Cryptosporidiosis, also known as crypto, is a parasitic disease caused by Cryptosporidium, a genus of protozoan parasites in the phylum Apicomplexa. It affects the distal small intestine and can affect the respiratory tract in both immunocompetent (i.e., individuals with a normal functioning immune system) and immunocompromised (e.g., persons with HIV/AIDS or autoimmune disorders) 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 fomites in respiratory secretions.
Cryptosporidium is commonly isolated in HIV-positive 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 of the Cryptosporidium organism.
|Micrograph showing cryptosporidiosis. The cryptosporidium are the small, round bodies in apical vacuoles on the surface of the epithelium. H&E stain. Colonic biopsy.|
Cryptosporidiosis may occur as an asymptomatic infection, 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 immune system. Symptoms usually appear 5–10 days after infection (range: 2–28 days) and normally last for up to 2 weeks in immunocompetent individuals; symptoms are usually more severe and persist longer in immunocompromised individuals. Following the resolution of diarrhea, symptoms can reoccur after several days or weeks due to reinfection. The likelihood of re-infection 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 respiratory tract as well. In immunocompromised persons, cryptosporidiosis may disseminate to other organs, including the hepatobiliary system, pancreas, upper gastrointestinal tract, and urinary bladder; pancreatic and biliary infection can involve acalculous cholecystitis, sclerosing cholangitis, papillary stenosis, or pancreatitis.
Common signs and symptoms of intestinal cryptosporidiosis include:
Less common or rare signs and symptoms include:
Symptoms of upper respiratory cryptosporidiosis include:
Symptoms of lower respiratory cryptosporidiosis include:
Cryptosporidium is a genus of protozoan pathogens which is categorized under the phylum Apicomplexa. Other apicomplexan pathogens include the malaria parasite Plasmodium, and Toxoplasma, the causative agent of toxoplasmosis. 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 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:
DNA studies suggest a relationship with the gregarines rather than the coccidia. The taxonomic position of this group has not yet been finally agreed upon.
The genome of Cryptosporidium parvum was sequenced in 2004 and was found to be unusual amongst Eukaryotes in that the mitochondria seem not to contain DNA. A closely related species, C. hominis, also has its genome sequence available. CryptoDB.org is a NIH-funded database that provides access to the Cryptosporidium genomics data sets.
Infection is through contaminated material such as earth, water, uncooked or cross-contaminated food that has been in contact with the feces of an infected individual or animal. Contact must then be transferred to the mouth and swallowed. It is especially prevalent amongst those in regular contact with bodies of fresh water including recreational water such as swimming pools. Other potential sources include insufficiently treated water supplies, contaminated food, or exposure to feces. The high resistance of Cryptosporidium oocysts to disinfectants such as chlorine bleach enables them to survive for long periods and still remain infective. Some outbreaks have happened in day care related to diaper changes.
The following groups have an elevated risk of being exposed to Cryptosporidium:
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 study, are necessary to determine the sources of specific infections. Cryptosporidium is causing serious illness  more frequently in immunocompromised than in apparently healthy individuals. It may chronically sicken some children, as well as adults who are exposed and immunocompromised. A subset of the immunocompromised population is people with AIDS. Some sexual behaviors can transmit the parasite directly.
Cryptosporidium spp. exist as multiple cell types which correspond to different stages in an infection (e.g., a sexual and asexual stage). As an oocyst – a type of hardy, thick-walled spore – 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 meronts  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.
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 from infections by C. parvum or C. hominis; however, immunocompetent individuals with C. muris infections have been observed excreting oocysts for seven months.
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. Previous infection in immunocompetent individuals produces little resistance to future infection, however it may decrease the severity of disease and the number of oocysts excreted.
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 stain. Giemsa staining can also be performed. Part of the small intestine can be stained with hematoxylin and eosin (H & E), which will show oocysts attached to the epithelial cells.
Detecting antigens is yet another way to diagnose the disease. This can be done with direct fluorescent antibody (DFA) techniques. It can also be achieved through indirect immunofluorescence assay. Enzyme-linked immunosorbent assay (ELISA) also detects antigens.
Polymerase chain reaction (PCR) is another way to diagnose cryptosporidiosis. It can even identify the specific species of Cryptosporidium. If the patient is thought to have biliary cryptosporidiosis, then an appropriate diagnostic technique is ultrasonography. If that returns normal results, the next step would be to perform endoscopic retrograde cholangiopancreatography.
Many treatment plants that take raw water from rivers, lakes, and reservoirs for public drinking water production use conventional filtration technologies. This involves a series of processes, including coagulation, flocculation, sedimentation, and filtration. Direct filtration, which is typically used to treat water with low particulate levels, includes coagulation and filtration, but not sedimentation. Other common filtration processes, including slow sand filters, diatomaceous earth filters and membranes will remove 99% of Cryptosporidium. Membranes and bag and cartridge filters remove Cryptosporidium product-specifically.
While Cryptosporidium is highly resistant to chlorine disinfection, with high enough concentrations and contact time, Cryptosporidium will be inactivated by chlorine dioxide and ozone treatment. The required levels of chlorine generally preclude the use of chlorine disinfection as a reliable method to control Cryptosporidium in drinking water. Ultraviolet light treatment at relatively low doses will inactivate Cryptosporidium. Water Research Foundation-funded research originally discovered UV's efficacy in inactivating Cryptosporidium.
One of the largest challenges in identifying outbreaks is the ability to identify Cryptosporidium in the laboratory. Real-time monitoring technology is now able to detect Cryptosporidium with online systems, unlike the spot and batch testing methods used in the past.
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 stool, and before eating. People should avoid contact with animal feces. They should also avoid possibly contaminated food and water. In addition, 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 6,500 feet (2,000 m) of altitude) will decontaminate it. Heating milk at 71.7 °C (161 °F) 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 NSF International National Sanitation Foundation. Bottled drinking water is less likely to contain Cryptosporidium, especially if the water is from an underground source.
People with cryptosporidiosis should not swim in communal areas because the pathogen can reside in the anal and genital areas and be washed off. They should wait until at least two weeks after diarrhea stops before entering public water sources, since oocysts can still be shed for a while. Also, they should stay away from immunosuppressed people. Immunocompromised people should take care to protect themselves from water in lakes and streams. They should also stay away from animal stools and wash their hands after touching animals. To be safe, they should boil or filter their water. They should also wash and cook their vegetables.
The US CDC notes the recommendation of many public health departments to soak contaminated surfaces for 20 minutes with a 3% hydrogen peroxide (99% kill rate) and then rinse them thoroughly, with the caveat that no disinfectant is guaranteed to be completely effective against Cryptosporidium. However, hydrogen peroxide is more effective than standard bleach solutions.
Symptomatic treatment primarily involves fluid rehydration, electrolyte replacement (sodium, potassium, bicarbonate, and glucose), and antimotility agents (e.g., loperamide). Supplemental zinc may improve symptoms, particularly in recurrent or persistent infections or in others at risk for zinc deficiency.
Immunocompetent individuals with cryptosporidiosis typically suffer a short (i.e., duration of less than 2 weeks) self-limiting course of diarrhea that may require symptomatic treatment and ends with spontaneous recovery; in some circumstances, antiparasitic medication may be required (e.g., recurrent, severe, or persistent symptoms); however reinfection frequently occurs.
As of 2015, nitazoxanide is the only antiparasitic drug treatment with proven efficacy for cryptosporidiosis in immunocompetent individuals; however, it lacks efficacy in severely immunocompromised patients. Certain agents such as paromomycin and azithromycin are sometimes used as well, but they only have partial efficacy.
In immunocompromised individuals, such as AIDS patients, cryptosporidiosis resolves slowly or not at all, and frequently causes a particularly severe and persistent form of watery diarrhea coupled with a greatly decreased ability to absorb key nutrients through the intestinal tract. As a result, infected individuals may experience severe dehydration, electrolyte imbalances, malnutrition, wasting, and potentially death. In general, the mortality rate for infected AIDS patients is based on CD4+ marker counts. Patients with CD4+ counts over 180 cells/mm³ recover with supportive hospital care and medication; but, in patients with CD4+ counts below 50 cells/mm³, the effects are usually fatal within 3 to 6 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.
The best treatment approach is to improve the immune status in immunodeficient individuals using highly active antiretroviral therapy that includes an HIV protease inhibitor along with continued use of antiparasitic medication. Antiparasitic drug treatment for immunocompromised individuals usually involves the combination of nitazoxanide, paromomycin, and azithromycin together; these drugs are only partially active in HIV/AIDS patients compared to their effect in immunocompetent persons. A Cochrane Collaboration review recommended that nitazoxanide be considered for use in treatment despite its reduced effectiveness in immunocompromised individuals.
Currently, research is being done in molecular-based immunotherapy. For example, synthetic isoflavone derivates have been shown to fight off Cryptosporidium parvum both in vitro and in animal studies. Derivates of nitazoxanide, known as thiazolides, have also shown promising results in vitro.
Cryptosporidiosis is found worldwide. It causes 50.8% of water-borne diseases that are attributed to parasites. In developing countries, 8–19% of diarrheal diseases can be attributed to Cryptosporidium. Ten percent of the population in developing countries excretes oocysts. In developed countries, the number is lower at 1–3%. The age group most affected are children from 1 to 9 years old.
A recombinant Cryptosporidium parvum oocyst 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 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 immunocompromised 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 in the serum of humans and animals infected with Cryptosporidium parvum react with several antigens, one of which is a 15 kDa 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 to CP15 confers passive immunity to mice. Currently, there is no vaccine or completely effective drug therapy against Cryptosporidium parvum in HIV/AIDS individuals.
The most important zoonotic reservoirs are cattle, sheep and goats. In addition, in recent years, cryptosporidiosis has plagued many commercial leopard gecko breeders. Several species of the Cryptosporidium family (C. serpentes and others) are involved, and outside of geckos it has been found in monitor lizards, iguanas and tortoises, as well as several snake species.
Recent evidence indicates that respiratory cryptosporidiosis may occur commonly in immunocompetent children with cryptosporidial diarrhea and unexplained cough. Findings from animal models, human case reports, and a few epidemiological studies suggest that Cryptosporidium may be transmitted via respiratory secretions, in addition to the more recognized fecal-oral route. ... Upper respiratory cryptosporidiosis may cause inflammation of the nasal mucosa, sinuses, larynx, and trachea, accompanied by nasal discharge and voice change (54, 61, 62). Cryptosporidiosis of the lower respiratory tract typically results in productive cough, dyspnea, fever, and hypoxemia (63,–66). ... While fecal-oral transmission is indisputably the major route of infection, transmission via coughing and fomites is also possible in situations of close contact (20). ... Because they lacked gastrointestinal symptoms and oocyst excretion, the latter cases establish the possibility of primary respiratory infection with Cryptosporidium, which may have been acquired by inhalation of expectorated droplets or by contact with fomites. ... This finding suggests that respiratory cryptosporidiosis may occur commonly in immunocompetent individuals.
After an incubation period of 5–10 days (range 2–28 days), an infected individual develops watery diarrhea ... fever may be low grade or nonexistent; ... Diarrhea, with or without crampy abdominal pain, may be intermittent and scant or continuous, watery, and copious; sometimes, the diarrhea is mucoid. ... Biliary tract involvement is seen in persons with AIDS who have very low CD4 cell counts and is common in children with X-linked immunodeficiency with hyper–immunoglobulin M (IgM). ... Other signs related to GI illness include right upper-quadrant or epigastric tenderness, icterus, and, rarely, ascites related to pancreatic involvement. Reactive arthritis that affects the hands, knees, ankles, and feet has been described.
Healthcare professionals might consider re-testing stool at least 1 week after the last dose of nitazoxanide only if symptoms do not resolve. In such cases, longer courses of treatment might be needed. Persistent symptoms may also represent re-infection
All 58 patients reported resolution of diarrhoea after 7 days of treatment with nitazoxanide. However, 40 (70.1%) patients reported recurrence of diarrhoea within 6 weeks of treatment. ... Our study demonstrates a high prevalence of cryptosporidiosis in immunocompetent adult patients. Nitazoxanide is the recommended antimicrobial drug for cryptosporidiosis. ... The frequency of cryptosporidiosis has not been well-defined. About 30% of the adult population of the United States are seropositive with over 10,500 cases reported in 2008. ... Although we gave 7 days of therapy and a satisfactory treatment response was obtained in the short term, there was a high recurrence rate.21 Paromomycin and/or azithromycin in combination with nitazoxanide have been tested in double blind randomized trials for the treatment of cryptosporidiosis in immunocomprised patients such as those with HIV/AIDS, and the results have been encouraging.18,22,23
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C. muris-infected subjects shed oocysts longer than occurred with other species studied in healthy volunteers. Three volunteers shed oocysts for 7 months. ... Thus, healthy adults are susceptible to C. muris, which can cause mild diarrhea and result in persistent, asymptomatic infection.
Infection may improve with nutritional supplementation, particularly with regimens including zinc or glutamine. ... Nitazoxanide significantly shortens the duration of diarrhea and can decrease the risk of mortality in malnourished children. Trials have also demonstrated efficacy in adults.[26, 27] ... Use of partially active antiparasitic drugs (eg, nitazoxanide or paromomycin combined with azithromycin) should be considered along with initiating antiretroviral therapy. ... Symptomatic therapy includes replacement of fluids, provision of appropriate nutrition, and treatment with antimotility agents. ... Replacement of fluids and electrolytes is the critically important first step in the management of cryptosporidiosis, particularly in patients with large diarrheal losses. Fluids should include sodium, potassium, bicarbonate, and glucose.
The results indicate that nitaxozanide reduces the load of parasites and may be useful in immunocompetent individuals. Due to the seriousness of the potential outcomes of cryptosporidiosis, the use of nitaxozanide should be considered in immunocompromised patients. The absence of effective therapy highlights the need to ensure that infection is avoided. ... For HIV-infected persons, highly active antiretroviral therapy (HAART) is the mainstay of preventing and managing cryptosporidiosis. HAART can lead to complete resolution of clinical symptoms and oocysts (Grube 1997; Maggi 2000; Miao 2000). This intervention is not available for HIV patients who are failing HAART or those unable to access HAART in developing countries. Among these immunocompromised persons without the option of an effective treatment for the underlying disease, supportive management, including rehydration therapy, electrolyte replacement, and anti-motility agents will remain the only alternatives for care until better drugs emerge.
The 1987 Carroll County Cryptosporidiosis outbreak was a significant distribution of the Cryptosporidium protozoan in Carroll County, Georgia. Between January 12 and February 7, 1987, approximately 13,000 of the 65,000 residents of the county suffered intestinal illness caused by the cryptosporidium parasite. Cryptosporidiosis is characterized by watery diarrhea, stomach cramps or pain, dehydration, nausea, vomiting and fever. Symptoms typically last for 1–4 weeks in immunocompetent individuals.The parasite was found to have been transmitted through the public water supply. State health authorities were first alerted to the situation by Mary R. Miles, a health center physician at the University of West Georgia in Carrollton, Georgia.A subsequent investigation by the Centers for Disease Control and Prevention (CDC) confirmed the presence of Cryptosporidium in water samples taken from the municipal water system on January 28, February 4 and February 5. Edward B. Hayes, the lead epidemiologist from CDC, was unable to pinpoint the source of the contamination but "suspected" it was either "infected cattle bathing in a river" that supplied Carrollton's water or a sewage spill later discovered near the municipal water treatment plant.Dennis D. Juranek, also an epidemiologist at the CDC, observed that the treatment plant had at all times met the safe-water standards set by the Environmental Protection Agency (EPA) and questioned whether the standards were "tough enough to ensure that treatment plants snare passing microorganisms." Juranek said: "The Carrollton outbreak would seem to point out that if you're just meeting [EPA] standards, it's probably not adequate."It is believed that removal of mechanical agitators at the flocculation stage resulted in the passage of particulates.1993 Milwaukee Cryptosporidiosis outbreak
The 1993 Milwaukee Cryptosporidiosis 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 (see Town of Lake water tower) was contaminated, and treated water showed turbidity levels well above normal. It was one of two water treatment plants for Milwaukee. The root cause of epidemic was never officially identified; initially it was suspected to be caused by the cattle genotype due to runoff from pastures. It was also thought that melting ice and snowmelt carrying Cryptosporidium may have entered the water treatment plants through Lake Michigan. MacKenzie et al. and the CDC showed that this outbreak was caused by Cryptosporidium oocysts that passed through the filtration system of one of the city's water-treatment plants, arising from a sewage treatment plant's outlet 2 miles upstream in Lake Michigan.
This abnormal condition at the water purification plant lasted from March 23 through April 8, after which, the plant was shut down. Over the span of approximately two weeks, 403,000 of an estimated 1.61 million residents in the Milwaukee area (of which 880,000 were served by the malfunctioning treatment plant) became ill with the stomach cramps, fever, diarrhea and dehydration caused by the pathogen. Deaths have been attributed to this outbreak, mostly among the elderly and immunocompromised people, such as people with AIDS.Antiprotozoal
Antiprotozoal agents (ATC code: ATC P01) is a class of pharmaceuticals used in treatment of protozoan infection.
Protozoans have little in common with each other (for example, Entamoeba histolytica, a unikont eukaryotic organism, is less closely related to Naegleria fowleri, a bikont eukaryotic organism, than it is to Homo sapiens, which belongs to the unikont phylogenetic group) and so agents effective against one pathogen may not be effective against another.
They can be grouped by mechanism or by organism. Recent papers have also proposed the use of viruses to treat infections caused by protozoa.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 plastid called an apicoplast, and an apical complex structure. The organelle is an adaptation that the apicomplexan applies in penetration of a host cell.
The Apicomplexa are unicellular and spore-forming. All species are obligate endoparasites of animals, except Nephromyces, a symbiont in marine animals, originally classified as a chytrid fungus. Motile structures such as flagella or pseudopods are present only in certain gamete stages.
The Apicomplexa are a diverse group that includes organisms such as the coccidia, gregarines, piroplasms, haemogregarines, and plasmodia.
Diseases caused by Apicomplexa include:
Cryptosporidiosis (Cryptosporidium parvum)
Cyclosporiasis (Cyclospora cayetanensis)
Cystoisosporiasis (Cystoisospora belli (formerly known as "Isospora Belli"))
Toxoplasmosis (Toxoplasma gondii)The name of the taxon Apicomplexa derives from two Latin words—apex (top) and complexus (infolds)—and refers to a set of organelles in the sporozoite. The Apicomplexa comprise the bulk of what used to be called the Sporozoa, a group of parasitic protozoans, in general without flagella, cilia, or pseudopods. Most of the Apicomplexa are motile, however, by use of a gliding mechanism
that uses adhesions and small static myosin motors. The other main lines were the Ascetosporea (now in Rhizaria), the Myxozoa (now known to be highly derived cnidarian animals), and the Microsporidia (now known to be derived from fungi). Sometimes, the name Sporozoa is taken as a synonym for the Apicomplexa, or occasionally as a subset.Bobbi Campbell
Robert Boyle "Bobbi" Campbell Jr. (January 28, 1952 – August 15, 1984) was a public health nurse and an early United States AIDS activist. In September 1981, Campbell became the 16th person in San Francisco to be diagnosed with Kaposi's sarcoma, when that was a proxy for an AIDS diagnosis. He was the first to come out publicly as a person with what came to be known as AIDS, writing a regular column in the San Francisco Sentinel, syndicated nationwide, describing his experiences and posting photos of his KS lesions to help other San Franciscans know what to look for, as well as helping write the first San Francisco safer sex manual.He rapidly became one of the leading activists co-founding People With AIDS San Francisco in 1982 and then, the following year, with HIV+ men from across the U.S., he co-wrote the Denver Principles, the defining manifesto of the People With AIDS Self-Empowerment Movement. Appearing on the cover of Newsweek and being interviewed on national news reports, Campbell raised the national profile of the AIDS crisis among heterosexuals and provided a recognizable face of the epidemic for affected communities. He also lobbied Margaret Heckler, Secretary of Health and Human Services in the Reagan administration over both practical issues and stigmatising medical practices affecting people with AIDS. He also continued to campaign for LGBT+ rights, speaking outside the 1984 Democratic National Convention a month before his death from cryptosporidiosis.Cryptosporidium
Cryptosporidium is a genus of apicomplexan parasitic alveolates that can cause a respiratory and gastrointestinal illness (cryptosporidiosis) that primarily involves watery diarrhea (intestinal cryptosporidiosis) with or without a persistent cough (respiratory cryptosporidiosis) in both immunocompetent and immunodeficient humans.Treatment of gastrointestinal infection in humans involves fluid rehydration, electrolyte replacement, and management of any pain. As of January 2015, nitazoxanide is the only drug approved for the treatment of cryptosporidiosis in immunocompetent hosts. Supplemental zinc may improve symptoms, particularly in recurrent or persistent infections or in others at risk for zinc deficiency. Cryptosporidium oocysts are 4–6 µm in diameter and exhibit partial acid-fast staining. They must be differentiated from other partially acid-fast organisms including Cyclospora cayetanensis.Cryptosporidium hominis
Cryptosporidium hominis, along with Cryptosporidium parvum, is among the medically important Cryptosporidium species. It is an obligate parasite of humans that can colonize the gastrointestinal tract resulting in the gastroenteritis and diarrhea characteristic of cryptosporidiosis. Unlike C. parvum, which has a rather broad host range, C. hominis is almost exclusively a parasite of humans. As a result, C. hominis has a low zoonotic potential compared to C. parvum. It is spread through the fecal-oral route usually by drinking water contaminated with oocyst laden feces. There are many exposure risks that people can encounter in affected areas of the world. Cryptosporidium infections are large contributors of child death and illness in heavily effected areas, yet low importance has been placed on both identifying the species and finding more treatment options outside of nitazoxanide for children and AIDS patients.Cryptosporidium parvum
Cryptosporidium parvum is one of several species that cause cryptosporidiosis, a parasitic disease of the mammalian intestinal tract.Primary symptoms of C. parvum infection are acute, watery, and nonbloody diarrhea. C. parvum infection is of particular concern in immunocompromised patients, where diarrhea can reach 10–15 l per day. Other symptoms may include anorexia, nausea/vomiting, and abdominal pain. Extra-intestinal sites include the lung, liver, and gall bladder, where it causes respiratory cryptosporidosis, hepatitis, and cholecystitis, respectively.Infection is caused by ingestion of sporulated oocysts transmitted by the faecal-oral route. In healthy human hosts, the median infective dose is 132 oocysts. The general C. parvum lifecycle is shared by other members of the genus. Invasion of the apical tip of ileal enterocytes by sporozoites and merozoites causes pathology seen in the disease.Infection is generally self-limiting in immunocompetent people. In immunocompromised patients, such as those with AIDS or those undergoing immunosuppressive therapy, infection may not be self-limiting, leading to dehydration and, in severe cases, death.Feline zoonosis
Feline zoonosis are the viral, bacterial, fungal, protozoan, nematode and arthropod infections that can be transmitted to humans from the domesticated cat, Felis catus. Some of these are diseases are reemerging and newly emerging infections or infestations caused by zoonotic pathogens transmitted by cats. In some instances, the cat can display symptoms of infection (these may differ from the symptoms in humans) and sometimes the cat remains asymptomatic. There can be serious illnesses and clinical manifestations in people who become infected. This is dependent on the immune status and age of the person. Those who live in close association with cats are more prone to these infections. But those that do not keep cats as pets are also able to acquire these infections because of the transmission can be from cat feces and the parasites that leave their bodies.People can acquire cat-associated infections through bites, scratches or other direct contact of the skin or mucous membranes with the cat. This includes 'kissing' or letting the animal lick the mouth or nose. Mucous membranes are easily infected when the pathogen is in the mouth of the cat. Pathogens can also infect people when there is contact with animal saliva, urine and other body fluids or secretions, When fecal material is unintentionally ingested, infection can occur. Feline zooinosis can be acquired by a person by inhalation of aerosols or droplets coughed up by the cat.In the United States, thirty-two percent of homes have at least one cat. Some contagious infections such as campylobacteriosis and salmonellosis cause visible symptoms of the disease in cats. Other infections, such as cat scratch disease and toxoplasmosis, have no visible symptoms and are carried by apparently healthy cats.List of MeSH codes (C03)
The following is a list of the "C" codes for MeSH. It is a product of the United States National Library of Medicine.
Source for content is here. (File "2006 MeSH Trees".)List of feline diseases
Feline disease are those infections or diseases that infect cats. Some of these cause symptoms, sickness or the death of the animal. Some of these are symptomatic in a cat but not in other cats. Some are opportunistic and tend to be more serious in cats that already have other sicknesses. Some of these can be treated and the animal can have a complete recovery. Others, like viral diseases, cannot be treated with antibiotics. This is because antibiotics are not effective against viruses.List of notifiable diseases
The following is a list of notifiable diseases arranged by country.Nitazoxanide
Nitazoxanide is a broad-spectrum antiparasitic and broad-spectrum antiviral drug that is used in medicine for the treatment of various helminthic, protozoal, and viral infections. It is indicated for the treatment of infection by Cryptosporidium parvum and Giardia lamblia in immunocompetent individuals and has been repurposed for the treatment of influenza. Nitazoxanide has also been shown to have in vitro antiparasitic activity and clinical treatment efficacy for infections caused by other protozoa and helminths; emerging evidence suggests that it possesses efficacy in treating a number of viral infections as well.Chemically, nitazoxanide is the prototype member of the thiazolides, a class of drugs which are synthetic nitrothiazolyl-salicylamide derivatives with antiparasitic and antiviral activity. Tizoxanide, an active metabolite of nitazoxanide in humans, is also an antiparasitic drug of the thiazolide class.North Battleford
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 Battlefords". North Battleford borders the Rural Municipality of North Battleford No. 437, as well as the North Battleford Crown Colony (census subdivision).The Battlefords are served by the Yellowhead Highway and Highway 4, Highway 26, Highway 29, and Highway 40.
Battlefords Provincial Park is 40 kilometres (25 mi) north on Highway 4.Seneca Lake State Park
Seneca Lake State Park is a 141-acre (0.57 km2) state park located in Seneca County, New York in the United States. 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.WHO Disease Staging System for HIV Infection and Disease in Adults and Adolescents
WHO Disease Staging System for HIV Infection and Disease in Adults and Adolescents was first produced in 1990 by the World Health Organization and updated in September 2005. It is an approach for use in resource limited settings and is widely used in Africa and Asia and has been a useful research tool in studies of progression to symptomatic HIV disease.Following infection with HIV, the rate of clinical disease progression varies enormously between individuals. Many factors such as host susceptibility and immune function, health care and co-infections, as well as factors relating to the viral strain may affect the rate of clinical disease progression.Water supply and sanitation in New Zealand
The provision of water supply and sanitation in New Zealand is generally of good quality in urban areas. It is provided by local government territorial authorities, which include city councils in urban areas and district councils in rural areas. The legal framework includes the Health Act 1956, amended in 2007, the Local Government Act 2002 and the Resource Management Act 1991.
Much of rural New Zealand relies on collection of rainwater for water supply and septic tanks for sewage disposal.Zoonosis
Zoonoses (also known as zoonosis and as zoonotic diseases) are infectious diseases caused by bacteria, viruses and parasites that spread between animals (usually vertebrates) and humans.Major modern diseases such as Ebola virus disease and salmonellosis are zoonoses. HIV was a zoonotic disease transmitted to humans in the early part of the 20th century, though it has now mutated to a separate human-only disease. Most strains of influenza that infect humans are human diseases, although many strains of swine and bird flu are zoonoses; these viruses occasionally recombine with human strains of the flu and can cause pandemics such as the 1918 Spanish flu or the 2009 swine flu. Taenia solium infection is one of the neglected tropical diseases with public health and veterinary concern in endemic regions. Zoonoses can be caused by a range of disease pathogens such as viruses, bacteria, fungi and parasites; of 1,415 pathogens known to infect humans, 61% were zoonotic. Most human diseases originated in animals; however, only diseases that routinely involve animal to human transmission, like rabies, are considered direct zoonosis.Zoonoses have different modes of transmission. In direct zoonosis the disease is directly transmitted from animals to humans through media such as air (influenza) or through bites and saliva (rabies). In contrast, transmission can also occur via an intermediate species (referred to as a vector), which carry the disease pathogen without getting infected. When humans infect animals, it is called reverse zoonosis or anthroponosis. The term is from Greek: ζῷον zoon "animal" and νόσος nosos "sickness".