Validation of the clinical tuberculosis screening algorithm used in Nigerian national tuberculosis control programme for screening people living with HIV

Abstract

Background: In high HIV prevalence, tuberculo sis diagnosis is challenging. Some countries hence use clinical algorithms to screen for tuberculosis in People Living with HIV (PLHIV). Objectives: The aim of the study was to validate the national algorithm for clinical tuberculosis screening of persons living with HIV who attend comprehensive HIV clinics. Methods: A cross-sectional study of PLHIV who presented with cough of at least 2 weeks duration between 2009 and 2011 at St Patrick’s Hospital, Ebonyi State, Nigeria. Sputum smear microscopy for acid fast bacilli was obtained from the participants. Results: Three hundred and twelve PLHIV were studied: 146 (46.8%) males and 166 (53.2%) females. Only 55 (17.6%) of the participants had smear positive pulmonary tuberculosis. Weight loss ( c 2 = 2.33; P = 0.127), hemoptysis ( c 2 = 0.03; P = 0.864), night sweats ( c 2 = 1.52; P = 0.218), fever ( c 2 = 3.49; P = 0.06), anorexia ( c 2 = 0.49; P = 0.484), chest pain ( c 2 = 2.48; P = 0.115), breathlessness ( c 2 = 0.63; P = 0.426) were not significant in PLHWA with/without pulmonary tuberculosis. Cough, fever, night sweat and weight loss combined gave a sensitivity of 97.0%, specificity of 10.9%, negative predictive value (NPV) of 93.3% and positive predictive value (PPV) of 21.8%. Conclusion: Findings suggest that though national screening algorithm is a valid tool to screen for tuberculosis in PLHIV, it will lead to many false positive results.