RESUMEN
ABSTRACT Background: Leprosy is a neglected chronic infection caused by Mycobacterium leprae, that is curable. The magnitude of the disease and severity of the debilitation it causes renders leprosy a public health problem. This study aimed to analyze the endemic profile of leprosy in the Murrupula district and evaluate the socioeconomic, clinical, and serological profiles of leprosy contacts. Methods: A cross-sectional study of patients with leprosy diagnosed between 2013 and 2017 and their household and community contacts was conducted in Murrupula District, Nampula Province, Mozambique. Interviews, simplified dermatoneurological examinations, Mycobacterium leprae flow (ML Flow) tests, and Mitsuda tests were performed. Results: Most of the leprosy cases were multibacillary. The patients had some degree of physical disability. ML Flow positivity was more common in household contacts of the patients diagnosed with leprosy and in community individuals who spontaneously presented for testing. In total, 17 patients were diagnosed with leprosy. Conclusions: This study revealed an active chain of transmission, hidden prevalence, and operational deficiencies in leprosy surveillance and care. The results suggest that the implementation of a public health policy for leprosy prevention and control in Nampula Province is necessary. In future, the possibility of expanding the policy to the entire country should be considered.
RESUMEN
Biópsias de pele oriundas dos serviços de diagnóstico da hanseníase podem ser grande fonte de material para estudos retrospectivos em genética humana e do Mycobacterium leprae. No entanto, os procedimentos de fixação e inclusão em parafina podem dificultar a obtenção de DNA de qualidade para amplificação por PCR. Assim, estas amostras requerem protocolos especiais para a extração do material genético. O objetivo deste trabalho é apresentar um método alternativo para extração de DNA com base na combinação de calor e digestão enzimática. Para tanto, os cortes foram aquecidos a 120º C em solução tampão de pH 9,0, submetidos à digestão enzimática com proteinase K e o DNA foi extraído por meio de solução de fenol:clorofórmio:álcool isoamílico. A amplificação por PCR para as regiões dos genes humanos TNF e LTA foi bem sucedida para 85,4% dos espécimes. Considerando o DNA do M. leprae, obtivemos amplificação em 67,6%, 48,5%, 36,7% e 64,8% para os marcadores TA18, GTA9, TTC e RLEP, respectivamente. Concluímos que este é um método de baixo custo que proporcionou um rendimento satisfatório de DNA de boa qualidade para emprego em PCR a partir de biópsias parafinadas de pele.
Skin biopsies from leprosy diagnostic services can be great sources of material for retrospective studies concerning human and Mycobacterium leprae genetic. However, fixation and paraffin embedding procedures make difficult to obtain good quality DNA to PCR amplification. Thus, paraffin-embedded samples require special protocols to DNA extraction. The aim of this paper is to present an alternative method for DNA extraction based on the combination of heat and enzymatic digestion. The sections were heated at 120ºC at pH 9.0, submitted to enzymatic digestion with proteinase K and the DNA was extracted by using phenol:chlorophorm:isoamilic alcohol. PCR amplification for regions in TNF and LTA human genes was successful for 85.4 % of specimens. Regarding M. lepraeDNA, we obtained amplification in 67.6%, 48.5%, 36.7% and 64.8% for the TA18, GTA9, TTC and RLEP markers, respectively. We conclude that this is an inexpensive method which provided a satisfactory yield of a good quality DNA for PCR from paraffin- embedded skin biopsies.