Evaluation of efficiency of nested multiplex allele-specific PCR assay for detection of multidrug resistant tuberculosis directly from sputum samples.

UNLABELLED: For an effective control of tuberculosis, rapid detection of multidrug resistant tuberculosis (MDR-TB) is necessary. Therefore, we developed a modified nested multiplex allele-specific polymerase chain reaction (MAS-PCR) method that enables rapid MDR-TB detection directly from sputum samples. The efficacy of this method was evaluated using 79 sputum samples collected from suspected tuberculosis patients. The performance of nested MAS-PCR method was compared with other MDR-TB detection methods like drug susceptibility testing (DST) and DNA sequencing. As rifampicin (RIF) resistance conforms to MDR-TB in greater than 90% cases, only the presence of RIF-associated mutations in rpoB gene was determined by DNA sequencing and nested MAS-PCR to detect MDR-TB. The concordance between nested MAS-PCR and DNA sequencing results was found to be 96·3%. When compared with DST, the sensitivity and specificity of nested MAS-PCR for RIF-resistance detection were determined to be 92·9 and 100% respectively. SIGNIFICANCE AND IMPACT OF THE STUDY: For developing- and high-TB burden countries, molecular-based tests have been recommended by the World Health Organization for rapid detection of MDR-TB. The results of this study indicate that, nested MAS-PCR assay might be a practical and relatively cost effective molecular method for rapid detection of MDR-TB from suspected sputum samples in developing countries with resource poor settings.

Anti-tuberculosis drug resistance in Bangladesh: reflections from the first nationwide survey.

OBJECTIVE: To determine the prevalence of tuberculosis (TB) drug resistance in Bangladesh. DESIGN: Weighted cluster sampling among smear-positive cases, and standard culture and drug susceptibility testing on solid medium were used. RESULTS: Of 1480 patients enrolled during 2011, 12 falsified multidrug-resistant TB (MDR-TB) patients were excluded. Analysis included 1340 cases (90.5% of those enrolled) with valid results and known treatment antecedents. Of 1049 new cases, 12.3% (95%CI 9.3-16.1) had strains resistant to any of the first-line drugs tested, and 1.4% (95%CI 0.7-2.5) were MDR-TB. Among the 291 previously treated cases, this was respectively 43.2% (95%CI 37.1-49.5) and 28.5% (95%CI 23.5-34.1). History of previous anti-tuberculosis treatment was the only predictive factor for first-line drug resistance (OR 34.9). Among the MDR-TB patients, 19.2% (95%CI 11.3-30.5; exclusively previously treated) also showed resistance to ofloxacin. Resistance to kanamycin was not detected. CONCLUSION: Although MDR-TB prevalence was relatively low, transmission of MDR-TB may be increasing in Bangladesh. MDR-TB with fluoroquinolone resistance is rapidly rising. Integrating the private sector should be made high priority given the excessive proportion of MDR-TB retreatment cases in large cities. TB control programmes and donors should avoid applying undue pressure towards meeting global targets, which can lead to corruption of data even in national surveys.

Repetitive transcranial magnetic stimulation in neuropathic pain secondary to malignancy: a randomized clinical trial.

BACKGROUND: Significant analgesic effects of repetitive transcranial magnetic stimulation (rTMS) have been found in several studies of patients with chronic pain of various origins, but never for malignancy. The objective of this study was to assess the efficacy of 10 sessions of rTMS over the primary motor cortex (M1) in patients suffering from malignant neuropathic pain. METHODS: Thirty-four patients were randomly allocated into one of two groups to receive real (20 Hz, 10 s, 10 trains with 80% intensity) or sham rTMS daily for 10 consecutive days. Patients were evaluated using a verbal descriptor scale (VDS), a visual analogue scale (VAS), Leeds assessment of neuropathic symptoms and signs (LANSS) and Hamilton rating scale for depression (HAM-D) at baseline, after the first, fifth and 10th treatment sessions, and then 15 days and 1 month after treatment. RESULTS: There were no significant differences between real and sham groups in the duration of illness or pain rating scores at the baseline. A significant 'Time × Group' interaction was recorded indicating that real and sham rTMS had different effects on the VDS, VAS, LANSS and HAM-D scales. Post-hoc testing showed that the group of patients treated with real rTMS had greater improvement in all scales that persisted up to 15 days, but were not present 1 month later. Significant positive correlations between the percentage of pain reduction and HAM-D after the 10th session and 15 days later were recorded. CONCLUSION: The results demonstrate that 10 rTMS sessions over the M1 can induce short-term pain relief in malignant neuropathic pain.