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1.
Schmallenberg virus (SBV), a novel orthobunyavirus that rapidly spread throughout north-western Europe in 2011, caused congenital malformations in lambs and goat kids (Van den Brom et al., 2012) and newborn calves (Hoffmann et al., 2012). The impact of the SBV epidemic seemed limited however, in terms of the number of affected herds with malformed offspring (European Food Safety Authority, 2012b). Nevertheless, little is known with regard to the overall within-herd impact of SBV infection. The objective of the current study was to quantify the impact of the 2011 SBV epidemic on the productivity of dairy cattle in the Netherlands and the district of Kleve, Germany.  相似文献   

2.
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3.
Diagnosing the cause of bovine congenital malformations (BCMs) is challenging for bovine veterinary practitioners and laboratory diagnosticians as many known as well as a large number of not-yet reported syndromes exist. Foetal infection with certain viruses, including bovine virus diarrhea virus (BVDV), Schmallenberg virus (SBV), blue tongue virus (BTV), Akabane virus (AKAV), or Aino virus (AV), is associated with a range of congenital malformations. It is tempting for veterinary practitioners to diagnose such infections based only on the morphology of the defective offspring. However, diagnosing a virus as a cause of BCMs usually requires laboratory examination and even in such cases, interpretation of findings may be challenging due to lack of experience regarding genetic defects causing similar lesions, even in cases where virus or congenital antibodies are present. Intrauterine infection of the foetus during the susceptible periods of development, i.e. around gestation days 60–180, by BVDV, SBV, BTV, AKAV and AV may cause malformations in the central nervous system, especially in the brain. Brain lesions typically consist of hydranencephaly, porencephaly, hydrocephalus and cerebellar hypoplasia, which in case of SBV, AKAV and AV infections may be associated by malformation of the axial and appendicular skeleton, e.g. arthrogryposis multiplex congenita. Doming of the calvarium is present in some, but not all, cases. None of these lesions are pathognomonic so diagnosing a viral cause based on gross lesions is uncertain. Several genetic defects share morphology with virus induced congenital malformations, so expert advice should be sought when BCMs are encountered.

Electronic supplementary material

The online version of this article (doi:10.1186/s13028-015-0145-8) contains supplementary material, which is available to authorized users.  相似文献   

4.
In November 2011, the new orthobunyavirus Schmallenberg virus (SBV) was identified in dairy cows that had induced fever, drop in milk production and diarrhoea in the Netherlands (Muskens et al., 2012. Tijdschrift voor Diergeneeskunde 137, 112–115) and a drop in milk production in cows in Northwestern Germany (Hoffmann et al., 2012. Emerging Infectious Diseases 18 (3), 469–472), in August/September 2011. This study aimed at quantifying risk factors for high within-herd prevalence of SBV and SBV-induced malformations in newborn calves in dairy herds in the Netherlands. Additionally, the within-herd impact of SBV infection on mortality rates and milk production was estimated.A case-control design was used, including 75 clinically affected case herds and 74 control herds. Control herds were selected based on absence of malformations in newborn calves and anomalies in reproductive performance. SBV-specific within-herd seroprevalences were estimated. Risk factors for high within-herd SBV seroprevalence (>50%) and the probability of malformed newborn calves in a herd were quantified. In addition, within-herd impact of SBV with regard to milk production and mortality was estimated.Animal-level seroprevalence was 84.4% (95% confidence interval (CI): 70.8–92.3) in case herds and 75.8% (95% CI: 67.5–82.5) in control herds. Control herds that were completely free from SBV were not present in the study. Herds that were grazed in 2011 had an increased odds (OR 9.9; 95% CI: 2.4–41.2)) of a high seroprevalence (>50%) compared to herds that were kept indoors. Also, when grazing was applied in 2011, the odds of malformations in newborn calves tended to be 2.6 times higher compared to herds in which cattle were kept indoors. Incidence of malformations in newborn calves at herd level was associated with both within-herd seroprevalence and clinical expression of the disease in adult cattle.The rate of vertical transmission of SBV to the fetus once a dam gets infected seemed low. A total of 146 stillborn or malformed calves were submitted by 65 farmers during the study period, of which 19 were diagnosed as SBV-positive based on pathological investigation and/or RT-qPCR testing of brain tissue. Based on these results combined with calving data from these herds we roughly estimated that at least 0.5% of the calves born between February and September 2012 have been infected by SBV.A drop in milk production was observed between the end of August 2011 and the first half of September (week 35–36), indicating the acute phase of the epidemic. During a 4-week period in which SBV infection was expected to have occurred, the total loss in milk production in affected dairy herds was around 30–51 kg per cow. SBV had no or limited impact on mortality rates which was as expected given the relatively mild expression of SBV in adult cows and the low incidence of malformations in newborn calves.  相似文献   

5.
Gross appearance and histologic lesions seen in 15 newborn lambs in an outbreak of congenital arthrogryposis with hydrocephalus or hydranencephaly (CAH) in Texas are described. Severe arthrogryposis with skeletal muscle hypoplasia was seen in limbs of affected lambs. Spinal column deformities were also present. Multiple central nervous system (CNS) malformations were present in CAH lambs including micrencephaly, cerebellar hypoplasia, micromelia, hydrocephalus, hydranencephaly, and porencephaly. Histologic lesions consisted primarily of areas of necrosis and loss of the paraventricular neuropil and motor neurons in the CNS and a resolving myositis with poorly developed myotubular myocytes in skeletal muscle. Seroepidemiologic studies on the flock and serologic data from heart blood taken from the stillborn affected lambs indicated that the outbreak was due to in utero infection with Cache Valley Virus.  相似文献   

6.
Schmallenberg virus (SBV), discovered in Europe in 2011, causes mild transient disease in adult ruminants, but fetal infection can lead to severe malformation in cattle, sheep and goats.To elucidate the pathogenesis of this novel orthobunyavirus, considerable efforts are required. A reliable and standardized infection model is essential for in vivo studies. In the present study, two groups of four cattle were inoculated with either serum passaged in cattle only or cell culture-grown virus. The replication of culture-grown SBV in cattle was reduced compared to virus inoculated via infectious serum. In a second experiment, the infectious serum was titrated in calves; the tested batch contained 102.83 infectious doses per mL. Hence, serum-borne virus that was only passaged in the natural host is a suitable option for a standardized SBV infection model.  相似文献   

7.
The initial viraemic phase of Schmallenberg virus (SBV) infection in bovine animals is characterized by the non-specific and inconspicuous clinical signs of pyrexia (>40 °C), drop in milk yield and sometimes diarrhea. As a result, the early detection of SBV epizootics can difficult, and typically only become apparent when the congenital form of the disease is observed. The aim of the study was to describe the course of the acute phase response and haematological findings in bovine calves following experimental SBV infection. No clinical signs except for increase in rectal temperature were observed in the calves inoculated subcutaneously with a Polish strain of SBV. Viral RNA was detected in serum at 2 and 4 days post inoculation (dpi). SBV antibodies were first detected by ELISA (9–21 dpi), and subsequently by virus neutralization test (14–32 dpi). The hematological parameters showed a reduction in mid-size leucocytes (MID), and also in red blood cell count (RBC). An increase in mean corpuscular hemoglobin was also observed in SBV infected calves. No significant difference in acute phase proteins (APP) was observed between experimentally infected and control calves, suggesting limited potential as diagnostic biomarker of acute SBV infection.  相似文献   

8.
Schmallenberg virus (SBV) is a novel orthobunyavirus, discovered in Germany in late 2011. It mainly infects cattle, sheep and goats and could lead to congenital infection, causing abortion and fetal abnormalities. SBV is transmitted by biting midges from the Culicoides genus and there is no evidence that natural infection occurs directly between ruminants. Here, we could detect SBV RNA in infected bull semen using qRT-PCR (three bulls out of seven tested positive; 29 positive semen batches out of 136). We also found that highly positive semen batches from SBV infected bulls can provoke an acute infection in IFNAR-/- mice, suggesting the potential presence of infectious virus in the semen of SBV infected bulls.  相似文献   

9.
A herpesvirus isolated from neonatal Angora kids (Capra hircus) with a relatively severe generalized infection was shown to be infective for adult goats as well as for kids. However, the virus lacked pathogenicity for either lambs or calves. Although a nonreciprocating serologic overlap exists between the caprine virus and the antibody to bovine herpesvirus (BHV-1), results of cross immunity tests in calves indicated that the 2 viruses are immunologically distinct. On the basis of these findings, the caprine virus seems to be a specific pathogen of goats. Accordingly, the designation of Herpesvirus caprae or caprine herpesvirus 1 seems taxonomically appropriate.  相似文献   

10.
An outbreak of congenital hydranencephaly and cerebellar hypoplasia occurred between November 1985 and May 1986 in Miyazaki, South Kyushu, Japan. Seventy-three calves had nervous signs of varying severity such as inability to stand, locomotor difficulties, defective vision and difficulty in sucking. At necropsy, 62 calves had macroscopic lesions in the central nervous system: hydranencephaly accompanied by cerebellar hypoplasia in 47; hydranencephaly alone in eight; and dilatation of the lateral ventricle in seven; none had arthrogryposis. Microscopically, all 62 cases involved various degrees of hypoplasia of neural components, such as total or partial thinning of the cerebral or cerebellar laminae. Heterotopia, such as abnormal islands of granule cells or Purkinje cells was also observed. Fourteen of these animals had other lesions such as non-purulent encephalitis, focal gliosis, neuronal degeneration, calcification or pseudocalcification, and cholesterol deposits, activation of vascular endothelial cells and haemorrhage. From the findings, these cases were considered to represent mainly hypoplasia of nerve tissue due to infection with a virus different from Akabane virus.  相似文献   

11.
An epizootic characterized by birth of calves severly ataxic and blind were encountered in 3 herds 7–8 months after outbreaks of bovine virus diarrhoea. Serological and virological investigations indicated introduction of bovine viral diarrhoea virus (BVDV) into previously virus-free herds, followed by transplacental virus infection of the fetuses of cows in the first trimester. Clinical, pathological, serological, and microbiological examinations were performed on 10 calves. Pathological findings included microcephaly and cerebellar hypoplasia, ocular malformations, and thymic hypoplasia. BVDV was isolated from tissue and blood of 7 calves, and 4 calves, 1 of which had not received colostrum, had virus-specific neutralizing antibodies.This is the first report on natural occurrence of congenital bovine infection with BVDV among Danish cattle herds resulting in abortion and birth of calves with severe debilitating congenital anomalies. It draws attention to the importance of this virus for bovines of all age groups.  相似文献   

12.
Inoculation of lambs with an ovine isolate of respiratory syncytial virus (RSV) by a combined intranasal and intratracheal route resulted in mild respiratory tract illness, with respiratory tract lesions. Lung lesions were characterized by bronchitis and bronchiolitis, hyperplasia of bronchial and bronchiolar epithelium, peribronchiolar and perivascular accumulations of lymphocytes, alveolar septal thickening, and collapse. Respiratory syncytial virus was recovered from the respiratory tract of inoculated lambs, and RSV antigen was demonstrated by immunoperoxidase staining of bronchiolar and alveolar epithelial cell in pneumonic lesions of lambs euthanatized on post-inoculation days 5 and 6. Other primary respiratory tract pathogens were not isolated. Clinical signs of respiratory tract illness or respiratory tract lesions did not develop in the in-contact control lamb. Inoculation of the ovine RSV isolate into calves and deer fawns resulted in infection in both species, and at necropsy, pneumonic lesions were present. A mild to moderate respiratory tract illness developed in the calves, but clinical disease was not seen in the fawns. Lung lesions in fawns were similar to those seen in lambs; lesions in calves were characterized by collapse, scattered areas of parenchymal necrosis, and bronchiolitis. Respiratory syncytial virus was reisolated from the lower respiratory tract of inoculated calves and fawns, and immunoperoxidase-positive epithelial cells were seen in pneumonic lesions. Other primary respiratory pathogens were not detected. Respiratory syncytial virus infection was not demonstrable in control animals that were in contact with inoculated animals.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

13.
In various districts (Cantons) of Switzerland 815 calves (a few days up to 6 months old), 382 lambs and 20 young goats (both groups 1-6 months old) were selected randomly for a single coprological examination (flotation method) for Giardia infection. In average 26.6% of the calves, 29.8% of the lambs and 4 of 20 young goats excreted Giardia cysts. In 9 Cantons the percentages of cyst excretors among the calves varied between 15 and 32, but these differences were not significant. Further there were no significant differences in the frequency of cyst excretion between calves of 3 different breeds and 2 age groups (up to 3 months old and 3 to 6 months). The intensity of cyst excretion was high and varied in random samples between 4.1 x 10(3) and 3.0 x 10(5) cysts per g of faeces in calves and between 2.2 x 10(3) and 1.6 x 10(5) in lambs. In 5 of 7 farms where calves and lambs were maintained simultaneously both animal species were Giardia infected. As expected, trophozoites of Giardia isolates from calves and lambs belonged to the Giardia duodenalis type and could not be differentiated on a morphological basis. Giardia cysts from calves (average measurements: 13.7 x 9.1 microns) and lambs (13.8 x 9.2 microns) were indistinguishable both morphologically and morphometrically. The results indicate that Giardia infections are frequent and geographically widely distributed in calves and lambs in Switzerland.  相似文献   

14.
A virus isolated from a yearling cross-bred ewe was identified as respiratory syncytial virus (RSV) by indirect immunofluorescence and by virus neutralization with bovine RSV antisera. The virus caused a mild conjunctivitis in 3-month-old lambs when inoculated alone. Although clinical signs of pneumonia were not observed, there was gross and microscopic evidence of pulmonary inflammation in the lungs of lambs inoculated with either the sheep RSV isolate alone or in conjunction with Pasteurella haemolytica. Lung lesions in the dual infection were more severe, with approximately 10% of the total lung mass affected. Lavage fluids from lambs inoculated with virus and bacteria contained approximately 3 times more inflammatory cells than from control lambs or lambs inoculated with virus only. The sheep RSV isolate was classified as a mild respiratory pathogen in lambs of this age. Speculations on the potential importance of this virus in interspecies transmission to cattle and goats were discussed.  相似文献   

15.
Schmallenberg disease (SBD) is an emerging disease transmitted mainly among ruminant species by biting midges of the genus Culicoides. Since the Schmallenberg virus (SBV) was first identified in Germany in late 2011, it rapidly spread to other European countries. The aims of the present study were to describe the first SBD outbreak in Spain and to assess the spread and risk factors associated with SBV infection in domestic ruminants from nearby farms during the following year. In March 2012, one malformed stillborn lamb from a sheep farm located in Cordoba province (Southern Spain) was subjected to necropsy. Pathological compatible lesions and molecular analyses confirmed the first SBV infection in Spain. Afterwards, serum samples from 505 extensively reared domestic ruminants from 29 farms were analysed using both blocking ELISA and virus neutralization test against SBV. The overall seroprevalence was 54.4% (CI95%: 50.0–58.7). Antibodies were detected in 70.6%, 46.0% and 34.8% of cattle, sheep and goats, respectively. A generalized estimating equation model indicated that the main risk factors associated with SBV infection were: species (cattle), age (adult), and absence of animal insecticide treatment. Pathological and molecular results confirmed the presence of SBV in Spain few months after it was firstly identified in Germany. The seroprevalence detected indicates a widespread circulation of SBV in nearby domestic ruminant farms one year after this first outbreak was reported in Spain. Further studies are warranted to determine the spatio-temporal trend of SBV in domestic ruminants in this country.  相似文献   

16.
Epizootic outbreaks of congenital malformations in sheep are rare and have, to the best of our knowledge, never been reported before in Europe. This paper describes relevant preliminary findings from the first epizootic outbreak of ovine congenital malformations in the Netherlands. Between 25 November and 20 December 2011, congenital malformations in newborn lambs on sheep farms throughout the country were reported to the Animal Health Service in Deventer. Subsequently, small ruminant veterinary specialists visited these farms and collected relevant information from farmers by means of questionnaires. The deformities varied from mild to severe, and ewes were reported to have given birth to both normal and deformed lambs; both male and female lambs were affected. Most of the affected lambs were delivered at term. Besides malformed and normal lambs, dummy lambs, unable to suckle, were born also on these farms. None of the ewes had shown clinical signs during gestation or at parturition. Dystocia was common, because of the lambs' deformities. Lambs were submitted for post-mortem examination, and samples of brain tissue were collected for virus detection. The main macroscopic findings included arthrogryposis, torticollis, scoliosis and kyphosis, brachygnathia inferior, and mild-to-marked hypoplasia of the cerebrum, cerebellum and spinal cord. Preliminary data from the first ten affected farms suggest that nutritional deficiencies, intoxication, and genetic factors are not likely to have caused the malformations. Preliminary diagnostic analyses of precolostral serum samples excluded border disease virus, bovine viral diarrhoea virus, and bluetongue virus. In December 2011, samples of brain tissue from 54 lambs were sent to the Central Veterinary Institute of Wageningen University Research, Lelystad. Real-time PCR detected the presence of a virus, provisionally named the Schmallenberg virus, in brain tissue from 22 of the 54 lambs, which originated from seven of eight farms that had submitted lambs for post-mortem examination. This Schmallenberg virus was first reported in Germany and seems to be related to the Shamonda, Aino, and Akabane viruses, all of which belong to the Simbu serogroup of the genus Orthobunyavirus of the family Bunyaviridae. These preliminary findings suggest that the Schmallenberg virus is the most likely cause of this epizootic of ovine congenital malformations, which is the first such outbreak reported in Europe.  相似文献   

17.
Recently weaned kid goats, lambs and calves, raised under worm-free conditions, were dosed with infective larvae of Ostertagia spp. and Cooperia spp. derived from naturally infected cattle. Each animal received a similar mixed dose of 60 000 infective larvae. Postmortem examination four weeks after infection revealed that the overall establishment of Ostertagia spp. in the kids was markedly less than in either the calves or the lambs, while the establishment in the lambs was marginally less than in the calves. Species composition of the Ostertagia burdens at necropsy differed widely between the host species. In the calves, O. ostertagi was the dominant species (57.8–73.4%), whereas in the lambs it was less successful (12.3–51.4%), and in the goats it was present in only very small numbers (0.0–3.8%). The proportion of O. crimensis present in the Ostertagia burden of each of the lost species was inversely related to the level of O. ostertagi present. A similar level of establishment of Cooperia spp. occurred in both lambs and calves, but no Cooperia established in the goats.  相似文献   

18.
The clinical and pathological findings after a natural intra‐uterine infection with BVD‐virus in a Friesian dairy herd are described. The virological and serological aspects will be discussed in a separate paper (30).

In a period of 4 years, 11 calves were hum with the following nervous symptoms: more or less serious incoördination, tremor, oscillating nystagmus, and a negative blinking reflex. The pupillary and sucking reflexe's were normal. No ocular defects, such as lenticular opacity or retinal atrophy were observed.

The first calf was born in 1979. Within 6 months the symptoms disappeared. After a normal conception and pregnancy this animal gave birth to 2 clinically normal calves in 1981 and 1982. The second calf died at the age of 2 months, due to an ulcerating enteritis.

In 1980, again 8 calves with the same nervous symptoms were born within a period of 3 months. Two calves died at the age of 3 days and 5 weeks respectively; 2 calves were sold when 10 days and 3 weeks old; one calf did not improve and was necropsied at the age of 17 days. The remaining 3 calves showed only a slight hypermetria when examined after 6 months. At that time nystagmus was only visible with ophthalmoscopy. Two calves were slaughtered when 10 months old. The last one, a bull, proved to be sterile and was necropsied at the age of 1 ½> year.

A calf, born in 1981, recovered within a week and was necropsied at the age of 15 days. The last calf, born in 1982, did not improve at all and was necropsied at the age of 14 days.

During these 4 years none of the other animals in the herd showed any symptoms due to an acute or chronic BVD‐virus infection.

At post mortem examination of 6 animals no macroscopically visible malformations were found. Hypomyelination and abnormal glial cells were evident in 5 cases, especially in the two youngest calves which did not show any improvement. One of them had an obvious thymic hypoplasia. The calf which recovered within a week showed only very slight changes. In one of the calves slaughtered at 10 months, inflammatory lesions were found in the brain. The diagnosis was confirmed by virological investigations.

Clinically as well as pathologically there was a close resemblance to Border disease in lambs and congenital tremor in piglets after prenatal exposure to Hog cholera virus.  相似文献   

19.
Four lambs and 3 calves, seronegative to bluetongue virus (BTV), were inoculated intravenously with a highly plaque-purified strain of BTV Serotype 10. A single calf and lamb served as controls and were inoculated with uninfected cell culture lysate. All BTV-inoculated lambs exhibited mild clinical manifestations of bluetongue, whereas infected calves were asymptomatic. Viremia persisted in BTV-infected lambs for 35-42 days, and for 42-56 days in BTV-infected calves. Neutralizing antibodies were first detected in sera collected at Day 14 post-inoculation (PI) from 2 BTV-infected calves and all 4 infected lambs, and at Day 28 PI in the remaining calf. The appearance of neutralizing antibody in serum did not coincide with clearance of virus from blood; BTV and specific neutralizing antibody coexisted in peripheral blood of infected lambs and calves for as long as 28 days. The sequential development, specificity and intensity of virus protein-specific humoral immune responses of lambs and calves were evaluated by immunoprecipitation of [35S]-labelled proteins in BTV-infected cell lysates by sera collected from inoculated animals at bi-weekly intervals PI. Sera from infected lambs and calves reacted most consistently with BTV structural proteins VP2 and VP7, and nonstructural protein NS2, and less consistently with structural protein VP5, and nonstructural protein NS1. Lambs developed humoral immune responses to individual BTV proteins more rapidly than calves, and one calf had especially weak virus protein-specific humoral immune responses; viremia persisted longer in this calf than any other animal in the study. The clearance of virus from the peripheral blood of BTV-infected lambs and calves is not caused simply by the production of virus-specific neutralizing antibody, however the intensity of humoral immune responses to individual BTV proteins might influence the duration of viremia in different animals.  相似文献   

20.
Organ distribution of Schmallenberg virus RNA in malformed newborns   总被引：1，自引：0，他引：1  
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