Waterborne Illness: Facts and Prevention

According to the U.S. Census Bureau (2014), in 2009 approximately 51 million people above the age of six participated in recreational swimming (p. 1).  For these people swimming is an excellent way to stay in shape and have fun.  Like any sport, swimming is not without its risks as there are several microbes and pathogens that can be present in the water and make people sick when they ingest it.  The Minnesota Department of Health (2014) lists eight common waterborne illnesses caused by these microbes and pathogens.  These illnesses, symptoms associated with them, and prevention steps swimmers can take to make sure that they do not contract one of these illnesses will be discussed below.

Causes of Waterborne Illness

            A parasite called Cryptosporidium causes "one of the most common waterborne diseases in the United States" - Cryptosporidiosis, more commonly known as "Crypto" (Minnesota Department of Health, 2015).  This parasite - found in the fecal matter of infected people - causes diarrhea and can survive for days even in properly maintained chlorinated pools due to its "tough outer shell" (Centers for Disease Control, 2015).  Other symptoms associated with this disease include "vomiting, stomach cramps, loss of appetite, weight loss, and a slight fever."  It is possible for a person with Crypto to show no symptoms of the illness, but the person can still pass along the germ through contaminated fecal matter (Minnesota Department of Health, 2015).

            Another very common waterborne illness called Giardiasis is caused by the parasite Giardia.  Like Cryptosporidium, Giardia is found in the feces of infected humans and survive for long periods of time in the environment (Minnesota Department of Health, 2015).  Giardiasis can be spread when contaminated fecal matter comes into contact with recreational water and swimmers ingest the contaminated water (Minnesota Department of Health, 2015).  Symptoms of Giardiasis include "diarrhea, gas or flatulence, greasy stool that can float, stomach or abdominal cramps, upset stomach or nausea, dehydration, and weight loss" (Centers for Disease Control, 2015).  People, especially children, can be infected and exhibit no symptoms while still passing the parasite to others (Minnesota Department of Health, 2015).

            Shigella is a bacterium that - like Cryptosporidium and Giardia - causes "a diarrheal illness called Shigellosis" (Minnesota Department of Health, 2012).  Shigella is found in the feces of infected people, and can be spread when other people come into contact with food, water, or surfaces that the infected person has had contact with (Minnesota Department of Health, 2012).  Symptoms of Shigellosis include "diarrhea (often bloody), abdominal pain, stomach cramps, and fever (Minnesota Department of Health, 2012).  As with Crypto and Giardiasis, people who have Shigellosis can exhibit no symptoms while still passing the bacterium to other people (Minnesota Department of Health, 2012).

            There are two more types of bacteria that can cause illness by ingesting water contaminated with them.  The first of these is a strain of Escherichia coli called E. coli 0157:H7.  According to the Centers for Disease Control and Prevention, E. coli bacteria are normally harmless and live in the intestines of healthy humans as a part of their digestive tract (2015).  However, the "0157 strain produces a powerful toxin that can cause severe illness" (Minnesota Department of Health, 2014).  Symptoms associated with the illness cause by the 0157 strain include diarrhea that is often bloody and abdominal cramps, while fever and vomiting are not present.  As with all of the other illnesses discussed thus far, people infected with the 0157 strain of E. coli can exhibit no symptoms while still carrying and spreading the bacterium (Minnesota Department of Health, 2014).

            Legionella pneumophila is another bacterium that can cause waterborne illness.  This bacterium causes Legionellosis, which includes two subcategories of diseases: Legionnaires' Disease and Pontiac Fever (Minnesota Department of Health, 2013).  People can become infected with Legionnaires' Disease by inhaling the water spray from water sources contaminated with the Legionella bacterium (Minnesota Department of Health, 2013).  Symptoms of Legionnaires' Disease include "muscle aches, headache, fatigue, loss of appetite, and coughing," and these symptoms are usually followed by a high fever (102-105 degrees), pneumonia, and occasionally abdominal pain and diarrhea" (Minnesota Department of Health, 2013).  It is important to note that Legionnaires' Disease is not spread from person to person (Minnesota Department of Health, 2013).

            Pontiac Fever is also caused by the bacterium Legionella pneumophila.  Like Legionnaires' Disease, it is caused by inhaling water spray that is contaminated with bacteria.  Symptoms of Pontiac Fever include "fever, chills, headache, muscle aches, loss of appetite, tiredness, and occasionally diarrhea" (Minnesota Department of Health, 2013).  Pontiac Fever also cannot be spread from person to person (Minnesota Department of Health, 2013).

            A source of water toxins that may not seem readily apparent to most people is harmful algal blooms.  According to the Minnesota Department of Health (2014), "[b]lue-green algae are not algae at all, but types of bacteria that are normally present in many lakes.  This type of bacteria thrives in warm, nutrient-rich water...[h]armful algal blooms (HABs) are blue-green algal blooms that contain toxins that can cause illness in humans..."  These toxins are called cyanotoxins, and while different toxins cause different illnesses and symptoms some common symptoms are "rash, blisters, cough, wheezing, congestion, sore throat, earache, eye irritation, diarrhea, vomiting, and headache" (Minnesota Department of Health, 2014).  In order to minimize risk of contracting an illness related to an algal bloom toxin, people should "avoid contact with water where harmful algal blooms may be occurring, use caution when fishing or consuming fish caught from waters where a bloom may be occurring, and use caution when taking algal supplements" (Minnesota Department of Health, 2014).

            Naegleria fowleri is an ameba that is also found in warm freshwater and soil and causes the rare but severe and often fatal brain infection known as Primary Amebic Meningoencephalitis, commonly abbreviated as "PAM" (Minnesota Department of Health, 2015).  The ameba "infects people by entering the body through the nose," which "usually happens when people go swimming or diving in warm freshwater, such as lakes or rivers" (Minnesota Department of Health, 2015).  A person cannot become infected with the ameba by swimming in a correctly maintained pool, and PAM cannot be spread from person to person (Minnesota Department of Health, 2015).  Symptoms of PAM include "headache, fever, nausea, and vomiting," with later symptoms being "stiff neck, confusion, lack of attention to people and surroundings, loss of balance, seizures, and hallucinations" (Minnesota Department of Health, 2015).

Preventing a Waterborne Illness

            While it may seem that contracting a waterborne illness while participating in recreational water activities is inevitable, there are steps that can be taken to minimize risk.  The CDC (2015) recommends that swimmers who have diarrhea refrain from swimming so as to keep contaminated fecal matter out of the water.  It is also recommended for swimmers to shower before they enter the water, and to avoid swallowing the water (Centers for Disease Control and Prevention, 2015).  The CDC (2015) also recommends implementing an "Every hour - everyone out!" policy.  This allows for kids to take bathroom breaks so as to not contaminate the water with feces that may contain disease-causing agents.  Checking the level of chlorine in the pool and making sure the pH is in the correct range can also be beneficial in preventing the spread of waterborne illnesses (Centers for Disease Control and Prevention, 2015). 

            Frequent hand washing is also encouraged to prevent the spread of waterborne illnesses (Minnesota Department of Health, 2015).  Hand washing allows for the germs that people may have picked up from coming into contact with infected persons or surfaces to be eliminated before eating or drinking.  This in turn prevents the non-infected person from ingesting the microbes or pathogens, and the person remains healthy.

            While there are several microbes and pathogens that can be present in recreational water and cause waterborne illnesses such as those described above, it is important to remember that the spread of these diseases can also be easily and effectively prevented by following the tips just discussed.  If a person is exhibiting any of the symptoms described above after partaking in recreational water activities it is recommended that he or she seek medical attention.  If each person does his or her part to prevent the spread of waterborne illnesses, recreational water activities such as swimming can continue to be enjoyed by everyone with minimal risk for disease.

Contact the Minnesota Department of Health for more information: 

visit www.health.state.mn.us, or call (651) 201-5414.

References

Centers for Disease Control and Prevention. (2015, April 16). E coli (Escherichia coli): General information. Retrieved from http://www.cdc.gov/ecoli/general/index.html.

Centers for Disease Control and Prevention. (2015, May 6). Healthy swimming/Recreational water: How can we prevent recreational water illnesses (RWIs)?: Steps for healthy swimming. Retrieved from http://www.cdc.gov/healthywater/swimming/rwi/rwi-prevent.html.

Centers for Disease Control and Prevention. (2015, May 20). Cryptosporidium ("Crypto"). Retrieved from http://www.cdc.gov/healthywater/swimming/rwi/illnesses/cryptosporidium.html.

Centers for Disease Control and Prevention. (2015, July 21). Parasites - Giardia: General information. Retrieved from http://www.cdc.gov/parasites/giardia/general-info.html.

Minnesota Department of Health. (2012, June 21). Shigellosis (Shigella) fact sheet.  Retrieved from http://www.health.state.mn.us/divs/idepc/diseases/shigellosis/shigella.html.

Minnesota Department of Health. (2013, April 02). Legionellosis (Legionella): Legionnaires' Disease and Pontiac Fever. Retrieved from http://www.health.state.mn.us/divs/idepc/diseases/legionellosis/index.html.

Minnesota Department of Health. (2013, April 02). About Legionellosis (Legionella). Retrieved from http://www.health.state.mn.us/divs/idepc/diseases/legionellosis/basics.html.

Minnesota Department of Health. (2013, April 02). About Pontiac Fever. Retrieved from http://www.health.state.mn.us/divs/idepc/diseases/legionellosis/pontiac.html.

Minnesota Department of Health. (2014, July 16). E. coli 0157:H7 and HUS fact sheet. Retrieved from http://www.health.state.mn.us/divs/idepc/diseases/ecoli/ecoli.html.

Minnesota Department of Health. (2014, September 3). Harmful algal blooms (HABs) fact sheet.            Retrieved from http://www.health.state.mn.us/divs/idepc/diseases/hab/hab.html.

Minnesota Department of Health. (2014, September 3). Causes and symptoms of harmful algal bloom-related illnesses. Retrieved from http://www.health.state.mn.us/divs/idepc/diseases/hab/basics.html.

Minnesota Department of Health. (2014, September 3). Preventing harmful algal bloom-related illnesses. Retrieved from http://www.health.state.mn.us/divs/idepc/diseases/hab/prevention.html.

Minnesota Department of Health. (2015, June 25). Cryptosporidiosis fact sheet. Retrieved from             http://www.health.state.mn.us/divs/idepc/diseases/cryptosporidiosis/crypto.html.

Minnesota Department of Health. (2015, June 25). Giardiasis fact sheet. Retrieved from http://www.health.state.mn.us/divs/idepc/diseases/giardiasis/giardia.html.

Minnesota Department of Health. (2015, July 14). Naegleria and primary amebic meningoencephalitis. Retrieved from http://www.health.state.mn.us/divs/idepc/diseases/naegleria/.

Minnesota Department of Health. (2015, September 02). Causes and symptoms of waterborne illness. Retrieved from http://www.health.state.mn.us/divs/idepc/dtopics/waterborne/basics.html.

United States Census Bureau. (2014). The 2012 statistical abstract: Participation in selected sports activities: 2009 [data file]. Retrieved from http://www.census.gov/compendia/statab/cats/arts_recreation_travel/recreation_and_leisure_activities.html.