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Relationships between Microbial Indicators and Pathogens in Recreational Water Settings
Citation:
Korajkic, A., B. McMinn, AND V. Harwood. Relationships between Microbial Indicators and Pathogens in Recreational Water Settings. International Journal of Environmental Research and Public Health. Molecular Diversity Preservation International, Basel, Switzerland, 15(12):2842, (2018). https://doi.org/10.3390/ijerph15122842
Impact/Purpose:
This review article describes relationships between indicator organisms (fecal indicator bacteria, alternative indicators, microbial source tracking markers) and pathogens (bacterial, viral, and protozoan) in marine/brackish and freshwater recreational waters.
Description:
Fecal pollution of recreational waters can cause scenic blight and pose a threat to public health, resulting in beach advisories and closures. Fecal indicator bacteria (total and fecal coliforms, Escherichia coli, enterococci), and alternative indicators of fecal pollution (Clostridium perfringens, bacteriophages) are routinely used in the assessment of sanitary quality of recreational waters. However, fecal indicator bacteria (FIB), and alternative indicators are found in the gastrointestinal tract of humans, and many other animals and therefore are considered general indicators of fecal pollution. As such, they are poor candidates for informing risk assessment and remediation strategies. Microbial source tracking (MST) genetic markers are closely associated with animal hosts and are used to identify fecal pollution sources. In this review we have examined 73 papers generated over 40 years that reported the relationship between at least one indicator and one pathogen group or species. Nearly half of the reports did not include statistical analysis, while the remainder were almost equally split between those that observed statistically significant relationships and those that did not. Statistical significance was reported less frequently in marine and brackish waters compared to freshwater, and the number of statistically significant relationships was considerably higher in freshwater (p alternative indicators > MST markers > pathogens). We also queried epidemiological studies utilizing these indicators and a similar trend emerged with the respect to weather conditions and water quality at beaches. While FIB, alternative indicators, and MST markers continue to be suitable indicators of general and host-associated fecal pollution, their relationship with pathogens, especially viral pathogens, is tenuous at best and likely influenced by many different factors such as variable shedding rates, differential fate and transport characteristics, as well as a broad range of site-specific factors.
URLs/Downloads:
DOI: Relationships between Microbial Indicators and Pathogens in Recreational Water Settings