Outbreaks Associated with Treated Recreational Water — United States, 2000–2014

Outbreaks associated with exposure to treated recreational water can be caused by pathogens or chemicals in venues such as pools, hot tubs/spas, and interactive water play venues (i.e., water playgrounds). During 2000-2014, public health officials from 46 states and Puerto Rico reported 493 outbreaks associated with treated recreational water. These outbreaks resulted in at least 27,219 cases and eight deaths. Among the 363 outbreaks with a confirmed infectious etiology, 212 (58%) were caused by Cryptosporidium (which causes predominantly gastrointestinal illness), 57 (16%) by Legionella (which causes Legionnaires' disease, a severe pneumonia, and Pontiac fever, a milder illness with flu-like symptoms), and 47 (13%) by Pseudomonas (which causes folliculitis ["hot tub rash"] and otitis externa ["swimmers' ear"]). Investigations of the 363 outbreaks identified 24,453 cases; 21,766 (89%) were caused by Cryptosporidium, 920 (4%) by Pseudomonas, and 624 (3%) by Legionella. At least six of the eight reported deaths occurred in persons affected by outbreaks caused by Legionella. Hotels were the leading setting, associated with 157 (32%) of the 493 outbreaks. Overall, the outbreaks had a bimodal temporal distribution: 275 (56%) outbreaks started during June-August and 46 (9%) in March. Assessment of trends in the annual counts of outbreaks caused by Cryptosporidium, Legionella, or Pseudomonas indicate mixed progress in preventing transmission. Pathogens able to evade chlorine inactivation have become leading outbreak etiologies. The consequent outbreak and case counts and mortality underscore the utility of CDC's Model Aquatic Health Code (https://www.cdc.gov/mahc) to prevent outbreaks associated with treated recreational water.

[1]  M. Arduino,et al.  Outbreaks Associated with Untreated Recreational Water — United States, 2000–2014 , 2018, MMWR. Morbidity and mortality weekly report.

[2]  S. Schrag,et al.  Vital Signs: Deficiencies in Environmental Control Identified in Outbreaks of Legionnaires' Disease - North America, 2000-2014. , 2016, MMWR. Morbidity and mortality weekly report.

[3]  Rosalind J Wright,et al.  Immediate Closures and Violations Identified During Routine Inspections of Public Aquatic Facilities - Network for Aquatic Facility Inspection Surveillance, Five States, 2013. , 2016, Morbidity and mortality weekly report. Surveillance summaries.

[4]  M. Beach,et al.  Effect of cyanuric acid on the inactivation of Cryptosporidium parvum under hyperchlorination conditions. , 2015, Environmental science & technology.

[5]  M. Beach,et al.  Swimming in the USA: beachgoer characteristics and health outcomes at US marine and freshwater beaches. , 2015, Journal of water and health.

[6]  J. Yoder,et al.  Cryptosporidiosis surveillance -- United States, 2011-2012. , 2015 .

[7]  G. Visvesvara,et al.  Successful Treatment of an Adolescent With Naegleria fowleri Primary Amebic Meningoencephalitis , 2015, Pediatrics.

[8]  Robert T. Rolfs,et al.  Promotion of Healthy Swimming After a Statewide Outbreak of Cryptosporidiosis Associated With Recreational Water Venues—Utah, 2008–2009 , 2012, MMWR. Morbidity and mortality weekly report.

[9]  M. Beach,et al.  Inactivation of Cryptosporidium parvum under chlorinated recreational water conditions. , 2008, Journal of water and health.

[10]  Lora E Fleming,et al.  Impacts of climate variability and future climate change on harmful algal blooms and human health , 2008, Environmental health : a global access science source.

[11]  Alfred P. Dufour,et al.  Rapidly Measured Indicators of Recreational Water Quality Are Predictive of Swimming-Associated Gastrointestinal Illness , 2005, Environmental health perspectives.

[12]  R. Donlan,et al.  Biofilms: Microbial Life on Surfaces , 2002, Emerging infectious diseases.

[13]  David F. Geary,et al.  American Society of Heating, Refrigerating and Air-conditioning Engineers Guideline 12-2000: Minimizing the Risk of Legionellosis Associated with Building Water Systems , 2002 .