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Updated: Aug 24, 2026
A Tuberculosis Molecular Bacterial Load Assay (TB-MBLA)
Published on: April 30, 2020
Using a bus service for transporting sputum specimens to the Central Reference Laboratory: effect on the routine TB
A D Harries1, J Michongwe, T E Nyirenda
1Community Health Science Unit, National Tuberculosis Control Programme, Lilongwe, Malawi. adharries@malawi.net
Setting:
All non-private hospitals in Malawi that registered TB cases in 2001, during which there was a bus service for transporting sputum specimens to the Central Reference Laboratory (CRL) for mycobacterial culture and drug sensitivity testing (CDST).
Objectives:
To determine the performance of the system of collecting and processing sputum specimens from patients with recurrent smear-positive pulmonary TB through to CDST.
Design:
Structured interviews with TB Officers, and retrospective data collection using TB and laboratory registers.
Results:
There were 964 patients with recurrent smear-positive PTB. TB Officers took responsibility for collecting and transporting sputum to the CRL, and 73% reported using the bus service. Sputum specimens from 384 (40%) patients arrived at the CRL. Of these, 40% were found to have negative concentrated smears at the CRL, and 36% of specimen sets arriving at CRL were successfully cultured for DST. Most specimens had been collected after the start of anti-tuberculosis treatment. Although delays in collection adversely affected culture, only 43% of specimen sets collected on or before the first day of treatment yielded Mycobacterium tuberculosis.
Conclusion:
Problems were identified at all stages of the system and strategies to remedy these are being put in place.
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