Cryptosporidiosis, sometimes informally called crypto, is a

parasitic disease A parasitic disease, also known as parasitosis, is an infectious disease caused by parasites. Parasites are organisms which derive sustenance from its host while causing it harm. The study of parasites and parasitic diseases is known as parasitolo ...

caused by ''

Cryptosporidium ''Cryptosporidium'', sometimes informally called crypto, is a genus of apicomplexan parasitic alveolates that can cause a respiratory and gastrointestinal illness (cryptosporidiosis) that primarily involves watery diarrhea (intestinal cryptosp ...

'', a genus of

protozoa Protozoa (singular: protozoan or protozoon; alternative plural: protozoans) are a group of single-celled eukaryotes, either free-living or parasitic, that feed on organic matter such as other microorganisms or organic tissues and debris. Histo ...

parasite Parasitism is a close relationship between species, where one organism, the parasite, lives on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson has ...

s in the phylum

Apicomplexa The Apicomplexa (also called Apicomplexia) are a large phylum of parasitic alveolates. Most of them possess a unique form of organelle that comprises a type of non-photosynthetic plastid called an apicoplast, and an apical complex structure. T ...

. It affects the distal small intestine and can affect the

respiratory tract The respiratory tract is the subdivision of the respiratory system involved with the process of respiration in mammals. The respiratory tract is lined with respiratory epithelium as respiratory mucosa. Air is breathed in through the nose to th ...

in both

immunocompetent In immunology, immunocompetence is the ability of the body to produce a normal immune response following exposure to an antigen. Immunocompetence is the opposite of immunodeficiency (also known as ''immuno-incompetence'' or being ''immuno-compro ...

(i.e., individuals with a normal functioning

immune system The immune system is a network of biological processes that protects an organism from diseases. It detects and responds to a wide variety of pathogens, from viruses to parasitic worms, as well as cancer cells and objects such as wood splinte ...

) and

immunocompromised Immunodeficiency, also known as immunocompromisation, is a state in which the immune system's ability to fight infectious diseases and cancer is compromised or entirely absent. Most cases are acquired ("secondary") due to extrinsic factors that a ...

(e.g., persons with

HIV/AIDS Human immunodeficiency virus infection and acquired immunodeficiency syndrome (HIV/AIDS) is a spectrum of conditions caused by infection with the human immunodeficiency virus (HIV), a retrovirus. Following initial infection an individual ...

autoimmune disorders An autoimmune disease is a condition arising from an abnormal immune response to a functioning body part. At least 80 types of autoimmune diseases have been identified, with some evidence suggesting that there may be more than 100 types. Nearly a ...

) individuals, resulting in watery diarrhea with or without an unexplained cough. In immunosuppressed individuals, the symptoms are particularly severe and can be fatal. It is primarily spread through the fecal-oral route, often through contaminated water; recent evidence suggests that it can also be transmitted via

fomite A fomite () or fomes () is any inanimate object that, when contaminated with or exposed to infectious agents (such as pathogenic bacteria, viruses or fungi), can transfer disease to a new host. Transfer of pathogens by fomites A fomite is any ina ...

s contaminated with respiratory secretions. ''Cryptosporidium'' is commonly isolated in

HIV-positive The human immunodeficiency viruses (HIV) are two species of ''Lentivirus'' (a subgroup of retrovirus) that infect humans. Over time, they cause AIDS, acquired immunodeficiency syndrome (AIDS), a condition in which progressive failure of the ...

patients presenting with diarrhea. Despite not being identified until 1976, it is one of the most common waterborne diseases and is found worldwide. The infection begins when a human consumes food or water containing

cysts A cyst is a closed sac, having a distinct envelope and division compared with the nearby tissue. Hence, it is a cluster of cells that have grouped together to form a sac (like the manner in which water molecules group together to form a bubble) ...

of the ''Cryptosporidium'' organism.

Signs and symptoms

Cryptosporidiosis may occur as an

asymptomatic infection In medicine, any disease is classified asymptomatic if a patient tests as carrier for a disease or infection but experiences no symptoms. Whenever a medical condition fails to show noticeable symptoms after a diagnosis it might be considered asym ...

, an acute infection (i.e., duration shorter than 2 weeks), as recurrent acute infections in which symptoms reappear following a brief period of recovery for up to 30 days, and as a chronic infection (i.e., duration longer than 2 weeks) in which symptoms are severe and persistent. It may be fatal in individuals with a severely compromised

Symptom Signs and symptoms are the observed or detectable signs, and experienced symptoms of an illness, injury, or condition. A sign for example may be a higher or lower temperature than normal, raised or lowered blood pressure or an abnormality showin ...

s usually appear 5–10 days after infection (range: 2–28 days) and normally last for up to 2 weeks in

individuals; symptoms are usually more severe and persist longer in

individuals. Following the resolution of diarrhea, symptoms can reoccur after several days or weeks due to reinfection. The likelihood of is high in immunocompromised adults, and low in those with normal immune systems. In immunocompetent individuals, cryptosporidiosis is primarily localized to the distal small intestine and sometimes the

as well. In immunocompromised persons, cryptosporidiosis may disseminate to other organs, including the

hepatobiliary system The biliary tract, (biliary tree or biliary system) refers to the liver, gallbladder and bile ducts, and how they work together to make, store and secrete bile. Bile consists of water, electrolytes, bile acids, cholesterol, phospholipids and ...

pancreas The pancreas is an organ of the digestive system and endocrine system of vertebrates. In humans, it is located in the abdomen behind the stomach and functions as a gland. The pancreas is a mixed or heterocrine gland, i.e. it has both an end ...

, upper gastrointestinal tract, and

urinary bladder The urinary bladder, or simply bladder, is a hollow organ in humans and other vertebrates that stores urine from the kidneys before disposal by urination. In humans the bladder is a distensible organ that sits on the pelvic floor. Urine enters ...

; pancreatic and biliary infection can involve acalculous cholecystitis, sclerosing cholangitis, papillary stenosis, or

pancreatitis Pancreatitis is a condition characterized by inflammation of the pancreas. The pancreas is a large organ behind the stomach that produces digestive enzymes and a number of hormones. There are two main types: acute pancreatitis, and chronic pancr ...

Intestinal cryptosporidiosis

Common signs and symptoms of intestinal cryptosporidiosis include: * Moderate to severe watery

diarrhea Diarrhea, also spelled diarrhoea, is the condition of having at least three loose, liquid, or watery bowel movements each day. It often lasts for a few days and can result in dehydration due to fluid loss. Signs of dehydration often begin wi ...

, sometimes contains mucus and rarely contains blood or

leukocytes White blood cells, also called leukocytes or leucocytes, are the cells of the immune system that are involved in protecting the body against both infectious disease and foreign invaders. All white blood cells are produced and derived from mult ...

** In very severe cases, diarrhea may be profuse and

cholera Cholera is an infection of the small intestine by some strains of the bacterium ''Vibrio cholerae''. Symptoms may range from none, to mild, to severe. The classic symptom is large amounts of watery diarrhea that lasts a few days. Vomiting and ...

-like with

malabsorption Malabsorption is a state arising from abnormality in absorption of food nutrients across the gastrointestinal (GI) tract. Impairment can be of single or multiple nutrients depending on the abnormality. This may lead to malnutrition and a variety ...

and

hypovolemia Hypovolemia, also known as volume depletion or volume contraction, is a state of abnormally low extracellular fluid in the body. This may be due to either a loss of both salt and water or a decrease in blood volume. Hypovolemia refers to the los ...

Low-grade fever Fever, also referred to as pyrexia, is defined as having a temperature above the normal range due to an increase in the body's temperature set point. There is not a single agreed-upon upper limit for normal temperature with sources using val ...

* Crampy

abdominal pain Abdominal pain, also known as a stomach ache, is a symptom Signs and symptoms are the observed or detectable signs, and experienced symptoms of an illness, injury, or condition. A sign for example may be a higher or lower temperature than ...

* Dehydration * Weight loss * Fatigue * Nausea and vomiting – suggests upper GI tract involvement and may lead to respiratory cryptosporidiosis *

Epigastric In anatomy, the epigastrium (or epigastric region) is the upper central region of the abdomen. It is located between the costal margins and the subcostal plane. Pain may be referred to the epigastrium from damage to structures derived from the f ...

right upper quadrant The human abdomen is divided into quadrants and regions by anatomists and physicians for the purposes of study, diagnosis, and treatment. The division into four quadrants allows the localisation of pain and tenderness, scars, lumps, and other ...

tenderness Less common or rare signs and symptoms include: *

Reactive arthritis Reactive arthritis, also known as Reiter's syndrome, is a form of inflammatory arthritis that develops in response to an infection in another part of the body (cross-reactivity). Coming into contact with bacteria and developing an infection can ...

(may affect the hands, knees, ankles, and feet) *

Jaundice Jaundice, also known as icterus, is a yellowish or greenish pigmentation of the skin and sclera due to high bilirubin levels. Jaundice in adults is typically a sign indicating the presence of underlying diseases involving abnormal heme meta ...

– suggests

hepatobiliary The biliary tract, (biliary tree or biliary system) refers to the liver, gallbladder and bile ducts, and how they work together to make, store and secrete bile. Bile consists of water, electrolytes, bile acids, cholesterol, phospholipids and ...

involvement *

Ascites Ascites is the abnormal build-up of fluid in the abdomen. Technically, it is more than 25 ml of fluid in the peritoneal cavity, although volumes greater than one liter may occur. Symptoms may include increased abdominal size, increased weight, ab ...

– suggests

pancreatic The pancreas is an organ of the digestive system and endocrine system of vertebrates. In humans, it is located in the abdomen behind the stomach and functions as a gland. The pancreas is a mixed or heterocrine gland, i.e. it has both an endocr ...

involvement

Respiratory cryptosporidiosis

Symptoms of

upper respiratory The respiratory tract is the subdivision of the respiratory system involved with the process of respiration in mammals. The respiratory tract is lined with respiratory epithelium as respiratory mucosa. Air is breathed in through the nose to t ...

cryptosporidiosis include: *

Inflammation Inflammation (from la, wikt:en:inflammatio#Latin, inflammatio) is part of the complex biological response of body tissues to harmful stimuli, such as pathogens, damaged cells, or Irritation, irritants, and is a protective response involving im ...

of the nasal mucosa, sinuses, larynx, or trachea * Nasal discharge * Voice change (e.g.,

hoarseness A hoarse voice, also known as dysphonia or hoarseness, is when the voice involuntarily sounds breathy, raspy, or strained, or is softer in volume or lower in pitch. A hoarse voice, can be associated with a feeling of unease or scratchiness in the ...

) Symptoms of lower respiratory cryptosporidiosis include: *

Cough A cough is a sudden expulsion of air through the large breathing passages that can help clear them of fluids, irritants, foreign particles and microbes. As a protective reflex, coughing can be repetitive with the cough reflex following three pha ...

Shortness of breath Shortness of breath (SOB), also medically known as dyspnea (in AmE) or dyspnoea (in BrE), is an uncomfortable feeling of not being able to breathe well enough. The American Thoracic Society defines it as "a subjective experience of breathing disc ...

* Fever *

Hypoxemia Hypoxemia is an abnormally low level of oxygen in the blood. More specifically, it is oxygen deficiency in arterial blood. Hypoxemia has many causes, and often causes hypoxia as the blood is not supplying enough oxygen to the tissues of the body ...

Reason

'' is a genus of

protozoan Protozoa (singular: protozoan or protozoon; alternative plural: protozoans) are a group of single-celled eukaryotes, either free-living or parasitic, that feed on organic matter such as other microorganisms or organic tissues and debris. Histo ...

pathogen In biology, a pathogen ( el, πάθος, "suffering", "passion" and , "producer of") in the oldest and broadest sense, is any organism or agent that can produce disease. A pathogen may also be referred to as an infectious agent, or simply a germ ...

s which is categorized under the

phylum In biology, a phylum (; plural: phyla) is a level of classification or taxonomic rank below kingdom and above class. Traditionally, in botany the term division has been used instead of phylum, although the International Code of Nomenclature f ...

. Other apicomplexan pathogens include the

malaria Malaria is a mosquito-borne infectious disease that affects humans and other animals. Malaria causes symptoms that typically include fever, tiredness, vomiting, and headaches. In severe cases, it can cause jaundice, seizures, coma, or death. S ...

parasite ''

Plasmodium ''Plasmodium'' is a genus of unicellular eukaryotes that are obligate parasites of vertebrates and insects. The life cycles of ''Plasmodium'' species involve development in a blood-feeding insect host which then injects parasites into a vert ...

'', and ''

Toxoplasma ''Toxoplasma gondii'' () is an obligate intracellular parasitic protozoan (specifically an apicomplexan) that causes toxoplasmosis. Found worldwide, ''T. gondii'' is capable of infecting virtually all warm-blooded animals, but felids, such as d ...

'', the causative agent of

toxoplasmosis Toxoplasmosis is a parasitic disease caused by ''Toxoplasma gondii'', an apicomplexan. Infections with toxoplasmosis are associated with a variety of neuropsychiatric and behavioral conditions. Occasionally, people may have a few weeks or months ...

. 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. ''Cryptosporidium'' is capable of completing its life cycle within a single host, resulting in microbial cyst stages that are excreted in

feces Feces ( or faeces), known colloquially and in slang as poo and poop, are the solid or semi-solid remains of food that was not digested in the small intestine, and has been broken down by bacteria in the large intestine. Feces contain a relati ...

and are capable of transmission to a new host via the fecal-oral route. Other vectors of disease transmission also exist. The pattern of ''Cryptosporidium'' life cycle fits well with 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 In the fields of molecular biology and genetics, a genome is all the genetic information of an organism. It consists of nucleotide sequences of DNA (or RNA in RNA viruses). The nuclear genome includes protein-coding genes and non-coding ge ...

of ''Cryptosporidium parvum'' was sequenced in 2004 and was found to be unusual amongst

Eukaryote Eukaryotes () are organisms whose cells have a nucleus. All animals, plants, fungi, and many unicellular organisms, are Eukaryotes. They belong to the group of organisms Eukaryota or Eukarya, which is one of the three domains of life. Bacte ...

s in that the

mitochondria A mitochondrion (; ) is an organelle found in the Cell (biology), cells of most Eukaryotes, such as animals, plants and Fungus, fungi. Mitochondria have a double lipid bilayer, membrane structure and use aerobic respiration to generate adenosi ...

seem not to contain DNA. A closely related species, ''C. hominis'', also has its genome sequence available. CryptoDB.org is a

NIH The National Institutes of Health, commonly referred to as NIH (with each letter pronounced individually), is the primary agency of the United States government responsible for biomedical and public health research. It was founded in the late ...

-funded database that provides access to the ''Cryptosporidium'' genomics data sets.

Transfer

Infection An infection is the invasion of tissues by pathogens, their multiplication, and the reaction of host tissues to the infectious agent and the toxins they produce. An infectious disease, also known as a transmissible disease or communicable dise ...

is through contaminated material such as earth,

water Water (chemical formula ) is an inorganic, transparent, tasteless, odorless, and nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere and the fluids of all known living organisms (in which it acts as a ...

, uncooked or cross-contaminated

food Food is any substance consumed by an organism for nutritional support. Food is usually of plant, animal, or fungal origin, and contains essential nutrients, such as carbohydrates, fats, proteins, vitamins, or minerals. The substance is inge ...

that has been in contact with the feces of an infected individual or

animal Animals are multicellular, eukaryotic organisms in the Kingdom (biology), biological kingdom Animalia. With few exceptions, animals Heterotroph, consume organic material, Cellular respiration#Aerobic respiration, breathe oxygen, are Motilit ...

. 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 ''

oocysts Apicomplexans, a group of intracellular parasites, have life cycle stages that allow them to survive the wide variety of environments they are exposed to during their complex life cycle. Each stage in the life cycle of an apicomplexan organism i ...

disinfectant A disinfectant is a chemical substance or compound used to inactivate or destroy microorganisms on inert surfaces. Disinfection does not necessarily kill all microorganisms, especially resistant bacterial spores; it is less effective than st ...

s such as

chlorine Chlorine is a chemical element with the Symbol (chemistry), symbol Cl and atomic number 17. The second-lightest of the halogens, it appears between fluorine and bromine in the periodic table and its properties are mostly intermediate betwee ...

bleach Bleach is the generic name for any chemical product that is used industrially or domestically to remove color (whitening) from a fabric or fiber or to clean or to remove stains in a process called bleaching. It often refers specifically, to ...

enables them to survive for long periods and still remain infective. Some outbreaks have happened in day care related to diaper changes. The following groups have an elevated risk of being exposed to ''Cryptosporidium'': * 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 even in cities that have a properly de-contaminated water supply. In a city with clean water, it may be that cases of cryptosporidiosis have other origins. Testing of water, as well as

epidemiological Epidemiology is the study and analysis of the distribution (who, when, and where), patterns and determinants of health and disease conditions in a defined population. It is a cornerstone of public health, and shapes policy decisions and evidenc ...

study, are necessary to determine the sources of specific infections. ''Cryptosporidium'' is causing serious illness more frequently in

than in apparently healthy individuals. It may chronically sicken some children, as well as adults who are exposed and

. A subset of the immunocompromised population is people with AIDS. Some sexual behaviors can transmit the parasite directly.

Life cycle

spp. In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate se ...

exist as multiple cell types which correspond to different stages in an infection (e.g., a sexual and asexual stage). As an

oocyst Apicomplexans, a group of intracellular parasites, have life cycle stages that allow them to survive the wide variety of environments they are exposed to during their complex life cycle. Each stage in the life cycle of an apicomplexan organism i ...

– a type of hardy, thick-walled

spore In biology, a spore is a unit of sexual or asexual reproduction that may be adapted for dispersal and for survival, often for extended periods of time, in unfavourable conditions. Spores form part of the life cycles of many plants, algae, f ...

– it can survive in the environment for months and is resistant to many common disinfectants, particularly chlorine-based disinfectants. After being ingested, the sporozoites within oocysts excyst (i.e., are released) in the small intestine. The released sporozoites subsequently 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

meront Apicomplexans, a group of intracellular parasites, have life cycle stages that allow them to survive the wide variety of environments they are exposed to during their complex life cycle. Each stage in the life cycle of an apicomplexan organism is ...

s 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.Murray, Patrick R., Ken S. Rosenthal, and Michael A. Pfaller. Medical Microbiology. 5th ed. Philadelphia: Elsevier Inc., 2005: 855–856. Zygotes are formed by

microgamete {{Short pages monitor

History

The organism was first described in 1907 by Tyzzer, who recognised it was a

coccidia Coccidia (Coccidiasina) are a subclass of microscopic, spore-forming, single-celled obligate intracellular parasites belonging to the apicomplexan class Conoidasida. As obligate intracellular parasites, they must live and reproduce within an a ...

Research

A recombinant ''Cryptosporidium parvum''

surface protein ( rCP15/60) vaccine has produced an antibody response in a large group of cows and also antibody response in calves fed rCP15/60-immune

colostrum Colostrum, also known as beestings or first milk, is the first form of milk produced by the mammary glands of mammals (including humans) immediately following delivery of the newborn. Colostrum powder is rich in high protein and low in sugar and ...

produced by these vaccinated cows. This is very promising. Human ''Cryptosporidium parvum'' infections are particularly prevalent and often fatal in neonates in developing countries and to

people, such as AIDS patients. There is no commercially available effective vaccine against ''Cryptosporidium parvum'', although passive immunization utilizing different zoite surface (glyco)proteins has shown promise. Developmental stages of the life cycle of the parasite might act as possible targets for vaccine development. The organism is detected in 65–97% of the surface-water supply in the United States and is resistant to most disinfectants used for the treatment of drinking water.

Antibodies An antibody (Ab), also known as an immunoglobulin (Ig), is a large, Y-shaped protein used by the immune system to identify and neutralize foreign objects such as pathogenic bacteria and viruses. The antibody recognizes a unique molecule of the ...

in the serum of humans and animals infected with ''Cryptosporidium parvum'' react with several antigens, one of which is a 15 protein ( CP15) located on the surface of the organism. This protein is a good candidate for use as a molecular vaccine because previous studies have shown that a

monoclonal antibody A monoclonal antibody (mAb, more rarely called moAb) is an antibody produced from a cell Lineage made by cloning a unique white blood cell. All subsequent antibodies derived this way trace back to a unique parent cell. Monoclonal antibodies ca ...

to CP15 confers

passive immunity Passive immunity is the transfer of active humoral immunity of ready-made antibodies. Passive immunity can occur naturally, when maternal antibodies are transferred to the fetus through the placenta, and it can also be induced artificially, when hi ...

to mice. Currently, there is no vaccine or completely effective drug therapy against ''Cryptosporidium parvum'' in HIV/AIDS individuals. A summary of discoveries presented at the most recent (June 2019) international symposium on ''Cryptosporidium'' has been published in 2020.

Other animals

The most important

zoonotic A zoonosis (; plural zoonoses) or zoonotic disease is an infectious disease of humans caused by a pathogen (an infectious agent, such as a bacterium, virus, parasite or prion) that has jumped from a non-human (usually a vertebrate) to a human. ...

reservoirs are

cattle Cattle (''Bos taurus'') are large, domesticated, cloven-hooved, herbivores. They are a prominent modern member of the subfamily Bovinae and the most widespread species of the genus ''Bos''. Adult females are referred to as cows and adult mal ...

sheep Sheep or domestic sheep (''Ovis aries'') are domesticated, ruminant mammals typically kept as livestock. Although the term ''sheep'' can apply to other species in the genus ''Ovis'', in everyday usage it almost always refers to domesticated s ...

and

goat The goat or domestic goat (''Capra hircus'') is a domesticated species of goat-antelope typically kept as livestock. It was domesticated from the wild goat (''C. aegagrus'') of Southwest Asia and Eastern Europe. The goat is a member of the a ...

s. In addition, in recent years, cryptosporidiosis has plagued many commercial

leopard gecko The leopard gecko or common leopard gecko (''Eublepharis macularius'') is a ground-dwelling lizard native to the rocky dry grassland and desert regions of Afghanistan, Iran, Pakistan, India, and Nepal. The leopard gecko has become a popular pet, ...

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.

Notable cases

Before 2000

* In 1987, 13,000 people in Carrollton, Georgia, United States, 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 outbreak occurred in

Milwaukee Milwaukee ( ), officially the City of Milwaukee, is both the most populous and most densely populated city in the U.S. state of Wisconsin and the county seat of Milwaukee County. With a population of 577,222 at the 2020 census, Milwaukee is ...

, Wisconsin, US. An estimated 403,000 people became ill, including 4,400 people hospitalized. The source of the Cryptosporidium is believed to be overflow from the Milwaukee area combined sanitary and storm sewer system into

Lake Michigan Lake Michigan is one of the five Great Lakes of North America. It is the second-largest of the Great Lakes by volume () and the third-largest by surface area (), after Lake Superior and Lake Huron. To the east, its basin is conjoined with that o ...

, which was then taken into the Howard Avenue Water Purification Plant and distributed to an estimated 880,000 residents (of the 1.61 million residents in the

Milwaukee area The Milwaukee metropolitan area (also known as Metro Milwaukee or Greater Milwaukee) is a major metropolitan area located in Southeastern Wisconsin, consisting of the city of Milwaukee and the surrounding area. There are several definitions of the ...

who receive their drinking water from Lake Michigan). These residents, who receive their drinking water from Lake Michigan, were told to boil their water before drinking it. More people were affected in this one outbreak than the combined number of people affected in every cryptosporidiosis outbreak in the 24 years since then. An estimated 69 people died during the outbreak, according to the CDC. * The UK's biggest outbreak occurred in

Torbay Torbay is a borough and unitary authority in Devon, south west England. It is governed by Torbay Council and consists of of land, including the resort towns of Torquay, Paignton and Brixham, located on east-facing Tor Bay, part of Lyme ...

Devon Devon ( , historically known as Devonshire , ) is a ceremonial and non-metropolitan county in South West England. The most populous settlement in Devon is the city of Plymouth, followed by Devon's county town, the city of Exeter. Devon is ...

in 1995. * In the summer of 1996, ''Cryptosporidium'' affected approximately 2,000 people in

Cranbrook, British Columbia Cranbrook ( ) is a city in southeast British Columbia, Canada, located on the west side of the Kootenay River at its confluence with the St. Mary River (British Columbia), St. Mary's River. It is the largest urban centre in the region known as the ...

Canada Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tot ...

. Weeks later, a separate incident occurred in

Kelowna, British Columbia Kelowna ( ) is a city on Okanagan Lake in the Okanagan Valley in the southern interior of British Columbia, Canada. It serves as the head office of the Regional District of Central Okanagan. The name Kelowna derives from the Okanagan word ''ki ...

, where 10,000 to 15,000 people got sick.

2001–2009

* In April 2001, an outbreak occurred in the city of

North Battleford, Saskatchewan North Battleford is a city in west-central Saskatchewan, Canada. It is the seventh largest city in the province and is directly across the North Saskatchewan River from the Town of Battleford. Together, the two communities are known as "The Batt ...

, Canada. Between 5800 and 7100 people had 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, in the

Finger Lakes The Finger Lakes are a group of eleven long, narrow, roughly north–south lakes located south of Lake Ontario in an area called the ''Finger Lakes region'' in New York, in the United States. This region straddles the northern and transitional ...

region of

upstate New York Upstate New York is a geographic region consisting of the area of New York State that lies north and northwest of the New York City metropolitan area. Although the precise boundary is debated, Upstate New York excludes New York City and Long Is ...

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

Gwynedd Gwynedd (; ) is a county and preserved county (latter with differing boundaries; includes the Isle of Anglesey) in the north-west of Wales. It shares borders with Powys, Conwy County Borough, Denbighshire, Anglesey over the Menai Strait, and C ...

and

Anglesey Anglesey (; cy, (Ynys) Môn ) is an island off the north-west coast of Wales. It forms a principal area known as the Isle of Anglesey, that includes Holy Island across the narrow Cymyran Strait and some islets and skerries. Anglesey island ...

areas of

North Wales , area_land_km2 = 6,172 , postal_code_type = Postcode , postal_code = LL, CH, SY , image_map1 = Wales North Wales locator map.svg , map_caption1 = Six principal areas of Wales common ...

, the United Kingdom, suffered an outbreak of cryptosporidiosis. The outbreak may have been linked to the drinking water supply from

Llyn Cwellyn Llyn Cwellyn (''Llyn Quellyn'' in some antiquated texts) 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 Moel Eilio and Mynydd Mawr in the north ...

, but this is not yet confirmed. As a result, 231 people fell ill and the company

Welsh Water Welsh may refer to: Related to Wales * Welsh, referring or related to Wales * Welsh language, a Brittonic Celtic language spoken in Wales * Welsh people People * Welsh (surname) * Sometimes used as a synonym for the ancient Britons (Celtic peopl ...

(Dwr Cymru) advised 61,000 people to boil their water before use. * In March 2007, a suspected outbreak occurred in

Galway Galway ( ; ga, Gaillimh, ) is a City status in Ireland, city in the West Region, Ireland, West of Ireland, in the Provinces of Ireland, province of Connacht, which is the county town of County Galway. It lies on the River Corrib between Lo ...

Ireland Ireland ( ; ga, Éire ; Ulster Scots dialect, Ulster-Scots: ) is an island in the Atlantic Ocean, North Atlantic Ocean, in Northwestern Europe, north-western Europe. It is separated from Great Britain to its east by the North Channel (Grea ...

, after the source of water for much of the county,

Lough Corrib Lough 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 largest lake within the Republic of Ireland and the second largest on the island of Ireland (after Lough Nea ...

, 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 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 /ˈdaɪpə(r)/ (American and Canadian English) or a nappy ( Australian English, British English, and Hiberno-English) is a type of underwear that allows the wearer to urinate or defecate Defecation (or defaecation) follows dig ...

s. As of 10 September 2007 the

Utah Department of Health The Utah Department of Health is the Government of Utah's body responsible for public health. It is headquartered in the Cannon Health Building in Salt Lake City. Services In July 2014 the Utah Department of Health issued its first permits for ...

had reporte
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''

outbreak In epidemiology, an outbreak is a sudden increase in occurrences of a disease when cases are in excess of normal expectancy for the location or season. It may affect a small and localized group or impact upon thousands of people across an entire ...

attacked the

Western United States The Western United States (also called the American West, the Far West, and the West) is the region comprising the westernmost states of the United States. As American settlement in the U.S. expanded westward, the meaning of the term ''the Wes ...

: 230

Idaho Idaho ( ) is a state in the Pacific Northwest region of the Western United States. To the north, it shares a small portion of the Canada–United States border with the province of British Columbia. It borders the states of Montana and Wyom ...

residents, with hundreds across the

Rocky Mountain The Rocky Mountains, also known as the Rockies, are a major mountain range and the largest mountain system in North America. The Rocky Mountains stretch in straight-line distance from the northernmost part of western Canada, to New Mexico in ...

area; in the

Boise Boise (, , ) is the capital and most populous city of the U.S. state of Idaho and is the county seat of Ada County. On the Boise River in southwestern Idaho, it is east of the Oregon border and north of the Nevada border. The downtown area' ...

and

Meridian Meridian or a meridian line (from Latin ''meridies'' via Old French ''meridiane'', meaning “midday”) may refer to Science * Meridian (astronomy), imaginary circle in a plane perpendicular to the planes of the celestial equator and horizon * ...

areas;

Utah Utah ( , ) is a state in the Mountain West subregion of the Western United States. Utah is a landlocked U.S. state bordered to its east by Colorado, to its northeast by Wyoming, to its north by Idaho, to its south by Arizona, and to it ...

, 1,600

illnesses A disease is a particular abnormal condition that negatively affects the structure or function of all or part of an organism, and that is not immediately due to any external injury. Diseases are often known to be medical conditions that a ...

;

Colorado Colorado (, other variants) is a state in the Mountain West subregion of the Western United States. It encompasses most of the Southern Rocky Mountains, as well as the northeastern portion of the Colorado Plateau and the western edge of t ...

and other Western states —

Montana Montana () is a state in the Mountain West division of the Western United States. It is bordered by Idaho to the west, North Dakota and South Dakota to the east, Wyoming to the south, and the Canadian provinces of Alberta, British Columbi ...

, decrease. * On 25 June 2008, ''Cryptosporidium'' was found in England in water supplies in

Northampton Northampton () is a market town and civil parish in the East Midlands of England, on the River Nene, north-west of London and south-east of Birmingham. The county town of Northamptonshire, Northampton is one of the largest towns in England; ...

Daventry Daventry ( , historically ) is a market town and civil parish in the West Northamptonshire unitary authority in Northamptonshire, England, close to the border with Warwickshire. At the 2021 Census Daventry had a population of 28,123, making ...

, and some surrounding areas supplied from the

Pitsford Pitsford is a village and civil parish in West Northamptonshire in the United Kingdom. According to 2001 census, the parish's population was 636 people, increasing to 671 at the 2011 census. The village's name means 'Peoht's ford'. Pitsford ...

Reservoir, as reported on th
BBC
People in the affected areas were warned not to drink tap water unless it had been boiled.

Anglian Water Anglian Water is a water company that operates in the East of England. It was formed in 1989 under the partial Water privatisation in England and Wales, privatisation of the water industry. It provides water supply, sewerage and sewage treatment ...

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 the hottest of the four temperate seasons, occurring after spring and before autumn. At or centred on the summer solstice, the earliest sunrise and latest sunset occurs, daylight hours are longest and dark hours are shortest, wit ...

of 2008; many public swimming areas, water parks, and public pools in the Dallas/Fort Worth Metroplex of

Texas Texas (, ; Spanish language, Spanish: ''Texas'', ''Tejas'') is a state in the South Central United States, South Central region of the United States. At 268,596 square miles (695,662 km2), and with more than 29.1 million residents in 2 ...

suffered an outbreak of cryptosporidiosis. Burger's Lake in

Fort Worth Fort Worth is the fifth-largest city in the U.S. state of Texas and the 13th-largest city in the United States. It is the county seat of Tarrant County, covering nearly into four other counties: Denton, Johnson, Parker, and Wise. According ...

was the first to report such an outbreak. This prompted some, if not all, city-owned and private pools to close and hyperchlorinate. To the 13 August 2008 there were 400 reported cases of ''Cryptosporidium''. * In September 2008, a gym in

Cambridge Cambridge ( ) is a university city and the county town in Cambridgeshire, England. It is located on the River Cam approximately north of London. As of the 2021 United Kingdom census, the population of Cambridge was 145,700. Cambridge bec ...

, the United Kingdom, 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.

2010 and later

* In May 2010, the Behana creek water supply south of

Cairns Cairns (, ) is a city in Queensland, Australia, on the tropical north east coast of Far North Queensland. The population in June 2019 was 153,952, having grown on average 1.02% annually over the preceding five years. The city is the 5th-most-p ...

, Australia, was found to be contaminated by cryptosporidium. * In July 2010, a local sports center in Cumbernauld (Glasgow, UK) detected traces of cryptosporidium in its swimming pools, causing a temporary closure of the swimming pools. * In November 2010, over 4000 cases of cryptosporidiosis were reported in

Östersund Östersund (; sma, Staare) is an urban area (city) 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, ...

, 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

Skellefteå Skellefteå (, locally ) is a city in Västerbotten County, Sweden. It is the seat of Skellefteå Municipality, which had 73,246 inhabitants in 2021. The city is historically industrial, with mining being a large part of that industry, especial ...

, 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. * In May 2013, in Roscommon, Ireland, another outbreak of the cryptosporidiosis was reported and a boil water notice was issued. This was the second time the parasite was detected in a month in the Roscommon water supply. The source of one of the outbreaks had been linked to the agricultural community. At least 13 people were treated for Cryptosporidiosis.

References

* * * *

External links

''Cryptosporidiosis''
—

Centers for Disease Control and Prevention The Centers for Disease Control and Prevention (CDC) is the national public health agency of the United States. It is a United States federal agency, under the Department of Health and Human Services, and is headquartered in Atlanta, Georgi ...

Aquatics International Article Regarding Infection via Spray Parks

CryptoDB: The ''Cryptosporidium'' Genome Resource
{{Chromalveolate diseases Conoidasida Protozoal diseases Zoonoses Bovine diseases Cat diseases Immunodeficiency