novel sputum transport solution eliminates cold chain and supports routine tuberculosis testing in Nepal

ABSTRACT

This preliminary study evaluated the transport reagent OMNIgene SPUTUM [OMS] in a real-world, resource-limited setting: a zonal hospital and national tuberculosis [TB] reference laboratory, Nepal. The objectives were to [1] assess the performance of OMS for transporting sputum from peripheral sites without cold chain stabilization; and [2] compare with Nepal's standard of care [SOC] for Mycobacterium tuberculosis smear and culture diagnostics. Sixty sputa were manually split into a SOC sample [airline-couriered to the laboratory, conventional processing] and an OMS sample [OMS added at collection, no cold chain transport or processing]. Smear microscopy and solid culture were performed. Transport was 0-8 days. Forty-one samples [68%] were smear-positive using both methods. Of the OMS cultures, 37 [62%] were positive, 22 [36%] were negative, and one [2%] was contaminated. Corresponding SOC results were 32 [53%], 21 [35%], and seven [12%]. OMS "rescued" six [i.e., missed using SOC] compared with one rescue using SOC. Of smear-positives, six SOC samples produced contaminated cultures whereas only one OMS sample was contaminated. OMS reduced culture contamination from 12% to 2%, and improved TB detection by 9%. The results suggest that OMS could perform well as a no cold chain, long-term transport solution for smear and culture testing. The findings provide a basis for larger feasibility studies