Key Laboratory of Public Health Safety, Ministry of Education, and Department of Epidemiology, School of Public Health, Fudan University, Shanghai, China.
PLoS One. 2011 May 12;6(5):e19548. doi: 10.1371/journal.pone.0019548.
Transmission patterns of drug-resistant Mycobacterium tuberculosis (MTB) may be influenced by differences in socio-demographics, local tuberculosis (TB) endemicity and efficaciousness of TB control programs. This study aimed to investigate the impact of DOTS on the transmission of drug-resistant TB in eastern rural China.
We conducted a cross-sectional study of all patients diagnosed with drug-resistant TB over a one-year period in two rural Chinese counties with varying lengths of DOTS implementation. Counties included Deqing, with over 11 years' DOTS implementation and Guanyun, where DOTS was introduced 1 year prior to start of this study. We combined demographic, clinical and epidemiologic information with IS6110-based restricted fragment length polymorphism (RFLP) and Spoligotyping analysis of MTB isolates. In addition, we conducted DNA sequencing of resistance determining regions to first-line anti-tuberculosis agents.
Of the 223 drug-resistant isolates, 73(32.7%) isolates were identified with clustered IS6110RFLP patterns. The clustering proportion among total drug-resistant TB was higher in Guanyun than Deqing (26/101.vs.47/122; p,0.04), but not significantly different among the 53 multidrug-resistant isolates (10/18.vs.24/35; p,0.35). Patients with cavitary had increased risk of clustering in both counties. In Guanyun, patients with positive smear test or previous treatment history had a higher clustering proportion. Beijing genotype and isolates resistant to isoniazid and/or rifampicin were more likely to be clustered. Of the 73 patients with clustered drug-resistant isolates, 71.2% lived in the same or neighboring villages. Epidemiological link (household and social contact) was confirmed in 12.3% of the clustered isolates.
Transmission of drug-resistant TB in eastern rural China is characterized by small clusters and limited geographic spread. Our observations highlight the need for supplementing DOTS with additional strategies, including active case finding at the village level, effective treatment for patients with cavities and drug susceptibility testing for patients at increased risk for drug-resistance.
耐药结核分枝杆菌（MTB）的传播模式可能受社会人口统计学、当地结核病（TB）流行情况以及结核病控制项目有效性的差异影响。本研究旨在探讨直接面视下的短程化疗（DOTS）对中国东部农村地区耐药结核病传播的影响。
我们对在中国两个农村县的一年中所有耐药结核病患者进行了横断面研究，这两个县的 DOTS 实施时间长短不同。两个县分别为德清，实施 DOTS 超过 11 年；灌云，DOTS 是在本研究开始前 1 年引入的。我们将人口统计学、临床和流行病学信息与 MTB 分离株的 IS6110 限制片段长度多态性（RFLP）和 spoligotyping 分析相结合。此外，我们还对一线抗结核药物耐药决定区进行了 DNA 测序。
在 223 株耐药分离株中，有 73 株（32.7%）分离株的 IS6110RFLP 模式呈聚集性。在总耐药结核病中，灌云的聚集比例高于德清（26/101 与 47/122；p=0.04），但在 53 株耐多药结核病中无显著差异（10/18 与 24/35；p=0.35）。有空洞形成的患者在两个县都有更高的聚集风险。在灌云，痰检阳性或有既往治疗史的患者聚集比例更高。北京基因型和对异烟肼和/或利福平耐药的分离株更可能聚集。在 73 例聚集性耐药分离株患者中，71.2%的患者居住在同一或相邻的村庄。12.3%的聚集分离株有流行病学联系（家庭和社会接触）。
中国东部农村地区耐药结核病的传播特点是小聚集和有限的地理传播。我们的观察结果强调需要在 DOTS 的基础上补充其他策略，包括在村级开展主动发现病例、对有空洞形成的患者进行有效治疗以及对耐药风险增加的患者进行药物敏感性测试。
