Seroepidemiologic survey of the household contacts of leprosy patients

Abstract

OBJECTIVE: Leprosy is a disabling infectious disease caused by Mycobacterium leprae. This study aimed to investigate the prevalence of leprosy among household contacts of leprosy patients. METHODS: This study is a serological survey in household contacts of leprosy patients who had been treated or were undergoing treatment in the city of Presidente Prudente, São Paulo, Brazil, from 2006-2016, using clinical examination and screening for anti-Phenolic glycolipid-I antibodies with Mycobacterium leprae-flow serology. RESULTS: A total of 263 index cases of leprosy were identified during the study period. Of these, 53 were approached, and among their household contacts, 108 were examined. The ML-flow test was positive in 2 (1.85%) individuals, but clinical examination revealed no signs or symptoms of leprosy in them. Therefore, they were considered to have a subclinical infection. Leprosy was not confirmed in any household contacts. In this study, a lower percentage of household contacts, when compared to that in the literature, had a positive Mycobacterium leprae-flow test result. CONCLUSION: The use of Mycobacterium leprae-flow should be encouraged during the follow-up of at-risk populations, such as the household contacts of leprosy patients.

Early diagnosis of neural impairment in seropositive leprosy household contacts: The experience of a reference center in Brazil

“…Besides these clinical forms and the operational classification of WHO, a major challenge in this chronic disease is the definition of subclinical infection or latent leprosy. Even in the absence of symptoms, M. leprae is replicating and invading the host tissues ( 5 ), and biomarkers for the infection as anti-phenolic glycolipid-I (PGL-I) IgM antibodies have been recommended to detect a risk of infection in asymptomatic patients, especially household contacts. Some studies have also suggested a relation between infection in these patients and other biomarkers such as IL-6 and nutritional status ( 6 ), serum levels of IgA antibodies against NDO-HSA ( 7 ), CCL2 chemokine associated with IFN-γ ( 8 ), and IgM profile against NDO-HSA, LID-1, and NDOLID antigens, and monocytes and CD4+ lymphocyte frequency ( 9 ), beyond arginase activity ( 10 ) as a protective marker against this infection.…”

“…Leprosy household contacts present a risk for the development of the disease (11) and could maintain the spread of the M. leprae even if the index case is treated since some studies have shown positive PCR for M. leprae DNA in samples as nasal swabs, nasal turbinate biopsies, and/or peripheral blood in asymptomatic cases (12)(13)(14)(15). Considering that positive results for anti-PGL-I IgM in these household contacts are associated with a higher risk of becoming ill, the evaluation and serology anti-PGL-I IgM of these individuals are recommended (5).…”