Liquid mycobacterial culture outcomes after different sputum collection techniques before and during treatment. (May 2019)

• Record Type: Journal Article
• Authors: Lourens, Madeleine; Philips, Lauren; Kleinhans, Carmen C.; Friedrich, Sven O.; Martinson, Neil; Venter, Amour; van der Merwe, Lize; Diacon, Andreas H.
• Is Part Of: Tuberculosis. Volume 116(2019)
• Page Start: 17
• Page End: 21
• Publication Date: 2019-05
• Subjects: Chlorhexidine -- Mouth wash -- Sputum collection -- Tuberculosis -- HIV-Infection; AP Antero-posterior -- BMI Body Mass Index -- CXR Chest X-ray -- HREC Health Research Ethics Committee -- PA Postero-anterior -- PBS phosphate buffered saline -- Xpert Xpert MTB/RIF assay; 616.995
• DOI: 10.1016/j.tube.2019.03.008
• Languages: English
• ISSNs: 1472-9792

Abstract

Abstract: Setting: Mycobacterial sputum culture is a key diagnostic and research tool. Objective: To compare mycobacterial culture outcomes of three sputum collection methods. Design: We compared culture results within sets of three sputum samples collected from 18 HIV-infected adult tuberculosis patients at regular intervals up to 84 days after treatment initiation. The first sputum was collected at home and brought to the clinic, where a second and third sputum were consecutively collected under supervision following mouthwash with bottled water and chlorhexidine solution respectively. All sputa were processed for liquid culture in duplicate. Results: Out of 556 cultures 430 (77.3%), 91 (16.4%) and 35 (6.3%) were positive, negative or contaminated, respectively. The odds of contamination were higher with home collection and with water rinse than with chlorhexidine rinse (OR: 12.5, p < 0.001 and OR: 6.7, p = 0.015). Chlorhexidine rinse increased the odds of a negative culture compared to water rinse (OR: 3.5, p = 0.002). The odds of a positive culture were greater with water rinse than with home collection (OR: 2.5, p = 0.005). Water rinse significantly reduced time to culture positivity. Conclusion: Compared to sputum collected at home, chlorhexidine rinse reduces culture contamination and water rinse increases the rate and viable mycobacterial load of positive cultures.