Accessibility of bacteriological-based diagnosis and prevalence of drug resistant tuberculosis in previously treated tuberculosis patients

Abstract

Aims and objectivesMultidrug-resistant tuberculosis (MDR-TB) has become a major public health problem worldwide, which lays a heavy burden on low- and middle-income countries. Compared with newly diagnosed tuberculosis (TB) patients, patients with a history of anti-TB treatment have increased mortality and a higher prevalence of drug resistance. However, these patients are neglected by both global and national TB control programs and have met barriers to access to medical care for potential drug resistance. This study aims to understand the drug-resistance status of patients with previous treatment history and to determine the factors associated with the accessibility of bacteriological-based TB diagnosis. MethodsA cross-sectional study was conducted in 8 county/district TB clinics in three provinces (Jiangsu, Shandong and Sichuan) of China, where a global fund-supported MDR-TB control project had been initiated. TB patients who had at least one previous treatment episode were interviewed using a structured questionnaire. Information on demographics, socioeconomic status of patients, and their experiences on seeking TB diagnosis and treatment were collected. ResultsA total of 196 smear-positive TB patients were recruited, of which 78% (153/196) were male and the average age of these patients was 57years old. About 70% (137/196) of the subjects were farmers, and 63% (121/195) had less than 6years’ education. Among these patients, 120 cases (61.22%) received culture-based TB diagnosis in this treatment episode, while patients from Jiangsu province (versus Shandong/Sichuan aOR: 8.10/36.42, 95% CI: 2.70–24.25/12.20–108.66) and patients with a higher annual income per capita (aOR: 3.35, 95% CI: 1.26–8.92) were found to be more likely to reach culture tests after adjusting for gender and age. MTB complex and non-tuberculosis mycobacteria (NTM) strains were isolated from 92 and 10 patients, respectively, and the remaining 18 patients were negative to bacteria culture. Drug sensitivity testing (DST) for first-line anti-TB drugs, and kanamycin and ofloxacin, was completed for the 92 MTB isolates. The total proportion of drug-resistant tuberculosis was 52.48% (47/92), while the prevalence for resistance to a single drug, multidrug-resistant and other combinations of drug resistance were 16.30% (95% CI: 9.78–23.91%), 30.43% (95% CI: 21.74–40.22%), and 4.35% (95% CI: 1.09–8.70%), respectively. Resistance to isoniazid, rifampicin, streptomycin, ethambutol, kanamycin and ofloxacin was 36.96%, 35.87%, 23.91%, 10.87%, 4.35% and 6.52%, respectively. ConclusionsPatients with a previous treatment history are at extremely high risk of drug-resistant tuberculosis in China. The poor accessibility of bacteriological-based diagnosis may aggravate the difficulty of detection and control for drug-resistant TB patients. The next step of the anti-TB strategy should be focused on how to make bacteriological-based diagnosis cheaper, safer and more maneuverable and on how to assure the DST-guided treatment for these high-risk TB patients.