Sputum Culture Conversion in Multidrug-Resistant Tuberculosis
Summary
Sputum culture conversion—the change from a positive to consecutive negative mycobacterial cultures—is a central marker for monitoring the efficacy of treatment in multidrug-resistant tuberculosis (MDR-TB). As global efforts seek to improve outcomes in settings where resistance to first-line drugs is common, the timing of culture conversion emerging within two to four months of therapy has become a strong predictor of final treatment success. Delays in conversion are often linked to high baseline bacillary load, cavitary lung disease, undernutrition and additional resistance to key second-line agents. Early conversion not only signals patient response but also guides programme decisions on treatment duration, infection control and prevention of further transmission. Understanding regional determinants and optimising regimens to hasten conversion remain priorities in combating this persistent public health challenge.
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Sputum Culture Conversion in Multidrug-Resistant Tuberculosis publication trend
The graph below shows the total number of articles in sputum culture conversion in multidrug-resistant tuberculosis across all publications each year (not limited to Nature Index journals).
Technical terms
Sputum culture conversion: Achievement of two consecutive negative cultures from expectorated sputum, signalling effective bacteriological clearance.
Multidrug-resistant tuberculosis (MDR-TB): Disease caused by Mycobacterium tuberculosis strains resistant to at least isoniazid and rifampicin, the two most potent first-line drugs.
Sputum smear conversion: Transition from acid-fast bacilli visible on microscopy to negative smears, reflecting reduced mycobacterial load.
Culture reversion: Recurrence of a positive culture after initial conversion, indicating persistent or recurrent infection.
Intensive phase: Initial treatment period using a combination of multiple anti-tuberculosis drugs at higher doses to rapidly reduce bacterial burden.
References
- Time to sputum smear and culture conversions in multidrug resistant tuberculosis at University of Gondar Hospital, Northwest Ethiopia. PLOS ONE (2018).
- Factors affecting time to sputum culture conversion and treatment outcome of patients with multidrug-resistant tuberculosis in China. BMC Infectious Diseases (2018).
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