Diving Into Disease
By Mark Afanasyev
Highlights
There are a wide range of diseases that can be acquired by swimming in water.
Symptoms of infection can range from diarrhea, gastrointestinal inflammation, and fever.
Swimming-related diseases can be acquired from most bodies of water, including the ocean and disinfected public pools.
Introduction
Hand in hand with the summer season often comes swimming and water sports. However, there is something else that people should worry about other than sunburn or shark attacks. In practically every body of water, from oceans to hot tubs, there is a risk of acquiring a swimming-related disease. These diseases are water-borne, meaning they can be transmitted through consumption or contact with the water from swimming pools, lakes, rivers, and other aqueous locations. Thus, whether you are a professional swimmer or prefer to stand in the water, you should be aware of this risk.
Transmission and Symptoms
Swimming-related diseases are primarily acquired after the ingestion or contact with water, along with the inhalation of aerosols from contaminated water. The most common cause and symptom of this type of infection is diarrhea. Individuals afflicted with diarrhea are able to easily transmit the condition to others inadvertently. In fact, at any given time, people carry about 0.14 grams of feces on their bodies. This minute amount has the capacity to contaminate an entire pool, leaving others susceptible to infection. The most notorious causes of these diarrhea-causing infections is the parasitic infection Cryptosporidium (often referred to as “Crypto”) and Giardia, the viral infection Norovirus, and the bacterial infection Shigella and E. coli. It is important to note that symptoms are not limited to diarrhea. Norovirus infection can cause inflammation of the stomach and intestines, not to mention the set of ailments that could result from skin, ear, respiratory, and eye infections. Moreover, infections by Crypto can be life-threatening for immune-compromised individuals, those who have weakened immune systems due to pregnancy, medication, and other medical conditions.
These diseases are not only limited to recreational man-made areas; infection is a prevalent issue in open water as well. For instance, many virologists and journalists had called for the relocation of the Olympic 10K Marathon Swim at the 2016 Rio Olympic Games. Widespread pollution and drug-resistant bacteria were cited to be a significant threat to swimmers at the competition.
Algal blooms are another cause for concern among open-water swimmers. Freshwater and marine algae can undergo a rapid increase in population, also known as a bloom, leading to the depletion of sunlight, nutrition, and oxygen from the ecosystem. The resulting starvation and death of fish and plants, along with the release of toxins by some algae, can pose a serious threat to the health of humans and other animals.
Prevention
There are some simple ways that you could avoid swimming-related illness. It is important to keep water out of your mouth and to dry your ears after your swim. Avoid defecating or urinating in the water. Stay out of the water if you have diarrhea, and shower before you get in the water. Standard levels of chlorine in swimming pools are insufficient to eradicate Crypto, causing frequent outbreaks and closures of public pools. Moreover, a CDC study found that more than 10% of inspections of pools, hot tubs, and water playgrounds led to closure due to improper levels of disinfecting chemicals, such as chlorine and bromine. Unfortunately, as mentioned before, the risk of acquiring disease is present in practically any body of water, so it is important to be vigilant of the water condition in which you are swimming.
References
https://www.cdc.gov/healthywater/swimming/swimmers/rwi.html
https://www.cdc.gov/dotw/rwis/index.html
https://newsnetwork.mayoclinic.org/discussion/mayo-clinic-minute-swimming-pool-sickness/
https://www.openwaterswimming.com/contracting-diseases-in-open-water/