of new technologies compared with current methods, the performance testing and quality assurance needed for new technologies, the history and current responsibilities of the Supranational Reference Laboratory Network, and the contributions of FIND and the EXPAND-TB program to the scaling up of laboratory capacity in India.
As discussed earlier, the lack of diagnostic capacity has been a crucial barrier to the treatment of MDR TB. Today, however, at least 20 new diagnostic technologies are in different stages of development, and expanding laboratory capacity has become a global priority.
Ideally, DST should have at least the following characteristics:
Culture methods, which are regarded as the gold standard, are still widely used today, but have limitations, including
Several rapid assays measure resistance directly from clinical specimens. For example, a meta-analysis showed that the nitrate reductase assay (NRA) has a pooled sensitivity for detection of isoniazid and rifampicin resistance of 94 percent and 96 percent, respectively (Bwanga et al., 2009). The same analysis found a pooled sensitivity for the microscopic observation drug susceptibility (MODS) assay of 92 percent and 96 percent, respectively.
1 This section is based on the presentation of Camilla Rodrigues, Consultant Clinical Mi-crobiologist and Chair of Infection Control, Hinduja Hospital.