莱姆病可见于任何年龄段患者,但在两个年龄段人群中的发病率最高:10-19 岁和 50-59 岁。[3]Hengge UR, Tannapfel A, Tyring SK, et al. Lyme borreliosis. Lancet Infect Dis. 2003 Aug;3(8):489-500.http://www.ncbi.nlm.nih.gov/pubmed/12901891?tool=bestpractice.com 男性和女性受累情况相同。[3]Hengge UR, Tannapfel A, Tyring SK, et al. Lyme borreliosis. Lancet Infect Dis. 2003 Aug;3(8):489-500.http://www.ncbi.nlm.nih.gov/pubmed/12901891?tool=bestpractice.com 发病时间通常在 5 月至 10 月之间,主要与这个时期户外活动增加有关。[2]Wormser GP, Dattwyler RJ, Shapiro ED, et al. The clinical assessment, treatment, and prevention of Lyme disease, human granulocytic anaplasmosis, and babesiosis: clinical practice guidelines by the Infectious Diseases Society of America. Clin Infect Dis. 2006 Nov 1;43(9):1089-134.http://cid.oxfordjournals.org/content/43/9/1089.fullhttp://www.ncbi.nlm.nih.gov/pubmed/17029130?tool=bestpractice.com[3]Hengge UR, Tannapfel A, Tyring SK, et al. Lyme borreliosis. Lancet Infect Dis. 2003 Aug;3(8):489-500.http://www.ncbi.nlm.nih.gov/pubmed/12901891?tool=bestpractice.com[4]Steere AC. Lyme disease. N Engl J Med. 2001 Jul 12;345(2):115-25.http://www.ncbi.nlm.nih.gov/pubmed/11450660?tool=bestpractice.com 早期莱姆病通常发生于春末和夏初,但是有时候会发生于秋季。莱姆病多发生于北半球的温带地区,包括北美、欧洲和亚洲。据报告,美国(东北部、中大西洋区及中西部偏北地区)、斯堪的纳维亚半岛、德国、澳大利亚、斯洛文尼亚、瑞典、俄罗斯、中国和日本均有高发病率的流行疫区。[6]Schwartz AM, Hinckley AF, Mead PS, et al. Surveillance for Lyme disease - United States, 2008-2015. MMWR Surveill Summ. 2017 Nov 10;66(22):1-12.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5829628/http://www.ncbi.nlm.nih.gov/pubmed/29120995?tool=bestpractice.com
在欧洲,莱姆病最常见于中欧和斯堪的纳维亚国家,发病率约为每年每 100,000 人中有 155 例新发病例。瑞典南部曾有报告发病率高于 450/100,000 人每年。[7]Stanek G, Strle F. Lyme borreliosis. Lancet. 2003 Nov 15;362(9396):1639-47.http://www.ncbi.nlm.nih.gov/pubmed/14630446?tool=bestpractice.com[8]Bennet L, Halling A, Berglund J. Increased incidence of Lyme borreliosis in southern Sweden following mild winters and during warm, humid summers. Eur J Clin Microbiol Infect Dis. 2006 Jul;25(7):426-32.http://www.ncbi.nlm.nih.gov/pubmed/16810531?tool=bestpractice.com
莱姆病是最常见的媒介传播感染,是美国最常见的一种法定报告传染病。2008 年至 2015 年期间,美国共有 275,589 人被诊断患有莱姆病;在此期间,每年报告超过 30,000 例诊断病例(高度疑似和确诊病例)。[6]Schwartz AM, Hinckley AF, Mead PS, et al. Surveillance for Lyme disease - United States, 2008-2015. MMWR Surveill Summ. 2017 Nov 10;66(22):1-12.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5829628/http://www.ncbi.nlm.nih.gov/pubmed/29120995?tool=bestpractice.com
美国疾病预防控制中心指出,并不是对每个诊断病例都进行了报告。[9]Centers for Disease Control and Prevention. How many people get Lyme disease? September 2015 [internet publication].https://www.cdc.gov/lyme/stats/humancases.html 导致发病率增加的可能因素包括疾病报告系统的完善、更多林区开发、蜱虫迁移至新的地区以及鹿群数量增加。[10]Adams DA, Thomas KR, Jajosky RA, et al. Summary of notifiable infectious diseases and conditions - United States, 2015. MMWR Morb Mortal Wkly Rep. 2017 Aug 11;64(53):1-143.https://www.cdc.gov/mmwr/volumes/64/wr/mm6453a1.htmhttp://www.ncbi.nlm.nih.gov/pubmed/28796757?tool=bestpractice.com[11]Zhang X, Meltzer MI, Pena CA, et al. Economic impact of Lyme disease. Emerg Infect Dis. 2006 Apr;12(4):653-60.https://www.ncbi.nlm.nih.gov/pmc/journals/http://www.ncbi.nlm.nih.gov/pubmed/16704815?tool=bestpractice.com[12]Groseclose SL, Brathwaite WS, Hall PA, et al. Summary of notifiable diseases - United States, 2002. MMWR Morb Mortal Wkly Rep. 2004 Apr 30;51(53):1-84.http://www.cdc.gov/mmwr/PDF/wk/mm5153.pdfhttp://www.ncbi.nlm.nih.gov/pubmed/15123988?tool=bestpractice.com
可能合并感染巴贝虫病或埃立克体病(边虫病)。这是由于肩突硬蜱可能也会传播巴贝西虫和嗜吞噬细胞无形体。一项研究发现,在莱姆病患者中,大约 2% 的患者同时感染巴贝西虫,大约 2% 的患者同时感染嗜吞噬细胞无形体。[13]Steere AC, McHugh G, Suarez C, et al. Prospective study of coinfection in patients with erythema migrans. Clin Infect Dis. 2003 Apr 15;36(8):1078-81.http://cid.oxfordjournals.org/content/36/8/1078.longhttp://www.ncbi.nlm.nih.gov/pubmed/12684924?tool=bestpractice.com