You are here:
SURVEILLANCE FOR WATERBORNE DISEASE AND OUTBREAK ASSOCIATED WITH RECREATIONAL WATER - UNITED STATES 2003-2004
Citation:
DZIUBAN, E. J., J. L. LIANG, G. F. CRAUN, P. YU, J. PAINTER, M. R. MOORE, R. L. CALDERON, M. J. BEACH, AND S. L. ROY. SURVEILLANCE FOR WATERBORNE DISEASE AND OUTBREAK ASSOCIATED WITH RECREATIONAL WATER - UNITED STATES 2003-2004. MORTALITY & MORBIDITY WEEKLY REPORT. Center for Disease Control, 55(12):1-30, (2006).
Impact/Purpose:
To summarize data on waterborne disease outbreaks associated with recreational water that occurred during January 2003-December 2004
Description:
Problem/Condition: Since 1971, the Centers for Disease Control and Prevention (CDC), the U.S. Environmental Protection Agency, and the Council of State and Territorial Epidemiologists have maintained a collaborative surveillance system for collecting and periodically reporting data related to occurrences and causes of waterborne disease and outbreaks (WBDOs). Initially only covering outbreaks related to drinking water, analysis of WBDOs associated with recreational water was added in 1978. This surveillance system is the primary source of data concerning the scope and effects of WBDOs in the United States.
Reporting Period Covered: This summary includes data on WBDOs associated with recreational water that occurred during January 2003-December 2004, and one previously unreported outbreak from 2002.
Description of the System: Public health departments in the states, territories, localities, and the Freely Associated States hold primary responsibility for detecting and investigating WBDOs, and for voluntarily reporting them to CDC on a standard form. While the surveillance system includes data for outbreaks associated with drinking water, recreational water, and water not intended for drinking, only outbreaks associated with recreational water are reported in this summary.
Results: During 2003-2004, 62 WBDOs associated with recreational water were reported by 26 states and the territory of Guam. Illness occurred in 2,698 persons, resulting in 58 hospitalizations and one death. The median outbreak size was 14 persons (range: 1-617). Illinois reported the most WBDOs (n=10), Ohio reported six WBDOs, and Georgia and Wisconsin both reported five WBDOs. Of the 62 WBDOs, 30 (48.4%) were outbreaks of gastroenteritis resulting from infectious agents, chemicals or toxins, 13 (21.0%) were outbreaks of dermatitis, and seven (11.3%) were outbreaks of acute respiratory illness. The remaining WBDOs resulted in primary amebic meningoencephalitis (n=1), meningitis (n=1), leptospirosis (n=1), otitis externa (n=1), and mixed illnesses (n=8). WBDOs associated with gastroenteritis resulted in 1,945 of 2,698 (72.1%) illnesses. Thirty-five (56.5%) WBDOs and 22 (73.3%) gastroenteritis outbreaks occurred during the months of June through August. Forty-three (69.4%) WBDOs occurred at treated water venues, resulting in 2,446 (90.7%) cases of illness. The etiologic agent was confirmed in 44 (71.0%) of the 62 WBDOs, suspected in 15 (24.2%), and unidentified in three (4.8%). Twenty (32.3%) WBDOs had a bacterial etiology, 15 (24.2%) parasitic, six (9.7%) viral, and three (4.8%) chemical or toxin. Among the 30 gastroenteritis outbreaks, Cryptosporidium was confirmed as the causal agent in 11 (36.7%), and all but one of these took place in treated water venues where Cryptosporidium caused 55.6% (10/18) of the gastroenteritis outbreaks.
This is the first year that recreational water-related Vibrio infections have been included in this summary; 142 Vibrio illnesses reported to the Cholera and Other Vibrio Illness Surveillance System were associated with recreational water exposure. These illnesses were analyzed separately from all other reported WBDOs. The most commonly reported species were V. vulnificus, V. alginolyticus, and V. parahaemolyticus. V. vulnificus illnesses associated with recreational water exposure had the highest Vibrio illness hospitalization rate (87.2%) and mortality rate (12.8%).
Interpretation: The number of WBDOs captured in this surveillance system and the trends in recreational water-associated disease and outbreaks are consistent with previous years. Outbreaks, especially the largest ones, are most likely to be associated with summer months, treated water venues, and gastrointestinal illness. Over 60% of illnesses reported for 2003-2004 were associated with the seven largest outbreaks (>100 cases). Deficiencies leading to WBDOs were identified in each type of recreational water venue, including problems with venue design, usage, and maintenance. The geographic variability in reported WBDOs is likely related to the sensitivity of surveillance systems in different states and localities. Multiple factors, including the sensitivity of surveillance, can affect whether WBDOs are recognized and investigated. Reporting bias can also arise because larger outbreaks, and those with shorter incubation periods or affecting populations that do not disperse widely, are more likely to be identified and subsequently investigated and reported.
Public Health Action: CDC uses WBDO surveillance data to: 1) identify the etiologic agents, types of aquatic venues, water treatment systems, and deficiencies associated with outbreaks; 2) evaluate the adequacy of efforts (i.e., regulations and public awareness activities) for providing safe recreational water; 3) establish public health prevention priorities, which might lead to improved water-quality regulations and prevention measures at the local, state, and federal levels.