Laboratory
Liquid culture using MGIT PDF Print E-mail

In 2010 CTRL started doing liquid culture using the MGIT machine. A total of 335 fresh sputum samples from new AFB patients were cultured using liquid media; of these 200 (69.7%) were positive, 30 (8.9%) negative and 35 (10.4%) were contaminated.  A total of 105 (52.5%) of the positive cultures were set  for DST using proportional method. The DST results revealed that 45 (42.8%) were susceptible to all the four fist line anti-TB drugs while 7(6.7%) were resistant to Isoniazid, 1 (0.9%) to Rifampicin, 3 (2.9%) to Streptomycin and 2 (1.9%) to Ethambutol.

Last Updated on Thursday, 14 March 2013 11:28
 
Specimen AFB microscopy and solid culture PDF Print E-mail

In 2010, a total of 8,849 specimens were referred to the CTRL for AFB smear microscopy and culture examinations. Of these 5,961 (67.4%) were samples from Muhimbili National Hospital (MNH) for routine AFB microscopy examination only, 2015 (22.8%) were from different regions for culture and DST as part of MDR-TB surveillance while 873 (9.9%) were from TB HAART and other studies submitted for culture and DST. Overall, CTRL cultured 2,870 sputum specimens using solid culture method on Lowenstein-Jensen media of which 1,632 (56.9%) were positive isolates and were set for DST. DST results are available for 1,270 culture isolates.

Of these, 712 (56%) of all positive isolates with DST results were sensitive to all four first line anti-TB drugs. In addition, 66 (5.2%) of  the positive isolates had  resistance to one or more anti-TB drugs and 77 isolates (6.1 %) were multi-drug resistant and 2 isolates were Mycobacterium Other than Tuberculosis (MOTT). 

The culture analysis shows that there is an increase in the rate of smear positive and culture positive which comes close to 90% towards the end the year which is the aimed target.
However, the problem is false negative cultures (smear positive and culture negative) and a too low contamination rate of 1% annually.  In addition, the CTRL managed to isolate tuberculosis from 20 to 30% smear negatives,  increasing trend parallel with the smear positive from culture and DST.

Last Updated on Thursday, 14 March 2013 11:01
 
Laboratory Services PDF Print E-mail

The program laboratory networking consists of three levels; one central reference laboratory at Muhimbili National Hospital also called  the Central Tuberculosis Reference Laboratory (CTRL), two TB zone laboratories (Bugando Medical Centre and Kilimanjaro Christian Medical Centre) and 995 diagnostic centres at peripheral health centres levels.  However, in 2010 the two zone TB laboratories did not  perform any cultures on Mycobacterium tuberculosis nor drug susceptibility testing (DST) was because of lack of human resources. 

In 2010, CTRL continued to maintain Quality Assurance Programme in 13 regions in collaboration with external partners. CTRL has also introduced liquid culture technology using MGIT 960 which takes 2 - 3 weeks to get results.  CTRL has also introduced rapid molecular methods for DST using the Line Probe Assay (LPA). In this regard one HAIN machine is currently undergoing validation for local use. 

CTRL has also established a proven capacity to routinely perform DST against all positive culture Mtb isolates for 4 first-line anti-TB drugs (streptomycin, Isoniazid, Rifampicin and Ethambutol). CTRL is also building capacity to do drug susceptibility testing for MTb isolated from re-treatment cases (relapses or  failures) with results available usually in 4 weeks. The drugs covered are Kanamycin and Ofloxacin.

Last Updated on Thursday, 14 March 2013 11:29