MMWR Surveill Summ. 2024 Mar 14;73(1):1-23. doi: 10.15585/mmwr.ss7301a1.
PROBLEM/CONDITION: 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.
问题/情况：美国各州、领土和自由联系州的公共卫生机构通过国家暴发报告系统（NORS）向 CDC 调查和自愿报告水传播疾病暴发。本报告总结了 NORS 饮用水暴发的流行病学、实验室和环境数据，包括公共和私人饮用水系统的数据。该报告介绍了暴发促成因素（即导致暴发的实践和因素），并首次将暴发分类为生物膜病原体或肠病相关。
2015-2020 年。
CDC 于 2009 年推出了 NORS，作为一个基于网络的平台，公共卫生部门可自愿输入暴发信息。通过 NORS，CDC 收集由细菌、病毒、寄生虫、化学物质、毒素和未知病原体引起的肠病暴发以及非肠病的食源性和水传播暴发的报告。NORS 用户提供的饮用水暴发数据（如已知）包括 1）病例、住院和死亡人数；2）病原体（已确认或疑似）；3）涉及的水系统类型（例如，社区或个人或私人）；4）暴露的环境（例如，医院或医疗保健设施；酒店、汽车旅馆、旅馆或客栈；或私人住宅）；以及 5）描述暴发和描述促成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 起与饮用水有关的暴发和 454 种促成因素类型。报告的病因包括 187 种（87%）与生物膜相关、24 种（11%）肠病相关、2 种（1%）未知和 1 种（<1%）化学物质或毒素。共有 172 起（80%）暴发与公共供水系统有关，22 起（10%）与不明供水系统有关，17 起（8%）与个人或私人系统有关，2 起（0.9%）与其他系统有关；一种（0.5%）系统类型未报告。饮用水相关暴发导致至少 2140 例疾病、563 例住院（病例的 26%）和 88 例死亡（病例的 4%）。个人或私人供水系统涉及 944 例（43%）病例、52 例（9%）住院和 14 例（16%）死亡。肠病相关病原体与所有疾病的 1299 例（61%）有关，与 10 例（2%）住院有关。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 1225 例（94%）病例。饮用水源最常被确定为肠病暴发的促成因素（n = 34；7%）。当知道水源（例如地下水）时（n = 14），在 13 起肠病暴发中确定了水井（n = 13；93%）。大多数与生物膜相关的暴发报告都涉及军团菌（n = 184；98%）；两例非结核分枝杆菌（NTM）（1%）和一例假单胞菌（0.5%）暴发构成了其余部分。军团菌相关暴发一般呈上升趋势在研究期间（2015 年 14 例，2016 年 31 例，2017 年 30 例，2018 年 34 例，2019 年 33 例，2020 年 18 例）。军团菌相关暴发导致所有疾病的 786 例（37%）、544 例（97%）住院和 86 例（98%）死亡。军团菌也是 160 起公共供水系统暴发的病因。暴发报告将前提或使用点位置最常作为军团菌和其他生物膜相关病原体暴发的促成因素（n = 287；63%）。2015 年和 2019 年，NORS 将军团菌报告为两起私人住宅（2 起）暴发的原因。
观察到的生物膜和肠病饮用水病原体促成因素的范围说明了饮用水相关疾病预防的复杂性，以及需要从水源到龙头的预防策略。军团菌相关暴发的数量呈上升趋势，是报告的饮用水暴发的主要原因，包括住院和死亡。在本报告所述期间，与水井有关的肠病暴发占病例的近一半。本报告加强了 CDC 对美国水传播疾病和饮用水相关疾病的发病和卫生保健费用影响的估计，这些疾病表明，生物膜相关病原体、NTM 和军团菌已成为与水传播和饮用水相关疾病有关的住院和死亡的主要原因。
公共卫生部门、监管机构和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，指导暴发应对和预防计划，并支持饮用水法规制定工作。
