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In this review cryptosporidiosis has been discussed from the historical, clinicopatholoqical, etiological and epidemiological points of view. This ubiquitous protozoan ogranism parasitizes different species of birds, amphibian, fishes., repitles and mammals, was primarily identified, characterized and reported by Tyzzer in 1907. At the present time it is known that the organism to be an important zoonotic, may produce infection and clinical, disease in different species of animals.
Infection and severity of clinical manifestations may be influenced by the state of immunity. in immunocompromized hosts, the infection and clinical signs and symptoms may be severe and sometimes fatal. The clinical manifestations may be a reflection of organs infected, ie, gasterointestinal tract pancreas, billiary tract, lung and conjunctiva.
The cryptosporidial infection has been reported in small intestine of several species of animals by author in Iran, including chickens, calves, lambs and small white labratory mice. In addition, the author has been recently diagnosed cryptosporidiosis of chiken bursa of fabricius and cloaca therefore it is reported. In all cases of cryptosporidiosis diagnosed (except in mice), the presence of cryptosporidium was associated with clinical signs and symptoms. Due to the importance of cryptosporidial infection in human and animals, . he diagnostic laboratories should be aware of the different techniques used in clinical laboratory diagnosis of the organism. In this paper, several useful and available diagnostic methods such as
histopathology using routine staining and histochemical and immunohistochemical staining of tissue speciemens obtained from biopsy or autopsy procedures, ar1d suspected biological excreta, such as fecal materials or respiratory secretion using several laboratory techniques,
have been discuss, During the last decade invasive methods were replaced by the several laboratory tests to indentify oocysts in fecal materials and respiratory secretions as following:
A- Sheater's sugar floatation technique, direct examination of prepared,
fresh unstained slides by a suitable phase contrast microscope
B - Available staining procedures for fecal material or suspected
secretions.
1 - Acid fast stainining Modified Kinyouin cold technique)
2 - Negative staininq
3 - Safranine - methylene blue
4 - Auramine - o, Auramin - Rhodamine
5 Mepacrine
6 - Immunoflourescence staining techniques
7 - Giemsa's stain
Modified kinyouin cold technique is the best method chosen for detection of oocysts in fecal materials, recommended for medical or veterinary medical diagnostic labratories. Auramine - 0 or Auramin Rhodamine staining method is more sensitive, could detect more oocysts in the speciemens. .Staining with mepacrine (a flourescence dye), is simply performed, inexpensive and fast; a suitable method for screening purposes, In the positive cases, the specimens could be stained further by the acid fast methocl, if required.
Immunoflourescence techniques are more sensitive and specific. The method is useful when the number of oocysts in the specimens is little (in asymptomatic carriers).