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Recreational Water Illnesses
Recreational Water Illnesses, commonly referred to as RWIs, are diseases that individuals can contract while enjoying recreational water environments, such as swimming pools, hot tubs, spas, water parks, lakes, rivers, and oceans. These illnesses are caused by a variety of pathogens, including bacteria, viruses, and parasites, which can flourish in contaminated water.
What is the most common cause of RWIs? What is the least common?
According to the Centers for Disease Control and Prevention's (CDC) National Outbreak Reporting System (NORS), Legionella was the most common cause of outbreaks, accounting for 38% of the cases in 2021. Norovirus and Salmonella were the least common, each accounting for 3% of the outbreak cases, with June seeing the highest number of cases.
What are the four main types of RWIs?
Gastrointestinal illnesses
Symptoms include diarrhea, vomiting, and abdominal cramps.
Skin, ear, and eye infections
Common conditions include swimmer’s ear, hot tub rash, and conjunctivitis (also known as pink eye).
Respiratory illnesses
Common conditions include Legionnaires’ disease and Pontiac fever.
Neurological illnesses
A rare but severe condition like primary amebic meningoencephalitis (PAM).
What are the common pathogens?
Bacteria
E. coli, Pseudomonas aeruginosa, Legionella, Staphylococcus aureus
Viruses
Norovirus, hepatitis A virus, adenovirus
Parasites
Cryptosporidium, Giardia, Naegleria fowleri
Fungi
Trichophyton, Candida
What are the transmission routes?
Ingestion
Swallowing contaminated water while engaging in water-related activities, such as swimming, wading, or playing in the water.
Direct contact
Coming in contact with contaminated water through the skin, eyes, ears, or nose.
Inhalation
Breathing in aerosolized water droplets, such as those generated by hot tubs, water features, or spray features.
Person-to-person transmission
From one infected individual to others, especially in shared recreational water environments.
Prevention tips for common RWIs
Cryptosporidiosis
Avoid swallowing water while swimming. Wash hands thoroughly with soap and water after water activities, and ensure proper chlorination of swimming pools and water parks.
Legionellosis
Regularly clean and disinfect hot tubs and cooling towers, maintain proper water temperature and chlorine levels, and avoid inhaling mist or vapor from contaminated water sources.
Shiga Toxin-Producing E. coli
Practice good hygiene, avoid swimming in water contaminated with fecal matter, and ensure proper cooking and handling of food to prevent foodborne transmission.
Naegleria fowleri
Avoid nasal exposure to warm freshwater. Use nose clips or hold your nose shut during water activities, and use properly treated water for nasal irrigation or neti pots.
Giardia lamblia
Treat untreated water before consumption, practice good hygiene, avoid swallowing water from untreated sources, and wash fruits and vegetables thoroughly before eating.
Swimmer's Itch
Avoid freshwater bodies known to harbor swimmer’s itch. Dry off thoroughly with a towel after getting out of the water. Take a shower with soap and water, wear protective clothing, and consider using repellents on exposed skin.
Where can I get more information?
Illinois Department of Public Health
Division of Environmental Health
Swimming Facilities Program
Call: 217-782-5830
Email: DPH.SwimmingFacilities@illinois.gov
