8 Common Water Borne Diseases You Don’t Want to Get

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Most of us are lucky to have access to an endless supply of clean, pathogen-free drinking water.

City water in the US is treated with chemical disinfectants to kill microorganisms and protect water as it travels through the distribution system to our home.

However, that doesn’t mean that you’re guaranteed never to be exposed to pathogens in your water at some point in your life, especially if you regularly travel to developing countries or you get your drinking water from a private well.

Researching waterborne diseases is the first step towards reducing your likelihood of getting sick from your drinking water.

📌 Key Takeaways:

  • Waterborne pathogens come from human and animal waste.
  • Some of the common water-related illnesses are E. coli, giardiasis, cryptosporidiosis, cyclosporiasis, legionellosis, typhoid fever, noroviruses, and cholera.
  • You can reduce your risk of exposure to diseases in drinking water by practicing good hygiene, getting vaccinated before visiting certain countries, filtering/disinfecting potentially unclean drinking water or drinking bottled water, and taking steps to prevent contamination of private wells.

🧫 Where Do Waterborne Pathogens Come From?

The most common sources of waterborne pathogens are human and animal waste.

There are a few ways that water supplies may become contaminated by these sources, including by proximity to leaking or overflowing septic systems, direct contamination (such as animals pooping in rivers or streams), or agricultural runoff.

Extreme weather, such as flooding, hurricane rainfall, and storm surges may also cause contamination of normally clean water sources with microbes and pathogens.

Pathogen in water

⚗️ What Is A Waterborne Disease?

A waterborne disease is a water-related illness that’s caused by drinking water that’s contaminated with microscopic organisms that are dangerous to human health.

There are tens of different organisms that could contaminate drinking water supplies, including various species of bacteria, viruses, and protozoan cysts.

Waterborne diseases simply wouldn’t exist if we were all able to follow safe hygiene and sanitation practices. Thankfully, water-related disease has been declining in the past few decades, but that doesn’t mean the problem is even close to being resolved.

Note: A waterborne disease is caused by disease-causing microorganisms, and is NOT the same as an adverse health effect that’s caused by drinking high levels of non-living contaminants (such as lead and arsenic) with health risks. These contaminants could still make you sick, but they don’t cause infectious diseases.

🩺 Common Waterborne Diseases

Here are some of the common waterborne diseases that you may be exposed to if you drink from an unclean water source:

Escherichia Coli (E. coli)

E. coli is a type of bacteria that has both beneficial and dangerous strains. Dangerous E. coli is spread via contamination from animal waste.

Some of the most commonly reported symptoms of dangerous E. coli strains include:

  • Diarrhea
  • Stomach cramps
  • Fever

Symptoms usually occur within 3-4 days of being exposed to the pathogen, but it may take up to 14 days for symptoms to present themselves. It usually takes 5-10 days for symptoms to go away.

Most people recover from E. coli without treatment, with rest, hydration (with clean water), and over-the-counter medication for diarrhea. However, children and older people are more likely to develop life-threatening symptoms, and you should contact your doctor if you or anyone else has bloody diarrhea.

The best way to avoid E. coli is to stay away from drinking water supplies that are possibly contaminated with animal or human feces.

Escherichia coli from animal waste


Giardiasis is a waterborne disease that’s caused by a tiny parasite called giardia.

Giardia can contaminate surface water and groundwater supplies, including ponds, wells, streams, and even swimming pools. Giardia is only present in water supplies if they’re contaminated by infected people or animals.

Some of the common symptoms of giardiasis include:

  • Abdominal pain
  • Diarrhea
  • Nausea
  • Cramps
  • Bloating
  • Weight loss

Giardiasis usually runs its course after 2-6 weeks. However, it can cause long-term complications, especially in the intestines.

There are no treatments that prevent giardiasis, but you can avoid the infection with good sanitation and hygiene management, including washing your hands often, drinking clean, uncontaminated water, and avoiding swallowing water while swimming.

If your symptoms don’t lessen over time, you may need to make an appointment with your doctor, who will likely prescribe you antibiotics or anti-parasitic medications.


Cryptosporidiosis is a diarrheal disease that’s caused by ingesting food or water that’s contaminated with a parasite called cryptosporidium,

Crypto is one of the most common recreational water diseases in the USA, and is spread from the fecal matter of an infected person or animal.

You may be exposed to crypto through contact with animals, swimming in contaminated water, drinking contaminated water, or eating contaminated foods.

Some of the common symptoms of crypto are:

  • Watery diarrhea
  • Vomiting
  • Stomach pain
  • Loss of appetite
  • Fever
  • Weight loss

Most healthy people should recover from cryptosporidiosis after about 14 days. It’s common for crypto symptoms to come and go in intensity, so you may have several cycles of feeling better, then worse, then better again before you eventually recover.

Drinking plenty of clean water should help you to recover without the risk of dehydration.

You can reduce your likelihood of exposure to crypto by washing your hands regularly with soapy water, only drinking filtered, disinfected water, avoiding swallowing water while swimming in lakes or rivers, and washing your hands after touching animals or being in animal environments.

Diarrhea due to cryptosporidium-contaminated water


Cyclosporiasis is a waterborne illness that’s caused by exposure to cyclospora cayetanensis, a parasite that affects the intestinal tract and causes diarrhea.

The contaminant infects people who eat or drink unsafe food and water. It’s a problem in many tropical, developing countries, and is less common in the US, but outbreaks occasionally occur due to importing contaminated food.

Some of the symptoms of Cyclosporiasis include:

  • Watery diarrhea
  • Vomiting
  • Loss of appetite
  • Stomach cramps
  • Weight loss
  • Nausea
  • Muscle aches
  • Lethargy

You’ll likely experience symptoms within one week after coming in contact with food or drinking water contaminated with this parasite, and the illness may last from a few days to a month or longer.

Cyclosporiasis is another disease that causes relapses, so your symptoms may go away and return several times before you properly recover from the illness.

Most people should recover from cyclosporiasis by resting and drinking plenty of clean water. Your doctor may prescribe an antibiotic treatment if your symptoms are severe or persistent.


Legionellosis is a collection of diseases that are caused by inhaling airborne water droplets that contain legionella bacteria. The most serious and well known of these diseases is legionnaires’ disease.

You don’t get sick from drinking water contaminated with legionella, but you may be affected by inhaling water vapor (such as from cooking water, spas and jacuzzis, or shower water).

Some of the symptoms of legionnaires’ disease are:

  • Fever and high temperature
  • Muscle aches
  • Cough
  • Diarrhea
  • Headache

Sometimes, legionnaires’ disease can evolve into pneumonia, which can be fatal, especially to older people and people with compromised immune systems. Most cases of legionnaires’ are treated with antibiotics.

Diagnosing legionnaires’ disease can often be difficult because its symptoms are similar to the flu. Your doctor may ask for a urine sample or take a sample of your blood for testing.

Feeling sick after drinking water

👨‍🔬 Continue Reading: Legionella Treatment in Water: A Comprehensive Guide

Typhoid Fever

Typhoid fever is a waterborne disease characterized by loss of appetite and prolonged episodes of fever.

This disease is caused by salmonella typhi bacteria, which is transmitted in contaminated water and food.

Typhoid fever is thankfully rare in industrialized parts of the world, but it still occurs in developing countries.

Some of the symptoms of typhoid fever are:

  • Nausea
  • Fever
  • Headache
  • Constipation or diarrhea
  • Sweating
  • Loss of appetite
  • Weight loss

If you’re planning to travel to a region that has poor sanitation and substandard drinking water quality, you can get a vaccination that will prevent you from getting this specific waterborne disease from ingesting contaminated drinking water.

Antibiotic treatment is the most effective way to treat typhoid fever.


Noroviruses are a group of viruses, otherwise known as viral gastroenteritis, which cause the stomach and the intestines to become inflamed.

You can become infected with noroviruses, after drinking, or swimming in and swallowing, water contaminated with the viruses, as well as from eating foods that have been contaminated by an infected person.

Common symptoms of noroviruses include:

  • Nausea
  • Diarrhea
  • Vomiting
  • Fever
  • Muscle aches
  • Headache

Symptoms usually appear within 24-48 hours of contact with the virus, and usually lasts for 1-2 days.

All types of noroviruses are very contagious and may be dangerous if they infect young children, the elderly, or people with weakened immune systems.

Man experience stomach pain due to noroviruses


Cholera is a diarrheal disease that causes intestinal infection as a result of exposure to the Vibrio cholerae bacteria, usually in contaminated water or food.

The symptoms of cholera vary from one person to the next. While most people experience mild symptoms or no symptoms at all, around 1 in 10 people experience severe symptoms, including:

  • Severe watery diarrhea
  • Vomiting
  • Restlessness
  • Leg cramps
  • Thirst

Dehydration is one of the most serious side effects of cholera, and can lead to kidney failure, coma, shock, and even death if left untreated.

Cholera outbreaks haven’t occurred in the US for at least the past century, but the disease still exists in many developing countries and is still a major global health concern.

📉 How To Reduce Your Risk Of Waterborne Diseases

Fortunately, folks who live in the US and have access to a municipal drinking water supply are unlikely to be exposed to many of the waterborne diseases on this list.

However, if you get your water from a private well or you’re planning on traveling to a country with poor sanitation and dirty drinking water, here are some of the ways you can reduce your risk of contracting waterborne diseases.

  • Get vaccinated – Before you book a trip, Google what vaccines you might need, or be advised to get, in order to travel safely. Many of these vaccines aren’t offered to US citizens because we’re not at risk of certain microorganisms that are present in other parts of the world, so don’t assume that you’re already vaccinated.
  • Practice good personal hygiene – Regardless of your situation, one of the easiest ways to prevent waterborne diseases is to wash your hands thoroughly and regularly, especially after using the toilet and handling animals, and before cooking.
  • Prevent contamination of private wells – If you’re on a private well, prevent drinking water contamination by ensuring the ground around the well slopes away, which will drain runoff in the opposite direction. Any septic tanks on your property should be at least 50 feet away from the well.
  • Disinfect/filter your water – Depending on your situation, you may also need to disinfect or filter your drinking water. There are disinfection systems, like UV purifiers and chlorination systems, that you can install in your home to treat well water. Or, if you’re traveling abroad, consider a portable water purification device, like a bottle filter or a squeeze filter, that you can use to purify a potentially contaminated drinking water supply.
  • Drink bottled water – If in doubt, stick to filtered bottled water, especially if you’re traveling overseas.
Whole house water filter and sediment filter next to uv water filter

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🔚 Final Word

Waterborne diseases are thankfully rare in the US – but that doesn’t mean that you’re completely safe against exposure to disease-causing pathogens in your local drinking water supply.

If you have any reason to believe that your drinking water quality might be compromised, switch to bottled water and test your water for waterborne contaminants. Or, if you think you’ve contracted one of the water-related diseases on this list, especially if you’re experiencing severe diarrhea or any other symptoms that have persisted for several weeks, contact your doctor to arrange a checkup.

  • Brian Campbell
    President & CEO, CWS, CWR

    Brian Campbell, a WQA Certified Water Specialist (CWS) and Certified Water Treatment Representative (CWR) with 5+ years of experience, helps homeowners navigate the world of water treatment. After honing his skills at Hach Company, he founded his business to empower homeowners with the knowledge and tools to achieve safe, healthy water. Brian's tested countless devices, from simple pitchers to complex systems, helping his readers find the perfect fit for their unique needs.

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