Demonstration studies on three tests near completion
With the end of demonstration studies
of three tests – liquid culture growth
detection, liquid culture-based drug susceptibility
test systems and a lateral flow assay for
Mycobacterium tuberculosis species complex
identification – FIND is preparing to submit
results to the World Health Organization’s
Strategic and Technical Advisory Group for
Tuberculosis (STAG-TB).
The studies indicate that liquid culture and
liquid culture-based drug susceptibility testing
systems can be incorporated in lower income
regions to improve diagnosis of multi-drug
resistant TB and sputum smear-negative TB in
HIV-positive patients, childhood TB, and
extra-pulmonary TB. Consistent with the
large body of published literature on liquid
culture, the projects also show higher rates of
mycobacterial isolation and a shorter time-to-detection
compared to culture on solid media.
However, since liquid culture and drug susceptibility
test (DST) systems are more complex
than solid culture, higher bacterial contamination
and an increased frequency of nontuberculous
mycobacterial (NTM) isolation
must be addressed. A rapid method to differentiate
M. tuberculosis complex from other
mycobacterial species is essential.
Regarding costs, FIND is to explore possibilities
for significant reductions in commercial
prices for the public health sector and nonprofit
private sector in lower income countries
since prices are higher for liquid culture systems
compared to solid media. In the next
year, FIND expects to have an additional body
of data available on liquid culture and DST
performance, as well as on detailed costing and
patient impact.
The end of the testing period is a great milestone
for FIND and the next major step will be
the roll out of these technologies in appropriately
selected laboratories in high endemic
countries.
|
