Estudo comparativo entre diferentes técnicas de coloração em baciloscopia e teste rápido ML Flow para o diagnóstico, classificação clínica e controle da hanseníase

Abstract

To evaluate staining techniques for bacilloscopy of intradermal smears by Ziehl-Neelsen and Auramine O, associating them with the results of the ML Flow test to verify their contribution to the diagnosis and help in the clinical classification of leprosy. METHODS: A prospective study was carried out with 94 patients suspected of having the disease, treated by spontaneous demand, in the period from 2020 to 2021 in health units in the region of São José do Rio Preto-SP. For bacilloscopy, the collection and staining methods recommended by the Ministry of Health were performed. The smears were first stained with Auramine O, and after reading by fluorescence, they were stained by Ziehl-Neelsen. The ML Flow test was performed according to the protocol described by Bührer-Sékula. For the agreement analysis, the Kappa index was used and the significant values of p≤ 0.05 were considered to verify the association between the variables. RESULTS: Thirty-one patients were diagnosed with leprosy, with higher positivity detected by the ML Flow Test (28.7%), followed by positive bacilloscopy by Ziehl-Neelsen (22.4%) and Auramine O (16.0%). A better agreement was observed between the results of the ML Flow and Ziehl-Neelsen bacilloscopy tests (Kappa= 0.72). The results obtained between the smear microscopy techniques by Ziehl-Neelsen and Auramine O had substantial agreement (Kappa = 0.79), according to the criteria of Landis and Koch. Twenty-seven patients were classified as multibacillary, and 85.2% of cases were associated with positive results by the ML Flow test. CONCLUSION: Among the three laboratory techniques evaluated, the ML Flow test had the highest performance and positivity. As it is a quick and easy-to-perform test, it can be a useful and effective tool in the early diagnosis of leprosy cases.