Water-borne Infections in British Columbia

HealthLinkBC File Number: 
Last Updated: 
March 2014

What are water-borne infections?

Water-borne infections are any illnesses caused by drinking water contaminated with certain germs, like bacteria, viruses, or parasites.

The contamination can be by bacteria such as Salmonella or Campylobacter, viruses, or small parasites including Cryptosporidia, Giardia, and on rare occasions Toxoplasma.

How are water-borne infections spread?

Water-borne infections happen when animal or human waste (feces) containing these germs gets into the drinking water systems. This is more likely when public and private drinking water systems get their water from surface waters, such as: rain, creeks, ponds, rivers and lakes.

Surface water can be contaminated when infected animals, pets or humans defecate (have a bowel movement) in, or near, the surface water. Infected animals can include: pets, livestock, poultry, or wild animals like beaver, deer or rodents. Runoff of human waste from landfills, septic fields, sewer pipes, or residential or industrial developments can also infect surface water.

Do outbreaks happen in British Columbia?

When many people get sick from a water-borne infection it is called an outbreak.

Outbreaks can happen when the source of drinking water is not properly treated or when water storage tanks or reservoirs become infected with germs.

Occasional cases of water-borne infections that occur outside of an outbreak are difficult to identify, because most of the types of illness spread by water can also be spread by food or directly from other people or animals.

What are the symptoms of water-borne infections?

Many people who get infected with a more common water-borne infection will have no symptoms at all, and probably will not even know they have been infected. Over time, the germ moves through your digestive system and leaves your body through your feces.

If you do get sick, how you feel depends on the type of infection. For many water-borne infections, you start feeling sick 2 to 10 days after drinking the infected water. You might have diarrhea, stomach cramps, nausea, vomiting, and a fever. If you have fever, swollen glands, or changes in your vision, see your health care provider.

Who is more likely to get sick?

People who have a greater chance of getting sick include:

  • people with weakened immune systems, such as persons who HIV/AIDS, persons who have had an organ or bone marrow transplant, or who have had cancer treatment;
  • babies;
  • older adults; and
  • people with a chronic disease.

These people can have severe reactions and serious complications. There is a chance these people could die from the infection. Speak to your healthcare provider if you have a weakened immune system and you are concerned about the quality of the water in your community. You might be told to boil drinking water or install a water filter system. For more information, see HealthLinkBC File #56 Preventing Water-borne Infections For People with Weakened Immune Systems.

Although there is little chance of getting Toxoplasmosis through drinking water, this disease is a concern for pregnant women. For more information, see HealthLinkBC File #43 Toxoplasmosis.

What should I do if I think I have a water-borne infection?

See your health care provider as soon as possible if:

  • you are very sick;
  • your illness does not go away within a few days; or
  • you have a weakened immune system.

Notify your local public health unit so that the source of infection can be located and controlled.

How can I keep from getting a water-borne infection?

Do not drink water directly from lakes, streams, rivers, springs or ponds, which may be infected by the feces of infected wild animals, pets, or humans.

If your community has a boil water advisory or notice, or you are concerned about the quality of the water in your community, see HealthLinkBC File #49b Disinfecting Drinking Water.

Who is in charge of safe drinking water?

It is the job of the local water supplier to provide safe drinking water. A water supplier is the local agency or person that owns and operates the community's system for collecting and delivering drinking water.

The water supplier may be your local or regional government. Many smaller public drinking water systems in British Columbia are owned and run by private persons or water companies. If you own your home and have your own water supply, such as a well, then you are your own water supplier.

No matter who the water supplier is, they must make sure drinking water is properly treated before delivering it to those who drink it.

For more information, see HealthLinkBC File #05b Should I Get My Well Water Tested? or contact your local environmental health officer.

Should I treat my water?

Always treat your water if:

  • Your community is given a boil water notice.
  • You get your drinking water directly from a stream, river, lake, or shallow well.
  • Tests of your water show it has E.coli in it. A positive test is an indication that your water has been contaminated with human feces.
  • A flood, earthquake, or other disaster has disrupted the water supply in your community.
  • You are traveling in an area where water is not well treated.
  • You have a weakened immune system. For more information see HealthLinkBC File #56 Preventing Water-borne Infections For People with Weakened Immune Systems.

Boiling is the best way to kill bacteria, viruses and parasites. Generally, water must be boiled for at least 1 minute, and this must be increased to 2 minutes if you are at an altitude of over 2000m. For more information, see HealthLinkBC File #49b Disinfecting Drinking Water.

If your water needs treatment, only use treated water for drinking, brushing teeth, making ice cubes, and putting in recipes that call for water.

If your tap water needs treatment, using bottled water is also an option.

Can I use a water filtration system to disinfect my water?

It depends on the type of water filter system you use. Jug-type water filters (such as Brita®), are not made to remove germs from an unsafe water supply. If you have poured unsafe water through this type of filter, throw the filter out and replace it with a new one.

Some built-in water filter systems can be used to treat your water for germs. If you plan to install a water filter system, make sure it can remove particles down to 1 micron and it includes a disinfection process such as chlorination or ultraviolet light. Use a supplier who can help you properly install and maintain your system.

To work well, water filtration systems must be checked and cleaned, and have their filters replaced regularly.

Is it an emergency?

If you or someone in your care has chest pains, difficulty breathing, or severe bleeding, it could be a life-threatening emergency. Call 9-1-1 or the local emergency number immediately.
If you are concerned about a possible poisoning or exposure to a toxic substance, call Poison Control now at 1-800-567-8911.

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