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Transmission and epidemiology of zoonotic protozoal diseases

PostPosted: Wed Jan 09, 2013 12:06 pm
by patoco
Here is the West, it is uncommon to acquire parasitic conditions that lead to lymphedema. Indeed, toxoplasmosis is the main one here. But, caution needs to be exercised with our beloved household pets as we can also get other parasitic conditions that can due to the fact they lead to infections, seriously effect our edema. This is the case with Zoonotic Protozoal diseases

Transmission and epidemiology of zoonotic protozoal diseases of companion animals.

Jan 2013

Esch KJ, Petersen CA.


Department of Veterinary Pathology, College of Veterinary Medicine, Iowa State University, Ames, Iowa, USA.


SUMMARY Over 77 million dogs and 93 million cats share our households in the United States. Multiple studies have demonstrated the importance of pets in their owners' physical and mental health. Given the large number of companion animals in the United States and the proximity and bond of these animals with their owners, understanding and preventing the diseases that these companions bring with them are of paramount importance. Zoonotic protozoal parasites, including toxoplasmosis, Chagas' disease, babesiosis, giardiasis, and leishmaniasis, can cause insidious infections, with asymptomatic animals being capable of transmitting disease. Giardia and Toxoplasma gondii, endemic to the United States, have high prevalences in companion animals. Leishmania and Trypanosoma cruzi are found regionally within the United States. These diseases have lower prevalences but are significant sources of human disease globally and are expanding their companion animal distribution. Thankfully, healthy individuals in the United States are protected by intact immune systems and bolstered by good nutrition, sanitation, and hygiene. Immunocompromised individuals, including the growing number of obese and/or diabetic people, are at a much higher risk of developing zoonoses. Awareness of these often neglected diseases in all health communities is important for protecting pets and owners. To provide this awareness, this review is focused on zoonotic protozoal mechanisms of virulence, epidemiology, and the transmission of pathogens of consequence to pet owners in the United States.


Re: Transmission and epidemiology of zoonotic protozoal dise

PostPosted: Wed Jan 09, 2013 12:13 pm
by patoco
Protozoan Diseases - CRYPTOSPORIDIOSIS


Extracellular protozoal organisms - similar to coccidia. Genus: Cryptosporidium, it remains unsettled whether more than one species exists. Taxonomy of species somewhat controversial but considered to be infective across species lines.


Rodents, birds (particularly turkeys and chickens), ruminants, fish, reptiles, cats, dogs, rabbits, NHP's. Children over 2 years of age, animal handlers, travelers, homosexual men, and close personal contacts of infected individuals (families, health care and day-care workers) may be particularly likely to be infected. More than a dozen outbreaks have been reported in day-care centers around the world. Two major waterborne outbreaks have been documented. Cryptosporidium antibodies were detected in the serum of 20 of 23 cats (87%) suggesting that the exposure rate may be high.


Fecal-oral transmission is from animals to humans or humans to humans; waterborne transmission is also important. Oocysts passed in stool are fully sporulated and infectious; infection occurs as a result of their ingestion. In humans and animals, the full life cycle occurs within a single host. The organisms attach to the microvillous borders of enterocytes of the small bowel and also are found free in mucosal crypts. The host cell membrane deteriorates, leaving the parasitic membrane in direct contact with epithelial cell cytoplasm. The organisms do not, however, invade the tissues.


Severe watery diarrhea in neonatal calves and lambs. In turkeys and chickens, the parasites are reported to occur in the sinuses, trachea, bronchi, cloaca, and bursa of Fabricius. The respiratory disease causes coughing, gasping, and airsacculitis. In reptiles, cryptosporidiosis is frequently reported in association with postprandial regurgitation. The organism affects the GI mucosa, resulting in marked thickening of the rugae and loss of segmented motility.


In immunocompetent persons, infection varies from no symptoms to mild enteritis to marked watery diarrhea (up to 10 stools daily) without mucus or gross or microscopic blood. Low-grade fever, malaise, nausea, vomiting, abdominal cramps, anorexia and weight loss may occur. The infection is generally self-limited and lasts a few days to about 2 weeks. In immunologically deficient patients, the illness is characterized by profuse (up to 15L daily), cholera-like diarrhea and by fever, severe malabsorption, marked weight loss, and lymphadenopathy. In AIDS, infection may involve any part of the GI tract, and multisystemic involvement has been described, especially involving the respiratory tract.


Diagnosis is by detection of oocysts in stool by a variety of flotation or concentration methods or by mucosal biopsy, followed by special staining methods that use modifications of an acid-fast stain (routine fecal staining methods do not detect the organisms). Three stools should be examined over 5 days. A fluorescein-labeled IgG monoclonal antibody test has recently become available to detect oocysts.


No successful treatment has been developed so far. Generally, no treatment other than supportive is needed in immunocompetent persons since it is self-limiting. In immunoincompetent persons, spiramycin, zidovudine (AZT), paromomycin, octreotide, and eflornithine have been reported of value.


Waterborne outbreaks of cryptosporidiosis.


Chalmers RM.


Cryptosporidium Reference Unit, Public Health Wales, Singleton Hospital, Swansea, UK. E- mail:


Water is the most commonly reported vehicle of transmission in Cryptosporidium outbreaks. While mains drinking water quality is highly regulated in industrialised countries, treated recreational water venues remain highly variable and these have emerged as important settings in the transmission of cryptosporidiosis. Epidemiological investigations of outbreaks benefit from supplementary microbiological evidence and, more recently, the application of molecular typing data to link isolates from cases to each other and to suspected sources. This article documents how waterborne Cryptosporidium outbreaks are identified and reported, how such outbreaks have acted as drivers of regulatory change, and some of the recent developments in the detection and investigation of these outbreaks and their spread, especially the application of molecular typing assays.


Clinical and subclinical infections with Cryptosporidium in animals.

Jan 2013

Santín M.


Cryptosporidium spp. are frequent parasites of livestock and companion animals, raising questions about the clinical significance of such infections. Cryptosporidium infections have a wide spectrum of clinical signs that can vary from asymptomatic to serious infection to death. In neonatal ruminants, cryptosporidiosis is considered an important disease characterised by diarrhoea and mortality. In companion animals most infections are asymptomatic but severe clinical illness has also been reported in dogs, cats and horses. In birds, three main clinical forms of cryptosporidiosis are primarily seen in naturally occurring infections, i.e. respiratory, intestinal, and renal. In reptiles, cryptosporidiosis is an emerging problem given that infections are frequently chronic and lethal. Molecular tools have been developed to detect and differentiate Cryptosporidium at the species/genotype and subtype levels. The use of those tools has led to a more in-depth understanding of the genetic diversity of Cryptosporidium which plays an important role in the diverse clinical presentations of cryptosporidiosis. This review presents an overview of the current knowledge on clinical cryptosporidiosis in livestock, pets, and other animals.

Full Text:

Taylor, Francis Online

Cryptosporidiosis: prevalence and water-related outbreaks of infection.


[Article in Russian]

Turbabina NA.


The data available in the literature show that 1.5-3% of Russia's population is carriers of cryptosporidium oocysts. Cryptosporidia are ascertained to be able to cause diarrhea of varying severity in preschool children. However, cryptosporidiosis in the latter is not frequently diagnosed. The urgency of the problem of cryptosporidiosis is also due to the practically ubiquitous prevalence of the causative agent in nature and to the role of this infection in the development of perinatal diseases, as well as complications in immunocompetent patients (infected and uninfected with AIDS virus). Cryptosporidiasis is an HIV-associated infection and of great importance for the diagnosis of AIDS.


Evaluation of garlic plant and indinavir drug efficacy in the treatment of cryptosporidiosis in experimentally immumosuppressed rats.


Potential effects of global environmental changes on cryptosporidiosis and giardiasis transmission.

Trends in Parasitology

Outbreak of cryptosporidiosis associated with a man-made chlorinated lake--Tarrant County, Texas, 2008.


Innate immune responses against Cryptosporidium parvum infection.


McDonald V, Korbel DS, Barakat FM, Choudhry N, Petry F.


Centre for Digestive Diseases, Barts and the London School of Medicine, Queen Mary College University of London, UK.


Cryptosporidium parvum infects intestinal epithelial cells and is commonly the parasite species involved in mammalian cryptosporidiosis, a major health problem for humans and neonatal livestock. In mice, immunologically mediated elimination of C. parvum requires CD4(+) T cells and IFN-γ. However, innate immune responses also have a significant protective role in both adult and neonatal mice. NK cells and IFN-γ have been shown to be important components in immunity in T and B cell-deficient mice but IFN-γ-dependent resistance has also been demonstrated in alymphocytic mice. Epithelial cells may play a vital role in immunity since once infected these cells have increased expression of inflammatory chemokines and cytokines and demonstrate antimicrobial killing mechanisms, including production of NO and antimicrobial peptides. TLRs facilitate the establishment of immunity in mice and are involved in the development of inflammatory responses of infected epithelial cells and also dendritic cells.