B Maharjan1, C D Kelly-Cirino2, A Weirich2, P S Curry2, H Hoffman3, K Avsar3, B Shrestha1. 1. German Nepal TB Project (GENETUP)/Nepal Anti-Tuberculosis Association, Kathmandu, Nepal. 2. DNA Genotek, Ottawa, Ontario, Canada. 3. Kuratorium Tuberkulose in der Welt, München-Gauting, Germany.
Abstract
SETTING: German Nepal TB Project, National Tuberculosis Reference Laboratory, Kathmandu, Nepal. OBJECTIVE: To evaluate whether transporting samples in OMNIgene®•SPUTUM (OM-S) reagent from a peripheral collection site to a central laboratory in Nepal can improve tuberculosis (TB) detection and increase the sensitivity of Xpert® MTB/RIF testing. DESIGN: One hundred sputum samples were split manually. Each portion was assigned to the OM-S group (OM-S added at collection, airline-couriered without cold chain, no other processing required) or the standard-of-care (SOC) group (samples airline-couriered on ice, sodium hydroxide + N-acetyl-L-cysteine processing required at the laboratory). Smear microscopy and Xpert testing were performed. RESULTS: Transport time was 2-13 days. Overall smear results were comparable (respectively 58% and 56% smear-negative results in the OM-S and SOC groups). The rate of smear-positive, Mycobacterium tuberculosis-positive (MTB+) sample detection was identical for both treatment groups, at 95%. More smear-negative MTB+ samples were detected in the OM-S group (17% vs. 13%, P = 0.0655). CONCLUSION: Sputum samples treated with OM-S can undergo multiday ambient-temperature transport and yield comparable smear and Xpert results to those of SOC samples. Further investigation with larger sample sizes is required to assess whether treating sputum samples with OM-S could increase the sensitivity of Xpert testing in smear-negative samples.
SETTING: German Nepal TB Project, National Tuberculosis Reference Laboratory, Kathmandu, Nepal. OBJECTIVE: To evaluate whether transporting samples in OMNIgene®•SPUTUM (OM-S) reagent from a peripheral collection site to a central laboratory in Nepal can improve tuberculosis (TB) detection and increase the sensitivity of Xpert® MTB/RIF testing. DESIGN: One hundred sputum samples were split manually. Each portion was assigned to the OM-S group (OM-S added at collection, airline-couriered without cold chain, no other processing required) or the standard-of-care (SOC) group (samples airline-couriered on ice, sodium hydroxide + N-acetyl-L-cysteine processing required at the laboratory). Smear microscopy and Xpert testing were performed. RESULTS: Transport time was 2-13 days. Overall smear results were comparable (respectively 58% and 56% smear-negative results in the OM-S and SOC groups). The rate of smear-positive, Mycobacterium tuberculosis-positive (MTB+) sample detection was identical for both treatment groups, at 95%. More smear-negative MTB+ samples were detected in the OM-S group (17% vs. 13%, P = 0.0655). CONCLUSION: Sputum samples treated with OM-S can undergo multiday ambient-temperature transport and yield comparable smear and Xpert results to those of SOC samples. Further investigation with larger sample sizes is required to assess whether treating sputum samples with OM-S could increase the sensitivity of Xpert testing in smear-negative samples.