Leprosy incidence and risk estimates in a 33-year contact cohort of leprosy patients

Abstract

Reduction in incidence has been associated with the introduction of novel approaches, like chemo/immune-prophylaxis. Incidence determined through follow-up cohort studies can evaluate the implementation of these innovative policies towards control and prevention. We have assessed the incidence in our contacts cohort over past 33 years, considering the effect of demographic and clinical variables. Survival analysis was used to estimate the risk of leprosy. A total of 9024 contacts were evaluated, of which 192 developed leprosy, resulting in an overall incidence of 1.4/1000 person-years. The multivariate analysis showed that the major risk factors were (i) contact from MB index cases and (ii) consanguinity (iii) intra household contact. Lower risk was detected for contacts with BCG scar who were revaccinated. There was a significant decrease in accumulated risk between the 2011–2019 period compared with 1987, probably linked to the improvement in laboratory tools to monitor contacts, thereby providing early diagnosis of contacts at intake and reduction of transmission. Our findings suggest that a combination of contact surveillance and tracing, adequate neurodermatological examination, and availability of molecular tools is highly effective in supporting early diagnosis, while a second dose of the BCG vaccination can exert extra protection.

Temporal trend, distribution and spatial autocorrelation of leprosy in Brazil: ecological study, 2011 to 2021

“…Despite the slight increase observed at the end of the historical series in the South and Southeast regions, states in these regions have had the lowest disease detection rates 1,14 . These findings suggest that there is better implementation of leprosy prevention and control measures in these regions 14 , with an increase in the active search for cases, epidemiological surveillance, and health education for the population 14,21 .…”

Tendência temporal, distribuição e autocorrelação espacial da hanseníase no Brasil: estudo ecológico, 2011 a 2021

“…A despeito do ligeiro aumento observado ao fim das séries históricas das Regiões Sul e Sudeste, reconhece-se que seus estados têm apresentado os menores coeficientes de detecção da doença 1,14 . Esses achados sugerem que há melhor implementação das medidas de prevenção e controle da hanseníase nessas regiões 14 , com aumento na busca ativa de casos, na vigilância epidemiológica e na educação em saúde da população 14,21 .…”

Fatores associados à limitação de atividade em casos novos de hanseníase em município hiperendêmico do Nordeste, Brasil

“…33,35,36 Recentemente, um elevado número de investigações tem buscado compreender a influência dos determinantes sociais na dinâmica de transmissão da hanseníase no Brasil. [35][36][37][38][39][40] Estudos realizados no próprio estado da Bahia mostraram que a manutenção da transmissão pode estar associada a: densidade domiciliar, proporção de extremamente pobres, renda per capita, desigualdade de renda e nível de ocupação. 41,42 Por outro lado, em áreas endêmicas, é possível que as melhorias sociais gerais resultem, pelo menos em um primeiro momento, em aumento do número de diagnósticos, já que diminui a prevalência oculta.…”