Giardia in Water: How to Treat It
Giardia, or Giardia lamblia, is a tiny parasite that causes a nasty stomach bug known as Giardiasis. The symptoms, which include diarrhoea, vomiting, gas and abdominal pain can last for up to six weeks. Despite the word Giardiasis being unfamiliar to many, according to the EPA, giardiasis is the “most commonly reported intestinal protozoan infection worldwide” with around 200 million people infected with the bug each year.
Giardiasis is very contagious, and it’s an infection that doesn’t discriminate — it can be found in every country, and it can affect people of all ages.
Luckily, the stomach bug can be treated with antibiotics. But even still, the prolonged symptoms can make it a very unpleasant illness. Giardiasis is also very contagious — it is spread from person to person, particularly amongst children, or contracted from contaminated surfaces, food or water. So stopping the spread of giardia is hugely important.
How Does Giardia Lamblia Spread?
Giardia parasites can thrive in the soil, so if food isn’t properly washed or cooked before it’s consumed it can cause giardiasis. Giardia lamblia is also one of the most common water contaminants. If water from an untreated water source like a lake or well is swallowed, this can cause people to develop the stomach bug. Contaminated water sources can also include recreational waters that are used by wildlife and unfiltered swimming pools. Giardia can also work its way into water supplies if effective water treatment systems aren’t used.
Travelling to developing countries can increase people’s risk of contracting the bug. Water supplies in developing countries may not be properly treated, and there may be an increased risk of consuming contaminated food.
How Does Giardia Get into Water?
Infected people can take precautions and ensure hand hygiene to prevent the spread of the bug, and contaminated food can be washed and cooked to remove or kill the parasites. However, when Giardia lamblia is found in water supplies, it can require more extensive prevention and control measures.
But how exactly does Giardia enter water sources?
The parasite can transfer from contaminated soil to water sources, or water may be infected by untreated sewage or agricultural runoff. If an infected person goes swimming, this can also cause water to become contaminated.
How to Test Water for Giardia?
Testing water to see if it’s contaminated with Giardia is difficult and test results aren’t always accurate. A sample of the water will need to be tested by an accredited water testing laboratory who will inspect the sample on a microscopic level. However, even if the test results come back negative, this doesn’t necessarily mean the water supply is free of Giardia. It may simply mean that there weren’t any Giardia cysts in the sample.
Because tests are complex and often costly, they’re usually carried out if someone drank from or swam in the water source that starts to show symptoms of Giardiasis.
How to Treat Giardia in Water?
If water has tested positive for Giardia contamination, or it’s suspected that there is Giardia in water, it may need to be treated. It’s not always necessary to treat water sources. For example, lakes, rivers and ponds may contain Giardia cysts but if the water isn’t used by humans, the contaminated water may not pose a threat.
However, if any water supply that is used for recreational purposes or drinking water is contaminated, it’s of paramount importance that the water is treated as soon as possible.
Boiling water for a minute or longer kills Giardia, making it safe to drink or use for cooking. After it has been boiled, water should be left to cool, stored in a clean, air-tight container, and then refrigerated. This method of Giardia treatment is only suitable for disinfecting small amounts of water, like from a private well, for instance.
For Giardia treatment on a larger scale, water purification systems and filters should be used. Giardia is resistant to chlorine and chloramine, which means chlorine disinfection systems are ineffective. Ultraviolet water purification systems, on the other hand, are hugely effective at deactivating Giardia cysts. Low doses of UV light will render the parasites inactive and therefore harmless.
At atg Evoqua, we’re experts on UV water treatment systems. We offer leading UV technology for drinking water, aquatic facilities, wastewater and more. Get in touch with us today to find out more about which water treatment system is right for your business.