Alene Kefyalew Addis, Viney Kerri, McBryde Emma S, Clements Archie C A
Research School of Population Health, College of Medicine, Biology and Environment, The Australian National University, Canberra, Australian Capital Territory, Australia.
Institute of Public Health, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia.
PLoS One. 2017 Feb 9;12(2):e0171800. doi: 10.1371/journal.pone.0171800. eCollection 2017.
Understanding the geographical distribution of multidrug-resistant tuberculosis (MDR-TB) in high TB burden countries such as Ethiopia is crucial for effective control of TB epidemics in these countries, and thus globally. We present the first spatial analysis of multidrug resistant tuberculosis, and its relationship to socio-economic, demographic and household factors in northwest Ethiopia.
An ecological study was conducted using data on patients diagnosed with MDR-TB at the University of Gondar Hospital MDR-TB treatment centre, for the period 2010 to 2015. District level population data were extracted from the Ethiopia National and Regional Census Report. Spatial autocorrelation was explored using Moran's I statistic, Local Indicators of Spatial Association (LISA), and the Getis-Ord statistics. A multivariate Poisson regression model was developed with a conditional autoregressive (CAR) prior structure, and with posterior parameters estimated using a Bayesian Markov chain Monte Carlo (MCMC) simulation approach with Gibbs sampling, in WinBUGS.
A total of 264 MDR-TB patients were included in the analysis. The overall crude incidence rate of MDR-TB for the six-year period was 3.0 cases per 100,000 population. The highest incidence rate was observed in Metema (21 cases per 100,000 population) and Humera (18 cases per 100,000 population) districts; whereas nine districts had zero cases. Spatial clustering of MDR-TB was observed in districts located in the Ethiopia-Sudan and Ethiopia-Eritrea border regions, where large numbers of seasonal migrants live. Spatial clustering of MDR-TB was positively associated with urbanization (RR: 1.02; 95%CI: 1.01, 1.04) and the percentage of men (RR: 1.58; 95% CI: 1.26, 1.99) in the districts; after accounting for these factors there was no residual spatial clustering.
Spatial clustering of MDR-TB, fully explained by demographic factors (urbanization and percent male), was detected in the border regions of northwest Ethiopia, in locations where seasonal migrants live and work. Cross-border initiatives including options for mobile TB treatment and follow up are important for the effective control of MDR-TB in the region.
了解埃塞俄比亚等高结核病负担国家耐多药结核病（MDR-TB）的地理分布，对于有效控制这些国家乃至全球的结核病流行至关重要。我们对埃塞俄比亚西北部的耐多药结核病进行了首次空间分析，并分析了其与社会经济、人口和家庭因素的关系。
采用贡德尔大学医院耐多药结核病治疗中心2010年至2015年期间确诊的耐多药结核病患者数据进行生态研究。地区层面的人口数据从埃塞俄比亚国家和地区人口普查报告中提取。使用莫兰指数（Moran's I）统计量、局部空间自相关指标（LISA）和Getis-Ord统计量探索空间自相关性。在WinBUGS中，采用具有条件自回归（CAR）先验结构的多元泊松回归模型，并使用贝叶斯马尔可夫链蒙特卡罗（MCMC）模拟方法和吉布斯抽样估计后验参数。
共有264例耐多药结核病患者纳入分析。六年期间耐多药结核病的总体粗发病率为每10万人口3.0例。梅特马（每10万人口21例）和胡梅拉（每10万人口18例）地区的发病率最高；而九个地区的病例数为零。在埃塞俄比亚与苏丹和埃塞俄比亚与厄立特里亚边境地区的一些地区观察到耐多药结核病的空间聚集，这些地区有大量季节性移民居住。耐多药结核病的空间聚集与地区的城市化水平（相对风险：1.02；95%置信区间：1.01, 1.04）和男性比例（相对风险：1.58；95%置信区间：1.26, 1.99）呈正相关；在考虑这些因素后，不存在残余的空间聚集。
在埃塞俄比亚西北部边境地区季节性移民生活和工作的地方，检测到耐多药结核病的空间聚集，且这一现象完全由人口因素（城市化和男性比例）所解释。包括流动结核病治疗和随访方案在内的跨境举措对于有效控制该地区的耐多药结核病至关重要。
