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

• Published in: Memórias do Instituto Oswaldo Cruz Vol. 110; no. 7; pp. 898 - 905
• Main Authors: Nepomuceno Gondim Costa Lima, Luana, Cunha Frota, Cristiane, Maria Salani Mota, Rosa, Livia Freitas Almeida, Rosa, Araci de Andrade Pontes, Maria, de Sá Gonçalves, Heitor, Cunha Rodrigues, Laura, Kendall, Carl, Kerr, Ligia
• Format: Journal Article
• Language: English
• Published: Fundação Oswaldo Cruz, Fiocruz 01-11-2015; Instituto Oswaldo Cruz, Ministério da Saúde
• Subjects: Brazil; case-control; leprosy; Mycobacterium leprae; nasal carriage; RLEP PCR
• ISSN: 1678-8060; 0074-0276; 1678-8060
• DOI: 10.1590/0074-02760150178

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.