North Carolina Department of Health and Human Services, Raleigh, NC, USA.
Epidemic Intelligence Service, Centers for Disease Control and Prevention, Atlanta, GA, USA.
Public Health Rep. 2024 Jan-Feb;139(1):79-87. doi: 10.1177/00333549231159159. Epub 2023 Mar 27.
On September 23, 2019, the North Carolina Division of Public Health identified a legionellosis increase in western North Carolina; most patients had recently attended the North Carolina Mountain State Fair. We conducted a source investigation.
Cases were fair attendees with laboratory-confirmed legionellosis and symptom onset within 2 to 14 days (Legionnaires' disease) or ≤3 days (Pontiac fever). We conducted a case-control study matching cases to non-ill fair attendees as control participants and an environmental investigation, and we performed laboratory testing ( bacteria culture and polymerase chain reaction) of 27 environmental samples from fairgrounds and hot tubs and 14 specimens from case patients. We used multivariable unconditional logistic regression models to calculate adjusted odds ratios for potential exposure sources and risk factors.
Of 136 people identified with fair-associated legionellosis, 98 (72%) were hospitalized and 4 (3%) died. Case patients were more likely than control participants to report walking by hot tub displays (adjusted odds ratio = 10.0; 95% CI, 4.2-24.1). Complete hot tub water treatment records were not kept, precluding evaluation of water maintenance conducted on display hot tubs. sequence types (STs) were consistent among 10 typed clinical specimens (ST224) but distinct from the only positive environmental sample from the fair (ST7 and ST8).
Hot tub displays were identified as the most likely outbreak source, making this the largest hot tub-associated Legionnaires' disease outbreak worldwide. Following the investigation, the North Carolina Division of Public Health and the Centers for Disease Control and Prevention released guidance on mitigating risk of exposure from hot tub displays. Results highlight the importance of properly maintaining equipment that aerosolizes water, including hot tubs intended for display purposes only.
2019 年 9 月 23 日，北卡罗来纳州公共卫生部发现北卡罗来纳州西部军团病发病率上升；大多数患者最近参加了北卡罗来纳州山地州博览会。我们进行了病因调查。
病例为实验室确诊的军团病且症状在 2 至 14 天（军团病）或≤3 天（庞蒂亚克热）内出现的博览会上的患者。我们进行了病例对照研究，将病例与非患病博览会上的参与者作为对照，并进行了环境调查，对来自博览会场地和热水浴缸的 27 个环境样本以及 14 个病例患者的样本进行了实验室检测（细菌培养和聚合酶链反应）。我们使用多变量非条件逻辑回归模型计算潜在暴露源和危险因素的调整比值比。
在确定的 136 名与博览会相关的军团病患者中，98 人（72%）住院，4 人（3%）死亡。与对照组相比，病例患者更有可能报告走过热水浴缸展示区（调整比值比=10.0；95%CI，4.2-24.1）。由于没有保留完整的热水浴缸水处理记录，因此无法评估展示用热水浴缸的水维护情况。10 份定型临床标本的序列类型（ST）一致（ST224），但与博览会上唯一阳性环境样本（ST7 和 ST8）不同。
热水浴缸展示区被确定为最可能的暴发源，这是全球最大的与热水浴缸相关的军团病暴发。调查后，北卡罗来纳州公共卫生部和疾病预防控制中心发布了关于减轻接触热水浴缸展示区风险的指南。结果强调了正确维护可能使水雾化的设备（包括仅用于展示目的的热水浴缸）的重要性。
