Klebsiella pneumoniae Oropharyngeal Carriage in Rural and Urban Vietnam and the Effect of Alcohol Consumption

IntroductionCommunity acquired K. pneumoniae pneumonia is still common in Asia and is reportedly associated with alcohol use. Oropharyngeal carriage of K. pneumoniae could potentially play a role in the pathogenesis of K. pneumoniae pneumonia. However, little is known regarding K. pneumoniae oropharyngeal carriage rates and risk factors. This population-based cross-sectional study explores the association of a variety of demographic and socioeconomic factors, as well as alcohol consumption with oropharyngeal carriage of K. pneumoniae in Vietnam.Methods and Findings1029 subjects were selected randomly from age, sex, and urban and rural strata. An additional 613 adult men from a rural environment were recruited and analyzed separately to determine the effects of alcohol consumption. Demographic, socioeconomic, and oropharyngeal carriage data was acquired for each subject. The overall carriage rate of K. pneumoniae was 14.1% (145/1029, 95% CI 12.0%–16.2%). By stepwise logistic regression, K. pneumoniae carriage was found to be independently associated with age (OR 1.03, 95% CI 1.02–1.04), smoking (OR 1.9, 95% CI 1.3–2.9), rural living location (OR 1.6, 95% CI 1.1–2.4), and level of weekly alcohol consumption (OR 1.7, 95% CI 1.04–2.8).ConclusionModerate to heavy weekly alcohol consumption, old age, smoking, and living in a rural location are all found to be associated with an increased risk of K. pneumoniae carriage in Vietnamese communities. Whether K. pneumoniae carriage is a risk factor for pneumonia needs to be elucidated.

引言：社区获得性肺炎克雷伯菌（Klebsiella pneumoniae）肺炎在亚洲仍较为常见，且据报道与饮酒行为存在关联。肺炎克雷伯菌的口咽部定植可能在其肺炎的发病机制中发挥潜在作用。然而，目前关于肺炎克雷伯菌口咽部定植率及其相关危险因素的研究仍较为匮乏。本项基于人群的横断面研究旨在探讨越南人群中，各类人口学、社会经济因素以及饮酒行为与肺炎克雷伯菌口咽部定植的关联。

方法与结果：研究对象按年龄、性别以及城乡分层随机抽取1029名；此外额外招募了613名农村成年男性并单独开展分析，以明确饮酒行为的影响效应。收集所有研究对象的人口学、社会经济资料以及口咽部定植相关数据。肺炎克雷伯菌的总体定植率为14.1%（145/1029，95%置信区间：12.0%~16.2%）。经逐步逻辑回归分析显示，肺炎克雷伯菌定植与以下因素独立相关：年龄（比值比OR=1.03，95%置信区间：1.02~1.04）、吸烟（OR=1.9，95%置信区间：1.3~2.9）、居住于农村地区（OR=1.6，95%置信区间：1.1~2.4）以及周饮酒量水平（OR=1.7，95%置信区间：1.04~2.8）。

结论：在越南社区人群中，周饮酒量中等至过量、高龄、吸烟以及居住于农村地区，均与肺炎克雷伯菌定植风险升高存在关联。肺炎克雷伯菌定植是否为肺炎的危险因素，仍有待进一步阐明。