Dados do Trabalho

Título

Molecular epidemiology of leprosy in Recife, Pernambuco, Brazil.

Introdução

Leprosy is generally caused by Mycobacterium leprae and a public health problem in Brazil, reporting 20,684 new patients between 2010 and 2019. The metropolitan region of Recife in Pernambuco is highly endemic for the disease and 4.9% are children under 15 years indicate considerable level of active transmission. Risk factors for transmission needs to be better investigated.

Objetivo(s)

Characterize by molecular methods the circulating genotypes in supposedly newly diagnosed patients from January 2012 to January 2017.

Material e Métodos

Slit skin smears (SSS) from 708 confirmed leprosy patients were submitted to DNA extraction, for DNA detection and quantification, we performed qPCR for 16S and RLEP targets and DNA fingerprints of Mycobacterium leprae strains were determined by Multi-Lo-VNTR Analysis (MLVA).

Resultados e Conclusão

A negative bacterial load was observed in 204 (8.7%) patients while 105 (14.8%) were paucibacillary (IB<2) and 399 (56.3%) multibacillary (IB≥2). Reanalysis of the patient data showed us that 75 (10.6%) had been previously diagnosed with leprosy; among the latter, 31 (41,3%) presented relapse/reinfection, 40 (53.3%) suffered from therapeutic failure and four (5.3%) had abandoned treatment. Most of the patients were male (73.3%), between 15 and 59 years old (74.3%), colored (59.8%), incomplete elementary school-II (26.7%), presented lesions (99.4%) and, 74.4% resided in Recife. Among the 708 samples, 622 (87.7%) presented a positive qPCR for one or two of the evaluated targets and met our established criteria for MLVA typing so we propose that qPCR as a tool to select samples for genotyping. Based on genotypes including 13 VNTRs, 179 (52.2%) of 343 isolates belonged to one of the 31 clusters, suggesting high level of (recent) transmission during the study period. Two large clusters, including respectively 36 (10.5%) and 39 (11.4%) isolates were observed and the reason for this is discussed. When associating clustering with clinical and demographic data, we observed age, bacillary load, year of collection and length of residence in the region as possible risk factors; no association was observed between clustering and being patients MB, having less<15 years, race, level of schooling and others. Our data demonstrated both considerable variability of M. leprae genotypes and the existence of two large clusters that together include 22% of the genotyped isolates.

Palavras-chave

Leprosy, Mycobacterium leprae, molecular epidemiology.