RESUMO
Current prevention methods for the transmission of Mycobacterium leprae, the causative agent of leprosy, are inadequate as suggested by the rate of new leprosy cases reported. Simple large-scale detection methods for M. leprae infection are crucial for early detection of leprosy and disease control. The present study investigates the production and seroreactivity of a recombinant polypeptide composed of various M. leprae protein epitopes. The structural and physicochemical parameters of this construction were assessed using in silico tools. Parameters like subcellular localization, presence of signal peptide, primary, secondary, and tertiary structures, and 3D model were ascertained using several bioinformatics tools. The resultant purified recombinant polypeptide, designated rMLP15, is composed of 15 peptides from six selected M. leprae proteins (ML1358, ML2055, ML0885, ML1811, ML1812, and ML1214) that induce T cell reactivity in leprosy patients from different hyperendemic regions. Using rMLP15 as the antigen, sera from 24 positive patients and 14 healthy controls were evaluated for reactivity via ELISA. ELISA-rMLP15 was able to diagnose 79.17% of leprosy patients with a specificity of 92.86%. rMLP15 was also able to detect the multibacillary and paucibacillary patients in the same proportions, a desirable addition in the leprosy diagnosis. These results summarily indicate the utility of the recombinant protein rMLP15 in the diagnosis of leprosy and the future development of a viable screening test.
RESUMO
Leprosy remains a public health problem in Brazil, and the Mato Grosso do Sul State (MS) had the seventh highest rate of detection of new cases in the country in 2015 (26.59 per 100,000 inhabitants) which was classified as very high. This work aimed to determine the epidemiological characteristics of leprosy in MS. Descriptive statistics were performed with data from the Information System on Diseases of Compulsory Declaration (SINAN) between 2001 and 2015, with all patients included in the system serving as the sample. Clinical forms of multibacillary (MB) leprosy predominated in MS during the study period, with a clear positive trend from 2009 to 2015 and a peak in the detection rate of new cases (NCDR) in 2014 corresponding to 40.39 per 100,000 population (p<0.001). The most affected groups were men (56.7%) aged 20-59 years (70.52%), an economically active population. We observed that Northern MS had the highest overall NCDR in the State. In cities bordering other countries, NCDRs were significantly lower than in those of other analyzed cities. There was no dependency ratio correlating NCDRs in cities with higher or lower indexes with basic care coverage (p=0.799) and human development index (p=0.887). In conclusion, the large number of patients with MB leprosy indicates that the diagnosis of leprosy is delayed in MS, perhaps due to difficulties related to diagnostic methods. This situation contributes to the continuing prevalence of leprosy in MS.