The relationship of Cryptosporidium sp. infection of the bursa of Fabricius, intestinal tract, and respiratory system of chickens in Georgia, 1974-1988

During 1974-1984, cryptosporidiosis was diagnosed in slightly more than 1% (63/6050 = 1.04%) of histopathology reports on chickens and turkeys made at two Georgia diagnostic laboratories. During 1985-1988, cryptosporidiosis was diagnosed in almost 6% (157/2622 = 5.99%) of histopathology reports on chickens and turkeys made at the two laboratories. Intestinal and respiratory Cryptosporidium sp. infections have increased significantly (p less than 0.01) with time. During the same period, there was no statistical pattern for bursa of Fabricius Cryptosporidium sp. infections, and there was no relationship between the incidence of bursal infections and the incidence of either respiratory or intestinal infections.     

Cryptosporidiosis in neonatal calves: 277 cases (1986-1987)

From January 1986 through December 1987, 277 cases of cryptosporidiosis in calves were diagnosed by the South Dakota State University Diagnostic Laboratory. Cryptosporidium sp was the only pathogen identified in 142 (51.3%) of the calves. Concurrent infections with rotavirus, coronavirus, Escherichia coli, Salmonella sp, bovine viral diarrhea virus, or other pathogens were identified in the remaining 135 calves. After elimination of cases involving autolyzed specimens or calves with chronic diarrhea, records of 11 calves with acute, severe cryptosporidiosis were identified in which Cryptosporidium sp was the only pathogen.     

Light-microscopic lesions associated with naturally occurring bursal cryptosporidiosis in chickens

Information concerning histologic significance of naturally occurring bursal Cryptosporidium sp. infection in chickens was obtained by retrospective examination of histopathology reports and clinical data from histology accessions received during 1986. Cryptosporidiosis was diagnosed in 197 bursas. In two-thirds of the accessions, more than 50% of the examined bursas were infected with Cryptosporidium sp. The histologic morphologic lesion diagnosis for Cryptosporidium sp.-infected bursas most often was marked diffuse chronic-active superficial purulent protozoal bursitis with mucosal epithelial hyperplasia. Our study clearly indicates that Cryptosporidium sp. is associated with inflammation and disturbed growth in chicken bursas. Additionally, our data indicate that Cryptosporidium sp. infection is not dependent on bursal damage attributable to other agents, including infectious bursal disease virus.     

Renal Cryptosporidiosis (Cryptosporidium baileyi) in specific-pathogen-free chickens experimentally coinfected with Marek's disease virus

Renal Cryptosporidiosis was experimentally induced during a study to investigate the pathogenicity of Cryptosporidium baileyi in specific-pathogen-free (SPF) chickens coinfected with Marek's disease virus (MDV). Cryptosporidium baileyi was administered orally at 4 days of age to chickens previously infected at hatching (day 0) with the HPRS 16 strain of oncogenic MDV. Three control groups received MDV at hatching, C. baileyi on day 4, or placebo consisting of distilled water. Renal cryptosporidiosis lesions were induced in the group coinfected with MDV and C. baileyi. The kidneys were markedly swollen and pale, with visible urate crystals in the ureters and surface tubules. Oocysts of C. baileyi were demonstrated in six of seven cases tested by a scoring method with modified Sheather's sugar solution on renal tissue scrapings and were confirmed in three cases by histologic examination of paraffin-embedded kidney sections. Histologic study also revealed subacute interstitial nephritis, acute ureteritis, and attachment of cryptosporidia on the epithelial cell surface of the ureters and collecting ducts, collecting tubules, and distal convoluted tubules. Various developmental stages of the parasite were present in the kidney sections. To our knowledge, this is the first report of experimentally induced renal cryptosporidiosis in SPF chickens coinfected with MDV.     

广东鸡,鸭隐孢子虫种类鉴定与致病性研究

从有患轻微呼吸道症状的鸡和鸭的粪便中分离到隐孢子虫卵囊，并在其组织切片中观察到隐孢子虫。根据卵囊的形态和大小、虫体寄生部位，确定鸡、鸭均为贝氏隐孢子虫感染。用上述鸡、鸭粪便中分离的卵囊，分别经口感染２日龄鸡和鸭各１５只以探索其致病性。感染鸡出现明显呼吸道症状，将引起死亡，气管、支气管、气囊、肺和法氏囊出现大体与显微病变。感染鸭则症状和病变都较鸡轻。结果表明：鸭对贝氏隐孢子虫感染的抵抗力比鸡强。     

Performance and oocyst shedding in broiler chickens orally infected with Cryptosporidium baileyi and Cryptosporidium meleagridis

To study effects of experimental cryptosporidiosis, broiler chickens were infected per os with 5 x 10(5) oocysts of Cryptosporidium baileyi and Cryptosporidium meleagridis. In the first experiment, chickens were infected with oocysts of C. baileyi at the age of 7, 14, and 21 days. In the second experiment, chickens were infected with oocysts of C. baileyi, C. meleagridis, or both cryptosporidial species at the age of 7 days. Although clinical signs of infection were apparent, neither final live weight nor mortality was significanty influenced in chickens infected with a single Cryptosporidium species. In chickens infected with C. meleagridis, the growth retardation was observed in the 2-wk period after infection. The compensatory growth, however, started when the oocyst shedding had ceased. The number of oocysts in excreta specimens of chickens infected with C. meleagridis was two to three times lower than in excreta of chickens infected with C. baileyi. Chickens infected with both C. baileyi and C. meleagridis (5 x 10(5) oocysts of each) had significantly lower final live weight and worse feed efficiency than chickens of other groups. Concurrent infection did not influence individual C. baileyi or C. meleagridis oocyst shedding.     

Interaction of Marek's disease virus and Cryptosporidium baileyi in experimentally infected chickens

Histocompatible B13/B13 white specific-pathogen-free leghorn chickens were used to investigate the effect of coinfection with Cryptosporidium baileyi and the HPRS 16 strain of Marek's disease virus (MDV) in chickens and to assess the pathogenicity of C. baileyi when MDV is given before or after the parasite. Groups of chickens concurrently infected with C. baileyi orally inoculated at day (D)4 and MDV inoculated at hatching (C4M0 group) or at D8 (C4M8 group) were compared with relevant control groups inoculated with only C. baileyi at D4 (C4 group), only MDV at hatching (M0 group) or at D8 (M8 group), and an uninoculated control group (UC group). The chickens were kept in isolator units until the end of the experiment at D62. Our results showed a considerable synergistic effect in concurrently infected chickens and more severe consequences when chickens received MDV before C. baileyi infection. In fact, except for a slight transitory weakness, the chickens in C4 group remained free of overt clinical signs and there was no mortality. However, coinfection with both pathogens induced more lasting or permanent oocyst shedding. Severe clinical cryptosporidiosis with weakness, anorexia, depression, growth retardation, and chronic and severe respiratory disease causing death occurred in all chickens in the C4M0 group between D12 and D43 and in 67% of the chickens in the C4M8 group between D17 and D57. Eighty-two percent and 33%, respectively, died before the development of specific Marek's disease lesions. Mortality rates were 27% and 33% in the M0 and M8 groups, respectively. The presence of MDV enhanced the establishment of more lasting cryptosporidial infection in the respiratory tract, esophagus, crop, proventriculus, and kidneys (only in C4M0 group) as well as in bursa of Fabricius, ceca, and cloaca. Serologic analysis showed that chickens with chronic cryptosporidiosis in the C4M8 group had an increased level of C. baileyi-specific immunoglobulin A. Our results may explain some cases of mortality in chickens naturally infected with MDV and Cryptosporidium.     

Experimental biliary cryptosporidiosis in broiler chickens

Biliary cryptosporidiosis was studied by inoculation of 2 x 10(5) Cryptosporidium baileyi oocysts (AU-B1 isolate) into the gall bladders of ten 6-day-old broiler chickens. Clinical signs of disease were not seen. Three of the 10 chickens developed biliary tract infections, based on histologic examination of tissue sections. Lesions seen in the gall bladders of these birds included epithelial hyperplasia and infiltration of the underlying connective tissue with mononuclear leukocytes. One of these birds also had involvement of the hepatic bile ducts. The bile ducts were mildly dilated and contained lesions similar to those seen in the gall bladder. Few to many cryptosporidia were present in the gall bladders and bile ducts of infected birds. Chickens may be of use in the study of biliary cryptosporidiosis, a common sequel to enteric infection in humans with human immunodeficiency virus infection.     

Cryptosporidiosis in a feline leukemia virus-positive cat

A 4-year-old FeLV-positive cat with a 1-year history of intermittent diarrhea and subsequent anorexia, depression, and weight loss had enteric cryptosporidiosis at necropsy. Cryptosporidium sp is an important cause of gastroenteritis and diarrhea in various species, including human beings with acquired immunodeficiency syndrome. A major determinant of the severity of the disease caused by Cryptosporidium sp is the immunologic status of the affected animal. Cryptosporidiosis should be included in the differential diagnosis of protracted diarrhea in FeLV-positive cats. Because cryptosporidiosis now is recognized as a zoonosis, cats with this disease should be considered a potential source of human infection.     

Cryptosporidium infection as a cause of calf diarrhea

Cryptosporidiosis is a self-limiting protozoal disease of the intestinal tract. Although identified as possible agents of calf diarrhea less than 15 years ago, Cryptosporidium spp. are now believed to be common in calves and in many other host animal species worldwide. Recent literature on all aspects of cryptosporidiosis in calves is reviewed, predicaments in diagnosis and management are discussed, and public health concerns are raised.     

Pathogenesis of Newcastle disease in commercial and specific pathogen-free turkeys experimentally infected with isolates of different virulence

The pathogenesis of five different Newcastle disease virus (NDV) isolates representing all pathotypes was examined in commercial and specific pathogen-free (SPF) turkeys. Experimentally-infected birds were monitored clinically and euthanatized, with subsequent tissue collection, for examination by histopathology, by immunohistochemistry for the presence of NDV nucleoprotein, and by in situ hybridization for the presence of replicating virus. Clinically, the lentogenic pathotype did not cause overt clinical signs in either commercial or SPF turkeys. Mesogenic viruses caused depression in some birds. Turkeys infected with velogenic neurotropic and velogenic viscerotropic isolates showed severe depression, and neurologic signs. Histologic appearances for all strains had many similarities to lesions observed in chickens inoculated with the various isolates; that is, lesions were present predominantly in lymphoid, intestinal, and central nervous tissues. However, in general, disease among turkeys was less severe than in chickens, and turkeys could be considered a subclinical carrier for some of the isolates.     

Small-intestinal cryptosporidiosis in a chicken

Severe small-intestinal cryptosporidiosis was diagnosed in a chicken that had diarrhea, was weak, and had failed to thrive. Intestine segments also were parasitized by Eimeria sp. and bacteria. Disseminated foci of malignant lymphocytes were present in several organs. Spontaneously occurring intestinal cryptosporidiosis has not been reported in chickens.     

Experimental infections in domestic ducks with Cryptosporidium baileyi isolated from chickens

Oral inoculation of 13 ducks (Anas platyrhynchos) with 1 x 10(6) Cryptosporidium baileyi oocysts produced patent infections but no clinical signs of disease. Intratracheal inoculation of 13 ducks with 1 x 10(6) C. baileyi oocysts produced only mild clinical signs of respiratory disease, no deaths, and gross lesions of airsacculitis in only three ducks. The distribution of developmental stages of C. baileyi in ducks was similar to that observed in experimentally infected chickens and turkeys. Results of this study indicate that ducks are more resistant to experimentally induced respiratory cryptosporidiosis caused by C. baileyi than are chickens and turkeys.     

Diarrhea associated with small-intestinal cryptosporidiosis in a budgerigar and in a cockatiel

Small-intestinal cryptosporidiosis has not been described in budgerigars or cockatiels. Organisms of the genus Cryptosporidium were found during histologic examination of segments of small intestine from a budgerigar with chronic weight loss and from a cockatiel that died acutely. Parasitism was accompanied by non-purulent inflammation (lymphocytes and plasma cells predominated). Bacterial and viral pathogens were not isolated. The death of the budgerigar was attributed to malassimilation interpreted to have been caused by Cryptosporidium. The cause of death in the cockatiel was inhalation pneumonia. Because the index of suspicion for cryptosporidiosis was low, samples for isolation of Cryptosporidium were not collected. In the future, cryptosporidiosis should be included as a differential diagnosis for weight loss and death in pet birds, and isolation and speciation of Cryptosporidium sp. should be attempted and reported.     

The effect of heating against Cryptosporidium oocysts

The effect of heat treatment was examined against oocysts of Cryptosporidium parvum, Cryptosporidium muris and chicken Cryptosporidium sp. isolated in Japan. The oocysts of these species were exposed at 50, 55, 60 and 70 degrees C for 5, 15, 30 and 60 sec in water bath, respectively. To determine the infectivity of heated oocysts, the nice and chickens were inoculated with the treated oocysts and the oocyst output in the feces after inoculation was examined. In C. parvum and chicken Cryptosporidium sp., the oocysts were not detected from mice or chickens which were received oocysts heated at 55 degrees C for 30 sec, 60 degrees C for 15 sec and 70 degrees C for 5 sec. In C. muris, the oocysts were not detected from mice which were received oocysts heated at 55 degrees C for 15 sec, 60 degrees C for 15 sec and 70 degrees C for 5 sec. Consequently, it was clarified that the infectivity of Cryptosporidium oocysts to mice and chickens was lost by heating at 55 degrees C for 30 sec, 60 degrees C for 15 sec and 70 degrees C for 5 sec.     

Pulmonary cryptosporidiosis in simian immunodeficiency virus-infected rhesus macaques

Cryptosporidiosis is a common opportunistic infection in the gastrointestinal tract of human and nonhuman primates with AIDS. Pulmonary infection associated with Cryptosporidium spp. has not been previously reported in monkeys. Two macaques experimentally infected with simian immunodeficiency virus (SIV) had lesions containing cryptosporidial organisms involving the trachea, lungs, bile ducts, pancreas, and intestine. The pulmonary sections revealed moderate to severe bronchopneumonia associated with cryptosporidiosis. Numerous 2-4 microm oval Cryptosporidium spp. organisms were present in the cytoplasm of alveolar macrophages, multinucleated giant cells, and intestinal epithelial cells. Giant cells were positive for SIV by in situ hybridization. These are the first reported cases of cryptosporidiosis with involvement of pulmonary parenchyma in SIV-infected macaques.     

The effect of a single disinfection of a farm on cryptosporidiosis infection in calves

The disinfection of a farm with Dikonit (active substance: sodium dichlorocyanuran) exerted no significant influence on the course of the spreading of cryptosporidiosis infections in newborn calves. The oocysts of Cryptosporidium sp., isolated from the faeces of a spontaneously infected calf and left in a 2.5% disinfecting solution of Dikonit under laboratory conditions for four hours, did not lose their viability. Laboratory mice experimentally infected with these "disinfected" oocysts, began to produce oocysts of Cryptosporidium sp. the sixth day from infection. The findings of different developmental stages of this protozoan obtained during the histological examination of the intestinal tissue of test mice are also considered as evidence of successful experimental infection. The cryptosporidium-free period which lasted only 14 days from disinfection was mainly due to thorough mechanical cleaning of the area where the calves were kept after birth. This is also proved by the results of the examination of old residues of calf faeces scraped from the floors: only individual individual oocysts of Cryptosporidium sp. were found in these samples.     

Proliferative enteritis in leopard geckos (Eublepharis macularius) associated with Cryptosporidium sp. infection.

Twenty-three leopard geckos (Eublepharis macularius) with various clinical histories of weight loss, anorexia, lethargy, and diarrhea were submitted either intact or as biopsy specimens to the University of Florida Anatomic Pathology Service. Gross necropsy findings in the intact geckos included marked reduction of subcutaneous adipose tissue stores at the tail base and mild thickening and reddening of the small intestine. Histologic examination revealed Cryptosporidium sp. infection associated with hyperplasia and mononuclear inflammation of the small intestine in all geckos. Parasites and lesions were only rarely observed in the stomach and large intestine of geckos. The histologic and ultrastructural lesions in the small intestine of leopard geckos infected with Cryptosporidium sp. have not been well characterized previously. This report implicates Cryptosporidium sp. as the cause of disease in the geckos and describes the range of histologic lesions observed.     

Experimental pathogenesis for chickens, turkeys, and pigeons of exotic Newcastle disease virus from an outbreak in California during 2002-2003

Exotic Newcastle disease virus (NDV) isolated from chickens during the 2002-2003 California outbreak (CA exotic Newcastle disease [END] virus) was inoculated into 4-week-old specific-pathogen-free (SPF) White Leghorn chickens, 3-week-old SPF Beltsville White turkeys, 6-week-old commercial Broad Breasted White turkeys, and 10- to 20-week-old racing pigeons, and the clinicopathologic features of disease were compared. Birds were monitored clinically and euthanized sequentially with collection of tissues. Tissues were examined by histopathology, by immunohistochemistry to detect viral nucleoprotein, and by in situ hybridization to detect viral mRNA. Clinically, infected chickens and SPF turkeys showed severe depression, and all died or were euthanized because of severe clinical signs by day 5 postinoculation. In these birds, histologic lesions were widespread and virus was detected in multiple organs. All infected commercial turkeys showed mild depression, and incoordination was observed in some birds. Histologic lesions were mild, and viral distribution was limited. In pigeons, only 1 bird showed overt clinical disease, and histologic lesions and viral distribution were present in limited organs. Consequently, susceptibility to highly virulent NDV was shown to vary among chickens, SPF turkeys, commercial turkeys, and pigeons. Additionally, we have evidence of CA END virus subclinical infections that suggest pigeons could be subclinical carriers of other virulent NDV.     

Histologic incidence and distribution of Cryptosporidium sp. infection in chickens: 68 cases in 1986

In 1986, a retrospective examination of histologic data determined that 68 histology accessions at the Georgia Poultry Laboratories had a diagnosis of cryptosporidiosis. These cases represented 6.4% of the 1065 histologic examinations of chickens performed at the facility. Of the protozoan infections, only Eimeria sp. was diagnosed more frequently (105/1065 = 9.9%). Infected chickens came from 11 companies. Most of the cases were significantly (chi 2 = 103, df = 10, P less than 0.001) associated with two of these companies. These chickens ranged in age from 14 to 51 days. The number of cases per age group was significantly correlated (r = 0.85, t = 3.98, df = 6, P less than 0.01) with the number of cases per age group of the population of histology accessions. Additionally, cases of cryptosporidiosis had a significantly (P less than 0.05) uneven temporal distribution in that few cases were diagnosed during the winter.