The feasibility of sputum transportation system in China: effect of sputum storage on the mycobacterial detection.

ABSTRACT

Sputum transportation from county-level to prefecture-level is an ideal strategy to cover the shortage of the laboratory capability in the resource-poor setting. Here, we firstly evaluated the feasibility of sputum transportation system in China by analyzing the culture and molecular diagnosis results from 1982 smear-positive patients with different delay in processing for culture. In this study, the total contamination rate was 2.32% and the total smear positive/culture negative (S+/C-) rate was 7.57%. We found that sputum specimens refrigerated for no more than 7 d before mycobacterial detection did not affect culture significantly. In addition, the invalid result rates among 0-3 d, 3-7 d, and 7+ d group were 3.63%, 3.14%, and 12.48%, respectively. Statistic analysis revealed that molecular diagnostic results while the invalid result rate of genechip for the specimen with more than 7 d delay was significantly higher (P<0.001). The refrigerators equipped in county laboratories, transport at low temperature and frequent transport services once a week will ensure the feasibility of sputum transportation system in China.