鸡隐孢子虫病治疗试验

作者以高免血清和隐孢子虫卵囊裂解物等10种药物,对113例人工感染鸡病例分4批次共12组进行了治疗试验,以临床症状、剖检变化、排出卵囊的数量及增重额度等指标判定疗效,其结果表明,高免血清及卵囊裂解物对本病具有良好的治疗效果,尤其高免血清的疗效更佳,为本病的治疗创出了新路。     

鸡隐孢子虫病治疗试验

作者以高免血清和隐孢子虫卵囊裂解物等10种药物，对113例人工感染鸡病例分4批次共12组进行了治疗试验，以临床症状、剖检变化、排出卵囊的数量及增重额度等指标判定疗效，其结果表明，高免血清及卵囊裂解物对本病具有良好的治疗效果，尤其高免血清的疗效更佳，为本病的治疗创出了新路。     

宁夏鸡隐孢子虫病调查及人工感染试验

１９９４年８月至１９９６年１０,对宁夏回族自治区银南,银北,固原３地区１２县（市）４个鸡场共计４５９０４只鸡进行了隐孢子虫感染情况抽样调查。结果,隐孢子虫阳性率达３６．８１％,其中蛋用鸡阳性率为３７．５３％,肉用鸡阳性率为３６．２３％,差异不显著,银南,银北,固原三地区阳性率分别为５４．５５％,４１．９４％和１１．００％,银南地区感染率显著高于固原地区。     

鸡隐孢子虫病的防治

鸡隐孢子虫病是一种原虫病.该病不仅对鸡的呼吸系统和肠道造成严重的伤害,还具有较高的感染率和死亡率,严重的影响养殖户的经济效益.因此,做好鸡隐孢子虫病的防治工作十分重要.本文主要从鸡隐孢子虫病的病原学、流行病学、临床症状、病理变化和诊断等方面对鸡隐孢子虫病进行综述,期望为鸡隐孢子虫病的防治提供理论参考.     

鸡隐孢子虫病流行病学调查研究

隐孢子虫病(Cryptosporidiosis)乃是由隐孢子虫属(Cryptosporidium)引起的一种原虫病,同时它又是一种人畜共患病。1907年Tyzzer首次在小鼠胃腺粘膜中发现Cryptosporidium muris。长期以来,隐孢子虫病并未被人们重视。1971年,Paneiera等在美国发现第一例牛犊孢子虫病,特别是1976年Nime又发现了第一例儿童患者之后,才被人们重视。 近年来隐孢子虫病作为人获得性免疫缺陷综合征(艾滋病)的常见并发症,更加得到人们的重视。它也是造成艾滋病患者死亡的主要原因之一;患者发生腹泻,每天可排出6～7公升稀粪,甚至可达到17公升。到目前为止共发现44例,其中15人死亡。 1982年,Keese在检查接触过家畜的健康人时,在12个病人粪便中发现虫体。Moon用患隐孢子虫病的人     

一种威胁养鸡业的鸡隐孢子虫病

隐孢子虫病(Cryptosporidiosis)乃是由隐孢子虫(Cryptosporidium)引起的一种原虫病,同时它又是一种人畜共患病。1907年,Ty33er首先在小鼠胃腺粘膜中发现隐孢子虫(Cryptosporidium muris)。长期以来隐孢子虫并未被人们重视。1971年,Paneiera等在美国发现第一例牛犊隐孢子虫病,特别是1976年Nime又发现了第一例儿童患者之后,才被人们所重视。近年来隐孢子虫病作为人获得性免疫缺陷综合症(艾滋病)的常见并发症,更加得到人们的重视。它也是造成艾滋病患者死亡的主要原因之一。     

Intestinal cryptosporidiosis in chickens

In a retrospective examination of histopathology reports from Aug. 1, 1985, through Sept. 31, 1987, 10 cases of small- or large-intestinal cryptosporidiosis (not epithelial cryptosporidiosis of the bursa of Fabricius) were found in chickens. Infection was evenly distributed among young chickens. Incidence of intestinal cryptosporidiosis increased during 1987. Although all infected birds were clinically ill, signs or gross lesions of intestinal disease were not always present. In all cases, mild to marked histologic lesions were associated with Cryptosporidium sp.; however, intestinal tracts were not cultured for other infectious agents. The numbers of Cryptosporidium sp. and character of inflammatory response were not significantly correlated. A difference (P = 0.01) among intestinal segment (small vs. large) infection with Cryptosporidium was seen. Light-microscopic appearance and organ distribution of Cryptosporidium sp. suggest that in addition to C. baileyi, other Cryptosporidium species infect chickens. Until the diagnostic procedure for outbreaks of gastrointestinal disease in poultry routinely includes histopathology, fecal flotation, and virus, bacteria, and chlamydia cultures, and until species of Cryptosporidium are isolated, identified, reported, and investigated experimentally, the importance of intestinal cryptosporidiosis in chickens will remain unknown.     

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.     

Rapid cytologic diagnosis of respiratory cryptosporidiosis in chickens

A method is presented for the rapid cytologic detection of cryptosporidial oocysts in Diff-Quik and modified Kinyoun acid-fast-stained tracheal imprints. On Diff-Quik-stained preparations, cryptosporidial oocysts were observed attached to the apical ends of respiratory epithelial cells or scattered throughout the imprint. These oocysts were round to oval, measured approximately 6 to 7 micron in diameter, and appeared faintly blue with fine pink granules. In modified Kinyoun acid-fast-stained tracheal imprints, the oocysts usually were pink to bright red against a blue background. Cytologic examination of tracheal imprints following Diff-Quik and modified Kinyoun acid-fast staining provides a rapid, reliable, and economical method for diagnosis of respiratory cryptosporidiosis in poultry.     

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.     

Experimental cryptosporidiosis and infectious bursal disease virus infection of specific-pathogen-free chickens

Specific-pathogen-free chickens orally inoculated at 4 days of age with a moderately pathogenic vaccine strain of infectious bursal disease virus (IBDV) and/or at 5 days of age with Cryptosporidium baileyi oocysts remained free of overt clinical signs throughout a 16-day period postinoculation (PI). The prepatency period for C. baileyi oocyst shedding was shorter in chickens receiving higher numbers of oocysts, but once shedding was detected, there were no obvious differences in shedding patterns among groups receiving 10(3) through 10(6) oocysts. On days 8 and 16 PI, cryptosporidia were located primarily in the bursae of Fabricius. IBDV exposure was associated with bursal follicle atrophy, whereas C. baileyi infection resulted in bursal epithelial hypertrophy and hyperplasia, mild follicle atrophy, and heterophil infiltration of the bursal mucosa. Examination of experimental groups of 30 birds each indicated that concurrent infection with both agents resulted in more severe bursal lesions, more infected birds, and greater numbers of cryptosporidia in infected tissues. At the termination of the trial, 16 days PI, Cryptosporidium infection was associated with a 6% decrease in mean body weight compared with controls.     

Chemoprophylaxis of cryptosporidiosis in chickens, using halofuginone, salinomycin, lasalocid, or monensin

Chemoprophylaxis of Cryptosporidium baileyi infections was attempted by feeding 4 groups of chicks diets containing 3 mg of halofuginone/kg of feed, 60 mg of salinomycin/kg, 75 mg of lasalocid/kg, or 110 mg of monensin/kg. Rations were fed 5 days before oral or intratracheal inoculation with oocysts and were continued for 20 days. None of the drugs prevented C baileyi infections. Clinical signs of respiratory tract disease and gross lesions of airsacculitis were observed in intratracheally inoculated birds in all treatment groups and nonmedicated controls. Orally inoculated birds did not develop clinical signs of infection. Pathogenic bacteria were not isolated from the respiratory tract systems of any chicks. Halofuginone delayed the establishment of infections of the bursa of Fabricius and cloaca, but not of the trachea.     

Abomasal cryptosporidiosis in cattle

A 6-week-old calf and nine feedlot steers shed oocysts similar to Cryptosporidium muris-like oocysts. There were massive populations of this Cryptosporidium in the peptic glands of most of these animals. The oocysts were larger and more oval than the frequently reported type which is generated in the intestines of many animal species and thought to be similar to Cryptosporidium parvum. The pattern of shedding of this newly discovered Cryptosporidium in the steers was continuous over a period of months whereas the C. parvum-like oocysts cease to be shed 1 to several weeks after onset. The nature of the host-parasite interaction in abomasal cryptosporidiosis is yet to be determined. Morphologic changes that resulted from the interaction were an approximate 10% increase in abomasal mucosal thickness, widening of gland lumens in the middle region, and atrophy of epithelium in the same region.     

Fatal cryptosporidiosis in quail

Young quails kept in wire-floored cages experienced high mortality, beginning at age 5 days, from diarrhea that was unresponsive to antibiotic therapy. At necropsy, the small intestine had clear fluid content and the cecum was distended by brown foamy fluid. Histopathologic findings in the small intestine were shortened villi with detached enterocytes at the tip. Cryptosporidium sp. (confirmed by electron microscopy) were numerous in the microvillous border. Neither bacterial nor viral pathogens were detected. No infection was established in day-old chickens gavaged with feces and intestinal contents from infected quails. Thorough cleansing of the cages followed by application of commercial bleach prevented recurrence.