在全球范围内,下呼吸道感染是最为致命的感染性疾病,在 2016 年全球范围内共造成 300 万人死亡。[3]World Health Organization. The top 10 causes of death. May 2018 [internet publication].http://www.who.int/mediacentre/factsheets/fs310/en/ CAP 是一个严重的卫生健康问题,在全球范围内所有年龄组患者都有较高的并发症发病率和死亡率,并且是医疗保健资源的主要负担。[4]Mandell LA, Wunderink RG, Anzueto A, et al. Infectious Diseases Society of America/American Thoracic Society consensus guidelines on the management of community-acquired pneumonia in adults. Clin Infect Dis. 2007 Mar 1;44(suppl 2):S27-S72.http://cid.oxfordjournals.org/content/44/Supplement_2/S27.longhttp://www.ncbi.nlm.nih.gov/pubmed/17278083?tool=bestpractice.com
一项文献综述发现,欧洲的 CAP 年均总发病率在1.07/1000 人·年-1.2/1000 人·年,以及 1.54/1000-1.7/1000。[5]Torres A, Peetermans WE, Viegi G, et al. Risk factors for community-acquired pneumonia in adults in Europe: a literature review. Thorax. 2013 Nov;68(11):1057-65.http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3812874/http://www.ncbi.nlm.nih.gov/pubmed/24130229?tool=bestpractice.com CAP 发病率随年龄而上升,在年龄≥65 岁的成人中,发病率高达 14 /1000 人·年,且男性发病率似乎显著高于女性。[5]Torres A, Peetermans WE, Viegi G, et al. Risk factors for community-acquired pneumonia in adults in Europe: a literature review. Thorax. 2013 Nov;68(11):1057-65.http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3812874/http://www.ncbi.nlm.nih.gov/pubmed/24130229?tool=bestpractice.com 这是欧洲的第五大死亡原因。[6]Alimi Y, Lim WS, Lansbury L, et al. Systematic review of respiratory viral pathogens identified in adults with community-acquired pneumonia in Europe. J Clin Virol. 2017 Oct;95:26-35.http://www.ncbi.nlm.nih.gov/pubmed/28837859?tool=bestpractice.com 估计患者病死率为:门诊 1%-5%,普通病房 5.7%-14% ,而 ICU 则为 34%-50% (通气患者死亡率尤其高)。[7]Fine MJ, Smith MA, Carson CA, et al. Prognosis and outcomes of patients with community-acquired pneumonia: a meta-analysis. JAMA. 1996;275:134-141.http://www.ncbi.nlm.nih.gov/pubmed/8531309?tool=bestpractice.com[8]Alkhayer M, Jenkins PF, Harrison BD. The outcome of community acquired pneumonia treated on the intensive care unit. Respir Med. 1990;84:13-16.http://www.ncbi.nlm.nih.gov/pubmed/2115190?tool=bestpractice.com 据另一项研究报告,欧洲不同国家/地区之间的 CAP 死亡率差异很大,最低不到 1%,而最高则达到 48%。[9]Welte T, Torres A, Nathwani D. Clinical and economic burden of community-acquired pneumonia among adults in Europe. Thorax. 2012;67:71-79.http://www.ncbi.nlm.nih.gov/pubmed/20729232?tool=bestpractice.com 肺炎球菌肺炎的死亡率约为 5%,伴有相关性菌血症的成人患者死亡率较高,介于 6% 至 30% 之间。[10]Lin SH, Lai CC, Tan CK, et al. Outcomes of hospitalized patients with bacteraemic and non-bacteraemic community-acquired pneumonia caused by Streptococcus pneumoniae. Epidemiol Infect. 2011;139:1307-1316.http://www.ncbi.nlm.nih.gov/pubmed/20974020?tool=bestpractice.com[11]Garcia-Vidal C, Ardanuy C, Tubau F, et al. Pneumococcal pneumonia presenting with septic shock: host- and pathogen-related factors and outcomes. Thorax. 2010 Jan;65(1):77-81.http://www.ncbi.nlm.nih.gov/pubmed/19996337?tool=bestpractice.com
在美国,成人社区获得性肺炎 (CAP) 的年发病率估计为 24.8 例/10,000 人。[12]Jain S, Self WH, Wunderink RG, et al. Community-acquired pneumonia requiring hospitalization among US adults. N Engl J Med. 2015 Jul 30;373(5):415-27.http://www.nejm.org/doi/full/10.1056/NEJMoa1500245http://www.ncbi.nlm.nih.gov/pubmed/26172429?tool=bestpractice.com 如果综合考虑肺炎和流感的共同影响,则二者是 2016 年美国第八大致死原因(每 100,000 人中 13.5 人死亡),并且是当年主要感染原因。[13]Kochanek KD, Murphy SL, Xu J, et al. Deaths: final data for 2016. Natl Vital Stat Rep. 2018 Jul;67(5):1-76.https://www.cdc.gov/nchs/hus/