Chronic fascioliasis in farmed and wild greater rheas (Rhea americana)

From 50 farmed Rhea americana slaughtered for human consumption, adult forms and eggs of Fasciola hepatica were found in 4. The other three livers were free of flukes but did show lesions caused by larval fluke migration. Histological lesions were similar to those caused by flukes in cattle and sheep. The rheas were from an endemic area of ruminant fascioliasis in Southern Brazil. F. hepatica eggs were also found in faecal samples of wild rheas from another endemic area in Southern Brazil. It is likely that the rheas play a role in the transmission of the disease to ruminants and could be jeopardizing the control of this parasitosis in endemic areas. From the best of our knowledge this is the first report of fascioliasis in R. americana.     

Herd evaluation of Fasciola hepatica infection levels in Louisiana cattle by an enzyme-linked immunosorbent assay

An enzyme-linked immunosorbent assay (ELISA) was evaluated as a method of determining relative immunoconversion rates in calves and how immunoconversion rates and strength of optical density values correlate with prevalence of Fasciola hepatica fecal egg shedding. Ten to 55 calves and cows were examined from each of 10 separate beef cattle herds in central and southern Louisiana. Infection prevalence rates for calves averaged 8% higher when ELISA optical density values were used than those when fecal egg count data were used. Of 55 calves in 8 herds that were ELISA positive, 39 were shedding F hepatica eggs; of 53 calves that were shedding eggs, 14 were ELISA negative. Significant correlation of calf fecal and ELISA prevalence was observed for 8 herds by linear regression analysis. A chi 2 analysis showed that calf ELISA and fecal egg shedding data were not independent. Results indicate that positive ELISA reactions for as few as 10 to 15 calves from the fall calf crop of a given herd are sufficiently accurate to be used to assess F hepatica herd infection rates, the likelihood of liver condemnations at feedlot destinations, and variation between individual farms in fascioliasis infection risk. The test was less valuable as a diagnostic test when used in adult animals previously exposed to F hepatica or on an individual animal basis.     

应用酶标SPA Dot-ELISA同时检测牛羊血吸虫病和肝片吸虫病

采用给雄性家兔注射黄牛、水牛、山羊ＩｇＧ混合液（１∶１∶１）制备的兔抗黄牛、水牛和山羊ＩｇＧ连接酶标ＳＰＡ，解决了酶标ＳＰＡ与牛羊血吸虫和肝片吸虫免疫复合物相结合的技术关键，并制成了可同时用于牛羊血吸虫病和肝片吸虫病诊断的酶试剂。建立了Ｄｏｔ－ＥＬＩＳＡ同时检测牛羊血吸虫病和肝片吸虫病技术，能测出人工感染１～１５０条虫体７～４２ｄ病畜抗体，阳性检出率达１００％。     

Studies on the pathology of dicrocoeliasis and fascioliasis in the goat. I. The histopathology of the liver and bile ducts

Comparative studies were made on the histopathology of the liver and bile ducts in dicrocoeliasis and fascioliasis of the goat. Investigations revealed certain similarities in the nature of the pathological phenomena produced by D. dendriticum and F. hepatica. However, a feature peculiar to fascioliasis was the migratory tracks of immature flukes in the liver parenchyma. Further, the lesions produced by fascioliasis were distinctly more pronounced than those present in dicrocoeliasis.In both parasitic diseases the bile-duct walls showed glandular hyperplasia, increased frequency of goblet cells and globule leucocytes, and extensive fibrosis in the outer layers. The desquamation produced by Dicrocoelium remained superficial whereas Fasciola was capable of causing deep erosions in the walls of the main bile ducts. The bile-duct walls did not become calcified. Increased fibrosis was present in the interlobular areas, too, but only fascioliasis produced extensive disorganisation of the hepatic architecture, due to the scars originating from repaired migratory tracks. The liver parenchymal cells were degenerated, showed decreased glycogen but were increasingly infiltrated by neutral fats.Keyword: Dicrocoelium dendriticum, Fasciola hepatica, liver, bile ducts     

The incidence and seasonal dynamics of yersinioses (Y. pseudotuberculosis, Y. enterocolitica), staphylococcoses and pasteurelloses in hares from 1976 to 1982

In the years 1976-1982, 2071 dead hares from 64 districts of the Czech Socialist Republic were examined. The diseases under study killed 400 hares (19.3%). Pseudotuberculosis which killed 210 hares (10.14%) from 46 districts of the Czech Socialist Republic (71.9%) is considered as the most important hare population regulator. The highest occurrence of diseases was recorded in 1978. Pseudotuberculosis was of seasonal nature with the highest incidence in November and December. The second most widespread disease was pasteurellosis which killed 126 hares (6.08%) from 36 districts of the Czech Socialist Republic (56.3%). This disease dominated in 1976 and occurred seasonally, the highest incidence being recorded in autumn (November), winter (January) and spring (March). The infections induced by the bacteria Yersinia enterocolitica were not very widespread and killed 32 hares (1.45%) from 20 districts of the Czech Socialist Republic (31.3%). The highest number of cases was recorded in 1977. The monthly pattern of the development of the disease had three peaks - in November, January and April. Staphylococcosis killed 32 hares (1.54%) from 14 districts in the Czech Socialist Republic (21.9%). The highest number of cases was recorded in 1976. The disease occurred throughout the year with the highest incidence in November, April and February. This seasonal dynamics correlated positively with the worsened natural conditions for hare's life and with the reduction of the natural resistance of their organisms. A particular negative influence was exerted by bad climatic and food conditions, and by the monodietary type of nutrition in the autumn fasting period. The disease occurrence was also examined in relation to the animals' age; besides the infections with the Y. enterocolitica bacteria, the diseases prevailed in the adult individuals, which was partly due to the higher proportion of adult animals among the hares investigated.     

Natural Fasciola hepatica infection in nutria (Myocastor coypus) in Uruguay

Fascioliasis, the zoonotic disease caused by the trematode Fasciola hepatica, is expanding worldwide, with a 17 million people at risk. Rodents, often recognized as a major source of zoonotic diseases, are affected by F. hepatica, with some species playing important roles in the disease epidemiology. The case reported here in a nutria or kiyá (Myocastor coypus) is the first documented case of F. hepatica in this species in Uruguay. Parasitic burden and total egg production detected are markedly higher than reported previously for this species, confirming its potential role as an effective reservoir and disseminator of liver flukes. Although further research is needed, nutria should be considered when designing effective control programs for fascioliasis.     

Serum antibody isotype responses of Fasciola-infected sheep and cattle to excretory and secretory products of Fasciola species

This study investigated the immunoglobulin isotype responses of sheep and cattle chronically infected with Fasciola hepatica and Fasciola gigantica to adult F. hepatica excretory/secretory products (Fh-ES) or F. gigantica excretory/secretory products (Fg-ES), respectively. An antibody enzyme-linked immunosorbent assay (Ab-ELISA) was used to determine serum antibody (total Ig, IgG(1), IgM, IgG(2) and IgA) responses. At necropsy, the mean number of flukes recovered was lower in cattle than in sheep. All F. hepatica and F. gigantica infected sheep and cattle showed an increased total Ig levels from 3 to 4 weeks post-infection (wpi). Among isotypes IgG(1) was most dominant while IgM was the earliest (2 wpi) to be detected in both sheep and cattle infected with both F. hepatica and F. gigantica animals. IgG(2) response was early (2 wpi) in sheep infected by F. hepatica but there was no response in sheep infected with F. gigantica. There was a late and strong IgG(2) response in cattle infected with both flukes. The IgA isotype showed an early and a clear biphasic response in sheep with F. hepatica but was less pronounced in F. gigantica infected sheep. While IgA response to Fh-ES was noticed 5 wpi in F. hepatica infected cattle, it appeared much later (21 wpi) in those infected with F. gigantica. The dominance of IgG(1) isotype in infected sheep and cattle suggest an associated Th2 response. This early response to adult Fasciola spp. ES antigen suggests an early exposure to the antigen presumably through the cross-reacting ES products of juvenile flukes. There is clearly difference in IgG(2) isotype response in cattle (resistant) compared to sheep (susceptible). The late IgG(2) response in cattle may suggest late Th1 involvement in bovine cellular responses to adult Fh-ES/Fg-ES.     

Correlation between egg-shedding and uterus development in Fasciola hepatica human and animal isolates: applied implications

The emission of Fasciola hepatica eggs in faeces is usually subject to oscillations along time in animals as well as humans. Thus, looking for alternative biological markers reflecting eggs shed per gram of faeces (epg) with lower oscillations may be useful. This study analyzes the possible relationship between liver-fluke uterus area and epg. Uterus area (UA) development of adult F. hepatica obtained at different days post infection (dpi) in a Wistar rat model with isolates obtained from cattle, sheep, pigs and humans from the endemic human fascioliasis zone of the Northern Bolivian Altiplano was analyzed and compared with the number of eggs shed per gram of faeces as obtained through the Kato-Katz technique. The morphometric study of the UA of liver flukes was carried out using image analysis software. The multiple regression model shows that UA is dependent on dpi and isolate. The evolution of UA vs dpi followed a damped model. This work shows a positive relationship between liver-fluke UA and egg production. The complete absence of eggs in the uteri of some parasite individuals at 300 dpi was observed, which corresponds to the cessation of egg shedding in the advanced chronic stage. The results obtained suggest the necessity to characterize the isolates employed with regard to geographical as well as host origin in fascioliasis studies in which egg production is used as a biological tag.     

Fasciola hepatica: comparison of flukes from Korea and the United States by isoelectric focusing banding patterns of whole-body protein.

Comparisons were made between the flukes from Chonnam, Korea and Oregon, USA by isoelectric focusing (IEF) of whole-body protein. Adult Fasciola hepatica were recovered from bile ducts of Korean native cattle. Whole-body protein of the flukes was subjected to IEF, and the banding patterns of the fluke protein were compared with those of North American F. hepatica recovered from experimentally infected calves. The overall banding pattern of F. hepatica from Korea was essentially identical to that of F. hepatica from the United States. These results provide further support for the usefulness of this technique in differentiating Fasciola species in other geographical areas.     

Bluetongue infections in Louisiana cattle

Bluetongue virus (BTV) serotype 17 was isolated from cattle with clinical signs of bluetongue disease during 1978 and 1979 epizootics. Bovine sera from 6 herds located in an epizootic region were examined in 1979 for antibodies, using an immunodiffusion (ID) test. Of 300 sera, 164 (54.7%) were seropositive. Sera from statewide surveys of Louisiana cattle in July to August 1980 and December 1980 to January 1981 were tested for BTV antibodies, using the ID test. Fifty-eight of 70 herds (82.9%) and 164 of 597 (27.5%) individual cattle tested in July to August 1980 were seropositive. Fifty-four of 63 (85.7%) herds and 170 of 600 (28.3%) individual cattle tested in December 1980 to January 1981 were seropositive. Significant differences (P less than 0.01) were found in the seropositive rates between the various geographic regions of the state during each survey. Adult breeding-age cattle in 3 sentinel herds were tested for BTV antibodies beginning in 1976 and continuing through January 1981. During this interval, the seropositive rate in 2 of 3 herds was increased. Also, individual cattle in all 3 of these herds converted from seronegative to seropositive, indicating exposure during a particular interval for each herd. The age distribution of seropositive cattle in a dairy indicated that 2-year-old cattle had a seropositive rate comparable with that of older animals in the herd, suggesting that the 2-year-old animals had been exposed to a BTV before they entered the breeding herd.     

The ability of diamphenethide to control immature Fasciola hepatica in sheep at a lower than standard dose level

Groups of eight Welsh Mountain sheep were dosed with diamphenethide at the rate of 70 mg/kg bodyweight at either one, four, six or eight weeks after artificial infection with approximately 300 Fasciola hepatica metacercariae. Comparisons were made with similarly infected but undosed sheep and with sheep which were neither infected nor dosed. The good clearance of flukes up to six weeks of age (above 97 per cent on pooled data) was reflected in the plasma concentrations of the accepted liver damage marker enzymes glutamate dehydrogenase and gamma-glutamyl transpeptidase. Highly significant correlations were demonstrated between the numbers of flukes recovered, the plasma levels of these enzymes and haemoglobin and plasma albumin values. At 70 mg/kg, diamphenethide was shown to be able to control F hepatica populations of up to six weeks of age. The systematic use of diamphenethide at this dose level at intervals of up to six weeks during the period of metacercarial challenge should prevent ovine fascioliasis.     

FASCIOLIASIS IN DAIRY COWS ON IRRIGATED PASTURE

The prevalence and severity of fascioliasis was studied in 87 dairy cows from 36 irrigated farms in Victoria. Evidence of Fasciola hepatica infection was found in 85 (98%) cows representing all but one of the herds. The mean fluke burden (7 ± 6) in cows treated with anthelmintics at drying off was lower (p < 0.05) than in untreated cows (24 ± 7). Haemoglobin levels in untreated cows (9.6 ± 0.4) were higher (p < 0.05) than values obtained from treated animals (8.2 ± 0.3). Severity of bile duct wall thickness and hepatic fibrosis was similar in both groups. None of the measured parameters was affected by the age of the cow. Although fascioliasis was prevalent in these cattle the level of infection was low.     

肝片吸虫感染致斑纹角马死亡案例调查

首次报道了国内圈养斑纹角马肝片吸虫病确诊病例。诊断依据：（1）提示性临床症状：贫、消瘦、营养不良;（2）尸体剖检特征性病理变化：胆管显著扩张和胆管内挤排出大量肝片吸虫成虫的虫体;（3）肝片吸虫感染强度测定：运用麦克马斯特法测定了病死角马肝片吸虫感染强度为1 600个/g;（4）中间宿主调查：角马的饲养区内发现大量椎实螺,椎实螺体内含有大量的肝片吸虫尾蚴;（5）组织病理学检查：细支气管和肺泡腔内见有童虫的虫体结构。首次证实了角马肝片吸虫感染时,童虫在移行过程中可误移至肺,导致肺的病理变化。该病的发生与环境潮湿多水、环境中存在大量椎实螺而未被重视有关。肝片吸虫宿主范围广,应重视易感动物的生活环境,定期粪检确定感染率和感染强度,以及选择有效的药物防治,这是科学预防该病的关键。     

The effectiveness of the drugs Dovenix and Bilevon(R)-Injection against liver fascioliasis (Fasciola hepatica, Linné 1758) in cattle]

Dovenix and Bilevon-injection (manufactured by SPECIA, France and BAYER, West Germany, respectively) were tested for their anthelmintic efficacy against Fasciola hepatica in cattle. The drugs proved highly effective against both adult and immature flukes. The faeces of the treated animals were negative for F. hepatica eggs when examined 91 days after the treatment. In experiments with rats Dovenix and Bilevon-injection were tolerated up to eight times and ten times higher doses than the normal therapeutic dose, respectively.     

Immunisation against ringworm in cattle

Immunisation against dermatomycoses in cattle was introduced in Gausdal, Norway, in 1979. A programme was implemented in which a six-year period of mandatory vaccination of all cattle was followed by vaccination on a voluntary basis. The prevalence of infected herds fell from 70 per cent in 1979 to 0 per cent in 1987. During the last five years, no newly infected herds have been registered in Gausdal. Proper disinfection of premises, the isolation of infected animals and other hygienic measures contributed to the successful result.     

Failure of a recombinant Schistosoma bovis-derived glutathione S-transferase to protect cattle against experimental Fasciola hepatica infection

The potential of a recombinant Schistosoma bovis 28-kDa glutathione S-transferase (rSb28GST) to protect cattle against Fasciola hepatica was tested in a vaccination trial. Thirty two calves were randomly divided into four groups of eight animals. Calves of the three vaccine groups received two intramuscular injections at 3 weeks interval, of 0.250mg rSb28GST in either aluminium hydroxide (Al(OH)(3)), Quil A, or PBS emulsified in an equal volume of Freund's complete adjuvant (FCA).Animals of the control group received injections of Al(OH)(3)/PBS only. All animals were challenged orally with a total of 360 metacercariae of F. hepatica, spread over 6 weeks.All groups of vaccinated animals produced measurable IgG antibody titers to rSb28GST after vaccination. Animals immunised with FCA adjuvanted vaccine had the highest and more durable antibody titers and only sera from this group recognised an approximately 24kDa protein band from F. hepatica, that is thought to be a F. hepatica GST. Despite a good antibody response differences in cumulative faecal egg output between the groups were not statistically significant. In addition, no significant difference was found between groups in terms of total worm numbers or percentage of immature flukes recovered at necropsy. In conclusion, the recombinant S. bovis 28kDa GST was not found to adequately protect cattle against experimental F. hepatica challenge, using either aluminium hydroxide, Quil A or FCA as adjuvant.     

The effect of newer anthelmintics on Fasciola hepatica in experimentally infected rats]

The reports deals with the results of testing seven new antihelminthics for Fasciola hepatica in the experimentally invaded Wistar rat. The greatest influence on juvenile flukes (2 and 4 weeks of age) was exerted by diamphenetid (Coriban) applied in a single dose of 100 mg kg-1. Hexachlorophene applied in the dose of 50 mg kg-1 showed the highest effect on sexually mature flukes. All the tested antihelminthics of the halogenated salicylanilide group were ineffective on juvenile stages and only slightly effective on mature F. hepatica flukes. It follows from the results that the effectiveness of some antifasciolics on laboratory animals need not always be in correlation with their effect in ruminants - hence it is necessary to verify the results obtained in laboratory animals and to check them on natural F. hepatica hosts.     

两种片形吸虫感染家兔的试验比较

用大片形吸虫和肝片形吸虫感染家兔以便选择大片形吸虫对动物的最佳感染量,及明确肝片形吸虫和大片形吸虫的生物学和对动物宿主的致病力的差别。结果显示肝片形吸虫虫体在兔体内发育成熟的时间早于大片形吸虫,感染成活率更高,对动物的病理损害明显比感染大片形吸虫兔的病变要轻。本试验证实这两种片形吸虫除了形态学的差异外,在对动物致病力、病理损害等方面确实存在差别。     

A cross-sectional coprological survey of liver flukes in cattle and sheep from an area of the southern Italian Apennines

A cross-sectional coprological survey of liver flukes (Fasciola hepatica and Dicrocoelium dendriticum) was conducted on 81 bovine farms and 197 ovine farms with animals pasturing in an area (3971 km(2)) of the southern Italian Apennines. The farms were selected to be uniformly distributed throughout the study area using geographical information system (GIS) software. Between June 1999 and March 2000, faecal samples were collected from 975 cattle and 3940 sheep and examined using a modified McMaster technique. The results were subjected to statistical analysis and point distribution maps (PDMs) were drawn by GIS.Cattle of 9 of the 81 (11.1%) farms were positive for F. hepatica and of 43 (53.1%) for D. dendriticum. Sheep of 8 of the 197 (4.1%) farms were positive for F. hepatica and of 133 (67.5%) for D. dendriticum. Co-infection was found in cattle of 2 (2.5%) farms, and in sheep of 8 (4.1%) farms.The findings of the present survey show that D. dendriticum was the predominant liver fluke found in cattle and sheep with respect to egg count numbers for both farms and animals. In addition, the general trends of the PDMs show that D. dendriticum was widely and homogeneously spread throughout the study area, whereas F. hepatica was present only in a few concentrated zones of the study area that had both positive bovine and positive ovine farms.     

Potential for the spread of Fasciola hepatica in cattle in Oklahoma

In 29 central and western Oklahoma counties, 42 ranches were investigated for indigenous Fasciola hepatica infections and their suitability for the transmission of liver fluke. A 10-year retrospective study of Oklahoma cattle based on samples submitted to the Oklahoma Animal Disease Diagnostic Laboratory also was done. Indigenous fascioliasis was found in cattle in 12 counties (9 central and western counties identified in the combined field and retrospective studies and 3 additional eastern counties identified on the basis of the retrospective study). Factors essential for survival of free-living stages of F hepatica and for snail species necessary for propagation of the fluke existed in much of Oklahoma. Snails capable of serving as intermediate hosts for transmission of the fluke reportedly have been found in 41 of the 77 Oklahoma counties. Lymnaeid snails were detected in 4 counties in the field study.