Mem Inst Oswaldo Cruz, Rio de Janeiro, 112(12) December 2017
Evidence of hidden leprosy in a supposedly low endemic area of Brazil
1Universidade de São Paulo, Faculdade de Medicina de Ribeirão Preto, Departamento de Clínica Médica, Divisão de Dermatologia, Ribeirão Preto, SP, Brasil
2Universidade Federal do Pará, Laboratório de Dermato-Imunologia, Marituba, PA, Brasil
3Universidade Federal do Pará, Laboratório de Epidemiologia Espacial, Castanhal, PA, Brasil
4Colorado State University, Department of Microbiology, Immunology and Pathology, Fort Collins, CO, USA
OBJECTIVES Show that hidden endemic leprosy exists in a municipality of inner São Paulo state (Brazil) with active surveillance actions based on clinical and immunological evaluations.
METHODS The study sample was composed by people randomly selected by a dermatologist during medical care in the public emergency department and by active surveillance carried out during two days at a mobile clinic. All subjects received a dermato-neurological examination and blood sampling to determine anti-PGL-I antibody titers by enzyme-linked immunosorbent assay (ELISA).
RESULTS From July to December 2015, 24 new cases of leprosy were diagnosed; all were classified as multibacillary (MB) leprosy, one with severe Luciou2019s phenomenon. Seventeen (75%) were found with grade-1 or 2 disability at the moment of diagnosis. Anti-PGL-I titer was positive in 31/133 (23.3%) individuals, only 6/24 (25%) were positive in newly diagnosed leprosy cases.
CONCLUSIONS During the last ten years before this study, the average new case detection rate (NCDR) in this town was 2.62/100,000 population. After our work, the NCDR was raised to 42.8/100,000. These results indicate a very high number of hidden leprosy cases in this supposedly low endemic area of Brazil.