Angel, M

Muzanyi, G

Nakamate, T

Nyole, S

Ogwang, S

AJOL - African Journals Online

African Health Sciences Vol 11 No 4 December 2011 605Short CommunicationImpact of  directly observed sputum collection on sputum culturecontamination rates*Muzanyi G1, Angel M1, Nakamate T1, Ogwang S2 ,Nyole S31. Uganda-Case Western reserve university research collaboration2. Joint Clinical research center, Kampala Uganda3. National TB and leprosy control programme clinic Mulago hospitalAfrican Health Sciences 2011; 11(4): 605 – 606*Correspondence author:Dr Grace MuzanyiMakerere-Case Western Reserve UniversityResearch CollaborationMakerere UniversityKampala, UgandaTelephone: +256 772 437028 or + 256 758 695782Email:gxm62@case.edu,gracemuzanye@yahoo.com,gmuzanye@mucwru.or.ugBackgroundTB sputum culture contamination is relativelycommon despite strong lab decontaminationprocedures. The sources of  sputum contaminationinclude: normal flora, level of  oral hygiene, labmethodology and techniques of  sputum collection.The techniques of sputum collection may includebut not limited to specific instructions by healthworkers to patients about collecting sputum2, 3.Whether the patients understand and put theinstructions in practice may not always be followed.In previous studies done on site at the mulago TBproject clinic, contamination rates have gone as highas 30%. In one study: impact of mouth rinsing onsputum culture contamination rates1, thecontamination rates were reduced from as high as22% to as low as 7% with the intervention of  mouthrising. It was then reported that patients sometimescarry sputum from home using unsterile containerswhich sputum is then transferred to the cliniccontainers without the knowledge of the clinic staff.The feeling was that this could be another source ofcontamination. It was hypothesized that by directlyobserving sputum collection, we can further reducethe sputum culture contamination rates.ObjectiveTo determine the effect of  directly observed sputumcollection on sputum culture contamination rates.MethodsWith standardized lab decontamination proceduresand sputum collection techniques, we collected 6000baseline and non-baseline sputum samples over aperiod of  46months. The initial twenty four monthshad no directly observed sputum collection butpatients were given standardized instructions on howto collect sputum. Sputum cultures were done onMGIT and 7H10.The subsequent 22months had theintervention procedure in which patients weredirectly observed while collecting sputum followingthe standardized instructions2.ResultsFor all samples collected in the initial twenty fourmonths in which there was no directly observedsputum collection: the median positivity rate was17.55% for baseline and 26.7 % for non-baselinesamples. The median contamination rate for bothmedia combined was 4.2% for baseline and 9.02%for non-baseline where as for the interventional arm:Median positivity rates were 98.85% for baseline and31.45% for non-baseline. Median contamination rateswere: 0% for baseline (p-value=0.0005) and 14.15%for non-baseline (p=0.8419).Overall for baseline andnon-baseline combined on both media, the pre-intervention median contamination rate was 7.4%where as the interventional contamination rate was6.0 %( p=0.68).ConclusionDirectly observed sputum collection understandardized instructions significantly reduces theAfrican Health Sciences Vol 11 No 4 December 2011606culture contamination rates for baseline (diagnostic)samples but does not significantly reduce rates ofsputum culture contamination for non-baseline(follow up) samples.AcknowledgmentWe would like to thank CDC-TBTC Atlanta,Uganda-Case research collaboration, Joint Clinicalresearch center and the national TB and Leprosycontrol programme for all the support in onewayor another that made this study a success.References1. Muzanye G, Karen M, Mayanja H, John J et al:Impact of mouth rinsing on sputum culturecontamination rates. Afr Health Sci. 2009 Sep;9 (3):200 - 2052. Alisjahbana B, van Crevel R, Danusantoso H,Gartinah T, Soemantri E S, Nelwan RH, et al.Better patient instruction for sputum sampling canimprove microscopic tuberculosis diagnosis. Int JTuberc Lung Dis 2005; 9:814-817.3. Khan MS, Dar O, Sismanidis C, Shah K, Godfrey-Faussett P. Improvement of  tuberculosis casedetection and reduction of discrepancies betweenmen and women by simple sputum-submissioninstructions: a pragmatic randomized controlledtrial. Lancet 2007; 369:1955-1960.

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Short communication: Impact of directly observed sputum collection on sputum culture contamination rates

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Short communication: Impact of directly observed sputum collection on sputum culture contamination rates

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