Prevalence and distribution of bovine coccidia in Japan

A field survey was carried out on prevalence of bovine coccidia in 9 prefectures of Japan in the autumn of 1985. A total of 1,015 fecal samples was obtained from dairy and beef cattle more than 2 weeks old. Coccidial oocysts were found in 59.0% of all the samples examined. There were no significant differences in the prevalence between dairy and beef cattle of the same age group. The prevalence was the highest in the animals between 6 and 11 months old and decreased to 25% in those more than 24 months old. In the majority of the samples positive for oocysts, OPG (the number of oocysts per gram of feces) was less than 200. No clinical coccidiosis was found except in a few cases. Eleven Eimeria and one Isospora species were identified. Of these species, E. bovis and E. ellipsoidalis were the most prevalent, followed by E. aubrunensis, E. brasiliensis, and E. cylindrica in all the prefectures. The other species identified were E. canadensis, E. alabamensis, E. zuernii, E. wyomingensis, E. bukidnonesis, E. subspherica, and Isospora sp. in the order of frequency. Isospora sp. will be a pseudoparasite caused by the contamination with feces of passerine birds.     

Ovine coccidiosis: effect of the antibiotic monensin against Eimeria ninakohlyakimovae and other naturally occurring coccidia of sheep

Sixteen female and 16 male lambs were used in 4 groups to determine the effect of monensin on naturally occurring and experimentally induced coccidiosis. Determinations of numbers of oocysts discharged, quantities of feces discharged, feed consumption, and weight gain were made for female and male lambs in each group. The effect of experimentally induced and naturally occurring coccidiosis on the performance of each group was compared. Nonmedicated lambs, experimentally inoculated with Eimeria ninakohlyakimovae, gained the least weight. Lambs naturally infected with coccidia gained next best and inoculated lambs, in 2 groups medicated with 10 or 20 ppm of monensin in the feed, gained best. The average net gain for the 4 groups was 7.8, 9.7, 13.7, and 13.7 kg. The medicated lambs required less feed/kilogram of weight gain than did the nonmedicated lambs. In general, female lambs were more severely affected by the coccidia, consumed more feed, produced more fecal material, and gained less weight than did male lambs.     

Description of Eimeria pavonina (coccidia) of peafowl in Germany

There are only a few reports about the occurrence of coccidia in peafowl and no reports about the occurrence of Eimeria spp. in peafowl kept in Europe. Here, we describe the occurrence of Eimeria pavonina in diseased peafowl from Germany. In January 2011, one young peacock kept in an aviary showed a marked depression. No parasites were detected in samples from the diseased bird, but in samples of birds from the same and other aviaries, coccidian counts were between 400/g and 66,000/g. All peacocks were treated with toltrazuril. After treatment, the clinical condition of the diseased bird improved but, two weeks afterwards, other birds in the aviary were still shedding coccidia in their feces. Based on morphology, the coccidia were identified as E. pavonina. Parts of the 18s rRNA gene and the cytochrome oxidase subunit 1 (cox-1) gene were sequenced. A phylogenetic tree based on the 18s rRNA sequence placed the Eimeria sp. from peafowl closest to Eimeria spp. found in pheasants and partridges as well as to Eimeria meleagrimitis. A phylogenetic tree based on the sequence of cox-1 in contrast suggested a closer relationship to Eimeria necatrix and Eimeria tenella.     

Gel-Bead Delivery of Eimeria oocysts protects chickens against coccidiosis

Vaccines composed of either virulent or attenuated Eimeria spp. oocysts have been developed as an alternative to medication of feed with ionophore drugs or synthetic chemicals. The purpose of this study was to evaluate the use of gel-beads containing a mixture of Eimeria acervulina, Eimeria maxima, and Eimeria tenella oocysts as a vaccine against coccidiosis. Newly hatched chicks (Gallus gallus domesticus) were either sprayed with an aqueous suspension of Eimeria oocysts or were allowed to ingest feed containing Eimeria oocysts-incorporated gel-beads. Control day-old chicks were given an equivalent number of Eimeria oocysts (10(4) total) by oral gavage. After 3 days, chicks were randomly assigned to individual cages, and feces were collected between days 5 and 8 postinfection. All samples were processed for total Eimeria oocysts. At 4 wk of age, all chickens and a control nonimmunized group received a high-dose E acervulina, E maxima, and E. tenella challenge infection. Oocyst excretion by chicks fed gel-beads or inoculated by oral gavage was 10- to 100-fold greater than that of chicks spray-vaccinated with the Eimeria oocysts mixture (log 6.3-6.6 vs. log 4.8). Subsequent protection against challenge as measured by weight gain and feed conversion efficiency was significantly greater (P < 0.05) in gel-bead and oral gavage groups compared with spray-vaccinated or nonimmunized groups. Also, gel-bead and oral gavage groups showed no significant difference (P > 0.05) in weight gain and feed conversion efficiency compared with nonchallenged controls. These findings indicate that incorporation of Eimeria spp. oocysts in gel-beads may represent an effective way to deliver live oocyst vaccines to day-old chicks for preventing subsequent outbreaks of coccidiosis in the field.     

Immunization of chukar partridges against coccidia (Eimeria kofoidi and Eimeria legionensis) with low doses of live oocysts

Experiments were conducted to determine whether chukar partridge (Alectoris chukar) chicks would develop protective immunity after inoculation with coccidia. Young chukar chicks in battery cages inoculated with 100 or more oocysts of Eimeria kofoidi or Eimeria legionensis had significant protection at challenge 4 wk later, as measured by greatly reduced oocyst shedding and improved weight gain as compared with unvaccinated, challenged controls. However, when birds were housed in litter pens and vaccinated by various regimens (including two species of chukar coccidia at 100/dose), coccidiosis rapidly spread through all treatments and caused significant mortality. Vaccination with Coccivac-T or with 100 oocysts of Eimeria dispersa did not prevent mortality resulting from accidental contamination, and feed treatment with a Lactobacillus competitive-exclusion product had no benefit. Most if not all of the mortality was from E. kofoidi. This study illustrated the natural fecundity of chukar coccidia in a floor-pen environment where multiplication rate and reinfection combine to produce clinical disease from a small original exposure. Further, these results cast doubt on the potential use of low doses of live oocysts as a vaccine in the chukar partridge.     

鸡球虫病弱毒疫苗的免疫机理及研究进展

鸡球虫病是由艾美耳属球虫引起的一种危害性极其严重的寄生原虫病,呈世界性分布,是最主要的鸡病之一。目前主要用抗球虫药物对其进行防制,但随着耐药虫株的产生和药物残留对肉禽品质及人体健康的影响等问题的出现,对鸡球虫活疫苗的研究成为研究热点。作者对鸡球虫弱毒疫苗的免疫机理及其鸡胚传代致弱方法、理化致弱方法和早熟选育致弱法的研究进展作一概述,并对鸡球虫弱毒疫苗的应用前景进行了展望。     

双抗夹心—ELISA诊断牛隐孢子虫病

为了建立双抗体夹心—ＥＬＩＳＡ检测牛粪便中隐孢子虫卵囊抗原的方法。采用抗小球隐孢子虫（Ｃ．ｐａｒｖｕｍ）卵囊壁单克隆抗体,经对６０头份牛粪便样本分别进行抗酸染色和双抗夹心—ＥＬＩＳＡ检测,结果抗酸染色法检出１２头份有隐孢子虫卵囊,而ＥＬＩＳＡ除对抗酸染色阳性的１２份粪样判为阳性外,还对抗酸染色阴性的４份粪样判为阳性,且不与牛球虫、牛结肠小袋纤毛虫发生类属反应。此外,本试验在稀释液中加入ＥＤＴＡ,并增加了反应温度,使得试验在抗体包被板并封闭后３０ｍｉｎ结束整个检测过程。结果表明,双抗体夹心—ＥＬＩＳＡ是敏感性高、特异性强的诊断牛隐孢子虫病的方法。     

柔嫩艾美耳球虫广西南宁株的分离及鉴定

利用从南宁市郊养鸡场球虫病鸡粪便中收集的球虫混合种卵囊感染小鸡,再应用单卵囊分离感染技术,从感染鸡盲肠中收集的卵囊分离纯化获得1株纯种球虫,经鸡体传代增殖,对该虫株的卵囊大小和卵形指数、潜在期、排卵高峰期、最短孢子化时间、寄生部位、致病性等指标进行观察和测定。结果测得该虫株卵囊的平均大小为(25.743±1.94126)μm×(21.4±1.85985)μm,平均卵型指数为1.2067±0.07;潜在期为140 h;其排卵囊峰期在第6～9天,最高峰在第7天;最短孢子化时间为19 h;寄生部位在盲肠;对两周龄的艾维茵鸡,当使用5×104的孢子化卵囊感染剂量时死亡率为7.5%。根据这些测定和观察到的指标综合鉴定该分离株球虫为柔嫩艾美耳球虫,并命名为柔嫩艾美耳球虫广西南宁株(Eimeria.tenella-GXNN),该研究结果为进一步研究本地区鸡球虫病的药物治疗和免疫预防等奠定了基础。     

Comparison of Eimeria species distribution and salinomycin resistance in commercial broiler operations utilizing different coccidiosis control strategies

The purpose of the present study was to evaluate the species composition and salinomycin sensitivity of Eimeria oocysts isolated from commercial broiler farms that differed by means of coccidiosis control (anticoccidial drugs [ACD] vs. live oocyst vaccines [VAC]). A comparison of Eimeria species composition and salinomycin sensitivity was also made before and after a producer switched from salinomycin to live oocyst vaccines. In general, no significant difference was observed in the concentration of Eimeria spp. oocysts in litter from VAC-utilizing farms compared to litter from ACD-utilizing farms. Application of PCR-based methods to detect coccidia found that Eimeria species distribution in litter from VAC operations more closely resembled the species composition in the live oocyst vaccines. Drug sensitivity testing found that Eimeria oocysts from VAC operations displayed greater salinomycin sensitivity as measured by weight gain and feed conversion efficiency compared to oocysts from ACD farms. These findings provide additional evidence for the usefulness of live oocyst vaccines to restore ionophore sensitivity in poultry operations that contain an ionophore-resistant population of Eimeria spp. oocysts.     

Clinical coccidiosis in a boar stud.

This report describes an outbreak of coccidiosis in a boar stud. A live, untreated, adult boar with a history of diarrhea was submitted to the Iowa State University Veterinary Diagnostic Laboratory, Ames, IA. For a 3-month period, approximately 40% of the boars in this stud had developed gray to brown diarrhea that lasted 1-3 days. Affected boars did not lose condition, and antibiotic therapy did not appear to affect the clinical course ofthe disease. At necropsy, the distal ileum was palpably thickened and covered by a thick, yellow-green, fibrinous exudate. Microscopic changes in the ileum consisted of an erosive enteritis associated with the presence of numerous coccidia within mid to superficial villus enterocytes. The mucosa was covered by a fibrinous exudate admixed with numerous nonsporulated coccidian oocysts. A light growth of Salmonella enterica serovar Derby was isolated from the small intestine of this animal, but laboratory tests were negative for Lawsonia and Brachyspira spp. Individual or paired fecal samples were obtained from 6 additional boars experiencing similar clinical signs. Numerous Eimeria spinosa oocysts were identified in these samples. Neither Salmonella nor Brachyspira spp. were cultured from submitted fecal samples. Necropsy of a live boar and examination of feces from 6 additional animals confirmed that the mild, sporadic, transient diarrhea in this boar stud was due to coccidiosis.     

Husbandry risk factors associated with subclinical coccidiosis in young cattle

This paper describes an observational longitudinal study of cattle farms in England and Wales, which aimed to identify management practices associated with the presence of Eimeria spp. infection in young cattle. Thirty cattle farms situated in England and Wales were selected and one group of more than 20 young cattle aged 5-18 months of age was monitored on each farm. Three variables were identified as significantly associated with status in a multivariable model. The odds of finding Eimeria spp. were lower on farms that kept sheep on the same premises as the cattle, as was an increase in the maximum age within the sampled group. The latter probably reflects the development of post-infection immunity within the sampled animals. Good water-trough hygiene protected against Eimeria spp. oocyst excretion, with the odds of detection being higher on farms where it was reported that the water troughs were not cleaned and emptied more than once per month. The value of frequent emptying and cleaning of water troughs in reducing the exposure of calves to Eimeria spp. and thus lowering the impact of coccidiosis, both clinical and subclinical should be communicated to cattle farmers.     

Bovine coccidiosis: protective effects of low-level infection and coccidiostat treatments in calves

Twenty coccidia-free Holstein bull calves were allotted to groups to study effects of treatment with lasalocid and decoquinate on subsequent resistance to coccidiosis (Eimeria spp infections). Calves fed medicated rations of either drug at dosages of 50 mg/kg of feed (approx 1.2 mg/kg of body weight) had significantly fewer oocysts (P less than 0.01) than did nontreated controls regardless of other procedures used. Treated calves premunized with 2,000 oocysts/day for 5 days and later challenge inoculated with 200,000 oocysts did not develop diarrhea, unless the drugs were withdrawn from feed. Animals premunized (2,000 oocysts/day for 5 days) in absence of drug were no more resistant to the challenge inoculation than nonpremunized animals. These results indicated that lasalocid and decoquinate were efficacious coccidiostats and protected calves as long as they were administered. Cessation of drug treatment usually resulted in appearance of oocysts in feces and diarrhea. Premunization alone cannot be expected to prevent coccidiosis when animals are exposed to large numbers of oocysts.     

Higher incidence of Eimeria spp. field isolates sensitive for diclazuril and monensin associated with the use of live coccidiosis vaccination with paracox-5 in broiler farms

Twenty European Eimeria spp. field isolates were subjected to an anticoccidial sensitivity test (AST). The anticoccidial drugs tested were diclazuril (Clinacox) and monensin (Elancoban). The assay was performed in a battery cage trial. Infected medicated birds were compared with an unmedicated control group. Coccidial lesion scores and oocyst shedding were used as parameters. The results of the AST show that resistance is common amongst coccidiosis field isolates, especially Eimeria acervulina (68% and 53% resistance for diclazuril and monensin, respectively). Resistance is less frequent amongst Eimeria maxima (38% and 50% resistance for diclazuril and monensin, respectively) and Eimeria tenella isolates (23% and 38% resistance for diclazuril and monensin, respectively). A highly significant influence of the coccidiosis prevention program (live coccidiosis vaccination with Paracox-5 vs. anticoccidial drugs in feed) on the sensitivity patterns of Eimeria spp. field isolates for both diclazuril (P= 0.000) and monensin (P= 0.001) was found. Further, when looking at the single species and each anticoccidial drug level, significantly more sensitivity of E. acervulina for monensin (P= 0.018), E. maxima for diclazuril (P = 0.009), and E. tenella for diclazuril (P = 0.007) was found in isolates originating from vaccinated flocks. Moreover, for E. acervulina and diclazuril, E. maxima and monensin, and E. tenella and monensin a trend toward higher sensitivity of isolates for these products was found when live coccidiosis vaccination was applied. The present study shows that sensitivity for the anticoccidial drugs diclazuril and monensin is more frequent in Eimeria spp. field isolates originating from broiler farms where a coccidiosis vaccination policy is followed.     

Control of Isospora suis-induced coccidiosis on a swine farm

Results of a program designed to control neonatal porcine coccidiosis on a total confinement, farrow-to-finish swine farm are reported. The control program consisted of washing, phenol disinfection, and steam cleaning of farrowing houses and treatment of sows with amprolium HCl before and after farrowing. Before initiation of the control program, 88.9% of the sows examined in the farrowing house were negative for coccidian oocysts, 9.9% were positive for Eimeria spp, and 1.2% were positive for Isospora suis. Most pigs nursing on sows before initiation of the control program had diarrhea at 5 to 10 days of age, which led to dehydration and weight loss. Morbidity was high, and mortality was moderate. Composite fecal samples from these litters were all positive (100%) for I suis. After initiation of the control program, 99.6% of the sows examined in the farrowing house were negative for coccidian oocysts and 0.4% were positive for Eimeria spp. Clinical signs of coccidiosis were rarely present in nursing pigs examined after the control program was initiated; however, I suis was still present in 19.8% of the composite fecal samples from pigs examined. An association between oocyst production in sows and I suis infections in pigs was not found in the present study. Oocysts of Eimeria spp were not found in the feces from the pigs.     

The seasonal incidence of coccidia infections in trade cattle,sheep, and goats in Nigeria

Summary

A survey of coccidia infections in trade cattle, sheep, and goats was undertaken in Nigeria between April 1978 and March 1979.

Faecal examinations showed coccidia oocysts in 1,456 (56 per cent) of 2,600 calves, 832 (80 per cent) out of 1,040 sheep, and 468 (45 per cent) out of 1,040 goats. There were relatively few coccidia oocysts between October and March and peaks occurred in August and September. Nine species of Eimeria were identified in bovine faeces, and seven species in both sheep and goats.

Eimeria bovis and E. zurnii are predominant in cattle, whereas E. faurei and E. ninakohlyakimovae have the highest percentage occurrence in sheep and goats in Nigeria. The effects of seasonal influences on the abundance of coccidia oocysts among ruminants in Nigeria are stressed.     

Application of polymerase chain reaction based on ITS1 rDNA to speciate Eimeria

A method was developed to recover Eimeria spp. oocysts directly from poultry litter and determine which species of Eimeria were present using polymerase chain reaction (PCR) based on the ITS1 rDNA sequence. The species composition of Eimeria oocysts was also compared before and after propagation in susceptible chickens to determine if the relative proportion of each species changed after expansion. In samples from two broiler operations, ITS1-PCR was able to detect Eimeria spp. oocysts recovered from litter, with Eimeria acervulina, Eimeria maxima, and Eimeria praecox being the predominant species present therein. Although Eimeria tenella was found in one sample, the other species--Eimeria brunetti, Eimeria necatrix, and Eimeria mitis-were not detected. The species composition as determined by ITS1-PCR did not appear to appreciably alter after expansion in susceptible chickens. The described method represents a rapid means for determining the major Eimeria species in a poultry operation and may be helpful in choosing a particular live oocyst vaccine formulation to protect chickens against coccidiosis.     

复方球虫散对人工感染鸡球虫病治疗效果的临床试验

为科学、客观地评价复方球虫散对实验性鸡球虫病的防治效果,采用人工接种柔嫩艾美耳球虫孢子化卵囊的方法复制鸡球虫病,使用纯中药组方复方球虫散进行鸡球虫病的临床疗效试验,观察并计算复方球虫散对试验鸡的死亡率、相对增重率、病变值和卵囊值的影响,并求出复方球虫散的抗球虫指数(ACI).试验结果表明:复方球虫散按1.0%拌料混饲,对鸡球虫病有较好的治疗效果.     

Quantitative determination of coccidian oocysts in beef calves from the coastal plain area of Georgia (U.S.A.)

For two consecutive years, determinations were made of the prevalence and abundance of coccidian oocysts from crossbred beef calves raised on Bahia grass pastures in the coastal plain area of Georgia. Of the 534 fecal samples collected during the survey, 461 (86.3%) contained one or more species of coccidian oocysts. The total mean oocysts per gram of feces (OPG) was significantly different (P less than 0.10) between the two years. Thirteen species of Eimeria were found during both years of the survey. Eimeria bovis was the most prevalent species found in the survey; E. ellipsoidalis, however, had the greatest number of OPG. Eimeria bukidnonensis, E. pellita, and E. brasiliensis were the least prevalent species and also had the lowest numbers of OPG. Only one clinical case of coccidiosis was seen. A nine-month-old calf had E. zuernii coccidiosis; it excreted E. zuernii oocysts in several fecal samples before the clinical disease appeared.     

Spatial Epidemiology of Escherichia coli O157:H7 in Dairy Cattle in Relation to Night Roosts Of Sturnus vulgaris (European Starling) in Ohio,USA (2007–2009)

The goal of our study was to use spatial scan statics to determine whether the night roosts of European starlings (Sturnus vulgaris) act as point sources for the dissemination of Escherichia coli O157:H7 among dairy farms. From 2007 to 2009, we collected bovine faecal samples (n = 9000) and starling gastrointestinal contents (n = 430) from 150 dairy farms in northeastern Ohio, USA. Isolates of E. coli O157:H7 recovered from these samples were subtyped using multilocus variable‐number tandem repeat analysis (MLVA). Generated MLVA types were used to construct a dendrogram based on a categorical multistate coefficient and unweighted pair‐group method with arithmetic mean (UPGMA). Using a focused spatial scan statistic, we identified statistically significant spatial clusters among dairy farms surrounding starling night roosts, with an increased prevalence of E. coli O157:H7‐positive bovine faecal pats, increased diversity of distinguishable MLVA types and a greater number of isolates with MLVA types from bovine‐starling clades versus bovine‐only clades. Thus, our findings are compatible with the hypothesis that starlings have a role in the dissemination of E. coli O157:H7 among dairy farms, and further research into starling management is warranted.     

Use of toltrazuril in pullet breeding flocks raised on floors with anticoccidial-free feed

In 28 replacement pullet flocks with flock size of 4,000 to 25,000 birds Toltrazuril (experimental preparation, 2.5% solution, approx. 7 mg/kg body weight) was administered for a period of two days in the drinking water for metaphylactic purpose and therapeutic use, respectively. All flocks were reared without anticoccidial feed additives. Exposition to Eimeria spp. was recorded by examination of faecal samples and intestinal scrapings. Clinical flock control was achieved by vets at eight to ten day intervals. Toltrazuril was characterized by short application period, rapid mode of action, significant reduction of oocyst shedding, good compatibility and acceptance thus proving superior to conventional chemotherapy of coccidiosis. The results suggest that, even without administration of anticoccidial feed additives. Toltrazuril is an effective agent for therapeutic use in acute coccidiosis. Under insufficient management and rearing conditions repeated metaphylactic application has to be considered.