Cryptosporidiosis
Encyclopedia
Cryptosporidiosis, also known as crypto, is a parasitic disease
caused by Cryptosporidium, a protozoa
n parasite in the phylum Apicomplexa. It affects the intestine
s of mammal
s and is typically an acute short-term infection. It is spread through the fecal-oral route
, often through contaminated water; the main symptom is self-limiting diarrhea
in people with intact immune systems. In immunocompromised individuals, such as AIDS
patients, the symptoms are particularly severe and often fatal. Cryptosporidium is the organism most commonly isolated in HIV positive patients presenting with diarrhea. Treatment is symptomatic, with fluid rehydration, electrolyte correction and management of any pain. Despite not being identified until 1976, it is one of the most common waterborne diseases and is found worldwide. The parasite is transmitted by environmentally hardy microbial cyst
s (oocysts) that, once ingested, exist in the small intestine
and result in an infection of intestinal epithelial tissue.
n.
of the Phylum Apicomplexa and causes a diarrheal illness called cryptosporidiosis. Other apicomplexan pathogens include the malaria
parasite Plasmodium
, and Toxoplasma, the causative agent of toxoplasmosis
. Unlike Plasmodium, which transmits via a mosquito
vector, Cryptosporidium does not require an insect vector and is capable of completing its life cycle within a single host, resulting in microbial cyst stages which are excreted in feces
and are capable of transmission to a new host. However, studies show that synanthropic filth flies may be involved in the transmission of human and animal cryptosporidiosis.
The pattern of Cryptosporidium life cycle fits well that of other intestinal homogeneous coccidian genera of the suborder Eimeriina: macro- and microgamonts develop independently; a microgamont gives rise to numerous male gametes; and oocysts serving for parasites' spreading in the environment.
Electron microscopic studies made from the 1970s have shown the intracellular, although extracytoplasmic localization of Cryptosporidium species.
These species possess a number of unusual features:
DNA studies suggest a relationship with the gregarines rather than the coccidia. The taxonomic position of this group has not yet been finally agreed upon.
The genome
of Cryptosporidium parvum was sequenced in 2004 and was found to be unusual amongst Eukaryote
s in that the mitochondria seem not to contain DNA
. A closely related species, C. hominis, also has its genome sequence available. CryptoDB.org is a NIH-funded database that provides access to the Cryptosporidium genomics data sets.
A number of Cryptosporidium infect mammals. In humans, the main causes of disease are C. parvum and C. hominis (previously C. parvum genotype 1). C. canis, C. felis, C. meleagridis, and C. muris can also cause disease in humans.
Cryptosporidiosis is typically an acute short-term infection but can become severe and non-resolving in children and immunocompromised individuals. In humans, it remains in the lower intestine and may remain for up to five weeks. The parasite is transmitted by environmentally hardy microbial cysts (oocysts) that, once ingested, exist in the small intestine and result in an infection of intestinal epithelial tissue.
is through contaminated material such as earth, water
, uncooked or cross-contaminated food
that has been in contact with the feces of an infected individual or animal
. Contact must then be transferred to the mouth and swallowed. It is especially prevalent amongst those in regular contact with bodies of fresh water including recreational water such as swimming pools. Other potential sources include insufficiently treated water supplies, contaminated food, or exposure to feces. The high resistance of Cryptosporidium oocysts to disinfectants such as chlorine
bleach
enables them to survive for long periods and still remain infective. Some outbreaks have happened in day care related to diaper changes.
s appear from two to ten days after infection, with an average of 7 days, and last for up to two weeks, or in some cases, up to one month. There are 3 possible forms of the illness in immunocompetent people. The disease can be asymptomatic or cause acute diarrhea or persistent diarrhea that can last for a few weeks. Diarrhea is usually watery with mucus. It is very rare to find blood or leukocytes in the diarrhea. As well as watery diarrhea, there is often stomach
pains or cramp
s and a low fever
. Other symptoms include nausea, vomiting, malabsorption and dehydration. The individuals who are asymptomatic
(have no symptoms) are nevertheless infective, and thus can pass on the infection to others. Even after symptoms have finally subsided an individual is still infective for some weeks.
Severe diseases, including pancreatitis
, can occur.
Immunocompromised people, as well as very young or very old people, can develop a more severe form of cryptosporidiosis. There are 4 clinical presentations for patients with AIDS. 4% have no symptoms, 29% have a transient infection, 60% have chronic diarrhea, and 8% have a severe, cholera-like infection. With transient infections diarrhea ends within 2 months and Cryptosporidium is no longer found in the feces. Chronic diarrhea is diarrhea that lasts for 2 or more months. The most severe form results in the patients excreting at least 2 liters of watery diarrhea per day. They can lose up to 25 liters per day. AIDS patients can have up to 10 stools per day. They experience severe malabsorption and can have 10% weight loss. Many of them never completely eliminate Cryptosporidium from their bodies.
When Cryptosporidium spreads beyond the intestine, as it can predominantly in patients with AIDS, it can reach the lungs, middle ear, pancreas, and stomach. Thus, one symptom is pain in the right upper quadrant. The parasite can infect the biliary tract, causing biliary cryptosporidiosis. This can result in cholecystitis and cholangitis.
Cryptosporidium has a spore
phase (oocyst) and in this state it can survive for lengthy periods outside a host. It can also resist many common disinfectants, notably chlorine-based disinfectants.
The life cycle of Cryptosporidium parvum consists of an asexual stage and a sexual stage. After being ingested, the oocysts excyst in the small intestine. They release sporozoites that attach to the microvilli of the epithelial cells of the small intestine. From there they become trophozoites that reproduce asexually by multiple fission, a process known as schizogony. The trophozoites develop into Type 1 meronts [1] that contain 8 daughter cells. These daughter cells are Type 1 merozoites, which get released by the meronts. Some of these merozoites can cause autoinfection by attaching to epithelial cells. Others of these merozoites become Type II meronts, which contain 4 Type II merozoites. These merozoites get released and they attach to the epithelial cells. From there they become either macrogamonts or microgamonts. These are the female and male sexual forms, respectively. This stage, when sexual forms arise, is called gametogony. Zygotes are formed by microgametes from the microgamont penetrating the macrogamonts. The zygotes develop into oocysts of two types. 20% of oocysts have thin walls and so can reinfect the host by rupturing and releasing sporozoites that start the process over again. The thick-walled oocysts are excreted into the environment. The oocysts are mature and infective upon being excreted. They can survive in the environment for months.
As few as 2 to 10 oocysts can initiate an infection. The parasite is located in the brush border of the epithelial cells of the small intestine. They are mainly located in the jejunum. When the sporozoites attach the epithelial cells’ membrane envelops them. Thus, they are “intracellular but extracytoplasmic”. The parasite can cause damage to the microvilli where it attaches. The infected human excretes the most oocysts during the first week. Oocysts can be excreted for weeks after the diarrhea subsides.
The immune system reduces the formation of Type 1 merozoites as well as the number of thin-walled oocysts. This helps prevent autoinfection. B cells do not help with the initial response or the fight to eliminate the parasite.
Other staining techniques include acid-fast staining, which will stain the oocysts red. One type of acid-fast stain is the Kinyoun technique. Giemsa staining can also be performed. Part of the small intestine can be stained with hematoxylin and eosin (H & E), which will show oocysts attached to the epithelial cells.
Detecting antigens is yet another way to diagnose the disease. This can be done with direct fluorescent antibody (DFA) techniques. It can also be achieved through indirect immunofluorescence assay. Enzyme-Linked ImmunoSorbent Assay (ELISA) also detects antigens.
Polymerase chain reaction (PCR) is another way to diagnose cryptosporidiosis. It can even identify the specific species of Cryptosporidium. If the patient is thought to have biliary cryptosporidiosis, then an appropriate diagnostic technique is ultrasonography. If that returns normal results, the next step would be to perform endoscopic retrograde cholangiopancreatography.
, nitazoxanide
, and azithromycin
are sometimes used, but they usually have only temporary effects.
Treatment is primarily supportive. Fluids need to be replaced orally. A lactose-free diet should be taken as tolerated. In rare situations, intravenous fluids may be required. Antibiotics are not usually helpful, and are primarily reserved for persons with severe disease and a weak immune system. Sometimes relapses happen.
Currently, the best approach is to improve the immune status in immunodeficient individuals, which causes the diarrhea resolve for itself in most of the cases. Biliar drainage may be needed in case the biliary tract is affected.
Currently, research is being done in molecular-based immunotherapy. For example, synthetic isoflavone derivates have been shown to fight off Cryptosporidium parvum in vitro and in a gerbil. Derivates of nitazoxanide, which are synthetic nitro- or nonnitrothiazolide compounds, have also shown promising results in vitro.
that take raw water from river
s, lake
s, and reservoirs for public drinking water
production use conventional filtration technologies. This involves a series of processes, including coagulation, flocculation, sedimentation, and filtration. Direct filtration, which is typically used to treat water with low particulate levels, includes coagulation and filtration, but not sedimentation. Other common filtration processes, including slow sand filter
s, diatomaceous earth filter
s and membranes will remove 99% of Cryptosporidium. Membranes and bag and cartridge filters remove Cryptosporidium product-specifically.
While Cryptosporidium is highly resistant to chlorine disinfection, with high enough concentrations and contact time, Cryptosporidium will be inactivated by chlorine dioxide and ozone treatment. The required levels of chlorine generally preclude the use of chlorine disinfection as a reliable method to control Cryptosporidium in drinking water. Ultraviolet light treatment at relatively low doses will inactivate Cryptosporidium. Water Research Foundation-funded research originally discovered UV's efficacy in inactivating Cryptosporidium.
One of the largest challenges in identifying outbreaks is the ability to identify Cryptosporidium in the laboratory
. Real-time monitoring technology is now able to detect Cryptosporidium with online systems, unlike the spot and batch testing methods used in the past.
The most reliable way to decontaminate drinking water which may be contaminated by Cryptosporidium is to boil it.
, sheep and goat
s. Additionally, in recent years, cryptosporidiosis has plagued many commercial leopard gecko
breeders. Several species of the Cryptosporidium family (C. serpentes and others) are involved, and outside of geckos it has been found in monitor lizards, iguanas and tortoises, as well as several snake species.
The following groups have an elevated risk of being exposed to Cryptosporidium:
Cases of cryptosporidiosis can occur in a city that does not have a contaminated water supply. In a city with clean water, it may be that cases of cryptosporidiosis have different origins. Testing of water, as well as epidemiological study, are necessary to determine the sources of specific infections. Note that Cryptosporidium typically does not cause serious illness in healthy people. It may chronically sicken some children, as well as adults who are exposed and immunocompromised. A subset of the immunocompromised population is people with AIDS. Some sexual behaviours can transmit the parasite directly.
Statistics for the United States - number of cases:
, and before eating. People should avoid contact with animal feces. They should also avoid possibly contaminated food and water. Additionally, people should refrain from engaging in sexual activities that can expose them to feces.
Standard water filtration may not be enough to eliminate Cryptosporidium; boiling for at least 1 minute (3 minutes above 6500 feet (1,981.2 m) of altitude) will decontaminate it. Heating milk at 71.7 °C for 15 seconds pasteurizes it and can destroy the oocysts' ability to infect. Water can also be made safe by filtering with a filter with pore size not greater than 1 micrometre, or by filters that have been approved for “cyst removal” by the US National Science Foundation
(NSF). Bottled drinking water is less likely to contain Cryptosporidium, especially if the water is from an underground source.
People who have cryptosporidiosis should not swim in communal areas because the pathogen can reside in the anal and genital areas and be washed off. They should wait until at least two weeks after diarrhea stops before entering public water sources, since oocysts can still be shed for a while. Also, they should stay away from immunosuppressed people. Immunocompromised people should take care to protect themselves from water in lakes and streams. They should also stay away from animal stools and wash their hands after touching animals. To be safe, they should boil or filter their water. They should also wash and cook their vegetables.
Parasitic disease
A parasitic disease is an infectious disease caused or transmitted by a parasite. Many parasites do not cause diseases. Parasitic diseases can affect practically all living organisms, including plants and mammals...
caused by Cryptosporidium, a protozoa
Protozoa
Protozoa are a diverse group of single-cells eukaryotic organisms, many of which are motile. Throughout history, protozoa have been defined as single-cell protists with animal-like behavior, e.g., movement...
n parasite in the phylum Apicomplexa. It affects the intestine
Intestine
In human anatomy, the intestine is the segment of the alimentary canal extending from the pyloric sphincter of the stomach to the anus and, in humans and other mammals, consists of two segments, the small intestine and the large intestine...
s of mammal
Mammal
Mammals are members of a class of air-breathing vertebrate animals characterised by the possession of endothermy, hair, three middle ear bones, and mammary glands functional in mothers with young...
s and is typically an acute short-term infection. It is spread through the fecal-oral route
Fecal-oral route
The fecal-oral route, or alternatively, the oral-fecal route or orofecal route is a route of transmission of diseases, in which they are passed when pathogens in fecal particles from one host are introduced into the oral cavity of another potential host.There are usually intermediate steps,...
, often through contaminated water; the main symptom is self-limiting diarrhea
Diarrhea
Diarrhea , also spelled diarrhoea, is the condition of having three or more loose or liquid bowel movements per day. It is a common cause of death in developing countries and the second most common cause of infant deaths worldwide. The loss of fluids through diarrhea can cause dehydration and...
in people with intact immune systems. In immunocompromised individuals, such as AIDS
AIDS
Acquired immune deficiency syndrome or acquired immunodeficiency syndrome is a disease of the human immune system caused by the human immunodeficiency virus...
patients, the symptoms are particularly severe and often fatal. Cryptosporidium is the organism most commonly isolated in HIV positive patients presenting with diarrhea. Treatment is symptomatic, with fluid rehydration, electrolyte correction and management of any pain. Despite not being identified until 1976, it is one of the most common waterborne diseases and is found worldwide. The parasite is transmitted by environmentally hardy microbial cyst
Microbial cyst
A microbial cyst is a resting or dormant stage of a microorganism, usually a bacterium or a protist, that helps the organism to survive in unfavorable environmental conditions. It can be thought of as a state of suspended animation in which the metabolic processes of the cell are slowed down and...
s (oocysts) that, once ingested, exist in the small intestine
Small intestine
The small intestine is the part of the gastrointestinal tract following the stomach and followed by the large intestine, and is where much of the digestion and absorption of food takes place. In invertebrates such as worms, the terms "gastrointestinal tract" and "large intestine" are often used to...
and result in an infection of intestinal epithelial tissue.
History
The organism was first described in 1907 by Tyzzer, who recognised it was a coccidiaCoccidia
Coccidia is a subclass of microscopic, spore-forming, single-celled obligate parasites belonging to the apicomplexan class Conoidasida. Coccidian parasites infect the intestinal tracts of animals, and are the largest group of apicomplexan protozoa....
n.
General characteristics of Cryptosporidium
Cryptosporidium is a protozoan pathogenPathogen
A pathogen gignomai "I give birth to") or infectious agent — colloquially, a germ — is a microbe or microorganism such as a virus, bacterium, prion, or fungus that causes disease in its animal or plant host...
of the Phylum Apicomplexa and causes a diarrheal illness called cryptosporidiosis. Other apicomplexan pathogens include the malaria
Malaria
Malaria is a mosquito-borne infectious disease of humans and other animals caused by eukaryotic protists of the genus Plasmodium. The disease results from the multiplication of Plasmodium parasites within red blood cells, causing symptoms that typically include fever and headache, in severe cases...
parasite Plasmodium
Plasmodium
Plasmodium is a genus of parasitic protists. Infection by these organisms is known as malaria. The genus Plasmodium was described in 1885 by Ettore Marchiafava and Angelo Celli. Currently over 200 species of this genus are recognized and new species continue to be described.Of the over 200 known...
, and Toxoplasma, the causative agent of toxoplasmosis
Toxoplasmosis
Toxoplasmosis is a parasitic disease caused by the protozoan Toxoplasma gondii. The parasite infects most genera of warm-blooded animals, including humans, but the primary host is the felid family. Animals are infected by eating infected meat, by ingestion of feces of a cat that has itself...
. Unlike Plasmodium, which transmits via a mosquito
Mosquito
Mosquitoes are members of a family of nematocerid flies: the Culicidae . The word Mosquito is from the Spanish and Portuguese for little fly...
vector, Cryptosporidium does not require an insect vector and is capable of completing its life cycle within a single host, resulting in microbial cyst stages which are excreted in feces
Feces
Feces, faeces, or fæces is a waste product from an animal's digestive tract expelled through the anus or cloaca during defecation.-Etymology:...
and are capable of transmission to a new host. However, studies show that synanthropic filth flies may be involved in the transmission of human and animal cryptosporidiosis.
The pattern of Cryptosporidium life cycle fits well that of other intestinal homogeneous coccidian genera of the suborder Eimeriina: macro- and microgamonts develop independently; a microgamont gives rise to numerous male gametes; and oocysts serving for parasites' spreading in the environment.
Electron microscopic studies made from the 1970s have shown the intracellular, although extracytoplasmic localization of Cryptosporidium species.
These species possess a number of unusual features:
- an endogenous phase of development in microvilli of epithelial surfaces
- two morphofunctional types of oocysts
- the smallest number of sporozoites per oocyst
- a multi-membraneous "feeder" organelle
DNA studies suggest a relationship with the gregarines rather than the coccidia. The taxonomic position of this group has not yet been finally agreed upon.
The genome
Genome
In modern molecular biology and genetics, the genome is the entirety of an organism's hereditary information. It is encoded either in DNA or, for many types of virus, in RNA. The genome includes both the genes and the non-coding sequences of the DNA/RNA....
of Cryptosporidium parvum was sequenced in 2004 and was found to be unusual amongst Eukaryote
Eukaryote
A eukaryote is an organism whose cells contain complex structures enclosed within membranes. Eukaryotes may more formally be referred to as the taxon Eukarya or Eukaryota. The defining membrane-bound structure that sets eukaryotic cells apart from prokaryotic cells is the nucleus, or nuclear...
s in that the mitochondria seem not to contain DNA
Mitochondrial DNA
Mitochondrial DNA is the DNA located in organelles called mitochondria, structures within eukaryotic cells that convert the chemical energy from food into a form that cells can use, adenosine triphosphate...
. A closely related species, C. hominis, also has its genome sequence available. CryptoDB.org is a NIH-funded database that provides access to the Cryptosporidium genomics data sets.
A number of Cryptosporidium infect mammals. In humans, the main causes of disease are C. parvum and C. hominis (previously C. parvum genotype 1). C. canis, C. felis, C. meleagridis, and C. muris can also cause disease in humans.
Cryptosporidiosis is typically an acute short-term infection but can become severe and non-resolving in children and immunocompromised individuals. In humans, it remains in the lower intestine and may remain for up to five weeks. The parasite is transmitted by environmentally hardy microbial cysts (oocysts) that, once ingested, exist in the small intestine and result in an infection of intestinal epithelial tissue.
Transmission
InfectionInfection
An infection is the colonization of a host organism by parasite species. Infecting parasites seek to use the host's resources to reproduce, often resulting in disease...
is through contaminated material such as earth, water
Water
Water is a chemical substance with the chemical formula H2O. A water molecule contains one oxygen and two hydrogen atoms connected by covalent bonds. Water is a liquid at ambient conditions, but it often co-exists on Earth with its solid state, ice, and gaseous state . Water also exists in a...
, uncooked or cross-contaminated food
Food
Food is any substance consumed to provide nutritional support for the body. It is usually of plant or animal origin, and contains essential nutrients, such as carbohydrates, fats, proteins, vitamins, or minerals...
that has been in contact with the feces of an infected individual or animal
Animal
Animals are a major group of multicellular, eukaryotic organisms of the kingdom Animalia or Metazoa. Their body plan eventually becomes fixed as they develop, although some undergo a process of metamorphosis later on in their life. Most animals are motile, meaning they can move spontaneously and...
. Contact must then be transferred to the mouth and swallowed. It is especially prevalent amongst those in regular contact with bodies of fresh water including recreational water such as swimming pools. Other potential sources include insufficiently treated water supplies, contaminated food, or exposure to feces. The high resistance of Cryptosporidium oocysts to disinfectants such as chlorine
Chlorine
Chlorine is the chemical element with atomic number 17 and symbol Cl. It is the second lightest halogen, found in the periodic table in group 17. The element forms diatomic molecules under standard conditions, called dichlorine...
bleach
Bleach
Bleach refers to a number of chemicals that remove color, whiten, or disinfect, often via oxidation. Common chemical bleaches include household chlorine bleach , lye, oxygen bleach , and bleaching powder...
enables them to survive for long periods and still remain infective. Some outbreaks have happened in day care related to diaper changes.
Symptoms
SymptomSymptom
A symptom is a departure from normal function or feeling which is noticed by a patient, indicating the presence of disease or abnormality...
s appear from two to ten days after infection, with an average of 7 days, and last for up to two weeks, or in some cases, up to one month. There are 3 possible forms of the illness in immunocompetent people. The disease can be asymptomatic or cause acute diarrhea or persistent diarrhea that can last for a few weeks. Diarrhea is usually watery with mucus. It is very rare to find blood or leukocytes in the diarrhea. As well as watery diarrhea, there is often stomach
Stomach
The stomach is a muscular, hollow, dilated part of the alimentary canal which functions as an important organ of the digestive tract in some animals, including vertebrates, echinoderms, insects , and molluscs. It is involved in the second phase of digestion, following mastication .The stomach is...
pains or cramp
Cramp
Cramps are unpleasant, often painful sensations caused by muscle contraction or over shortening. Common causes of skeletal muscle cramps include muscle fatigue, low sodium, and low potassium...
s and a low fever
Fever
Fever is a common medical sign characterized by an elevation of temperature above the normal range of due to an increase in the body temperature regulatory set-point. This increase in set-point triggers increased muscle tone and shivering.As a person's temperature increases, there is, in...
. Other symptoms include nausea, vomiting, malabsorption and dehydration. The individuals who are asymptomatic
Asymptomatic
In medicine, a disease is considered asymptomatic if a patient is a carrier for a disease or infection but experiences no symptoms. A condition might be asymptomatic if it fails to show the noticeable symptoms with which it is usually associated. Asymptomatic infections are also called subclinical...
(have no symptoms) are nevertheless infective, and thus can pass on the infection to others. Even after symptoms have finally subsided an individual is still infective for some weeks.
Severe diseases, including pancreatitis
Pancreatitis
Pancreatitis is inflammation of the pancreas. It occurs when pancreatic enzymes that digest food are activated in the pancreas instead of the small intestine. It may be acute – beginning suddenly and lasting a few days, or chronic – occurring over many years...
, can occur.
Immunocompromised people, as well as very young or very old people, can develop a more severe form of cryptosporidiosis. There are 4 clinical presentations for patients with AIDS. 4% have no symptoms, 29% have a transient infection, 60% have chronic diarrhea, and 8% have a severe, cholera-like infection. With transient infections diarrhea ends within 2 months and Cryptosporidium is no longer found in the feces. Chronic diarrhea is diarrhea that lasts for 2 or more months. The most severe form results in the patients excreting at least 2 liters of watery diarrhea per day. They can lose up to 25 liters per day. AIDS patients can have up to 10 stools per day. They experience severe malabsorption and can have 10% weight loss. Many of them never completely eliminate Cryptosporidium from their bodies.
When Cryptosporidium spreads beyond the intestine, as it can predominantly in patients with AIDS, it can reach the lungs, middle ear, pancreas, and stomach. Thus, one symptom is pain in the right upper quadrant. The parasite can infect the biliary tract, causing biliary cryptosporidiosis. This can result in cholecystitis and cholangitis.
Life cycle
Spore
In biology, a spore is a reproductive structure that is adapted for dispersal and surviving for extended periods of time in unfavorable conditions. Spores form part of the life cycles of many bacteria, plants, algae, fungi and some protozoa. According to scientist Dr...
phase (oocyst) and in this state it can survive for lengthy periods outside a host. It can also resist many common disinfectants, notably chlorine-based disinfectants.
The life cycle of Cryptosporidium parvum consists of an asexual stage and a sexual stage. After being ingested, the oocysts excyst in the small intestine. They release sporozoites that attach to the microvilli of the epithelial cells of the small intestine. From there they become trophozoites that reproduce asexually by multiple fission, a process known as schizogony. The trophozoites develop into Type 1 meronts [1] that contain 8 daughter cells. These daughter cells are Type 1 merozoites, which get released by the meronts. Some of these merozoites can cause autoinfection by attaching to epithelial cells. Others of these merozoites become Type II meronts, which contain 4 Type II merozoites. These merozoites get released and they attach to the epithelial cells. From there they become either macrogamonts or microgamonts. These are the female and male sexual forms, respectively. This stage, when sexual forms arise, is called gametogony. Zygotes are formed by microgametes from the microgamont penetrating the macrogamonts. The zygotes develop into oocysts of two types. 20% of oocysts have thin walls and so can reinfect the host by rupturing and releasing sporozoites that start the process over again. The thick-walled oocysts are excreted into the environment. The oocysts are mature and infective upon being excreted. They can survive in the environment for months.
Pathogenesis
The oocysts are ovoid or spherical and measure 5 to 6 micrometers across. When in flotation preparations they appear highly refractile. The oocysts contains up to 4 sporozoites that are bow-shaped.As few as 2 to 10 oocysts can initiate an infection. The parasite is located in the brush border of the epithelial cells of the small intestine. They are mainly located in the jejunum. When the sporozoites attach the epithelial cells’ membrane envelops them. Thus, they are “intracellular but extracytoplasmic”. The parasite can cause damage to the microvilli where it attaches. The infected human excretes the most oocysts during the first week. Oocysts can be excreted for weeks after the diarrhea subsides.
The immune system reduces the formation of Type 1 merozoites as well as the number of thin-walled oocysts. This helps prevent autoinfection. B cells do not help with the initial response or the fight to eliminate the parasite.
Diagnostic tests
There are many diagnostic tests for Cryptosporidium. They include microscopy, staining, and detection of antibodies. Microscopy can help identify oocysts in fecal matter. To increase the chance of finding the oocysts, the diagnostician should inspect at least 3 stool samples. There are several techniques to concentrate either the stool sample or the oocysts. The modified formalin-ethyl acetate (FEA) concentration method concentrates the stool. Both the modified zinc sulfate centrifugal flotation technique and the Sheather’s sugar flotation procedure can concentrate the oocysts by causing them to float. Another form of microscopy is fluorescent microscopy done by staining with auramine.Other staining techniques include acid-fast staining, which will stain the oocysts red. One type of acid-fast stain is the Kinyoun technique. Giemsa staining can also be performed. Part of the small intestine can be stained with hematoxylin and eosin (H & E), which will show oocysts attached to the epithelial cells.
Detecting antigens is yet another way to diagnose the disease. This can be done with direct fluorescent antibody (DFA) techniques. It can also be achieved through indirect immunofluorescence assay. Enzyme-Linked ImmunoSorbent Assay (ELISA) also detects antigens.
Polymerase chain reaction (PCR) is another way to diagnose cryptosporidiosis. It can even identify the specific species of Cryptosporidium. If the patient is thought to have biliary cryptosporidiosis, then an appropriate diagnostic technique is ultrasonography. If that returns normal results, the next step would be to perform endoscopic retrograde cholangiopancreatography.
Treatment
There is no reliable treatment for cryptosporidium enteritis; certain agents such as paromomycin, atovaquoneAtovaquone
Atovaquone is a chemical compound that belongs to the class of naphthalenes. Atovaquone is a hydroxy-1,4-naphthoquinone, an analog of ubiquinone, with antipneumocystic activity. Its average wholesale price is about US$2.13 per standard 250 mg. tablet...
, nitazoxanide
Nitazoxanide
Nitazoxanide, also known by the brand names Alinia and Annita is a synthetic nitrothiazolyl-salicylamide derivative and an antiprotozoal agent.Nitazoxanide is a light yellow...
, and azithromycin
Azithromycin
Azithromycin is an azalide, a subclass of macrolide antibiotics. Azithromycin is one of the world's best-selling antibiotics...
are sometimes used, but they usually have only temporary effects.
Treatment is primarily supportive. Fluids need to be replaced orally. A lactose-free diet should be taken as tolerated. In rare situations, intravenous fluids may be required. Antibiotics are not usually helpful, and are primarily reserved for persons with severe disease and a weak immune system. Sometimes relapses happen.
In the immunocompetent
The majority of immunocompetent individuals suffer a short (less than 2 weeks) self-limiting course that requires supportive care with rehydration and occasionally antidiarrhoeal medication, and ends with spontaneous recovery. Nitazoxanide is one drug that the US FDA has approved for use in immunocompetent people to combat diarrhea. Spiramycin can help shorten the amount of time oocysts are passed, as well as the duration of diarrhoea in children.In the immunocompromised
In immunocompromised individuals, such as AIDS patients, cryptosporidiosis resolves slowly or not at all, and frequently causes a particularly severe and permanent form of watery diarrhea coupled with a greatly decreased ability to absorb key nutrients through the intestinal tract. The result is progressively severe dehydration, electrolyte imbalances, malnutrition, wasting, and eventual death. Spiramycin can help treat diarrhea in patients who are in the early stages of AIDS. The mortality rate for infected AIDS patients is generally based on CD4+ marker counts; patients with CD4+ counts over 180 cells/mm³ generally recover with supportive hospital care and medication, but in patients with CD4+ counts below 50 cells/mm³, the effects are usually fatal within three to six months. During the Milwaukee cryptosporidiosis epidemic (the largest of its kind), 73% of AIDS patients with CD4+ counts lower than 50 cells/mm³ and 36% of those with counts between 50 and 200 cells/mm³ died within the first year of contracting the infection. In one AIDS patient from Iran, who had pulmonary cryptosporidiosis in addition to intestinal cryptosporidiosis, azithromycin and paromomycin helped to clear the infection.Currently, the best approach is to improve the immune status in immunodeficient individuals, which causes the diarrhea resolve for itself in most of the cases. Biliar drainage may be needed in case the biliary tract is affected.
Currently, research is being done in molecular-based immunotherapy. For example, synthetic isoflavone derivates have been shown to fight off Cryptosporidium parvum in vitro and in a gerbil. Derivates of nitazoxanide, which are synthetic nitro- or nonnitrothiazolide compounds, have also shown promising results in vitro.
Treatment of drinking water
Many treatment plantsWater purification
Water purification is the process of removing undesirable chemicals, materials, and biological contaminants from contaminated water. The goal is to produce water fit for a specific purpose...
that take raw water from river
River
A river is a natural watercourse, usually freshwater, flowing towards an ocean, a lake, a sea, or another river. In a few cases, a river simply flows into the ground or dries up completely before reaching another body of water. Small rivers may also be called by several other names, including...
s, lake
Lake
A lake is a body of relatively still fresh or salt water of considerable size, localized in a basin, that is surrounded by land. Lakes are inland and not part of the ocean and therefore are distinct from lagoons, and are larger and deeper than ponds. Lakes can be contrasted with rivers or streams,...
s, and reservoirs for public drinking water
Drinking water
Drinking water or potable water is water pure enough to be consumed or used with low risk of immediate or long term harm. In most developed countries, the water supplied to households, commerce and industry is all of drinking water standard, even though only a very small proportion is actually...
production use conventional filtration technologies. This involves a series of processes, including coagulation, flocculation, sedimentation, and filtration. Direct filtration, which is typically used to treat water with low particulate levels, includes coagulation and filtration, but not sedimentation. Other common filtration processes, including slow sand filter
Slow sand filter
Slow sand filters are used in water purification for treating raw water to produce a potable product. They are typically 1 to 2 metres deep, can be rectangular or cylindrical in cross section and are used primarily to treat surface water...
s, diatomaceous earth filter
Diatomaceous earth
Diatomaceous earth also known as diatomite or kieselgur/kieselguhr, is a naturally occurring, soft, siliceous sedimentary rock that is easily crumbled into a fine white to off-white powder. It has a particle size ranging from less than 1 micrometre to more than 1 millimetre, but typically 10 to...
s and membranes will remove 99% of Cryptosporidium. Membranes and bag and cartridge filters remove Cryptosporidium product-specifically.
While Cryptosporidium is highly resistant to chlorine disinfection, with high enough concentrations and contact time, Cryptosporidium will be inactivated by chlorine dioxide and ozone treatment. The required levels of chlorine generally preclude the use of chlorine disinfection as a reliable method to control Cryptosporidium in drinking water. Ultraviolet light treatment at relatively low doses will inactivate Cryptosporidium. Water Research Foundation-funded research originally discovered UV's efficacy in inactivating Cryptosporidium.
One of the largest challenges in identifying outbreaks is the ability to identify Cryptosporidium in the laboratory
Laboratory
A laboratory is a facility that provides controlled conditions in which scientific research, experiments, and measurement may be performed. The title of laboratory is also used for certain other facilities where the processes or equipment used are similar to those in scientific laboratories...
. Real-time monitoring technology is now able to detect Cryptosporidium with online systems, unlike the spot and batch testing methods used in the past.
The most reliable way to decontaminate drinking water which may be contaminated by Cryptosporidium is to boil it.
Non-human examples
The most important zoonotic reservoirs are cattleCattle
Cattle are the most common type of large domesticated ungulates. They are a prominent modern member of the subfamily Bovinae, are the most widespread species of the genus Bos, and are most commonly classified collectively as Bos primigenius...
, sheep and goat
Goat
The domestic goat is a subspecies of goat domesticated from the wild goat of southwest Asia and Eastern Europe. The goat is a member of the Bovidae family and is closely related to the sheep as both are in the goat-antelope subfamily Caprinae. There are over three hundred distinct breeds of...
s. Additionally, in recent years, cryptosporidiosis has plagued many commercial leopard gecko
Leopard gecko
The leopard gecko is a nocturnal ground-dwelling lizard naturally found in the deserts of southern Central Asia, and throughout Pakistan, to the northwestern parts of India. Unlike most geckos, leopard geckos possess movable eyelids...
breeders. Several species of the Cryptosporidium family (C. serpentes and others) are involved, and outside of geckos it has been found in monitor lizards, iguanas and tortoises, as well as several snake species.
Exposure risks
Cryptosporidiosis is found worldwide. It causes 50.8% of water-borne diseases that are attributed to parasites. In developing countries, 8-19% of diarrheal diseases can be attributed to Cryptosporidium. Ten percent of the population in developing countries excretes oocysts. In developed countries, the number is lower at 1-3%. The age group most affected is children from 1 to 9 years old.The following groups have an elevated risk of being exposed to Cryptosporidium:
- People who swim regularly in pools with insufficient sanitation (certain strains of Cryptosporidium are chlorine-resistant)
- Child care workers
- Parents of infected children
- People who take care of other people with cryptosporidiosis
- International travelers
- Backpackers, hikers, and campers who drink unfiltered, untreated water
- People, including swimmers, who swallow water from contaminated sources
- People who handle infected cattle
- People exposed to human feces through sexual contact
Cases of cryptosporidiosis can occur in a city that does not have a contaminated water supply. In a city with clean water, it may be that cases of cryptosporidiosis have different origins. Testing of water, as well as epidemiological study, are necessary to determine the sources of specific infections. Note that Cryptosporidium typically does not cause serious illness in healthy people. It may chronically sicken some children, as well as adults who are exposed and immunocompromised. A subset of the immunocompromised population is people with AIDS. Some sexual behaviours can transmit the parasite directly.
Statistics for the United States - number of cases:
| Year | Cases |
|---|---|
| 2006 | 5,936 |
| 2007 | 11,170 |
| 2008 | 7,749 |
Public health and prevention strategies
In the US the law requires doctors and labs to report cases of cryptosporidiosis to local or state health departments. These departments then report to the Center for Disease Control and Prevention. The best way to prevent getting and spreading cryptosporidiosis is to have good hygiene and sanitation. An example would be hand-washing. Prevention is through washing hands carefully after going to the bathroom or contacting stoolFeces
Feces, faeces, or fæces is a waste product from an animal's digestive tract expelled through the anus or cloaca during defecation.-Etymology:...
, and before eating. People should avoid contact with animal feces. They should also avoid possibly contaminated food and water. Additionally, people should refrain from engaging in sexual activities that can expose them to feces.
Standard water filtration may not be enough to eliminate Cryptosporidium; boiling for at least 1 minute (3 minutes above 6500 feet (1,981.2 m) of altitude) will decontaminate it. Heating milk at 71.7 °C for 15 seconds pasteurizes it and can destroy the oocysts' ability to infect. Water can also be made safe by filtering with a filter with pore size not greater than 1 micrometre, or by filters that have been approved for “cyst removal” by the US National Science Foundation
National Science Foundation
The National Science Foundation is a United States government agency that supports fundamental research and education in all the non-medical fields of science and engineering. Its medical counterpart is the National Institutes of Health...
(NSF). Bottled drinking water is less likely to contain Cryptosporidium, especially if the water is from an underground source.
People who have cryptosporidiosis should not swim in communal areas because the pathogen can reside in the anal and genital areas and be washed off. They should wait until at least two weeks after diarrhea stops before entering public water sources, since oocysts can still be shed for a while. Also, they should stay away from immunosuppressed people. Immunocompromised people should take care to protect themselves from water in lakes and streams. They should also stay away from animal stools and wash their hands after touching animals. To be safe, they should boil or filter their water. They should also wash and cook their vegetables.
Notable cases
- In 1987, 13,000 people in Carrollton, Georgia, became ill with cryptosporidiosis. This was the first report of its spread through a municipal water system that met all state and federal drinking water standards.
- In 1993, a waterborne cryptosporidiosis outbreakMilwaukee Cryptosporidium outbreakThe 1993 Milwaukee Cryptosporidium outbreak was a significant distribution of the Cryptosporidium protozoan in Milwaukee, Wisconsin, and the largest waterborne disease outbreak in documented United States history. The Howard Avenue Water Purification Plant was contaminated, and treated water...
occurred in Milwaukee, Wisconsin, USA. An estimated 403,000 people became ill, including 4,400 people hospitalized. An estimated 69 people died during the outbreak, according to the CDC.
- The UK's biggest outbreak occurred in TorbayTorbayTorbay is an east-facing bay and natural harbour, at the western most end of Lyme Bay in the south-west of England, situated roughly midway between the cities of Exeter and Plymouth. Part of the ceremonial county of Devon, Torbay was made a unitary authority on 1 April 1998...
in DevonDevonDevon is a large county in southwestern England. The county is sometimes referred to as Devonshire, although the term is rarely used inside the county itself as the county has never been officially "shired", it often indicates a traditional or historical context.The county shares borders with...
in 1995.
- In the summer of 1996, Cryptosporidium affected approximately 2,000 people in Cranbrook, British ColumbiaCranbrook, British ColumbiaCranbrook, British Columbia is a city in southeast British Columbia, located on the west side of the Kootenay River at its confluence with the St. Mary's River, It is the largest urban centre in the region known as the East Kootenay. As of 2006, Cranbrook's population is 18,267, and the...
, CanadaCanadaCanada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
. Weeks later, a separate incident occurred in Kelowna, British ColumbiaKelowna, British ColumbiaKelowna is a city on Okanagan Lake in the Okanagan Valley, in the southern interior of British Columbia, Canada. Its name derives from a Okanagan language term for "grizzly bear"...
, where 10,000 to 15,000 people got sick.
- In April 2001, an outbreak occurred in the city of North Battleford, SaskatchewanNorth Battleford, SaskatchewanIn the late 2000s a large number of Ruthenians have emigrated to Canada, concentrating in North Battleford.-History:Prior to European settlement, the Battlefords area was home to several aboriginal groups...
, Canada. Between 5800 and 7100 people suffered from diarrheal illness, and 1907 cases of cryptosporidiosis were confirmed. Equipment failures at the city's antiquated water filtration plant following maintenance were found to have caused the outbreak.
- In the summer of 2005, after numerous reports by patrons of gastrointestinal upset, a water park at Seneca Lake State ParkSeneca Lake State ParkSeneca Lake State Park is located in Seneca County, New York in the USA. The park is at the north end of Seneca Lake, one of the Finger Lakes. The park is south of and between Geneva and Waterloo...
, in the Finger LakesFinger LakesThe Finger Lakes are a pattern of lakes in the west-central section of Upstate New York in the United States. They are a popular tourist destination. The lakes are long and thin , each oriented roughly on a north-south axis. The two longest, Cayuga Lake and Seneca Lake, are among the deepest in...
region of upstate New YorkUpstate New YorkUpstate New York is the region of the U.S. state of New York that is located north of the core of the New York metropolitan area.-Definition:There is no clear or official boundary between Upstate New York and Downstate New York...
, USA was found to have two water storage tanks infected with Cryptosporidium. By early September 2005, over 3,800 people reported symptoms of a Cryptosporidium infection. The "Sprayground" was ordered closed for the season on 15 August.
- In October 2005, the GwyneddGwyneddGwynedd is a county in north-west Wales, named after the old Kingdom of Gwynedd. Although the second biggest in terms of geographical area, it is also one of the most sparsely populated...
and AngleseyAngleseyAnglesey , also known by its Welsh name Ynys Môn , is an island and, as Isle of Anglesey, a county off the north west coast of Wales...
areas of North WalesNorth WalesNorth Wales is the northernmost unofficial region of Wales. It is bordered to the south by the counties of Ceredigion and Powys in Mid Wales and to the east by the counties of Shropshire in the West Midlands and Cheshire in North West England...
(UK) suffered an outbreak of cryptosporidiosis. The outbreak may have been linked to the drinking water supply from Llyn CwellynLlyn CwellynLlyn Cwellyn is a reservoir in North Wales which supplies drinking water to parts of Gwynedd and Anglesey. It lies on the Afon Gwyrfai in Nant y Betws between the Snowdon Massif and Mynydd Mawr in the northern part of Snowdonia National Park. It has an area of , and is over deep...
, but this is not yet confirmed. As a result, 231 people fell ill and the company Welsh Water (Dwr Cymru) advised 61,000 people to boil their water before use.
- In March 2007, a suspected outbreak occurred in GalwayGalwayGalway or City of Galway is a city in County Galway, Republic of Ireland. It is the sixth largest and the fastest-growing city in Ireland. It is also the third largest city within the Republic and the only city in the Province of Connacht. Located on the west coast of Ireland, it sits on the...
, IrelandIrelandIreland is an island to the northwest of continental Europe. It is the third-largest island in Europe and the twentieth-largest island on Earth...
, after the source of water for much of the county, Lough CorribLough CorribLough Corrib is a lake in the west of Ireland. The River Corrib or Galway river connects the lake to the sea at Galway. It is the second largest lough in Ireland . It covers 178 km² and lies mostly in County Galway with a small area of its northeast corner in County Mayo.The first canal in...
, was suspected to be contaminated with the parasite. A large population (90,000 people), including areas of both Galway City and County, were advised to boil water for drinking, food preparation and for brushing teeth. On 21 March 2007, it was confirmed that the city and county's water supply was contaminated with the parasite. The area's water supply was finally given approval on 20 August 2007, five months after Cryptosporidium was first detected. Around 240 people are known to have contracted the disease; experts say the true figure could be up to 5,000.
- Hundreds of public pools in 20 Utah, USA counties were closed to young children in 2007, as children under 5 are most likely to spread the disease, especially children wearing diaperDiaperA nappy or a diaper is a kind of pant that allows one to defecate or urinate on oneself discreetly. When diapers become soiled, they require changing; this process is often performed by a second person such as a parent or caregiver...
s. As of 10 September 2007 the Utah Department of Health had reported 1302 cases of cryptosporidiosis in the year; a more usual number would be 30. On 25 September the pools were reopened to those not requiring diapers, but hyperchlorination requirements were not lifted.
- On 21 September 2007, a Cryptosporidium outbreakOutbreakOutbreak is a term used in epidemiology to describe an occurrence of disease greater than would otherwise be expected at a particular time and place. It may affect a small and localized group or impact upon thousands of people across an entire continent. Two linked cases of a rare infectious...
attacked the Western United StatesWestern United States.The Western United States, commonly referred to as the American West or simply "the West," traditionally refers to the region comprising the westernmost states of the United States. Because the U.S. expanded westward after its founding, the meaning of the West has evolved over time...
: 230 IdahoIdahoIdaho is a state in the Rocky Mountain area of the United States. The state's largest city and capital is Boise. Residents are called "Idahoans". Idaho was admitted to the Union on July 3, 1890, as the 43rd state....
residents, with hundreds across the Rocky Mountain area; in the Boise and MeridianMeridian, Idaho-History:The town was established in 1891 on the Onweiler farm north of the present site and was called Hunter. Two years later an I.O.O.F. lodge was organized and called itself Meridian because it was located on the Boise Meridian and the town was renamed...
areas; UtahUtahUtah is a state in the Western United States. It was the 45th state to join the Union, on January 4, 1896. Approximately 80% of Utah's 2,763,885 people live along the Wasatch Front, centering on Salt Lake City. This leaves vast expanses of the state nearly uninhabited, making the population the...
, 1,600 illnesses; ColoradoColoradoColorado is a U.S. state that encompasses much of the Rocky Mountains as well as the northeastern portion of the Colorado Plateau and the western edge of the Great Plains...
and other Western statesU.S. stateA U.S. state is any one of the 50 federated states of the United States of America that share sovereignty with the federal government. Because of this shared sovereignty, an American is a citizen both of the federal entity and of his or her state of domicile. Four states use the official title of...
- MontanaMontanaMontana is a state in the Western United States. The western third of Montana contains numerous mountain ranges. Smaller, "island ranges" are found in the central third of the state, for a total of 77 named ranges of the Rocky Mountains. This geographical fact is reflected in the state's name,...
, decrease.
- On 25 June 2008, Cryptosporidium was found in England in water supplies in NorthamptonNorthamptonNorthampton is a large market town and local government district in the East Midlands region of England. Situated about north-west of London and around south-east of Birmingham, Northampton lies on the River Nene and is the county town of Northamptonshire. The demonym of Northampton is...
, DaventryDaventryDaventry is a market town in Northamptonshire, England, with a population of 22,367 .-Geography:The town is also the administrative centre of the larger Daventry district, which has a population of 71,838. The town is 77 miles north-northwest of London, 13.9 miles west of Northampton and 10.2...
and some surrounding areas supplied from the PitsfordPitsfordPitsford is a village and civil parish in the Daventry district of the non-metropolitan county of Northamptonshire in the United Kingdom. At the time of the 2001 census, the parish's population was 636 people...
Reservoir, as reported on the BBC. People in the affected areas were warned not to drink tap water unless it had been boiled. Anglian WaterAnglian WaterAnglian Water is a privatised water company that operates in the East of England. Named for East Anglia, apart from Norfolk, Suffolk and Cambridgeshire it also covers Lincolnshire, Essex, Bedfordshire, Buckinghamshire, Northamptonshire, a small part of north Nottinghamshire and Greater London...
confirmed that 108,000 households were affected, about 250,000 people. They advised that water might not be fit for human consumption for many weeks. The boil notice was lifted for all the affected customers on 4 July 2008.
- Throughout the summerSummerSummer is the warmest of the four temperate seasons, between spring and autumn. At the summer solstice, the days are longest and the nights are shortest, with day-length decreasing as the season progresses after the solstice...
of 2008; many public swimming areas, water parks, and public pools in the Dallas/Fort Worth MetroplexDallas/Fort Worth MetroplexThe Dallas–Fort Worth–Arlington Metropolitan Statistical Area, a title designated by the U.S. Census as of 2003, encompasses 12 counties within the U.S. state of Texas. The area is divided into two metropolitan divisions: Dallas–Plano–Irving and Fort Worth–Arlington. Residents of the area...
of TexasTexasTexas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...
, USA suffered an outbreak of cryptosporidiosis. Burger's Lake in Fort WorthFort Worth, TexasFort Worth is the 16th-largest city in the United States of America and the fifth-largest city in the state of Texas. Located in North Central Texas, just southeast of the Texas Panhandle, the city is a cultural gateway into the American West and covers nearly in Tarrant, Parker, Denton, and...
was the first to report such an outbreak. This prompted some, if not all, city-owned and private pools to close and hyperchlorinate. To date, there have been 400 reported cases of Cryptosporidium.
- In September 2008, a gym in Cambridge, UK was forced to close its swimming pool until further notice after health inspectors found an outbreak of cryptosporidiosis. Environmental Health authorities requested that the water be tested after it was confirmed that a young man had been infected.
- In May 2010, the Behana creek water supply south of Cairns, Australia, was found to be contaminated by cryptosporidium.
- In July 2010, a local sport centre in Cumbernauld (Glasgow, UK) detected traces of cryptosporidium in its swimming pools, causing a temporarily closure of the swimming pools.
- In November 2010, over 4000 cases of cryptosporidiosis were reported in ÖstersundÖstersundÖstersund is an urban area in Jämtland in the middle of Sweden. It is the seat of Östersund Municipality and the capital of Jämtland County. Östersund is located at the shores of Sweden's fifth largest lake, Storsjön, opposite the island Frösön, and is the only city in Jämtland. Östersund is the...
, Sweden. The source of contamination was the tap water. In mid December 2010 the number of reported cases was 12,400 according to local media.
- As of April 2011, there has been an ongoing outbreak in SkellefteåSkellefteå-Industry:*Boliden AB, a big mining and smelting company*Alimak*Natural User Interface Technologies AB - NUITEQ, a promising emerging technology start-up company-Sports:*Skellefteå AIK, an ice hockey team in the highest Swedish league, Elitserien....
, Sweden. Although many people have been diagnosed with cryptosporidiosis, the source of the parasite has not yet been found. Several tests have been taken around the water treatment unit "Abborren", but so far no results have turned up positive. Residents are being advised to boil the tap water as they continue to search for the contaminating source.
- Since May 2011, there has been an ongoing outbreak in South Roscommon in Ireland. Although many people have been diagnosed with cryptosporidiosis, the source of the parasite has not yet been found. Testing continues and Roscommon County Council are now considering introducing Ultra Violet Filtration to their water treatment process in the next 12 months. Residents are being advised to boil the tap water and there is no sign of this boil notice being lifted in the near future.
See also
- Cryptosporidium was the basis of the 1998 TV film, Thirst, in which it mutates and passes through a town's water filters.
External links
- Cryptosporidiosis - Centers for Disease Control and PreventionCenters for Disease Control and PreventionThe Centers for Disease Control and Prevention are a United States federal agency under the Department of Health and Human Services headquartered in Druid Hills, unincorporated DeKalb County, Georgia, in Greater Atlanta...
- Aquatics International Article Regarding Infection via Spray Parks
- Monroe County Health Dept. Fact Sheet
- NYSDOH Crypto Fact Sheet
- NYS Dept. of State Parks Update, 8/26/05
- Treatment of Cryptosporidiosis from the AidsMeds site
- Azithromycin information
- Summary of treatment results with Azithromycin
- Galway City Council notice
- CryptoDB: The Cryptosporidium Genome Resource
- Boil Check: Postcode check for contaminated water areas UK site