Epidemiology and Infection

Original Papers

Comparison of symptoms and treatment outcomes between actively and passively detected tuberculosis cases: the additional value of active case finding

S. DEN BOONa1a2a3 c1, S. VERVERa2a3, C. J. LOMBARDa4, E. D. BATEMANa5, E. M. IRUSENa6, D. A. ENARSONa7, M. W. BORGDORFFa2a3 and N. BEYERSa1

a1 Desmond Tutu TB Centre, Stellenbosch University, South Africa

a2 KNCV Tuberculosis Foundation, The Hague, The Netherlands

a3 Academic Medical Centre, CINIMA, Amsterdam, The Netherlands

a4 Biostatistics Unit, Medical Research Council, Cape Town, South Africa

a5 Division of Pulmonology, Department of Medicine, University of Cape Town, Cape Town, South Africa

a6 Department of Internal Medicine, Stellenbosch University, Cape Town, South Africa

a7 International Union Against Tuberculosis and Lung Disease, Paris, France


Passive detection of tuberculosis (TB) cases may lead to delay in treatment which may contribute to increased severity of disease and mortality. Active case finding may be an alternative. In a community survey in Cape Town, South Africa, we actively detected 27 bacteriologically positive TB cases and compared those with 473 passively detected TB cases. Seven of 27 (26%) actively detected TB cases did not start treatment within 2 months and were considered initial defaulters. Those who did start treatment had similar treatment success rates as passively detected TB cases (both 80%) (OR 1·01, 95% CI 0·33–3·09). Passively detected cases reported the presence of the symptoms cough (OR 3·72, 95% CI 1·47–9·39), haemoptysis (OR 3·20, 95% CI 1·03–9·93), night sweats (OR 3·35, 95% CI 1·40–7·99), fever (OR 4·28, 95% CI 1·21–15·14), and weight loss (OR 11·14, 95% CI 4·17–29·74) more often than those detected actively. We conclude that although TB cases detected by a community survey are less symptomatic and are prone to a high initial default rate, active case finding can potentially identify a substantial portion of the existing caseload at an earlier stage of disease, thereby reducing the risk of transmission.

(Accepted November 08 2007)

(Online publication January 04 2008)


c1 Author for correspondence: Dr S. den Boon, KNCV Tuberculosis Foundation, PO Box 146, 2501 CC The Hague, The Netherlands. (Email: saskiadenboon@hotmail.com)