Prospects for new leprosy diagnostic tools, a narrative review considering ELISA and PCR assays

Abstract Slit skin smear and histopathological examinations are currently the main laboratory tools used to aid the diagnosis of leprosy. However, their sensitivity is low, and many cases are not detected. New methodologies have been studied to develop more accurate tests. This narrative review aims to raise attention to the results of molecular (polymerase chain reaction) and serological (Enzyme-Linked Immunosorbent Assay) tests applied to the diagnosis of leprosy, and to summarize the available information about the former. Original scientific articles published in indexed international journals, whose study involved aspects of the diagnosis and classification of leprosy cases or home contacts, were selected. The data were extracted independently using a standardized method that dictated the inclusion of the following information: diagnosis in Paucibacillary and Multibacillary cases and in household contacts; sample number; sample type; study design; studied variables; statistical analysis employed; main results; and limitations identified. In clinical practice, the results from molecular and serological tests are assessed separately, with moderate sensitivity and specificity. However, an integrated study of these methodologies has been suggested for greater accuracy in diagnosis.

A importância da busca ativa como estratégia de controle da hanseníase em territórios endêmicos / The importance of active surveillance as a strategy to control leprosy in endemic areas

De acordo com a literatura, contatos de casos de hanseníase apresentam maior risco de adoecimento e, nesse sentido, é primordial fortalecer e ampliar as ações de busca ativa de casos no âmbito da atenção primária de saúde, potencializando a ampliação do diagnóstico precoce, tratamento oportuno e demais medidas de vigilância, controle e reabilitação necessárias. Neste cenário, objetivou-se realizar a busca ativa de novos casos de hanseníase em um distrito rural do município de Mantena, MG, e caracterizar a situação socioeconômica e epidemiológica da doença na região. Foram realizadas visitas aos residentes do distrito e palestras informativas sobre a doença, sendo os moradores convidados a participar da pesquisa. Um total de 292 indivíduos foi examinado no período de julho de 2016 a fevereiro de 2017. Foram diagnosticados 27 casos novos, 22 dos quais eram multibacilares. Os graus de incapacidade 1 e 2 foram identificados em 74% da amostra. Sobre as variáveis socioeconômicas, a maioria dos casos possui baixa escolaridade e baixa renda familiar, além de todos os casos terem tido contato com a doença em algum momento. A busca ativa foi eficiente para a detecção de casos novos de hanseníase na população estudada e contribuiu para o controle da doença que é endêmica na região. Ademais, a busca ativa foi relevante, especialmente considerando a baixa instrução dos indivíduos e, portanto, menor acesso à informação.

Contacts of leprosy cases present a higher risk of illness and, therefore it is essential to strengthen and expand actions to actively search for cases in primary health care, thus intensifying early diagnosis, timely treatment and other surveillance measures, and improve control and rehabilitation. In this setting, we aimed to perform the active search of new cases of leprosy in the rural area of Mantena, MG, and to characterize the socioeconomic and epidemiological situation related to the disease in the region. For this purpose, visits were made to the residents of the region with informative talks about the disease, and subsequently inhabitants were invited to participate in the research. A total of 292 individuals were examined from July 2016 to February 2017. Twenty-seven new cases were diagnosed, 22 of which were multibacillary. Grade 1 and 2 physical disabilities were identified in 74% of the new cases. Regarding socioeconomic variables, the majority of the cases had little schooling and low family income. In addition, all cases had had contact with the illness, at some point. We conclude that the active search was efficient to detect new leprosy cases in the population, and it contributed to the control of the disease, which is endemic in the region. In addition, active search is an important methodology, especially when the population involved has little schooling and thus less access to information.