隐孢子虫病研究近况

隐孢子虫病(Ｃｒｙｔｏｒｒｉｏｄｉｓｉｓ)是一种人畜共患的、广泛存在的寄生性原虫病。病原是隐孢子虫,是仅次于轮状病毒的主要肠道疾病。隐孢子虫广泛寄生于哺乳动物、禽类、两栖类、鱼类及人的消化道及其它器官中,引起动物腹泻和隐性感染,它还能加速ＭＤ肿瘤的发生,与人的爱滋病(ＡＩＤＳ)有着密切的联系。对免疫力正常的动物来讲,其症状表现为自限性腹泻,当免疫功能缺损时,水泻不止而死亡。1　隐孢子虫病的分布及流行1907年Ｔｙｚｚｅｒ在小鼠胃腺粘膜中首次发现,1929年在鸡的盲肠上皮细胞中发现,自1971年发现第1例犊牛隐孢子虫病及197…     

野生动物隐孢子虫的种类和基因型

隐孢子虫病（Cryptosporidiosis）是一种全球性的人兽共患原虫病,具有广泛的宿主范围,可以感染鸟类、哺乳类、鱼类、爬行类、两栖类以及人在内的240多种动物。野生动物隐孢子虫做为人隐孢子虫病感染的重要传播来源,对其进行生物学研究具有重要的公共卫生意义。本文分别叙述了野生动物隐孢子虫的种类及基因型,为进一步研究野生动物的隐孢子虫病提供了有效的参考。     

隐孢子虫感染动物模型研究进展

隐孢子虫病可致人和多种动物的腹泻等症状,是一种人兽共患原虫病,给人类生命安全带来严重威胁,也给畜牧业带来巨大的损失。建立隐孢子虫的感染动物模型对研究隐孢子虫致病机理、免疫及筛选有效的治疗药物等均具有重要意义。文章就隐孢子虫卵囊的分离与纯化、试验用动物的选择、动物模型的建立方法及影响因素等研究做一综述,介绍了隐孢子虫感染动物模型的研究现状,并对该技术的发展前景进行了分析展望。     

隐孢子虫病检测技术研究进展

隐孢子虫是动物和人腹泻的重要病原,也是人类艾滋病患者的主要致死因素之一.当前,对隐孢子虫病的研究已成为全球寄生虫学研究领域的热点由,于迄今尚无治疗隐孢子虫病感染的特效药物,因此,快速、简便、准确地发现隐孢子虫是控制该病的关键.随着分子生物学技术的应用,隐孢子虫病的检测技术得到了极大的发展.笔者就近年来隐孢子虫病检测技术进行了简要综述.     

鸭隐孢子虫对鹅鸡鹌鹑鸽的感染性试验

隐孢子虫病是近年来发现的人畜共患病,是造成爱滋病患者死亡的重要原因之一。隐孢子虫寄生于哺乳类、鸟类、爬行类及鱼类的粘膜上皮中,有极广泛的宿主。从各种动物分离的隐孢子虫对其宿主以外的动物有广泛的交叉感染性,如从牛粪便中分离出的隐孢子虫可感染猫、狗、山羊、绵羊、豚鼠、人、大鼠、猪、兔、小鼠,由此引起在隐孢子虫分类学上的意见不一。Tzipori等(1980)认为隐孢子虫是单型属     

隐孢子虫病的流行现状

隐孢子虫病是由隐孢子虫(Cryptosporidium)寄生于人类、家养动物及多种野生动物胃肠道引起的一种严重的人畜共患胃肠疾病。该病不但威胁人类健康,亦严重影响畜牧业发展。近年来随着研究的深入,隐孢子虫的流行表现出许多新的特点,危害远远超出了人们的估计。这些特点主要表现在：感染家畜,增加人类感染风险;与动物其他病原混合感染危害加重;感染野生动物,具有自然疫源性;感染海洋和水生动物,造成水体污染;经水源和食物传播引起人类群体感染;暴发感染对人群危害严重。深入开展隐孢子虫病流行病及防控研究对提高公共卫生水平具有重要意义。     

隐孢子虫病防治试验对鸡生理生化指标的影响

隐孢子虫病是全世界流行的一种人畜共患病，是造成爱滋病患者死亡的重要原因之一，对牛、鸡的危害也十分严重，可造成巨大的经济报失，而且还能从动物直接传染给人，是人群发病的主要来源．孢孢子虫自Tyzeer1907年发现以来，前人在其形态、结构、大小、生活史等方面以及隐孢子虫病的流行病学、病理、诊断、防治等方面作了大量研究，但隐孢子虫对其患者的血液学参数及血液生理生化指标的影响这方面的报道较少．为了进一步探索隐孢子虫病的病机，寻找可行的防治方法，我们做了隐孢子虫病预防试验鸡的血液学参数及生理生化指标的测定。1．材料…     

分子生物学技术在隐孢子虫研究中的应用

隐孢子虫是顶复门原虫，主要寄生于人或动物的消化道上皮并引起腹泻，是寄生虫学、环境微生物学研究热点之一。分子生物学技术给隐孢子虫研究注入了强大动力，本文就其在隐孢子虫检测、分子流行病学调查、分类学以及药物设计等研究领域的应用作一综述。     

隐孢子虫研究进展

隐孢子虫病(Cryptosporidiosis)是由隐孢子虫(Cryptosporidium)引起的一种以腹泻为特征的人畜共患寄生原虫病。本病具有广泛的宿主类型，可以寄生于哺乳类、鸟类、爬行类及两栖类等150种以上的人和动物。对于免疫系统正在发育的幼儿和幼畜以及免疫缺陷病人，隐孢子虫入侵的机会较大，免疫系统发育正常的人和动物也能感染该病，但机会小一些。自Tyzzer(1907)在鼠胃腺中发现隐孢子虫以来，一直以为隐孢子虫感染并不常见，是一种条件性病原。直到1976年Nime才报道了第一例人的隐孢子虫病，从此以后，有关此病的报道越来越多，到了1986年，世界卫生组织(WHO)更将本病列为人的爱滋病(AIDS)怀疑指标之一。     

某奶牛场隐孢子虫及其他寄生虫感染情况调查

<正>奶牛常见寄生虫病种类较多,严重影响奶牛生产性能,有的甚至危及奶牛的生命。隐孢子虫是寄生于奶牛体内的一种常见寄生虫~([1])。1985年首次发现了犊牛感染隐孢子虫。隐孢子虫病是由隐孢子虫科隐孢子虫属的多种隐孢子虫寄生于肠黏膜上皮细胞和胃黏膜细胞内引起的一种原虫病,其病原隐孢子虫(Cryptosporidium)可广泛寄生于人类、禽类、哺乳类和两栖类等240多种动物~([2])。本病多发生于犊牛,以严重腹泻为特征。     

Therapy and prevention of cryptosporidiosis in animals

Cryptosporidiosis is a common gastro-intestinal illness in animals and man worldwide. The disease is devastating in immune-suppressed individuals but self-limiting in competent hosts. The infectious stages of the organism (oocysts) are shed in the faeces of affected individuals, survive in adverse environmental conditions and spread by direct contact or through contaminants (food, water). Due to the robustness of the oocysts, their tenacity, tiny size, and resistance to common disinfectants, the parasite is difficult to eradicate from contaminated environments. To obtain sufficient control both treatment of infected hosts and inactivation of oocysts are necessary. Several drugs are commonly used to treat cryptosporidiosis in man and very few in animals but none of them are completely effective in terms of both clinical and parasitological response. Only a few chemical agents are able to inactivate oocysts in the environment including water treatment plants but their application has certain limitations. Therefore, control of cryptosporidiosis remains a global challenge in both veterinary and human medicine. Extensive research has been performed on suitable drugs and disinfectants. Thousands of agents have been tested both in vivo and in vitro. Some are excitingly active in vitro but exhibit poor or no response in clinical trials. Currently, no single or combined drug therapy has proven to be completely effective against this disease. This article will focus on therapy and prevention of cryptosporidiosis in animals including perspectives for new drugs.     

Observations on the epidemiology of bovine cryptosporidiosis in India

The significance of Cryptosporidium as a causative agent of diarrhea has been assessed in bovine for a period of 2 years. A total of 940 faecal samples (470 samples in each year) both from diarrhoeic and non-diarrhoeic bovine (0-12 months age) were examined during three different seasons (rainy season, summer and winter). Overall Cryptosporidium was detected in 17.46% and 18.04% cases in first and second year, respectively. Out of 50.21% diarrhoeic and 49.79% non-diarrhoeic cases Cryptosporidium was detected in 26.79% and 8.13% in first year and 27.49% and 8.59% in second year. Year did not have any significant effect on the occurrence of cryptosporidiosis in bovine during this study period. The prevalence of cryptosporidiosis, both in diarrhoeic (61.64%) and non-diarrhoeic (47.22%) cases was highest in 0-1-month age group (P<0.01). Such a high percentage of cryptosporidiosis in clinically asymptomatic animals indicated that the particular age group of animals might be reservoir for the parasite. During this study period highest prevalence was recorded in rainy season (27.55%) followed by summer (16.99%) and winter (8.71%) (P<0.01). A total of 166 positive cases were genotyped. Molecular characterization of bovine cryptosporidiosis has been carried out by PCR-RFLP analysis of SSU rRNA gene and results indicated that Cryptosporidium parvum mainly responsible for diarrhea in bovine in India.     

隐孢子虫某些生物学特性研究

(1)对长春地区兔、小鼠、牛以及婴幼儿腹泻的隐孢子虫感染情况作了调查,其感染率分别为36%、90%、9/10和1/22;(2)对兔隐孢子虫卵囊排出规律的观察结果表明,每隔6～8d出现一个高峰期,在两个高峰期之间有时检不到卵囊;(3)交叉感染试验,从兔粪便中分离的卵囊经口感染BALB/c乳鼠和雏鸡后,在鼠粪便中检到卵囊,而在鸡粪便中未发现卵囊;(4)建立了兔和鼠的隐孢子虫病动物模型;(5)成功地进行了隐孢子虫体外培养试验;(6)鼠隐孢子虫病的治疗药物筛选结果,10~(-3)mol/L SM520和10~(-6)mol/LSMW在体外对隐孢子虫有杀灭作用;动物试验发现,中药配方I和SMW对鼠隐孢子虫有一定抑制作用.     

Prevalence and geographical distribution of Giardia spp. and Cryptosporidium spp. in dairy farms in Québec.

Giardiasis and cryptosporidiosis are parasitic infections of humans, domestic animals, and wildlife. In cattle, direct transmission through the contamination of barns and/or pasture appears to be the principal mode of infection. In Canada there is only one study reported in the literature on the prevalence of giardiasis and one study on the prevalence of cryptosporidiosis. These studies were done in Alberta and Manitoba, respectively. The purpose of this study was to determine the prevalence of Giardia spp. and Cryptosporidium spp. infections in dairy farms in Québec. Calves were sampled from 505 dairy farms. We are reporting that 45.7% of the farms were found to be positive for Giardia spp. and 88.7% were infected with Cryptosporidium spp.     

隐孢子虫病及其在牦牛中的流行现状

隐孢子虫病是由隐孢子虫寄生于人或动物所引起的常见寄生虫病,其主要症状为腹泻,是一种人兽共患病,不仅对畜牧业经济生产造成损失,也威胁着人类健康。论文从隐孢子虫病的病原学、临床症状、病理变化、诊断与防控以及该病在牦牛中的流行情况等方面进行综述,可为牦牛隐孢子虫病的研究提供参考。     

Prevalence of Cryptosporidium and Giardia in roe deer (Capreolus capreolus) and wild boars (Sus scrofa) in Galicia (NW, Spain)

Faecal samples from 224 roe deer (Capreolus capreolus) and 381 wild boars (Sus scrofa) shot during the 2008-2009 hunting season (August-January) in Galicia (NW Spain) were examined to determine the presence and intensity of infection by Cryptosporidium and Giardia. Analysis of a single sample from each of the roe deer revealed that the prevalence of cryptosporidiosis and giardiosis was 1.3% and 5.3% respectively. The prevalence of Giardia infection was significantly higher in juvenile female roe deer than in adult females, but no other significant differences were found in relation to age and sex. In wild boars, the prevalence of cryptosporidiosis and giardiosis was 7.6% and 1.3% respectively. The prevalence of Cryptosporidium infection was significantly higher in juvenile male wild boars than in adult males, but no other significant differences were found in relation to age or sex. In both groups of wild animals, the number of Cryptosporidium oocysts per gram of faeces (OPG) ranged from 5 to 200 and the number of Giardia cysts per gram of faeces (CPG) was between 5 and 47; there were no significant differences between the two groups with respect to number of infections. This is the first large study of Cryptosporidium and Giardia in roe deer and wild boars in hunting areas in Spain and the results demonstrate a low, but widespread prevalence of Cryptosporidium and Giardia in these animals.     

Prevalence of cryptosporidiosis in dairy cattle, cattle-keeping families, their non-cattle-keeping neighbours and HIV-positive individuals in Dagoretti Division, Nairobi, Kenya

This paper reports a study estimating the prevalence of cryptosporidiosis, an emerging zoonosis, in people and cattle in Dagoretti, Nairobi. A repeated cross-sectional survey was carried out among randomly selected cattle keepers in Dagoretti, their dairy cattle and their non-cattle-keeping neighbours in the dry and wet seasons of 2006. A survey was also carried out among a group of people living with human immunodeficiency virus (HIV). Faecal samples were examined for Cryptosporidium oocysts using the modified Ziehl-Neelsen method; 16?% of the samples were also examined using immunofluorescence antibody (IFA) technique. Quality control consisted of blind reviews of slides, examining split samples and confirming slide results with IFA. We found that members of dairy households had a dry season cryptosporidiosis prevalence of 4?% and wet season prevalence of 0.3?%, and non-dairy households, a prevalence of 5 and 0?%, respectively. The cattle dry season prevalence was 15?%, and the wet season prevalence, 11?%. The prevalence in people living with HIV was 5?%. The laboratory quality control system showed some inconsistency within and between different tests, indicating challenges in obtaining consistent results under difficult field and working conditions. In conclusion, this is the first reported study to simultaneously survey livestock, livestock keepers and their neighbours for cryptosporidiosis. We failed to find evidence that zoonotic cryptosporidiosis is important overall in this community. This study also draws attention to the importance of quality control and its reporting in surveys in developing countries.     

Age-related and housing-dependence of Cryptosporidium infection of calves from dairy and beef herds in South Bohemia, Czech Republic

Data of the prevalence, age-related and housing-dependence of naturally acquired cryptosporidiosis on 11 dairy and 11 beef farms in South Bohemia (Czech Republic) were collected. The farms were visited over four consecutive years (from 2002 to 2005). The prevalence of Cryptosporidium in pre-weaned (animals until second month of age) and post-weaned (animals from the third month of age) calves was determined. A total of 7001 faecal samples were collected, concentrated by Sheather's floatation method and stained by aniline-carbol-methyl violet. All samples were examined by light microscopy. Cryptosporidium parvum and C. andersoni oocysts were differentiated on morphological criteria. Of the 7021 specimens, 1814 (25.8%) were positive for Cryptosporidium oocysts; 561 samples (8%) for C. parvum and 1253 (17.8%) for C. andersoni. Pre-weaned dairy calves had higher infection levels of C. parvum than pre-weaned beef calves. The prevalence of C. parvum ranged from 1.4 to 56.5% on dairy farms. Only three cases of C. parvum oocysts shedding in pre-weaned calves on beef farms were found. Only one case of C. andersoni infection in pre-weaned calves was detected and no infections of C. parvum in post-weaned calves were found. The prevalence of C. andersoni reached 35.5% on dairy farms and 61.7% on beef farms. Calves that were on pasture all year long, had a lower probability of C. andersoni infection than those calves kept in a cowshed during the winter season.     

Prevalence and control of bovine cryptosporidiosis in German dairy herds

In a 5-year survey regarding its prevalence and importance in five German state veterinary laboratories Cryptosporidium was diagnosed annually in 19-36% of faecal samples either submitted to the laboratories or taken post mortem. In approximately half of the cases no other enteropathogens were detected. However, only 73% of 30 laboratories participating in a questionnaire survey routinely tested for this parasite, and the majority of researchers considered cryptosporidiosis to be of minor importance. In a placebo-controlled field study 152 suckling calves were treated daily against cryptosporidiosis either with sulfadimidine or with halofuginone (Halocur, Intervet) over 1 week. Treatment by oral drench started at the onset of diarrhoea in the herd. Oocyst excretion, faecal consistency and health status were recorded five times for a 3-week period. Oocyst excretion peaked 7-14 days in the placebo group after the onset of diarrhoea, and during that period prevalence and intensity of excretion were significantly lower in the halofuginone-treated group compared to the sulfadimidine and the placebo control groups. The health status (diarrhoea, dehydration) declined in all groups but was significantly (P<0.05-0.001) better in the halofuginone group in the first 2 weeks. Halofuginone effectively (P<0.05-0.001) reduced oocyst excretion and improved the health status of the treated animals, while sulfadimidine had no effect against Cryptosporidium.     

Sheep management and cryptosporidiosis in central Mexico

To establish the association between sheep farm management practices and cryptosporidiosis in Central Mexico, 37 farms were invited and questionnaires answered by owners. Faeces samples were taken from lambs under 3 months old and ewes in the farms. Parasites were identified by modified Ziehl-Neelsen stain. Questionnaire included: general farm information, facilities characteristics, facilities cleaning measures, water use and farm and animal management practices. Farms were grouped in a low (￡3,37%), medium (3.38-49.9%) and high basis (³50%) according to prevalence. Associations (OR) were calculated according to positivity, compared by chi-square test. A general prevalence of 34,33% was found. Five variables showed statistical significance (p<0.05). Associations found were: use of bed, grazing place, and bottle cleaning. The only association found between management practices and cryptosporidiosis that could represent a risk was the grazing place. This report is the first one in the country regarding predisposing conditions for cryptosporidiosis.