The authors systematically reviewed the literature on recreational exposure to freshwater cyanobacteria.

• Abstract
• Introduction
• Rationale and search criteria
• Recreational and in-field occupational exposure to cyanobacteria: anecdotal and case reports
• Discussion of anecdotal and case reports
• Epidemiology of recreational exposure to cyanobacteria
• Cyanobacteria and water-related disease: some complicating factors
• Freshwater-related dermatoses
• Possible under-diagnosis of cyanobacteria-related illness
• Conclusion
• References
• Tables & Additional File

Other explanations for disease need to be considered by both clinicians and epidemiologists in their respective endeavours. Epidemiological studies usually aim to identify and adjust for confounding variables such as smoking and age of study participants. The following sections will discuss some freshwater-related risk factors, mostly microbial, that may confound epidemiological studies and complicate clinical diagnoses of cyanobacteria-related illness linked to recreational exposures. The final section of this review will discuss the possibility of misdiagnosis from the opposite direction: a water-borne disease outbreak in Finland that was subject to epidemiological scrutiny, but cyanobacterial exotoxin contamination of reticulated supplies was apparently not considered at the time.