Hanifa Y., Mngadi K., Lewis J., Fielding K., Churchyard G., Grant A.D.
Aurum Institute for Health Research, Johannesburg, South Africa; Centre for the AIDS Programme of Research in South Africa (CAPRISA), University of KwaZulu-Natal, Durban, South Africa; London School of Hygiene and Tropical Medicine, London, United Kingdom; Aurum Institute for Health Research, 47 Main Street, Marshalltown, 2107, South Africa
Hanifa, Y., Aurum Institute for Health Research, Johannesburg, South Africa, Centre for the AIDS Programme of Research in South Africa (CAPRISA), University of KwaZulu-Natal, Durban, South Africa, Aurum Institute for Health Research, 47 Main Street, Marshalltown, 2107, South Africa; Mngadi, K., Aurum Institute for Health Research, Johannesburg, South Africa; Lewis, J., Aurum Institute for Health Research, Johannesburg, South Africa, London School of Hygiene and Tropical Medicine, London, United Kingdom; Fielding, K., London School of Hygiene and Tropical Medicine, London, United Kingdom; Churchyard, G., Aurum Institute for Health Research, Johannesburg, South Africa, Centre for the AIDS Programme of Research in South Africa (CAPRISA), University of KwaZulu-Natal, Durban, South Africa, London School of Hygiene and Tropical Medicine, London, United Kingdom; Grant, A.D., London School of Hygiene and Tropical Medicine, London, United Kingdom
SETTING: A South African hospital serving gold mine employees. OBJECTIVE: To determine the sensitivity and specificity of the Arkansas method for detecting isoniazid (INH) metabolites among South African adults and to examine the effect of smoking status on positive results. DESIGN: Urine specimens were collected from in-patients taking INH as part of tuberculosis treatment at 6, 12 and 24 h after a directly observed 300 mg oral dose. As a control group, a single urine specimen was collected from surgical in-patients not taking INH. Specimens were tested for INH using a commercially available dipstick. RESULTS: A total of 153 patients on INH and 60 controis were recruited. The sensitivity of the test was 93.3% (95%CI 88.1-96.8) at 6 h post INH, 93.4% (95%CI 88.2-96.8) at 12 h and 77% (95%CI 69.1-83.7) at 24 h. The specificity of the test was 98.3% (95%CI 91.1->99.9). There was no association between smoking status and colour change of positive results. CONCLUSIONS: This test is a useful method of monitoring adherence to TB treatment or preventive therapy among South Africans. However, it is less than 100% sensitive, especially with increasing time post dose, which should be taken into consideration when interpreting results for individual patients. © 2007 The Union.