Concordance between expected and observed bacilloscopy results of clinical forms of leprosy: a 6-year retrospective study in Recife, State of Pernambuco, Brazil.

INTRODUCTION: Operational classification of leprosy based on the number of skin lesions was conceived to screen patients presenting severe forms of the disease to enable their reception of a more intense multidrug regimen without having to undergo lymph smear testing. We evaluated the concordance between operational classification and bacilloscopy to define multibacillary and paucibacillary leprosy. METHODS: We selected 1,213 records of individuals with leprosy, who were untreated (new cases) and admitted to a dermatology clinic in Recife, Brazil, from 2000 to 2005, and who underwent bacteriological examination at diagnosis for ratification of the operational classification. RESULTS: Compared to bacilloscopy, operational classification demonstrated 88.6% sensitivity, 76.9% specificity, a positive predictive value of 61.8%, and a negative predictive value of 94.1%, with 80% accuracy and a moderate kappa index. Among the bacilloscopy-negative cases, 23% had more than 5 skin lesions. Additionally, 11% of the bacilloscopy-positive cases had up to 5 lesions, which would have led to multibacillary cases being treated as paucibacillary leprosy if the operational classification had not been confirmed by bacilloscopy. CONCLUSIONS: Operational classification has limitations that are more obvious in borderline cases, suggesting that in these cases, lymph smear testing is advisable to enable the selection of true multibacillary cases for more intense treatment, thereby contributing to minimization of resistant strain selection and possible relapse.

Concordance between expected and observed bacilloscopy results of clinical forms of leprosy: a 6-year retrospective study in Recife, State of Pernambuco, Brazil / Concordância entre os resultados observados e esperados da forma clinica da hanseníase de acordo com a baciloscopia: um estudo retrospectivo de seis anos em Recife, Estado de Pernambuco, Brasil

INTRODUCTION: Operational classification of leprosy based on the number of skin lesions was conceived to screen patients presenting severe forms of the disease to enable their reception of a more intense multidrug regimen without having to undergo lymph smear testing. We evaluated the concordance between operational classification and bacilloscopy to define multibacillary and paucibacillary leprosy. METHODS: We selected 1,213 records of individuals with leprosy, who were untreated (new cases) and admitted to a dermatology clinic in Recife, Brazil, from 2000 to 2005, and who underwent bacteriological examination at diagnosis for ratification of the operational classification. RESULTS: Compared to bacilloscopy, operational classification demonstrated 88.6% sensitivity, 76.9% specificity, a positive predictive value of 61.8%, and a negative predictive value of 94.1%, with 80% accuracy and a moderate kappa index. Among the bacilloscopy-negative cases, 23% had more than 5 skin lesions. Additionally, 11% of the bacilloscopy-positive cases had up to 5 lesions, which would have led to multibacillary cases being treated as paucibacillary leprosy if the operational classification had not been confirmed by bacilloscopy. CONCLUSIONS: Operational classification has limitations that are more obvious in borderline cases, suggesting that in these cases, lymph smear testing is advisable to enable the selection of true multibacillary cases for more intense treatment, thereby contributing to minimization of resistant strain selection and possible relapse.

INTRODUÇÃO: A classificação operacional da hanseníase baseada no número de lesões de pele foi concebida para selecionar pacientes que apresentam formas graves da doença para receber regime terapêutico mais intenso com múltiplas drogas sem o exame de baciloscopia da linfa. Nós avaliamos a concordância entre a classificação operacional e a baciloscopia para a definição de hanseníase multibacilar e paucibacilar. MÉTODOS: Nós selecionamos 1.213 registros de indivíduos com hanseníase não tratada (casos novos), atendidos em um Ambulatório de Dermatologia, em Recife, Brasil, no período de 2000 a 2005, que foram submetidos a exame bacteriológico ao diagnóstico para a ratificação da classificação operacional. RESULTADOS: Comparando com a baciloscopia, a classificação operacional baseada no número de lesões cutâneas mostrou sensibilidade de 88,6%, especificidade 76,9%, valor preditivo positivo de 61,8% e valor preditivo negativo de 94,1%, com uma precisão de 80% e um moderado índice kappa. Entre os casos com baciloscopia negativa, 23% tinham mais de cinco lesões de pele, recebendo um tratamento mais intensivo. Além disso, 11% dos casos baciloscopia positiva tinham até cinco lesões, o que induziriam casos multibacilares de serem tratados com hanseníase paucibacilar se a classificação operacional não tivesse sido confirmada pela baciloscopia. CONCLUSÕES: Concluímos que a classificação operacional tem limitações mais visíveis nos casos borderline, sugerindo que, nestes casos, o esfregaço seria aconselhável por permitir que os verdadeiros casos multibacilares fossem selecionados para um tratamento mais intenso, contribuindo para minimizar a seleção de cepas resistentes e uma possível recidiva.