Useful Info

Waterborne Diseases

Waterborne diseases are caused by pathogenic microorganisms which are directly transmitted when contaminated water is used. According to the World Health Organization, diarrheal disease accounts for an estimated 4.1% of the total DALY global burden of disease and is responsible for the deaths of 1.8 million people every year. It was estimated that 88% of that burden is attributable to unsafe water supply, sanitation and hygiene, and is mostly concentrated in children in developing countries.

Waterborne disease can be caused by protozoa, viruses, or bacteria, many of which are intestinal parasites.

Protozoal Infections

Disease and Transmission

Microbial Agent

Sources of Agent in Water Supply

General Symptoms

Amoebiasis (hand-to-mouth)

Protozoan (Entamoeba histolytica) (Cyst-like appearance)

Sewage, non-treated drinking water, flies in water supply

Abdominal discomfort, fatigue, weight loss, diarrhea, bloating, fever

Cryptosporidiosis (oral)

Protozoan (Cryptosporidium parvum)

Collects on water filters and membranes that cannot be disinfected, animal manure, seasonal runoff of water.

Flu-like symptoms, watery diarrhea, loss of appetite, substantial loss of weight, bloating, increased gas, nausea


Protozoan parasite (Cyclospora cayetanensis)

Sewage, non-treated drinking water

cramps, nausea, vomiting, muscle aches, fever, and fatigue

Giardiasis (oral-fecal) (hand-to-mouth)

Protozoan (Giardia lamblia) Most common intestinal parasite

Untreated water, poor disinfection, pipe breaks, leaks, groundwater contamination, campgrounds where humans and wildlife use same source of water. Beavers and muskrats create ponds that act as reservoirs for Giardia.

Diarrhea, abdominal discomfort, bloating, and flatulence


Protozoan phylum (Microsporidia), but closely related to fungi

The genera of Encephalitozoon intestinalis has been detected in groundwater, the origin of drinking water [3]

Diarrhea and wasting in immunocompromised individuals

Parasitic Infections (Kingdom Animalia)

Disease and Transmission

Microbial Agent

Sources of Agent in Water Supply

General Symptoms

Schistosomiasis (immersion)

Members of the genus Schistosoma

Fresh water contaminated with certain types of snails that carry schistosomes

Rash or itchy skin. Fever, chills, cough, and muscle aches

Dracunculiasis (Guinea Worm Disease)

Dracunculus medinensis

Stagnant water containing larvae

Allergic reaction, urticaria rash, nausea, vomiting, diarrhea, asthmatic attack.


Tapeworms of the genus Taenia

Drinking water contaminated with eggs

Intestinal disturbances, neurologic manifestations, loss of weight, cysticercosis


Fasciolopsis buski

Drinking water contaminated with encysted metacercaria

GIT disturbance, diarrhea, liver enlargement, cholangitis, cholecystitis, obstructive jaundice.

Hymenolepiasis (Dwarf Tapeworm Infection)

Hymenolepis nana

Drinking water contaminated with eggs

Abdominal pain, anorexia, itching around the anus, nervous manifestation

Echinococcosis (Hydatid disease)

Echinococcus granulosus

Drinking water contaminated with feces (usually canid) containing eggs

Liver enlargement, hydatid cysts press on bile duct and blood vessels; if cysts rupture they can cause anaphylactic shock


multiceps multiceps

contaminated drinking water with eggs

increases intacranial tension


Ascaris lumbricoides

Drinking water contaminated with feces (usually canid) containing eggs

Mostly, disease is asymptomatic or accompanied by inflammation, fever, and diarrhea. Severe cases involve Löffler's syndrome in lungs, nausea, vomiting, malnutrition, and underdevelopment.


Enterobius vermicularis

Drinking water contaminated with eggs

Peri-anal itch, nervous irritability, hyperactivity and insomnia

Bacterial Infections

Disease and Transmission

Microbial Agent

Sources of Agent in Water Supply

General Symptoms


Clostridium botulinum

Bacteria can enter a wound from contaminated water sources. Can enter the gastrointestinal tract by consuming contaminated drinking water or (more commonly) food

Dry mouth, blurred and/or double vision, difficulty swallowing, muscle weakness, difficulty breathing, slurred speech, vomiting and sometimes diarrhea. Death is usually caused by respiratory failure.


Most commonly caused by Campylobacter jejuni

Drinking water contaminated with feces

Produces dysentery like symptoms along with a high fever. Usually lasts 2–10 days.


Spread by the bacterium Vibrio cholerae

Drinking water contaminated with the bacterium

In severe forms it is known to be one of the most rapidly fatal illnesses known. Symptoms include very watery diarrhoea, nausea, cramps, nosebleed, rapid pulse, vomiting, and hypovolemic shock (in severe cases), at which point death can occur in 12–18 hours.

E. coli Infection

Certain strains of Escherichia coli (commonly E. coli)

Water contaminated with the bacteria

Mostly diarrhea. Can cause death in immunocompromised individuals, the very young, and the elderly due to dehydration from prolonged illness.

M. marinum infection

Mycobacterium marinum

Naturally occurs in water, most cases from exposure in swimming pools or more frequently aquariums; rare infection since it mostly infects immunocompromised individuals

Symptoms include lesions typically located on the elbows, knees, and feet (from swimming pools) or lesions on the hands (aquariums). Lesions may be painless or painful.


Caused by a number of species in the genera Shigella and Salmonella with the most common being Shigella dysenteriae

Water contaminated with the bacterium

Frequent passage of feces with blood and/or mucus and in some cases vomiting of blood.

Legionellosis (two distinct forms: Legionnaires’ disease and Pontiac fever)

Caused by bacteria belonging to genus Legionella (90% of cases caused by Legionella pneumophila)

Contaminated water: the organism thrives in warm aquatic environments.

Pontiac fever produces milder symptoms resembling acute influenza without pneumonia. Legionnaires’ disease has severe symptoms such as fever, chills, pneumonia (with cough that sometimes produces sputum), ataxia, anorexia, muscle aches, malaise and occasionally diarrhea and vomiting


Caused by bacterium of genus Leptospira

Water contaminated by the animal urine carrying the bacteria

Begins with flu-like symptoms then resolves. The second phase then occurs involving meningitis, liver damage (causes jaundice), and renal failure

Otitis Externa (swimmer’s ear)

Caused by a number of bacterial and fungal species.

Swimming in water contaminated by the responsible pathogens

Ear canal swells causing pain and tenderness to the touch


Caused by many bacteria of genus Salmonella

Drinking water contaminated with the bacteria. More common as a food borne illness.

Symptoms include diarrhea, fever, vomiting, and abdominal cramps

Typhoid fever

Salmonella typhi

Ingestion of water contaminated with feces of an infected person

Characterized by sustained fever up to 40°C (104°F), profuse sweating, diarrhea, less commonly a rash may occur. Symptoms progress to delirium and the spleen and liver enlarge if untreated. In this case it can last up to four weeks and cause death.

Vibrio Illness

Vibrio vulnificus, Vibrio alginolyticus, and Vibrio parahaemolyticus

Can enter wounds from contaminated water. Also got by drinking contaminated water or eating undercooked oysters.

Symptoms include explosive, watery diarrhea, nausea, vomiting, abdominal cramps, and occasionally fever.

Viral Infections

Disease and Transmission

Microbial Agent

Sources of Agent in Water Supply

General Symptoms

Adenovirus infection


Manifests itself in improperly treated water

Symptoms include common cold symptoms, pneumonia, croup, and bronchitis


Astrovirus, Calicivirus, Enteric Adenovirus, and Parvovirus

Manifests itself in improperly treated water

Symptoms include diarrhea, nausea, vomiting, fever, malaise, and abdominal pain

SARS (Severe Acute Respiratory Syndrome)


Manifests itself in improperly treated water

Symptoms include fever, myalgia, lethargy, gastrointestinal symptoms, cough, and sore throat

Hepatitis A

Hepatitis A virus (HAV)

Can manifest itself in water (and food)

Symptoms are only acute (no chronic stage to the virus) and include Fatigue, fever, abdominal pain, nausea, diarrhea, weight loss, itching, jaundice and depression.

Poliomyelitis (Polio)


Enters water through the feces of infected individuals

90-95% of patients show no symptoms, 4-8% have minor symptoms (comparatively) with delirium, headache, fever, and occasional seizures, and spastic paralysis, 1% have symptoms of non-paralytic aseptic meningitis. The rest have serious symptoms resulting in paralysis or death

Polyomavirus infection

Two of Polyomavirus: JC virus and BK virus

Very widespread, can manifest itself in water, ~80% of the population has antibodies to Polyomavirus

BK virus produces a mild respiratory infection and can infect the kidneys of immunosuppressed transplant patients. JC virus infects the respiratory system, kidneys or can cause progressive multifocal leukoencephalopathy in the brain (which is fatal).