■美国各州的公共卫生机构,属地,和自由相关的州通过国家暴发报告系统(NORS)调查并自愿向CDC报告水传播疾病暴发。本报告总结了NORS饮用水暴发流行病学,实验室,和环境数据,包括公共和私人饮用水系统的数据。该报告介绍了疫情的影响因素(即,导致疫情爆发的做法和因素)和,第一次,将爆发归类为生物膜病原体或相关的肠道疾病。
■2015-2020。
■CDC于2009年推出了NORS,作为一个基于网络的平台,公共卫生部门自愿输入疫情信息。通过NORS,CDC收集由细菌引起的肠道疾病暴发的报告,病毒,寄生,化学,毒素,和未知的病原体以及食源性和水传播的非肠道疾病暴发。NORS用户提供的数据,当已知时,对于饮用水爆发,包括1)病例数,住院治疗,和死亡;2)病原体(证实或怀疑);3)水系统的牵连类型(例如,社区或个人或私人);4)暴露的设置(例如,医院或医疗机构;酒店,汽车旅馆,lodge,或客栈;或私人住宅);5)描述疫情和表征影响因素所需的相关流行病学和环境数据。
■在2015-2020年期间,来自28个州的公共卫生官员自愿报告了214起与饮用水相关的暴发和454起促成因素类型。报告的病因包括187(87%)相关的生物膜,24(11%)肠道疾病相关,两个(1%)未知,和一种(<1%)化学物质或毒素。共有172起(80%)疫情与公共供水系统的水有关,22(10%)到未知的水系统,17(8%)到个人或私人系统,和两个(0.9%)到其他系统;一个(0.5%)系统类型没有报告。与饮用水相关的疫情导致至少2,140例疾病,563例住院(26%),88例死亡(占病例的4%)。944例(43%)涉及个人或私人供水系统,52(9%)住院,14人(16%)死亡。肠道疾病相关病原体涉及所有疾病的1,299(61%),和10(2%)住院。没有死亡报告。在这些疾病中,三种病原体(诺如病毒,志贺氏菌,和弯曲杆菌)或包括这些病原体的多种病因导致1,225例(94%)病例。最常见的是(n=34;7%)将饮用水源确定为肠道疾病暴发的促成因素。当水源(例如,地下水)已知(n=14),在13例(93%)肠道疾病暴发中发现了井。大多数与生物膜相关的暴发报告涉及军团菌(n=184;98%);其余的包括两次非结核分枝杆菌(NTM)(1%)和一次假单胞菌(0.5%)暴发。军团菌相关疫情在研究期间普遍增加(2015年14例,2016年31例,2017年30例,2018年34例,2019年33例,2020年18例)。军团菌相关的爆发导致786(37%)的所有疾病,544(97%)住院,和86(98%)的所有死亡。军团菌也是160例(92%)公共供水系统暴发的病因。爆发报告最频繁地将前提或使用点位置作为军团菌和其他与生物膜相关的病原体爆发的促成因素(n=287;63%)。军团菌在2015年和2019年被报告为私人住宅三起疫情的原因(2)。
■观察到的生物膜范围和肠道饮用水病原体的影响因素说明了饮用水相关疾病预防的复杂性以及对水源到水龙头预防策略的需求。随着时间的推移,军团菌相关疫情的数量有所增加,是报告的饮用水疫情的主要原因,包括住院和死亡。在本报告所述期间,主要与水井有关的肠道疾病暴发约占一半。本报告加强了CDC的努力,以估计水传播疾病对美国疾病和医疗保健成本的影响,这表明与生物膜相关的病原体,NTM,和军团菌已成为与水和饮用水相关的疾病住院和死亡的主要原因。
■公共卫生部门,监管者,饮用水合作伙伴可以利用这些发现来识别新出现的水传播疾病威胁,指导疫情应对和预防计划,并支持饮用水监管工作。
Public health agencies in U.S. states, territories, and freely associated states investigate and voluntarily report waterborne disease outbreaks to CDC through the National Outbreak Reporting System (NORS). This report summarizes NORS drinking water outbreak epidemiologic, laboratory, and environmental data, including data for both public and private drinking water systems. The report presents outbreak-contributing factors (i.e., practices and factors that lead to outbreaks) and, for the first time, categorizes outbreaks as biofilm pathogen or enteric illness associated.
2015-2020.
CDC launched NORS in 2009 as a web-based platform into which public health departments voluntarily enter outbreak information. Through NORS, CDC collects reports of enteric disease outbreaks caused by bacterial, viral, parasitic, chemical, toxin, and unknown agents as well as foodborne and waterborne outbreaks of nonenteric disease. Data provided by NORS users, when known, for drinking water outbreaks include 1) the number of cases, hospitalizations, and deaths; 2) the etiologic agent (confirmed or suspected); 3) the implicated type of water system (e.g., community or individual or private); 4) the setting of exposure (e.g., hospital or health care facility; hotel, motel, lodge, or inn; or private residence); and 5) relevant epidemiologic and environmental data needed to describe the outbreak and characterize contributing factors.
During 2015-2020, public health officials from 28 states voluntarily reported 214 outbreaks associated with drinking water and 454 contributing factor types. The reported etiologies included 187 (87%) biofilm associated, 24 (11%) enteric illness associated, two (1%) unknown, and one (<1%) chemical or toxin. A total of 172 (80%) outbreaks were linked to water from public water systems, 22 (10%) to unknown water systems, 17 (8%) to individual or private systems, and two (0.9%) to other systems; one (0.5%) system type was not reported. Drinking water-associated outbreaks resulted in at least 2,140 cases of illness, 563 hospitalizations (26% of cases), and 88 deaths (4% of cases). Individual or private water systems were implicated in 944 (43%) cases, 52 (9%) hospitalizations, and 14 (16%) deaths.Enteric illness-associated pathogens were implicated in 1,299 (61%) of all illnesses, and 10 (2%) hospitalizations. No deaths were reported. Among these illnesses, three pathogens (norovirus, Shigella, and Campylobacter) or multiple etiologies including these pathogens resulted in 1,225 (94%) cases. The drinking water source was identified most often (n = 34; 7%) as the contributing factor in enteric disease outbreaks. When water source (e.g., groundwater) was known (n = 14), wells were identified in 13 (93%) of enteric disease outbreaks.Most biofilm-related outbreak reports implicated Legionella (n = 184; 98%); two nontuberculous mycobacteria (NTM) (1%) and one Pseudomonas (0.5%) outbreaks comprised the remaining. Legionella-associated outbreaks generally increased over the study period (14 in 2015, 31 in 2016, 30 in 2017, 34 in 2018, 33 in 2019, and 18 in 2020). The Legionella-associated outbreaks resulted in 786 (37%) of all illnesses, 544 (97%) hospitalizations, and 86 (98%) of all deaths. Legionella also was the outbreak etiology in 160 (92%) public water system outbreaks. Outbreak reports cited the premise or point of use location most frequently as the contributing factor for Legionella and other biofilm-associated pathogen outbreaks (n = 287; 63%). Legionella was reported to NORS in 2015 and 2019 as the cause of three outbreaks in private residences (2).
The observed range of biofilm and enteric drinking water pathogen contributing factors illustrate the complexity of drinking water-related disease prevention and the need for water source-to-tap prevention strategies. Legionella-associated outbreaks have increased in number over time and were the leading cause of reported drinking water outbreaks, including hospitalizations and deaths. Enteric illness outbreaks primarily linked to wells represented approximately half the cases during this reporting period. This report enhances CDC efforts to estimate the U.S. illness and health care cost impacts of waterborne disease, which revealed that biofilm-related pathogens, NTM, and Legionella have emerged as the predominant causes of hospitalizations and deaths from waterborne- and drinking water-associated disease.
Public health departments, regulators, and drinking water partners can use these findings to identify emerging waterborne disease threats, guide outbreak response and prevention programs, and support drinking water regulatory efforts.