as LepVax and MiP. Meanwhile, it is well known that the infection and pathogenesis largely depend on the host's genetic background and immunity, with the onset of the disease being genetically regulated. The immune process heavily influences the clinical course of the disease. However, the impact of immune processes and genetic regulation of leprosy on pathogenesis and immunological levels is largely unknown. Therefore, we summarize the latest research progress in leprosy treatment, prevention, immunity and gene function. The comprehensive research in these areas will help elucidate the pathogenesis of leprosy and provide a basis for developing leprosy elimination strategies.

Drug Resistance (Dapsone, Rifampicin, Ofloxacin) and Resistance-Related Gene Mutation Features in Leprosy Patients: A Systematic Review and Meta-Analysis.

Dapsone (DDS), Rifampicin (RIF) and Ofloxacin (OFL) are drugs recommended by the World Health Organization (WHO) for the treatment of leprosy. In the context of leprosy, resistance to these drugs occurs mainly due to mutations in the target genes (Folp1, RpoB and GyrA). It is important to monitor antimicrobial resistance in patients with leprosy. Therefore, we performed a meta-analysis of drug resistance in Mycobacterium leprae and the mutational profile of the target genes. In this paper, we limited the study period to May 2022 and searched PubMed, Web of Science (WOS), Scopus, and Embase databases for identified studies. Two independent reviewers extracted the study data. Mutation and drug-resistance rates were estimated in Stata 16.0. The results demonstrated that the drug-resistance rate was 10.18% (95% CI: 7.85-12.51). Subgroup analysis showed the highest resistance rate was in the Western Pacific region (17.05%, 95% CI:1.80 to 13.78), and it was higher after 2009 than before [(11.39%, 7.46-15.33) vs. 6.59% (3.66-9.53)]. We can conclude that the rate among new cases (7.25%, 95% CI: 4.65-9.84) was lower than the relapsed (14.26%, 95 CI%: 9.82-18.71). Mutation rates of Folp1, RpoB and GyrA were 4.40% (95% CI: 3.02-5.77), 3.66% (95% CI: 2.41-4.90) and 1.28% (95% CI: 0.87-1.71) respectively, while the rate for polygenes mutation was 1.73% (0.83-2.63). For further analysis, we used 368 drug-resistant strains as research subjects and found that codons (Ser, Pro, Ala) on RpoB, Folp1 and GyrA are the most common mutation sites in the determining region (DRDR). In addition, the most common substitution patterns of Folp1, RpoB, and GyrA are Pro→Leu, Ser→Leu, and Ala→Val. This study found that a higher proportion of patients has developed resistance to these drugs, and the rate has increased since 2009, which continue to pose a challenge to clinicians. In addition, the amino acid alterations in the sequence of the DRDR regions and the substitution patterns mentioned in the study also provide new ideas for clinical treatment options.

Global epidemiology of leprosy from 2010 to 2020: A systematic review and meta-analysis of the proportion of sex, type, grade 2 deformity and age.

The objectives of this study were to explore global epidemiological characteristics of leprosy, and to provide reference for the construction of prevention strategies for leprosy. Computer retrieval of the study on the epidemiology of leprosy from 2010 to 2020 in Web of Science, PubMed, and SCOPUS databases were summarized. The included studies were assessed for the quality of the AHRQ; the proportions of the study indices were meta-analyzed with Stata 16.0. A random effects model was adopted to merge categories, including sex, type, grade 2 deformity (G2D) and age group for meta-analysis. The subgroup analysis used region as a stratification factor to analyze whether there were differences in the indicators. The meta-analysis included 30 studies totaling 11,353 cases. The global pooled proportion of male to female subjects with leprosy was 63% (95% CI 59%, 66%) to 37% (95% CI 34%, 41%), respectively. The pooled multibacillary proportion and paucibacillary proportion were 69% (95% CI 62%, 76%) and 31% (95% CI 24%, 38%), respectively. The pooled grade 2 deformity (G2D) proportion was 22% (95% CI 15%, 30%). Among age groups, the pooled children proportion was 11% (95% CI 8%, 13%), and the pooled adult proportion was 89% (95% CI 87%, 92%). The subgroup analysis indicated that epidemiological indicators varied from country to country. This study suggested that disparities existed between sex, type, grade 2 deformity (G2D) and age group characteristics of leprosy from country to country.