Cryptosporidiosis, also known as
crypto, is a
parasitic diseaseA parasitic disease is an infectious disease caused or transmitted by a parasite. Many parasites do not cause disease per se. Parasitic diseases can affect practically all living organisms, from plants to mammals...
caused by
Cryptosporidium, a
protozoaProtozoa or Cornelius protozoans Protozoa or Cornelius protozoans Protozoa or Cornelius protozoans (from Greek πρῶτον proton "first" and ζῷα zoa "animals"; singular protozoon; (the word "protozoan" is originally an adjective, used as a noun) are microorganisms classified as unicellular eukaryotes....
n parasite in the phylum
ApicomplexaThe Apicomplexa are a large group of protists, most of which possess a unique organelle called apicoplast and an apical complex structure involved in penetrating a host's cell. They are unicellular, spore-forming, and exclusively parasites of animals. Motile structures such as flagella or...
. It affects the
intestineIn anatomy, the intestine is the segment of the alimentary canal extending from the stomach to the anus and, in humans and other mammals, consists of two segments, the small intestine and the large intestine...
s of
mammalMammals are a class of vertebrate animals whose females are characterized by the possession of mammary glands while both males and females are characterized by sweat glands, hair, three middle ear bones used in hearing, and a neocortex region in the brain.Mammals are divided into three main...
s and is typically an acute short-term infection. It is spread through the
fecal-oral routeThe faecal-oral route, or alternatively, the oral-faecal route or orofaecal route is a route of transmission of diseases, in which they are passed when faecal particles from one host are introduced into the oral cavity of another potential host....
, often through contaminated water; the main symptom is self-limiting
diarrheaIn medicine, diarrhea , also spelled diarrhoea , is the condition of having frequent loose or liquid bowel movements. Acute diarrhea is a common cause of death in developing countries and the second most common cause of infant deaths worldwide...
in people with intact immune systems. In immunocompromised individuals, such as
AIDSAcquired 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 cystA microbial cyst is a resting or dormant stage of a microorganism, usually a bacterium or a protist, that helps the organism to survive 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 the...
s (oocysts) that, once ingested, exist in the
small intestineIn vertebrates, the small intestine is the part of the gastrointestinal tract following the stomach and followed by the large intestine, and is where the vast majority of digestion and absorption of food takes place. In invertebrates such as worms, the terms "gastrointestinal tract" and "large...
and result in an infection of intestinal epithelial tissue.
General characteristics of Cryptosporidium
Cryptosporidium is a protozoan
pathogenA pathogen , infectious agent, or germ, is a biological agent that causes disease or illness to its host....
of the Phylum
ApicomplexaThe Apicomplexa are a large group of protists, most of which possess a unique organelle called apicoplast and an apical complex structure involved in penetrating a host's cell. They are unicellular, spore-forming, and exclusively parasites of animals. Motile structures such as flagella or...
and causes a
diarrheaIn medicine, diarrhea , also spelled diarrhoea , is the condition of having frequent loose or liquid bowel movements. Acute diarrhea is a common cause of death in developing countries and the second most common cause of infant deaths worldwide...
l illness called cryptosporidiosis. Other apicomplexan pathogens include the
malariaMalaria is a vector-borne infectious disease caused by a eukaryotic protist of the genus Plasmodium. It is widespread in tropical and subtropical regions, including parts of the Americas, Asia, and Africa. Each year, there are approximately 350–500 million cases of malaria, killing between one and...
parasite
PlasmodiumPlasmodium is a genus of parasitic protists. Infection by these organisms is known as malaria. The genus Plasmodium was discovered in 1885 by Marchiafava and Celli. Currently over 200 species of this genus are recognized and new species continue to be described.Of the over 200 known species of...
, and
Toxoplasma, the causative agent of
toxoplasmosisToxoplasmosis 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 faeces of a cat that has itself...
. Unlike
Plasmodium, which transmits via a
mosquitoMosquito is a common insect in the family Culicidae...
vector,
Cryptosporidium does not utilize an insect vector and is capable of completing its life cycle within a single host, resulting in
microbial cystA microbial cyst is a resting or dormant stage of a microorganism, usually a bacterium or a protist, that helps the organism to survive 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 the...
stages which are excreted in
fecesFeces, faeces, or fæces is a waste product from an animal's digestive tract expelled through the anus during defecation.-Etymology:...
and are capable of transmission to a new host.
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 cystA microbial cyst is a resting or dormant stage of a microorganism, usually a bacterium or a protist, that helps the organism to survive 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 the...
s (oocysts) that, once ingested, excyst in the
small intestineIn vertebrates, the small intestine is the part of the gastrointestinal tract following the stomach and followed by the large intestine, and is where the vast majority of digestion and absorption of food takes place. In invertebrates such as worms, the terms "gastrointestinal tract" and "large...
and result in an infection of intestinal epithelial tissue.
The
genomeIn modern molecular biology the genome refers to all of its hereditary information encoded in DNA .The genome includes both the genes and the non-coding sequences of the DNA. The term was adapted in 1920 by Hans Winkler, Professor of Botany at the University of Hamburg, Germany...
of
Cryptosporidium parvum was sequenced in 2004 and was found to be unusual amongst
EukaryoteA eukaryote is an organism whose cells contain complex structures enclosed within membranes. The defining membrane-bound structure that sets eukaryotic cells apart from prokaryotic cells is the nucleus, or nuclear envelope, within which the genetic material is carried...
s in that the mitochondria seem not to
contain DNAMitochondrial DNA is the DNA located in organelles called mitochondria, structures within cells that convert the energy from food into a form that cells can use...
. 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.
Transmission
InfectionAn infection is the detrimental colonization of a host organism by a foreign species. In an infection, the infecting organism seeks to utilize the host's resources to multiply, usually at the expense of the host. The infecting organism, or pathogen, interferes with the normal functioning of the...
is through contaminated material such as earth,
waterWater is an ubiquitous chemical substance that is composed of hydrogen and oxygen and is essential for all known forms of life.In typical usage, water refers only to its liquid form or state, but the substance also has a solid state, ice, and a gaseous state, water vapor or steam. Water covers 71%...
, uncooked or cross-contaminated
foodFood is any substance, usually composed of carbohydrates, fats, proteins and water, that can be eaten or drunk by an animal, including humans, for nutrition or pleasure. Items considered food may be sourced from plants, animals or other categories such as fungus or fermented products like alcohol...
that has been in contact with the
fecesFeces, faeces, or fæces is a waste product from an animal's digestive tract expelled through the anus during defecation.-Etymology:...
of an infected individual or
animalAnimals are a major group of mostly 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...
. 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
chlorineChlorine Chlorine Chlorine ( , from the Greek word 'χλωρóς' (khlôros, meaning 'pale green'), is the chemical element with atomic number 17 and symbol Cl. It is a halogen, found in the periodic table in group 17 (formerly VII, VIIa, or VIIb). As the chloride ion, which is part of common salt and...
bleachA bleach is a chemical that removes colors or whitens, often via oxidation. Common chemical bleaches include household "chlorine bleach", a solution of approximately 3–6% sodium hypochlorite , and "oxygen bleach", which contains hydrogen peroxide or a peroxide-releasing compound such as sodium...
enables them to survive for long periods and still remain infective . Some outbreaks have happened in day care related to diaper changes.
Symptoms
SymptomA 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
stomachIn most mammals, the stomach is a hollow, muscular organ of the gastrointestinal tract , between the esophagus and the small intestine. It is involved in the second phase of digestion, following mastication . The word stomach is derived from the Latin stomachus, which derives from the Greek word...
pains or
crampFor the heraldic device, see cramp ; for the band, see The CrampsCramps are unpleasant, often painful sensations caused by contraction or over-shortening of muscles...
s and a low
feverFever is a frequent medical sign that describes an increase in internal body temperature to levels above normal...
. Other symptoms include nausea, vomiting , malabsorption and dehydration. Anorexia can occur, as can weight loss. The individuals who are
asymptomaticIn medicine, a disease is asymptomatic if a patient carries 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 infections...
(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
pancreatitisPancreatitis is inflammation of the pancreas that can occur in two very different forms. Acute pancreatitis is sudden while chronic pancreatitis "is characterized by recurring or persistent abdominal pain with or without steatorrhea or diabetes mellitus."...
, 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
Cryptosporidium has a
sporeIn biology, a spore is a reproductive structure that is adapted for dispersal and surviving for extended periods of time in unfavorable conditions...
phase (
oocystAn oocyst is the thick-walled spore phase of certain protists , such as Cryptosporidium and Toxoplasma. This state can survive for lengthy periods outside a host and is very resistant....
) and in this state it can survive for lengthy periods outside a host. It can also resist many common disinfectants, notably
chlorineChlorine Chlorine Chlorine ( , from the Greek word 'χλωρóς' (khlôros, meaning 'pale green'), is the chemical element with atomic number 17 and symbol Cl. It is a halogen, found in the periodic table in group 17 (formerly VII, VIIa, or VIIb). As the chloride ion, which is part of common salt and...
-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). 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 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...
,
nitazoxanideNitazoxanide, also known by the brand names Alinia and Annita is a synthetic nitrothiazolyl-salicylamide derivative and an antiprotozoal agent.Nitazoxanide is a light yellow crystalline powder...
, and
azithromycinAzithromycin is an azalide, a subclass of macrolide antibiotics.Azithromycin is one of the world's best-selling antibiotics, and is derived from erythromycin; however, it differs chemically from erythromycin in that a methyl-substituted nitrogen atom is incorporated into the lactone ring, thus...
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 immuno-competent
The majority of immuno-competent individuals suffer a short (less than 2 weeks) self-limiting course that requires supportive care with re-hydration and occasionally anti-diarrhoeal medication and ends with spontaneous recovery.
NitazoxanideNitazoxanide, also known by the brand names Alinia and Annita is a synthetic nitrothiazolyl-salicylamide derivative and an antiprotozoal agent.Nitazoxanide is a light yellow crystalline powder...
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 diarrhea 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. The probiotic
Saccharomyces boulardiiSaccharomyces boulardii is a tropical strain of yeast first isolated from lychee and mangosteen fruit in 1923 by French scientist Henri Boulard. It is related to, but distinct from, Saccharomyces cerevisiae in several taxonomic, metabolic, and genetic properties.S...
sold over the counter in pharmacies and health shops (Brand name Florastor in US and DiarSafe in UK) has been found to be a helpful natural treatment in managing diarrhoea of various infectious origins including cryptosporidium. Parenteral octreotide acetate can help decrease the number of stools passed. A treatment for patients with biliary cryptosporidiosis who have cholangitis in addition to papillary stenosis is endoscopic sphincterotomy.
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 non nitro- thiazolide compounds, have also shown promising results in vitro.
Treatment of drinking water
Many
treatment plantsWater purification is the process of removing undesirable chemicals, materials, and biological contaminants from raw water. The goal is to produce water fit for a specific purpose...
that take raw water from
riverA river is a natural watercourse, usually freshwater, flowing toward 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...
s,
lakeA lake is a terrain feature , a body of liquid on the surface of a world that is localized to the bottom of basin and moves slowly if it moves at all. Another definition is, a body of fresh or salt water of considerable size that is surrounded by land...
s, and reservoirs for public
drinking waterDrinking water or potable water is water of sufficiently high quality that it can be consumed or used without risk of immediate or long term harm...
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 filterSlow 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 filterDiatomaceous earth — also known as DE, TSS, diatomite, diahydro, kieselguhr, kieselgur, brand names include Celatom or celite — is a naturally occurring, soft, chalk-like sedimentary rock that is easily crumbled into a fine white to off-white powder, with a particle size extending from less than 1...
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
laboratoryA 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 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
goatThe 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: 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 geckoThe leopard gecko is a nocturnal ground-dwelling gecko found in the deserts of Pakistan, northern India, Afghanistan, and parts of Iran. Unlike most geckos, it possesses eyelids. It has become well-established in captivity, particularly through the pet industry...
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. Cryptosporidiosis has no vectors.
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. 10% 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
AIDSAcquired immune deficiency syndrome or acquired immunodeficiency syndrome is a disease of the human immune system caused by the human immunodeficiency virus ....
. 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, faeces, or fæces is a waste product from an animal's digestive tract expelled through the anus 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 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 FoundationThe 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 Cryptosporidium 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 1993, a waterborne cryptosporidiosis outbreak
The 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 Southeastern Wisconsin, USA. An estimated 403,000 people became ill, including 4,400 people hospitalized. More than 100 people died during the outbreak.
- The UK's biggest outbreak occurred in Torbay
Torbay 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 April 1, 1998...
in DevonDevon is a large county in England. The county is also referred to as Devonshire, although that is an unofficial name, rarely used inside of the county itself and often indicating a traditional or historical context. The county shares borders with Cornwall to the west and Dorset and Somerset to...
in 1995 when 575 people fell ill.
- In the summer of 1996, cryptosporidium affected approximately 2,000 people in Cranbrook, British Columbia
Cranbrook, British Columbia is a city in southeast British Columbia, seat of the Regional District of East Kootenay. As of 2006, Cranbrook's population is 18,947, and the metro population is 27,229....
, CanadaCanada is a country occupying most of northern North America, extending 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 is a city on Okanagan Lake in the Okanagan Valley of British Columbia, Canada. Its name derives from a native 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, Saskatchewan
North Battleford is a small city in west central Saskatchewan, Canada. It is located directly across the North Saskatchewan River from the town of Battleford...
, CanadaCanada is a country occupying most of northern North America, extending from the Atlantic Ocean in the east to the Pacific Ocean in the west and northward into the Arctic Ocean...
. 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 Park
Seneca 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 LakesThe Finger Lakes are a chain of lakes in the west-central section of Upstate New York that are a popular tourist destination. The lakes mainly are linear in shape, each lake oriented on a north-south axis. The two longest, Cayuga Lake and Seneca Lake, are among the deepest in America. Both are...
region of upstate New YorkUpstate New York is the region of New York State 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, but the term "Upstate" is sometimes used to refer to the whole of the state besides New York City...
, 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 August 15.
- In October 2005 Gwynedd
Gwynedd is a county in north-west Wales, named after the old Kingdom of Gwynedd. Although one of the biggest in terms of geographical area, it is also one of the most sparsely populated...
and AngleseyThe Isle of Anglesey , is an island and county off the northwest coast of Wales, with a predominantly Welsh-speaking population. It is connected to the mainland by two bridges spanning the Menai Strait: the original Menai Suspension Bridge , designed by Thomas Telford in 1826; and the newer...
areas of North WalesNorth Wales is the northernmost unofficial region of Wales, bordered to the south by Mid Wales and to the east by England.It comprises the island of Anglesey, the Llŷn peninsula and the Snowdonia mountain range, together with the catchments of the Rivers Conwy, Clwyd and Dee with the River Dyfi...
(UK) suffered an outbreak of Cryptosporidiosis. The outbreak may have been linked to the drinking water supply from Llyn 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, over 200 people fell ill and the company Welsh Water (Dwr Cymru) advised 61000 people to boil their water before use.
- In March 2007
March 2007 is the third month of the year. It began on a Thursday, and ended 31 days later on a Saturday.-International holidays:* March 1 - St Davids Day United Kingdom* March 4 - Purim * March 10 - Arba'een...
, a suspected outbreak occurred in GalwayGalway is the fastest growing and is the fifth largest city in Ireland and the only city in the province of Connacht. The city is located on the west coast of Ireland...
, IrelandIreland is the third-largest island in Europe and the twentieth-largest island in the world. It lies to the north-west of continental Europe and is surrounded by hundreds of islands and islets. To the east of Ireland, separated by the Irish Sea, is the island of Great Britain...
, after the source of water for much of the county, Lough CorribLough Corrib is a lake in the west of Ireland. The River Corrib/Galway river connects the lake to the sea at Galway. It is the second largest loch in Ireland . It covers some 165.6km²....
, 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 the all-clear 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 diaper
A diaper or nappy is a sponge-like garment which people wear who are incapable of controlling their bladder or bowel movements, or are unable or unwilling to use a toilet...
s. As of September 10, 2007 the Utah Department of Health had reported 1302 cases of cryptosporidiosis in the year; a more usual number would be 30. On September 25, the pools were re-opened to those not requiring diapers, but hyperchlorination requirements were not lifted.
- On September 21, 2007, Cryptosporidium outbreak
Outbreak is a term used in epidemiology to describe an occurrence of disease greater than would otherwise be expected in a particular time and place. It may be small and localized group or impact upon thousands of people across an entire continent. Two linked cases of a rare infectious disease may...
attacked the Western United StatesThe 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 IdahoIdaho is a state in the Pacific Northwest region of the United States of America. The state's largest city and capital is Boise. Residents are called "Idahoans." Idaho was admitted to the Union on 3 July 1890 as the 43rd state....
residents, with hundreds across the Rocky Mountain area; in the Boise and Meridian-Earth science:* Meridian , imaginary circle perpendicular to the celestial equator and horizon* Meridian , an imaginary arc on the Earth's surface from the North Pole to the South Pole-United States geography:* Meridian, California...
areas; UtahUtah is a western state of the United States. It was the 45th state admitted to the Union, on January 4, 1896. Approximately 80 percent of Utah's 2,736,424 people live along the Wasatch Front, centering around Salt Lake City. In contrast, vast expanses of the state are nearly uninhabited, making...
, 1,600 illnesses; ColoradoColorado is a U.S. state located in the Rocky Mountain region of the United States of America. It may also be considered to be part of the Western and Southwestern regions of the United States. Colorado entered statehood in 1876 and was nicknamed the “Centennial State”...
and other Western statesA U.S. state is any one of 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...
- MontanaMontana is a state in the Western United States. The western third of the state contains numerous mountain ranges; other '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 Northampton
Northampton is a large market town and local government district in the East Midlands region of England. It is about north-west of London and around south-east of Birmingham, and lies on the River Nene...
, DaventryDaventry is a market town in Northamptonshire, England, with a population of 22,367 . The town is also the administrative centre of the larger Daventry district, which has a population of 71,838. The town is 124 km north-northwest of London, 22.4 km west of Northampton and 16.4 km...
and some surrounding areas supplied from the PitsfordPitsford is a village in the Daventry district of the non-metropolitan county of Northamptonshire in the United Kingdom.Pitsford Hall is home to Northamptonshire Grammar School which runs Pitsford Hall weather station. Ironstone is quarried at Pitsford and was formerly transported by rail...
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 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 Summer
Summer is one of the four temperate seasons, marked by the time of year with the longest days, and lies between spring and autumn. The seasons are popularly considered to start on different dates in different cultures based on astronomy and regional meteorology. When it is summer in the southern...
of 2008; many public swimming areas, water parks, and public pools in the Dallas/Fort Worth MetroplexThe Dallas–Fort Worth–Arlington metropolitan area, a title designated by the U.S. Census as of 2003, encompasses 12 counties within the U.S. state of Texas. The metropolitan area is further divided into two metropolitan divisions: Dallas–Plano–Irving and Fort Worth–Arlington...
of TexasTexas is the second-largest U.S. state in both area and population, and the largest state in the contiguous United States.The name had wide usage among native Americans, meaning "friends" or "allies"...
, USA suffered an outbreak of Cryptosporidiosis. Burger's Lake in Fort WorthFort Worth is the seventeenth-largest city in the United States of America and the fifth-largest city within the state of Texas. Located in and a cultural gateway into the American West, the city covers nearly in Tarrant, Parker, and Denton counties, serving as the county seat for Tarrant...
was the first to report such an outbreak. This prompted some if not all city-owned & private pools to close and hyperchlorinate. To date, there have been 400 reported cases of Cryptosporidium
- 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.
- 1998 Sydney water crisis
The 1998 Sydney water crisis involved the supposed contamination of Sydney's main water supply, the Warragamba Dam, by the microscopic pathogens cryptosporidium and giardia between July and September 1998....
- 2002 Glasgow floods
The 2002 Glasgow floods was a series of Flash floods that occurred after Thunderstorms in the Scottish Lowlands in late July and early August 2002. The heaviest rainfall fell on the night of Tuesday 30 July 2002.- Overview :...
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