TITLE:
The Influence of Pyrazinamide Monoresistance on Treatment Outcomes in Tuberculosis Patients from Southern China
AUTHORS:
Shouyong Tan, Yunwei Rao, Jintao Guo, Yaoju Tan, Xingshan Cai, Haobin Kuang, Yanqiong Li, Wenyan Liu, Julius Mugweru, Bangxing Wang, Yuanyuan Cao, Changwei Wang, Ying Zhang, Tianyu Zhang
KEYWORDS:
Tuberculosis, Pyrazinamide, Treatment, Monoresistance
JOURNAL NAME:
Journal of Tuberculosis Research,
Vol.4 No.1,
March
9,
2016
ABSTRACT: This study aimed to explore the influence of pyrazinamide (PZA) monoresistance on the treatment outcome of otherwise drug susceptible tuberculosis (TB). A cohort of 194 TB patients that were infected with strains susceptible to isoniazid (INH), rifampin (RIF) and ethambutol (EMB) were included in a retrospective study at the Guangzhou Chest Hospital. We reported 148 (76.3%) PZA- susceptible TB cases and 46 (23.7%) PZA-monoresistance TB cases identified by the BACTEC MGIT 960 system. All patients were treated with the standard 6 months WHO recommended regimen, which included 2 months of INH + RIF + EMB + PZA in the intensive-phase, and the subsequent 4 months of INH + RIF during continuation-phase. Bacterial burden in the lungs was estimated using sputum smear acid-fast bacillary count while the lung lesions and cavitations were examined by X-ray at the end of first 2 months of chemotherapy. After intensive-phase treatment, there were 164 (84.5%) cases of smear-negative conversion and 151 (77.9%) cases of total or partial lesion elimination. The rates of smear-negative conversion (78.3%) and lesion elimination (39.1%) of the PZA-monoresistant patients were similar with the PZA-sensitive group (P > 0.05). However, lung cavitation was more likely to be resolved in PZA-sensitive patients than in the PZA-patients (X2 = 9.623, P = 0.002). The smear-negative conversion rates were 95.9% for the PZA-sensitive patients and 87.0% for the PZA-monoresistant patients after 6 months of treatment (X2 = 3.461, P = 0.063). Together, our data suggest that PZA-monoresistance contributes to the delay of resolution of the lung cavitations in the Southern China population without affecting the sputum conversion and lesion elimination rates.