Widespread nasal carriage of Mycobacterium lepraeamong a healthy population in a hyperendemic region of northeastern Brazil

Abstract

A case-control study was conducted to determine the presence of Mycobacterium leprae DNA in nasal secretions of leprosy cases and nonleprosy individuals in Fortaleza, Brazil. It included 185 cases identified by physicians at the Dona Libânia National Reference Centre for Sanitary Dermatology (CDERM). A control group (Co) (n = 136) was identified among individuals from CDERM not diagnosed as leprosy cases. To augment the spatial analysis of M. leprae specific repetitive element (RLEP) positive prevalence, an external group (EG) (n = 121), a convenience sample of healthy students, were included. Polymerase chain reaction for the RLEP sequence was conducted for all participants. Prevalence of RLEP positivity for cases and Co were 69.2% and 66.9%, respectively, significantly higher than for EG (28.1%), and reported elsewhere. Male sex, belonging to a lower socioeconomic status (D/E), history of a previous contact with a case and being older, were associated with being a leprosy case. Our geographical analysis demonstrated that the bacillus is widespread among the healthy population, with clusters of RLEP positive multibacillary cases concentrated in distinct areas of the city. Our results suggest that in endemic areas, as in Fortaleza, surveillance for both nonhousehold leprosy contacts and members of the general population living in cluster areas should be implemented.

Spatial distribution of leprosy in Brazil: a literature review

“…Table 1, Table 2 and Table 3 show the articles' summaries according to the scale used: two evaluated regions/ mesoregions 14,15 ; 13 used the scale of municipalities 10,[16][17][18][19][20][21][22][23][24][25][26][27] ; 4 evaluated districts [28][29][30][31] ; 6 studied neighborhoods [32][33][34][35][36][37] ; 7 analyzed the census tracts [38][39][40][41][42][43][44] ; and 3 investigated households [45][46][47] . Within each scale, the articles were organized by location: Brazil, Northern, Northeast, Midwest, and Southeast regions.…”

“…Within each scale, the articles were organized by location: Brazil, Northern, Northeast, Midwest, and Southeast regions. In all, 4 approached Brazil 10,16-18 , 7 studied the Northern region or the states of the Amazon region 14,19,20,[38][39][40]45 , 11 focused on the Northeast region [21][22][23]28,[32][33][34][35][36]40,41 , 4 the Midwest region 15,29,37,46 , and 12 the Southeast region [24][25][26][27]30,31,36,37,[42][43][44]47 .…”

“…Regarding districts, areas with greater detection r a t e s for leprosy corresponded with lower socioeconomic status, measured by social class and urban quality index 28,31 . The study by Lima et al was the only one that assessed the carrier status, and used a case-control approach, besides an external group.…”

“…The study by Lima et al was the only one that assessed the carrier status, and used a case-control approach, besides an external group. Spatial distribution of carriers was also characterized by clusters 28 .…”

Hanseníase: considerações sobre o desenvolvimento e contribuição (institucional) de instrumento diagnóstico para vigilância epidemiológica

“…Essa técnica permite o monitoramento do M. leprae em baixas concentrações e é relevante para detectar portadores assintomáticos, como ferramenta auxiliar para o diagnóstico da doença, evitando a utilização de outros métodos diagnósticos invasivos que elucidem do sítio de exposição ao bacilo e a possível rota de entrada do bacilo em humanos. Esses estudos complementariam outros sobre a transmissão da hanseníase e os fatores de risco para familiares intra e extradomiciliares 33,34 .…”