5 pathogens often found in drinking water:

Cathal Walsh
Environmental Blogger
Thursday, 16th May 2019
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5 pathogens often found in drinking water:

Water while also being one of the few necessities of life is also known as a vehicle of disease. Water can be easily contaminated and can carry a large amount of bacteria in the right conditions. Here is a list of the most common pathogens that may be found in water and what they can do to infected humans.  In making out this list we have chosen from the most common pathogens that can do harm to humans, there are plenty of inert pathogens in water as well.

Campylobacter Jejuni

Infection of a human with campylobacter jejuni causes a decision called campylobacteriosis. This can be caught from water as well as unpasteurized milk and chicken. If you are infected with campylobacteriosis the first symptoms may come on within 24 hours. The main symptoms then come on, these include cramps, diarrhoea, fever and pain. The illness tends to last for about 2-10 days.

Escherichia Coli

E-Coli bacteria live in the intestines of healthy humans and animals. Most E-Coli are relatively harmless but there are some strains which can cause violent sickness in those affected.  It is spread through faecal contamination. It is often caught by humans consuming undercooked or raw food.

Symptoms include nausea, vomiting , diarrhoea and abdominal pain and these can last around a week for healthy adults, sometimes longer for those with a compromised immune system.

Giardia Lamblia

This bacteria causes Giardiasis, an infection of the small intestine. Although it can be caught from food, the most common way people contract giardiasis is through coming into contact with or drinking water with the pathogen in it.  Symptoms of giardiasis generally show up around one to two weeks after exposure.  Symptoms of this include fever, nausea, vomiting, fatigue and a few others. Luckily in most cases of Giardiasis the infection clears up on its own. In more severe cases treatment with antibiotics may be needed.


Salmonella is a virus which comes mainly from the faecal matter of animals. It can then spread to any water which comes into contact with the faecal matter. The incubation period for salmonella ranges from several hours to two days as it is a disease that affects the intestinal tract. Symptoms include nausea, vomiting, abdominal cramps etc.

Overall symptoms last for about 2 to 7 days with diarrhoea potentially lasting longer. This is a very common infection but it can cause severe discomfort in those who catch it .

Legionella Pneumophila

Legionella pneumophila is a type of bacteria that causes a serious infection known as legionellosis, or Legionnaires’ disease. This is by far the most serious of the water pathogens in this list. The main way in which legionnaires is contracted is by breathing in the mist from water which contains the bacteria.  Symptoms include a cough, muscle pain, fever, diarrhoeas and headache.

If one catches legionella they will need treatment with a course of antibiotics to recover. Although  around 90 percent of those infected with the virus make a full recovery, it can result in grave sickness or death for those with compromised immune systems.


If you have any concerns about the quality of your water head to https://www.h2olabcheck.com/category and purchase a water test.





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