Waterborne diseases are caused by pathogenic microorganisms that most commonly are transmitted in contaminated fresh water, whether in bathing, washing, drinking, or in the preparation of food. Various forms of diarrheal disease probably are the most prominent examples, and according to the World Health Organization, it accounts for an estimated 4.1% of the total DALY global burden of disease, causing about 1.8 million human deaths annually. The World Health Organization estimates that 88% of that burden is attributable to unsafe water supply, sanitation and hygiene, and is mainly affects children in developing countries.[1]
The term "waterborne disease" generally is reserved for infections that predominantly are transmitted through contact with or consumption of infected water. Trivially, many infections might be transmitted by microbes or parasites that accidentally had got into water, but the fact that there might be an occasional freak infection, does not mean that it is useful to categorise such a disease as "waterborne". Nor is it common practice to refer diseases such as malaria as "waterborne" just because mosquitoes have aquatic phases in their life cycles, or because treating the water they inhabit happens to be an effective strategy in their control.
Microorganisms causing characteristically waterborne diseases include protozoa and bacteria, many of which are intestinal parasites, or invade the tissues or circulatory system through walls of the digestive tract. Various other waterborne diseases are caused by viruses; as a matter of convenience in this connection they might well be regarded as microorganisms. Yet other important classes of water-borne diseases are caused by metazoan parasites. Typical examples include certain Nematoda, that is to say "roundworms", and also certain members of the Schistosomatidae, a family of blood flukes. The latter usually infect victims that make skin contact with the water.
The blood flukes are the pathogens causing Schistosomiasis of various forms, more or less seriously affecting hundreds of millions of people world-wide. As for Nematode infections, one important water-borne nematodal disease is Dracunculiasis. It is acquired by swallowing water in which copepoda occur, that happen to be infected with Nematode larvae in the genus Dracunculus. The larvae cause guinea worm disease.[2]
Even before the establishment of the germ theory of disease, or any advanced understanding of the nature of water as a vehicle for transmitting disease, traditional beliefs cautioned against the consumption of water, rather favouring processed beverages such as beer, wine and tea. In the camel caravans that crossed Central Asia along the Silk Road, the explorer Owen Lattimore noted, "The reason we drank so much tea was because of the bad water. Water alone, unboiled, is never drunk. There is a superstition that it causes blisters on the feet."[3]
Contents |
| 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 |
| Cyclosporiasis | Protozoan parasite (Cyclospora cayetanensis) | Sewage, non-treated drinking water | cramps, nausea, vomiting, muscle aches, fever, and fatigue |
| Giardiasis (fecal-oral) (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 |
| Microsporidiosis | Protozoan phylum (Microsporidia), but closely related to fungi | The genera of Encephalitozoon intestinalis has been detected in groundwater, the origin of drinking water [4] | Diarrhea and wasting in immunocompromised individuals.. |
waterborne diseases are caused by pathogenic microorganisms....
| 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, generally in parasitised Copepoda | Allergic reaction, urticaria rash, nausea, vomiting, diarrhea, asthmatic attack. |
| Taeniasis | Tapeworms of the genus Taenia | Drinking water contaminated with eggs | Intestinal disturbances, neurologic manifestations, loss of weight, cysticercosis |
| Fasciolopsiasis | 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, severe weight loss, 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 |
| coenurosis | multiceps multiceps | contaminated drinking water with eggs | increases intacranial tension |
| Ascariasis | 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. |
| Enterobiasis | Enterobius vermicularis | Drinking water contaminated with eggs | Peri-anal itch, nervous irritability, hyperactivity and insomnia |
| Disease and Transmission | Microbial Agent | Sources of Agent in Water Supply | General Symptoms |
|---|---|---|---|
| Botulism | Clostridium botulinum | Bacteria can enter an open 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. |
| Campylobacteriosis | 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. |
| Cholera | 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 diarrhea, 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. |
| Dysentery | 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 |
| Leptospirosis | 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 |
| Salmonellosis | 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. |
| Disease and Transmission | Microbial Agent | Sources of Agent in Water Supply | General Symptoms |
|---|---|---|---|
| Adenovirus infection | Adenovirus | Manifests itself in improperly treated water | Symptoms include common cold symptoms, pneumonia, croup, and bronchitis |
| Gastroenteritis | 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) | Coronavirus | 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) | Poliovirus | 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). |
Waterborne diseases can have a significant impact on the economy, locally as well as internationally. People who are infected by a waterborne disease are usually confronted with related costs and not seldom with a huge financial burden. This is especially the case in less developed countries. The financial losses are mostly caused by e.g. costs for medical treatment and medication, costs for transport, special food, and by the loss of manpower. Many families must even sell their land to pay for treatment in a proper hospital. On average, a family spends about 10% of the monthly households income per person infected.[8]