人类非洲锥虫病 (human African trypanosomiasis, HAT) 仅可在撒哈拉以南非洲获得。撒哈拉以南的 36 个国家/地区中大约有 6500 万至 7000 万人存在感染风险。[8]Simarro PP, Cecchi G, Franco JR, et al. Estimating and mapping the population at risk of sleeping sickness. PLoS Negl Trop Dis. 2012;6(10):e1859.http://journals.plos.org/plosntds/article?id=10.1371/journal.pntd.0001859http://www.ncbi.nlm.nih.gov/pubmed/23145192?tool=bestpractice.com[9]World Health Organization. Trypanosomiasis, human African (sleeping sickness). February 2018. [internet publication].http://www.who.int/news-room/fact-sheets/detail/trypanosomiasis-human-african-(sleeping-sickness) 该疾病仅限于疫源地,整个撒哈拉以南非洲大约有 300 个疫源地。[10]World Health Organization. Report of a WHO meeting on elimination of African trypanosomiasis (Trypanosoma brucei gambiense). December 2012 [internet publication].http://apps.who.int/iris/bitstream/10665/79689/1/WHO_HTM_NTD_IDM_2013.4_eng.pdf
大多数感染 (97%) 是由冈比亚锥虫引起的。在采取防控措施后,新的病例报告数量已有所减少。2017 年报告了 1447 例病例(低于 2016 年的 2184 例和 2009 年的 9875 例)。[11]World Health Organization. WHO outlines criteria to assess elimination of sleeping sickness. July 2018 [internet publication].http://www.who.int/neglected_diseases/news/criteria-eliminate-sleeping-sickness/en/ 在过去 10 年中,70% 以上的病例发生在刚果民主共和国。[9]World Health Organization. Trypanosomiasis, human African (sleeping sickness). February 2018. [internet publication].http://www.who.int/news-room/fact-sheets/detail/trypanosomiasis-human-african-(sleeping-sickness)
冈比亚锥虫病主要出现在安哥拉、布基纳法索、喀麦隆、中非共和国、乍得、刚果、科特迪瓦、赤道几内亚、加蓬、加纳、几内亚、马拉维、尼日利亚、南苏丹、乌干达、坦桑尼亚联合共和国、赞比亚和津巴布韦。历史病源地包括贝宁、博茨瓦纳、布隆迪、埃塞俄比亚、冈比亚、几内亚比绍、肯尼亚、利比里亚、马里、莫桑比克、纳米比亚、尼日尔、卢旺达、塞内加尔、塞拉利昂、斯威士兰和多哥,但这些地方已有 10 多年未报告出现过患病病例。[9]World Health Organization. Trypanosomiasis, human African (sleeping sickness). February 2018. [internet publication].http://www.who.int/news-room/fact-sheets/detail/trypanosomiasis-human-african-(sleeping-sickness)[12]World Health Organization. Report of a WHO informal consultation on sustainable control of human African trypanososmiasis. Geneva: WHO; 2007.http://apps.who.int/iris/bitstream/10665/69848/1/WHO_CDS_NTD_IDM_2007.6_eng.pdf[13]Simarro PP, Cecchi G, Paone M, et al. The atlas of human African trypanosomiasis: a contribution to global mapping of neglected tropical diseases. Int J Health Geogr. 2010 Nov 1;9:57.http://ij-healthgeographics.biomedcentral.com/articles/10.1186/1476-072X-9-57http://www.ncbi.nlm.nih.gov/pubmed/21040555?tool=bestpractice.com
在非洲以外的地区,每年确诊的冈比亚锥虫感染病例数平均为 2 例,在美国的感染数估计为每 4 年 1 例。这些患者主要是以前生活在疾病流行国家的农村地区的移民和非洲人。[14]Simarro PP, Franco JR, Cecchi G, et al. Human African Trypanosomiasis in non-endemic countries (2000-2010). J Travel Med. 2012 Jan-Feb;19(1):44-53.http://www.ncbi.nlm.nih.gov/pubmed/22221811?tool=bestpractice.com
大多数罗得西亚锥虫病病例发生在乌干达。罗得西亚锥虫病的疫源地还包括坦桑尼亚、马拉维、赞比亚、肯尼亚、卢旺达、莫桑比克和津巴布韦。博茨瓦纳、布隆迪、埃塞俄比亚和纳米比亚也被认为是罗得西亚锥虫病流行的国家,但这些国家已有 20 多年未发现相关病例。[12]World Health Organization. Report of a WHO informal consultation on sustainable control of human African trypanososmiasis. Geneva: WHO; 2007.http://apps.who.int/iris/bitstream/10665/69848/1/WHO_CDS_NTD_IDM_2007.6_eng.pdf[13]Simarro PP, Cecchi G, Paone M, et al. The atlas of human African trypanosomiasis: a contribution to global mapping of neglected tropical diseases. Int J Health Geogr. 2010 Nov 1;9:57.http://ij-healthgeographics.biomedcentral.com/articles/10.1186/1476-072X-9-57http://www.ncbi.nlm.nih.gov/pubmed/21040555?tool=bestpractice.com
与冈比亚锥虫病相比,在非洲以外地区发现罗得西亚锥虫病病例的几率更高:每年平均确诊的病例数约为 6 例,而美国每年平均报告 1 例。这些患者主要是前往东非(坦桑尼亚、马拉维和赞比亚)的国家公园和野生动物保护区游览的旅游者和猎人。[4]Simarro PP, Jannin J, Cattand P. Eliminating human African trypanosomiasis: where do we stand and what comes next? PLoS Med. 2008 Feb;5(2):e55.http://journals.plos.org/plosmedicine/article?id=10.1371/journal.pmed.0050055http://www.ncbi.nlm.nih.gov/pubmed/18303943?tool=bestpractice.com[14]Simarro PP, Franco JR, Cecchi G, et al. Human African Trypanosomiasis in non-endemic countries (2000-2010). J Travel Med. 2012 Jan-Feb;19(1):44-53.http://www.ncbi.nlm.nih.gov/pubmed/22221811?tool=bestpractice.com[15]World Health Organization. Human African trypanosomiasis (sleeping sickness): epidemiological update. Wkly Epidemiol Rec. 2006 Feb 24;81(8):71-80.http://www.who.int/wer/2006/wer8108.pdfhttp://www.ncbi.nlm.nih.gov/pubmed/16673459?tool=bestpractice.com[16]Moore AC. Human African trypanosomiasis: a reemerging public health threat. In: Scheld WM, Murray BE, Hughes JM, eds. Emerging infections 6. Washington, DC: ASM; 2004:143-157.
HAT 的发病率在性别、年龄或种族上没有特殊差异,因为感染与促进传播媒介接触的活动有关。在非疾病流行国家/地区的个体中,病情发作更为急性。[17]Duggan AJ, Hutchinson MP. Sleeping sickness in Europeans: a review of 109 cases. J Trop Med Hyg. 1966 Jun;69(6):124-31.http://www.ncbi.nlm.nih.gov/pubmed/5940665?tool=bestpractice.com