Diseases Acquired via Recreational Bathing (Public Swimming Pools)

Epidemiological Investigations

All across the nation, people engage in various recreational activities that are dangerous and potentially life threatening - skydiving, rock climbing, mountain biking, whitewater river rafting and skiing. One activity that is supposed to be fun and safe, recreational bathing, has become a health risk. Recreational bathing includes swimming in pools, spas and hot tubs or wading/swimming in lakes, ponds, rivers, oceans or water parks. People become ill due to consumption of contaminated water, sometimes even when this water has been adequately chlorinated or sanitized.

There are several communicable diseases of concern that are commonly associated with recreational swimming, wading and use of bathing locations. EHA Consulting Group can assist in the epidemiological investigation and analysis of diseases associated with these recreational bathing activities and can provide you with expert consultation in legal matters related to outbreaks.

Related Diseases

Learn more about the diseases that our team of public health consultants can provide expert consultation including:


Also called bacillary dysentery, this is an acute bacterial disease characterized by fever, nausea, vomiting, cramps and diarrhea caused by Shigella species. In most cases, the stools contain blood and mucus. Shigella is transmitted directly or indirectly via the fecal-oral route and may occur due to the ingestion of contaminated food or water. Of great significance is the low infective dose of between 10-100 organisms. This disease may be acquired by swimming in contaminated surface waters or pools and spas.

E. coli

Escherichia coli O157:H7 is a serious disease causing organism that causes diarrhea ranging from mild, nonbloody stools to those that are virtually all blood. E. coli O157:H7 produces a toxin that damages the lining of the intestines resulting in hemorrhagic colitis. This organism has a very low infectious dose and is thought to cause over 90% of all cases of diarrhea-associated hemolytic uremic syndrome (HUS), a condition that causes acute renal failure, especially in young children, in North America. Waterborne transmission occurs from contaminated drinking water and from swimming in contaminated recreational waters.


Also called Weil disease, Canicola fever, Hemorrhagic jaundice, Mud fever or Swineherd disease, leptospirosis is a zoonotic bacterial disease characterized by fever, chills, severe myalgia, jaundice, rash and hemorrhage into the skin or mucous membranes. This disease is an occupational hazard for people that work on agricultural farms, fish farms, dairies, abattoirs and as sewer workers. Outbreaks may also occur among those exposed to surface waters such as rivers, streams, canals and lakes that have been contaminated by the urine of domestic and wild animals. This disease is a recreational hazard for bathers, campers and sportsmen in infected areas, but also has been attributed to wading or swimming in contaminated floodwaters.


Also known as Giardia enteritis, is a protozoan infection primarily of the small intestine. It is of particular concern as this infection has the ability to remain asymptomatic, may bring on acute diarrhea and may lead to intestinal disorders such as chronic diarrhea, steatorrhea, abdominal cramps, bloating, frequent loose and pale greasy stools, malabsorption of fats and fat-soluble vitamins and weight loss. This disease in found more frequently in children than it is adults especially in areas where poor sanitation occurs. It is most often associated with drinking unfiltered surface waters or from shallow wells, swimming or wading in contaminated freshwater and contaminated recreational waters such as swimming pools and wading pools.


Cryptosporidim parvum causes a parasitic infection that affects not only humans, but also, over 45 other different vertebrate animals including poultry, birds, fish, and small and large animals including dogs, cats, sheep and cattle. Asymptomatic infections are common and often contribute to the infection and spread of the organism to others. The major symptom in humans is diarrhea which is often profuse and watery, and also severe abdominal cramping. Other symptoms include malaise, fever, anorexia and vomiting. One of the more interesting characteristics of this waterborne disease is the appearance of oocysts which are highly resistant to chemical disinfectants commonly used to purify drinking water. The oocysts are highly infectious and are excreted in stools for several weeks after symptoms subside. In a moist environment, these oocysts may remain infective for periods of 2-6 weeks.

Hepatitis A

Also known as infectious hepatitis, epidemic hepatitis, epidemic jaundice, catarrhal jaundice, type-A hepatitis and HA, Hepatitis A is an illness that is commonly associated with raw sewage, and in the recreational swimming environment often becomes the most problematic when existing sewage systems become overburdened due to heavy rainfall or flooding. Since this disease is caused by a virus, it does not respond to antibiotics. Common source outbreaks have been related to contaminated water, infected food handlers and eating undercooked shellfish. While related to recreational swimming, hepatitis A can best be controlled by improving upon sanitary and hygienic practices to eliminate fecal contamination in food and water. Hepatitis A is a potential problem when large numbers of people congregate and where overcrowding, inadequate sanitation and drinking supplies exist.

Norwalk virus or Epidemic Viral Gastroenteropathy

(Norwalk agent disease, Norwalk-like disease, Viral gastroenteritis in adults, Epidemic viral gastroenteritis, Acute infectious nonbacterial gastroenteritis, Viral diarrhea, Epidemic diarrhea and vomiting, Winter vomiting disease, Epidemic nausea and vomiting). As the name implies, this illness, similar to Hepatitis A, is caused by a virus and not a bacteria. In recent years, this disease has been linked to outbreaks on several cruise ship lines. This virus is probably transmitted via the fecal-oral route, although several studies indicate transmission via human to human contact or via airborne transmission, as such, transmission via hot tubs and spas has been implicated in several outbreaks of Norwalk virus.

Naegleriasis and Acanthamoebiasis

Primary amoebic meningoencephalitis is caused by a free-living amoeboflagellate that invades the brain and meningeal linings of the spinal cord and brain via the nasal mucosa. The organism may also cause infections of the eyes and skin. The organism is distributed globally in the environment in both aquatic and soil habitats. Eye infections have occurred primarily in soft contact lens wearers from homemade saline solutions, and exposure to spas or hot tubs have been implicated as sources of corneal infection. Infections have most often been associated with swimming in lakes and ponds where infection is known, but no known infection has ever been traced to swimming pools. However, as a precaution, soft contact lens wearers should not wear lenses while swimming in hot tubs or pools.


Pseudomonas aeruginosa causes a variety of illnesses when associated with recreational swimming, but the the most common manifestation is "swimmer's ear and a variety of skin infections. The bacteria is commonly present in the environment, but grows well in warm water environments such as hot tubs and spas, since heat often breaks down the disinfection ability of pool chemicals. In the health care setting, Pseudomonas aeruginosa is the second most common source of nosocomial infection in intensive care units. When associated with recreational swimming, it is the source of skin rash often called "hot tub folliculitus". The skin rash often takes on the appearance of chicken pox. Even healthy individuals who are exposed to the bacterium in contaminated water sources such as hot tubs, whirlpools, spas and water parks may develop symptoms.


Also known as Bilarziasis or snail fever, this organism is a trematode infection. The most common manifestation in North America is a form of dermatitis often called "swimmer's itch" which is prevalent among bathers in lakes and ponds where snails abound. North American schistosomes do not mature in human beings, thus in this region the disease is typically mild and self-limiting. In other parts of the world, schistomiasis occurs when cercariae, released by the snail, in the water penetrate the human skin while a person is working, swimming or wading. The cercariae then enter the bloodstream, are carried to blood vessels of the lung, and migrate to the liver and veins of the abdominal cavity. Early symptoms include diarrhea, abdominal pain and enlarged liver, eventually leading to reduced liver functioning and possibly colorectal cancer.


Also known as Guinea worm disease or Dracontiasis, this is an infection of the subcutaneous tissue with a large nematode. A blister normally appears in the foot region of the body when the adult female worm is ready to expel its larvae into the environment. Other symptoms include burning and itching skin in the area of the lesion, fever, nausea, vomiting and diarrhea. When the infected body part is immersed in water, the blister erupts and larvae are discharged into the water. The larvae is transmitted by the ingestion of infected drinking water or while swimming in infected ponds. This disease remains endemic in only 13 sub-Saharan countries.

Tips on Healthy Recreational Swimming in Pools & Spas

EHA's Outbreak Response Team

EHA's team of public health epidemiologists stand ready to respond and investigate disease outbreaks associated with recreational swimming. As past regulatory inspectors responsible for inspection of pools and spas, our team has the expertise to investigate the means in which diseases are spread via recreational waters.