Related Experiment Video
Updated: May 8, 2026

The MODS method for diagnosis of tuberculosis and multidrug resistant tuberculosis
Published on: August 11, 2008
Factors predicting sputum smear conversion and treatment outcomes in new smear-positive pulmonary tuberculosis
Somkid Unsematham1, Pairaj Kateruttanakul
1Department of Medicine, Rajavithi Hospital, College of Medicine, Rangsit University, Bangkok, Thailand. somkidou@yahoo.com
Background:
Epidemiological studies indicated that the proportion of TB patients who remained smear-positive after two months of treatment could be greater than 20%. The lack of smear conversion in the second month of treatment was one of the predictors of treatment failure and relapse.
Objective:
To determine factors associated with the persisting positive smear after two months of treatment and its value in predicting treatment failure.
Material And Method:
A 3-year retrospective cohort study was conducted in a 1,200-bed government hospital in Thailand New smear-positive tuberculosis patients who had pretreatment drug susceptibility test, the result of 2-month sputum smear and treatment outcomes were selected. The pretreatment drug susceptibility pattern and statistically differences on variables between groups of patients were described
Results:
Three hundred fifty six patients were included in the present study. The level of pretreatment isoniazid resistance and multi-drug resistance were 13.8% and 3.1% respectively. Factors associated with the 2-month positive smear were male sex, high initial sputum acid-fast bacilli grades, and cavitary diseases. The presence of human immuno-deficiency virus infection, drug resistance and the 2-month positive smear were significantly associated with treatment failure.
Conclusion:
Male sex, high initial sputum acid-fast bacilli grades, and cavitary diseases were factors associated with the 2-month positive smear and increasing risk of treatment failure.
Related Concept Videos
Pulmonary Tuberculosis V
Latent tuberculosis infection occurs when TB bacteria are present in a person's body, but are not causing illness or symptoms. It is not contagious, and preventive treatment is crucial to avoid the progression...
Pulmonary Tuberculosis IV
Several diagnostic approaches are used to detect TB. The conventional method is the Tuberculin Skin Test (TST), also known as the Mantoux test. However, this method has...
Sputum Studies I: Gram Stain, cytology, and Acid-fast smear and culture
Gram Stain
The Gram Stain is an integral part of sputum studies. It involves the staining of sputum, which permits...
Pulmonary Tuberculosis III
The first classification is based on the development of the disease, and it includes the following categories:
Sputum Studies II: Culture and Sensitivity
Sputum culture and sensitivity is a medical procedure used to diagnose bacterial infections in the respiratory tract and select the most appropriate antibiotics for treatment. This process involves analyzing sputum samples of thick and opaque secretions produced in the lungs and airways. These samples are collected from patients and then sent to the laboratory for analysis.
The test can identify various pathogens responsible for respiratory infections, including Streptococcus,...
Pulmonary Tuberculosis I
Causative Organism
The primary infectious agent causing tuberculosis is Mycobacterium tuberculosis, a slow-growing, acid-fast, aerobic rod that exhibits sensitivity to heat and ultraviolet light. Instances of Mycobacterium bovis and Mycobacterium avium contributing to the development of TB infection are rare.
Mode of...