S Reddy1, S Ntoyanto1, Y Sakadavan1, T Reddy2, S Mahomed3, M Dlamini4, B Spooner5, G Ramjee1, A Coutsoudis6, N Ngomane7, K Naidoo8, K Mlisana9, P Kiepiela1. 1. HIV Prevention Research Unit. 2. Biostatistics Unit, South African Medical Research Council, Durban. 3. School of Laboratory Medicine and Medical Sciences, University of KwaZulu-Natal, Durban, Medical Microbiology Department, National Health Laboratory Services, Durban, Centre for the AIDS Programme of Research in South Africa, Durban. 4. Medical Microbiology Department, National Health Laboratory Services, Durban. 5. HIV Prevention Research Unit, Department of Paediatrics and Child Health, University of KwaZulu-Natal, Durban. 6. Department of Paediatrics and Child Health, University of KwaZulu-Natal, Durban. 7. eThekwini Health Unit, eThekwini Municipality, Durban, South Africa. 8. Centre for the AIDS Programme of Research in South Africa, Durban. 9. School of Laboratory Medicine and Medical Sciences, University of KwaZulu-Natal, Durban, Medical Microbiology Department, National Health Laboratory Services, Durban.
Abstract
SETTING: In South Africa, KwaZulu-Natal is the epicentre of the human immunodeficiency virus (HIV) epidemic, where approximately 70% of people with tuberculosis (TB) are co-infected with HIV. Undiagnosed TB contributes to high mortality in HIV-infected patients. Delays in diagnosing TB and treatment initiation result in prolonged transmission and increased infectiousness. OBJECTIVE: To evaluate the LoopampTM MTBC Detection kit (TB-LAMP; based on the loop-mediated isothermal amplification assay), smear microscopy and Xpert test with the gold standard of mycobacterial culture. METHODS: Sputum samples were collected from 705 patients with symptoms of pulmonary TB attending a primary health care clinic. RESULTS: The TB-LAMP assay had significantly higher sensitivity than smear microscopy (72.6% vs. 45.4%, P < 0.001), whereas specificity was slightly lower (99% vs. 96.8%, P = 0.05), but significantly higher than Xpert (92.9%, P = 0.004). There was no significant difference in sensitivity of smear-positive, culture-positive and smear-negative, culture-positive sputum samples using TB-LAMP vs. Xpert (respectively 95.9%/55.9% vs. 97.6%/66.1%; P =0.65, P = 0.27). The positive predictive value of TB-LAMP was significantly higher than that of Xpert (87.5% vs. 77.0%; P = 0.02), but similar to that of smear microscopy (94.2%; P = 0.18). The negative predictive value was respectively 91.9%, 92.5% (P = 0.73) and 83.1% (P = 0.0001). CONCLUSION: Given its ease of operability, the TB-LAMP assay could be implemented as a point-of-care test in primary health care settings, and contribute to reducing treatment waiting times and TB prevalence.
SETTING: In South Africa, KwaZulu-Natal is the epicentre of the human immunodeficiency virus (HIV) epidemic, where approximately 70% of people with tuberculosis (TB) are co-infected with HIV. Undiagnosed TB contributes to high mortality in HIV-infectedpatients. Delays in diagnosing TB and treatment initiation result in prolonged transmission and increased infectiousness. OBJECTIVE: To evaluate the LoopampTM MTBC Detection kit (TB-LAMP; based on the loop-mediated isothermal amplification assay), smear microscopy and Xpert test with the gold standard of mycobacterial culture. METHODS: Sputum samples were collected from 705 patients with symptoms of pulmonary TB attending a primary health care clinic. RESULTS: The TB-LAMP assay had significantly higher sensitivity than smear microscopy (72.6% vs. 45.4%, P < 0.001), whereas specificity was slightly lower (99% vs. 96.8%, P = 0.05), but significantly higher than Xpert (92.9%, P = 0.004). There was no significant difference in sensitivity of smear-positive, culture-positive and smear-negative, culture-positive sputum samples using TB-LAMP vs. Xpert (respectively 95.9%/55.9% vs. 97.6%/66.1%; P =0.65, P = 0.27). The positive predictive value of TB-LAMP was significantly higher than that of Xpert (87.5% vs. 77.0%; P = 0.02), but similar to that of smear microscopy (94.2%; P = 0.18). The negative predictive value was respectively 91.9%, 92.5% (P = 0.73) and 83.1% (P = 0.0001). CONCLUSION: Given its ease of operability, the TB-LAMP assay could be implemented as a point-of-care test in primary health care settings, and contribute to reducing treatment waiting times and TB prevalence.
Authors: David J Horne; Mikashmi Kohli; Jerry S Zifodya; Ian Schiller; Nandini Dendukuri; Deanna Tollefson; Samuel G Schumacher; Eleanor A Ochodo; Madhukar Pai; Karen R Steingart Journal: Cochrane Database Syst Rev Date: 2019-06-07
Authors: Sokleaph Cheng; Sok Heng Pheng; Seiha Heng; Guy B Marks; Anne-Laure Bañuls; Tan Eang Mao; Alexandra Kerléguer Journal: Biomed Res Int Date: 2020-06-01 Impact factor: 3.411
Authors: E Spooner; S Reddy; S Ntoyanto; Y Sakadavan; T Reddy; S Mahomed; K Mlisana; M Dlamini; B Daniels; N Luthuli; N Ngomane; P Kiepiela; A Coutsoudis Journal: Int J Tuberc Lung Dis Date: 2022-03-01 Impact factor: 3.427