Microbes in Drinking Water

Fact Sheet Series: Microbes in Drinking Water

What are Microbes?

Microbes are small organisms that are present in the environment and some are capable of causing diseases in humans. They are present all around us in air, soil and water. Prior to the advent of modern water treatment involving disinfections and filtration, water-borne diseases killed thousands of people all around the world. In areas that lack modern sanitation and water treatment, water-borne diseases are still a major contributor to mortality.

Types of Microbes causing waterborne illness?

	Bacteria: Diseases caused by water-borne bacteria include cholera and typhoid.
	Viruses: Water-borne viral diseases include polio, hepatitis, and various gastrointestinal diseases.
	Protozoa: Water-borne protozoa that cause disease include Giardia and Cryptosporidium.

These diseases usually occur as a result of inadequately treating drinking and wastewater.

Who is at Risk?

Everyone is at a risk for water borne disease. But infants, children, older persons and immuno-compromised people are generally at increased risk. Some persons maybe at higher risks depending on the organism, its mode of spread, and occupation, e.g. personnel at day care centers. Those on chemotherapy, organ or bone marrow recipients, persons with HIV or AIDS, are also at increased risk.

How are they Spread?

A person may be infected by drinking contaminated water, or by direct or hand-to-mouth transfer of the bacteria from feces or contaminated surfaces. Many people have no symptoms but can pass the disease on when they do not wash their hands after changing diapers or using the toilet.

What are the Symptoms?

Human symptoms for water-borne illnesses range from fever and malaise to the better known gastro intestinal symptoms such as diarrhea and stomachaches. Two to twelve days after contaminated food or water is swallowed symptoms may appear; the average is seven days. Most water-borne illnesses cause:

	Abdominal discomfort or cramping
	Fever
	Vomiting
	Diarrhea (characteristics of each depend on the pathogen).
	Loss of weight and fatigue may accompany several of the viral illnesses.
	Symptoms are more severe for people with weakened immune systems and can lead to death.

What is the treatment?

For most gastroenteritis is a self-limited disease of few days duration. The main risks are of dehydration and electrolyte imbalance. Maintaining a good hydration is the most important thing in gastroenteritis. There is generally treatment available for bacterial and protozoal infections but for viral its more symptomatic relief. For bacterial infection anti bacterial drugs can be given and for protozoal infections anti-protozoal drugs can be given.

How to Prevent?

	Always wash your hands before handling food especially after using the toilet or handling pets or soil.
	Wash fruits and vegetables with clean water, especially if you plan to eat them raw.
	Avoid unpastuerized milk and dairy products. Cooking kills germs.
	Don’t swallow water from lakes, rivers or pools. Water swallowed while swimming may contain harmful bacteria.
	Clean surfaces where diapers are changed after every use.
	More precautions are needed traveling to developing countries. Foods and drinks, in particular raw fruits and vegetables maybe contaminated if not washed properly.

Tests for Microbial quality of Drinking water?

	Coliform Test: It is more reliable for bacteria.
	Turbidity Test: It is more reliable for protozoa.

References:

Pierre Payment, (1999) Canadian Journal of Microbiology 45(8):709.

Brown BA, Oberste MS, Alexander JP Jr, Kennett ML, (1998) Journal of Virology 73:9969.

Siegel, Robert (1998) Humans and Viruses Course Reader.

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© 2002 WATERBORNE DISEASE CENTER
Department of Biostructure and Function, University of Connecticut Health Center
263 Farmington Avenue Farmington Connecticut 06030-3705 USA
Telephone (860) 679-2622 Fax (860) 679-2910
Email: DrRossomando@waterbornediseases.org