bovine viral diarrhoea, bovine herpesvirus and ... · both a non-cytopathic (ncp) and an...

Rev. sci. tech. Off. int. Epiz., 2003, 22 (3), 879-892

SummaryThis study reported field outbreaks of bovine viral diarrhoea virus (BVDV)infection, either alone or mixed with bovine herpesvirus-1 (BHV-1) and/orparainfluenza-3 virus (PI-3V) in Egypt during 2000. In Lower Egypt, young calves inthree cattle herds in El-Minufiya Province, El-Fayoum Province and ingovernmental quarantine in El-Behira Province, showed symptoms of enteritis,either alone or accompanied by respiratory manifestations. The affected herdswere visited and the diseased animals were clinically examined. Manyepidemiological aspects, such as morbidities, mortalities and case fatalities, aswell as the abortive rate, were calculated. Ethylenediamine tetra-acetic acid-blood samples, sterile nasal swabs and serum samples were obtained forvirological and serological diagnosis. The laboratory investigations revealed thatthe main cause of calf mortalities in the three herds was infection with BVDV,either alone, as on the El-Minufiya farm, or mixed with PI-3V, as on the El-Fayoumfarm, or mixed with both BHV-1 and PI-3V, as in the herd in governmentalquarantine in El-Behira Province. A total of nine dead calves from the three herdswere submitted for thorough post-mortem examination. Tissue samples fromrecently dead calves were obtained for immunohistochemical andhistopathological studies. The most prominent histopathological findings weremassive degeneration, necrosis and erosions of the lining epithelium of thealimentary tract. Most of the lymphoreticular organs were depleted oflymphocytes. In pneumonic cases, bronchopneumonia and atypical interstitialpneumonia were evident. The present study suggested that theimmunosuppressive effect of BVDV had predisposed the animals to secondaryinfection with BHV-1 and PI-3V. This study concluded that concurrent infectionwith BVDV, BHV-1 and PI-3V should be considered as one of the infectiouscauses of pneumoenteritis and, subsequently, the high morbidities and mortalitiesamong young calves in Egypt. Preventive and control measures against theseinfectious agents should therefore be adopted. All animals imported into Egyptshould be free from BVDV infection. Control programmes for the detection andremoval of BVDV-persistent cattle should be applied in cattle herds all over thecountry.

KeywordsBovine viral diarrhoea – Clinical symptom – Epidemiology – Immunohistochemistry –Infectious bovine rhinotracheitis – Parainfluenza-3 virus – Pathological investigation –Serology – Virological diagnosis.

N.M. Aly (1), G.G. Shehab (2) & I.H.A. Abd El-Rahim (3)

(1) Department of Virology, Animal Health Research Institute, Nadi El-Sayed Street, Dokki, Giza, P.O. Box 264,Cairo, Egypt(2) Department of Pathology, Animal Health Research Institute, Nadi El-Sayed Street, Dokki, Giza, P.O. Box 264,Cairo, Egypt(3) Department of Animal Medicine, Faculty of Veterinary Medicine, Assiut University, 71526 Assiut, Egypt

Submitted for publication: 14 May 2002Accepted for publication: 30 May 2003

Bovine viral diarrhoea, bovine herpesvirus andparainfluenza-3 virus infection in three cattleherds in Egypt in 2000

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IntroductionPneumoenteritis is generally considered to be the main hazardto calf health (60). Bovine viral diarrhoea virus (BVDV) is amajor pathogen for cattle and contributes to the genesis of awide variety of pathology ranging from inapparent or mildinfection to the inevitably fatal syndrome of mucosal disease(12). The BVDV belongs to the genus Pestivirus of the familyFlaviviridae. Both a non-cytopathic (ncp) and an antigenicallyrelated cytopathic (cp) BVDV can be isolated from persistentlyinfected animals suffering from mucosal disease (63).

Diseases associated with BVDV infection have been acontroversial subject because of the multiple clinical forms andmanifestations of the infection, the ability of the virus tosuppress the function of the immune system, and the complexepidemiology of the disease (6). The BVDV causes differentdiseases, including: bovine viral diarrhoea (BVD) infection,which is usually subclinical; mucosal disease, which is usuallyfatal; and congenital abnormalities in calves, caused by aninfection of the foetus in midgestation. The BVDV may alsocause reproductive failure and be immunosuppressive (22, 23,30, 48, 51, 57). The BVDV induces immunosuppresion (1, 10,11), which allows for secondary infection of the respiratorytract, and causes significant losses as a result of its interactionwith other pathogens (21, 26, 35).

The bovine herpesvirus-1 (BHV-1) and parainfluenza-3 (PI-3V)viruses are the principal causes of pneumonia in cattle (37). Therole of BVDV in the bovine respiratory disease complex iscontroversial (20). Abo El-Lail (4) described a respiratorydisease in cattle where both PI-3V and BVDV were involved. Ithas also been shown experimentally that initial infection withBVDV impairs the ability of infected calves to eliminate theBHV-1 from the infection site (52).

The bovine herpesvirus-1 is a double-strandeddeoxyribonucleic acid virus. It is a member of the genusVaricellovirus within the subfamily Alphaherpesvirinae, whichbelongs to the family Herpesviridae (58, 64). BHV-1 is aneconomically important pathogen. Infectious rhinotracheitis isone of the most common clinical symptoms of BHV-1 in cattle(28, 56). The viral glycoproteins, which are located on thesurface of the virion, play an important role in pathogenesis andimmunity (18, 45, 62). Latency is one of the major problemsassociated with the infection of cattle by BHV-1 (39). Infectiousbovine rhinotracheitis (IBR) is characterised by clinical signs ofupper respiratory tract disease, such as a mucopurulent nasaldischarge, and by conjunctivitis. Signs of general illness arefever, depression, inappetance, abortions and reduced milkyield. Mortality is low. Many infections run a subclinical course(49).

The parainfluenza-3 virus is a single stranded ribonucleic acidvirus. It is a member of the genus Paramyxovirus in the

subfamily Paramyxovirinae, which belongs to the familyParamyxoviridae (8). The PI-3V infection is commonlysubclinical. Clinical disease may not occur until otherpathogens are present or when adverse environmentalconditions precipitate clinical disease (55).

The aim of this study was to identify the infectious agents of thecalf mortalities in the three investigated cattle herds and toreport the epidemiological aspects and clinical manifestationsassociated with the outbreaks. The study also aimed to identifythe pathological alterations as well as the correspondingdistribution of the viral antigen in the tissues of the diseasedcalves by using the avidin biotin complex (ABC)immunoperoxidase technique.

Materials and methodsAnimalsA total of 157 (9.2%) of the 1,701 young calves in the threeinvestigated cattle herds, which contained 2,354 animals intotal, showed evidence of gastroenteritis with severe diarrhoea,either alone, as in Herd 1, or associated with respiratorymanifestations, as in Herds 2 and 3. These herds (Table I) wereas follows.

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Table IData on the three cattle herds included in the study of bovineviral diarrhoea virus outbreaks in Egypt in 2000

Descriptions Herd 1 Herd 2 Herd 3Total number of

animals

Date of investigation January February October2000 2000 2000

Number of animals 542 292 1,520 2,354

Dairy cattle 375 110 0 485

Age groups of calves:

< 1 month 10 12 0 22

> 1 - < 3 months 16 18 0 34

> 3 - < 6 months 28 32 0 60

> 6 - < 12 months 15 50 1,520 1,585

Total number of calves 69 112 1,520 1,701

Herd 1Herd 1 was a dairy farm known as Delta Misr dairy cattle farm,located in El-Minufiya Province, Lower Egypt. When theauthors visited the site, in January 2000, there were a total of542 cattle on this farm, including ninety-eight pregnant cowsand sixty nine young calves, from one week to eight monthsold. Liver, spleen and lung tissue samples were obtained fromthree aborted foetuses. Ethylenediamine tetra-acetic acid(EDTA)-blood samples and sterile nasal swabs were collectedfrom twelve clinically-diseased calves.

Herd 2Herd 2 was a Friesian dairy cattle farm in El-Fayoum Province.The cattle in this herd were imported from Germany. This dairyfarm was visited in February 2000, when it contained 110 dairycattle, seventy pregnant cows, twelve calves less than onemonth old, eighteen calves between one to three months old,thirty-two calves between three to six months old and fiftycalves from six to twelve months old. The authors collectedtissue samples from the liver, spleen and lung of two abortedfoetuses, and EDTA-blood samples and sterile nasal swabs wereobtained from sixteen clinically-ill calves.

Herd 3This was a herd of 1,520 fattened young calves aged from six totwelve months, imported from Romania and quarantined at thegovernmental animal quarantine in El-Behira Province. Thisquarantine facility was visited about three weeks after thearrival of the calves, by which time there were increasingnumbers of diseased calves due to the rapid spread of aninfection. On the day of investigation, forty eight calves weresuffering from signs of enteritis mixed with respiratorymanifestations. Nineteen sterile nasal swabs and nineteenEDTA-whole blood samples were collected from nineteendiseased calves. In addition, tissue samples from the mesentericlymph nodes, pulmonary lymph nodes, spleen and lung wereobtained from two calves that had recently died.

Clinical examinationAll of the diseased cattle in the three different infected herdswere clinically examined.

Pathological examinationsNine of the dead calves (two from Herd 1, three from Herd 2and four from Herd 3) were submitted for thorough post-mortem examination. Tissue specimens were taken from thetrachea, lungs, bronchial and mesenteric lymph nodes, spleen,liver, kidneys, rumen, abomasums and parts of the intestines.These samples were fixed in 10% neutral buffered formalin,processed routinely, and then sectioned 4 µm-5 µm thick. Theprepared sections were stained with haematoxylin and eosin forhistopathological examination, and by lendrum’s phloxin andtartrazine for demonstration of viral inclusion bodies (14).

Immunohistochemical studiesThe ABC immunoperoxidase technique was used as a rapidmethod of confirming the detection of BVDV, BHV-1 and PI-3Vin the different organs and tissues obtained from nine deadcalves at necropsy. The technique was applied on paraffinsections, in accordance with the method of Wilchek and Bayer(73). According to the intensity of the positive reaction, theresults were classified into four degrees from + to ++++.

Virological investigationsCell cultureMadian Darby bovine kidney (MDBK) cell culture was used toisolate BVDV from prepared buffy coats, nasal swabs and tissuesamples. The buffy coats and nasal swabs were preparedaccording to Abd El-Rahim et al. (3). The MDBK was also usedto isolate BHV-1 from the collected nasal swabs. The EDTA-blood samples (n 78) were centrifuged at 1,000 xg for 10 min.The plasma was removed and the buffy coat (leukocyticfraction) was aspirated with a sterile Pasteur-pipette into asterile tube and then 5 ml of minimum essential medium(MEM) with 2% foetal calf serum (FCS), which had beenproven to be free from both BVDV and BVD antibodies, wereadded. The mixtures were left at room temperature for 1 h andthen frozen at –70°C until used.

Each of the 78 sterile nasal swabs was transferred into a steriletube and 5 ml of MEM with 2% FCS and antibiotics (800 µgstreptomycin, 800 IU penicillin and 400 IU gentamycin/ml)were added, they were well mixed and left at room temperaturefor 1 h. The swabs were then kept at –70°C until inoculatedonto MDBK cell cultures. Tissue samples from aborted foetusesand the recently dead calves were ground in MEM with 2%FCS and antibiotics (800 µg streptomycin, 800 IU penicillinand 400 IU gentamycin/ml) and centrifuged at 1,000 xg for10 min. The supernatant fluids were separated and kept at–70°C until used for BVDV isolation. The prepared leukocyticfractions, nasal swabs and tissue suspensions were inoculatedonto MDBK cell cultures for isolation of BVDV according to themethod described by Clarke et al. (16).

Indirect immunofluorescent techniqueThe indirect immunofluorescent (IF) technique was used onthe inoculatd cell cultures with cytopathic effect (CPE) toidentify the cpBVDV. It was also used on inoculated cellcultures without CPE to detect ncpBVDV biotype. The IFtechnique was carried out according to OIE (Worldorganisation for animal health) standards (47).

Three blind passages of the tested samples were done on theinoculated cell cultures. If there was no evidence of any CPE,the third passage was conducted on MDBK tubes. Thus, tubecultures including flying cover slips were used to detectncpBVDV biotype by indirect IF technique. Both positive andnegative control samples were also included. The testedsamples were considered positive when there was a clear applegreen cytoplasmic fluorescence in the infected cell culture,while the negative control, non-infected cells, showed nofluorescence.

Haemagglutination and haemagglutination inhibitiontestsHaemagglutination (HA) and haemagglutination inhibition(HI) tests were applied, according to the method described by

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Post-mortem examinations of seven calves from Herds 2 and 3revealed the above-mentioned gross pathological lesions andalso linear haemorrhages in the tracheal and bronchial mucosa.Multiple patchy congested areas were seen on the pulmonarylobes.

Immunohistochemical findingsDetection of the viral antigens by ABC immunoperoxidasetechnique in tissues collected at autopsy is shown in Tables II,III and IV and in Figures 1, 2 and 3.


Lennette and Schmidt (40), to a total of 78 nasal swabs, in orderto detect PI-3V antigen.

Virus neutralisation testThe virus neutralisation (VN) test was used to identify BHV-1that had been isolated on MDBK tissue culture. The fixed virusvariable serum method described by Gillespie et al. (29) wasused.

Epidemiological studiesMany epidemiological aspects in the three affected herds werestudied, such as the incriminated sources of infection, the modeof transmission, age susceptibility, morbidities, mortalities andthe abortive rate.

ResultsClinical symptomsInspection of the affected calves in Herd 1 revealed a rise inbody temperature (up to between 40°C and 42°C), anorexia,severe depression, salivation, and profuse watery diarrhoeawith dehydration. Multiple erosions usually of 1 mm-5 mm indiameter were present in the mucosa of the muzzle, oral cavityand tongue. Higher infection and severe clinical manifestationswere observed among young calves from three to twelvemonths old. In addition to the previous clinical signs, othermanifestations observed in diseased animals in Herds 2 and 3were: severe respiratory and ocular manifestations, including anincrease in respiratory rate; serous or mucoid nasal discharge;respiratory dyspnoea; coughing and sneezing; andconjunctivitis with ocular discharge. Severe conjunctivitis withprofuse ocular discharge was noticed among affected calves inHerd 3. In Herds 1 and 2, abortion was observed amongpregnant cows. Congenital malformations were noticed inHerds 1 and 2, where some newborn calves were weak andblind, and sometimes had musculoskeletal deformities.

Post-mortem findingsNine dead calves from the three investigated herds weresubjected to post-mortem examinations. The most prominentaspect of the post-mortem examinations of two calves fromHerd 1 was the presence of multiple erosions of about 1 mm to5 mm in diameter on the muzzles, oral mucosa, tongue,ruminal pillars, abomasums, and small intestines. Congestionand severe haemorrhages were seen in the mucosal surfaces ofthe abomasums, small intestines and ileocecal valve. Necroticfoci were observed in the hepatic tissues. The bronchial andmesenteric lymph nodes were extremely congested andhaemorrhagic. The spleen was congested, while the kidneyswere pale in colour.

Table IIThe distribution and intensity of avidin biotin complex reactionagainst bovine viral diarrhoea (BVD), bovine herpesvirus-1(BHV-1) and parainfluenza-3 (PI-3) viruses in the tissue samplesobtained from two dead calves in Herd 1

OrgansDistribution and intensity of viral antigensBVD virus BHV-1 PI-3 virus

Trachea – – –

Lung + – –

Bronchial lymph nodes – – –

Mesenteric lymph nodes + + + – –

Tongue + + + – –

Spleen + + + – –

Rumen + + – –

Abomasum + + – –

Intestines + + + – –

Liver + + + – –

Kidneys + + + – –

Heart + – –

Table IIIThe location and intensity of avidin biotin complex reactionagainst bovine viral diarrhoea (BVD), bovine herpesvirus-1(BHV-1) and parainfluenza-3 (PI-3) viral antigens in the tissuesobtained from three dead calves in Herd 2

OrgansDistribution and intensity of viral antigensBVD virus BHV-1 PI-3 virus

Trachea – – +

Lung + – + + +

Bronchial lymph nodes – – + +

Mesenteric lymph nodes + + – –

Tongue + + + – –

Spleen + + – +

Rumen + + – –

Abomasum + + + – –

Intestines + + – +

Liver + + + – +

Kidneys + + – +

Heart + + – +

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submucosal layer of the trachea (Fig. 3a), the lining bronchialepithelium, the lymphocytes and macrophages of the spleen,the bronchial lymph nodes, the lumen of the blood vessels, thelining endothelial cells of the heart, in between the cardiacmuscle fibers and the lining endothelial cells of the renal bloodvessels, the glomerular capsule and the tuft capillaries, and inthe cytoplasm of the lining tubular epithelium.

The BVDV antigen was detected by immunohistochemicalassay in tissue samples from four dead calves from Herd 3(Table IV), which were also positive for virus isolation by thetissue culture method.


Table IVThe distribution and intensity of avidin biotin complex reactionagainst bovine viral diarrhoea (BVD), bovine herpesvirus-1(BHV-1) and parainfluenza-3 (PI-3) viral antigens in the tissuesamples collected from four dead calves in Herd 3

OrgansDistribution and intensity of viral antigensBVD virus BHV-1 virus PI-3 virus

Trachea – + + + + +

Lung – + + + + + +

Bronchial lymph nodes – + + + + +

Mesenteric lymph nodes + + + + –

Tongue + + + – –

Spleen + + + + + + + +

Rumen + + – –

Abomasum + + + – –

Intestines + + + +

Liver + + + + + +

Heart + + + + + +

Kidneys + + + + + +

Fig. 1Intestinal glands showing dense brown granules againstbovine viral diarrhoea virus antigen in their lining glandularepithelium (arrows). Avidin biotin complex immunoperoxidase– counter stained haematoxylin × 400

a) Mesenteric lymph nodesb) Spleen

Fig. 2The mesenteric lymph nodes and spleen revealing dense browngranules against bovine viral diarrhoea virus antigen within thelymphocytes and macrophages. Avidin biotin compleximmunoperoxidase – counter stained haematoxylin × 400

a) Trachea revealing dense brown granules against bovine herpesvirus-1 antigen inside thedegenerated mucosal epithelium and in the submucosal layer. Avidin biotin complex (ABC)immunoperoxidase – counter stained haematoxylin × 500b) Lung showing brown granules against parainfluenza-3 virus in the lining bronchial andalveolar epithelium. The ABC immunoperoxidase – counter stained haematoxylin × 250

Fig. 3Detection of viral antigens by ABC immunoperoxidasetechnique

An intense positive reaction against BVDV was seen in the basallayer of the mucosal layer of the tongue, the cytoplasm of thelining epithelium of most of the villi, the intestinal glands ofboth the small and large intestines (Fig. 1), the cytoplasm of thehepatic and kupfer cells, and within the lymphocytes andmacrophages of both the spleen and the mesenteric lymphnodes (Figs 2a and 2b).

Meanwhile intense positive reaction against PI-3 wasdemonstrated in the lining bronchial and alveolar epithelium(Fig. 3b). A severe positive reaction against BHV-1 viral antigenwas observed inside the degenerated mucosal epithelium, the

a) b)

a) b)

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Histopathological studiesMost of the histopathological lesions were confined to thealimentary and respiratory tracts, the lymphoreticular tissuesand the kidneys. In Herd 1, microscopical examination of thegastrointestinal tract revealed epithelial degeneration andnecrosis of the lining of the ruminal pillars. The necrotic cellswere sloughed leading to erosions or ulcerations withinflammatory cell aggregations mixed with fibrinous exudatesassociated with haemorrhage and thrombosis of most of thelymphatics. Examination of the abomasums revealed necrosisof the glandular epithelial cells in addition to haemorrhage anddilatation of the gland lumens. In the intestine, pathologicalchanges were prominent in all parts of the intestines (Figs 4aand 4b), and included severe damage and necrosis of theintestinal villi and sloughing of the lining epithelium. Themucosal glands were cystic. There was severe haemorrhage andcongestion of the submucosal blood vessels. The ileocecal valveshowed depletion in the Peyer’s patches and the villi appearedatrophied with excessive goblet cells formation. tract. The trachea showed variable degrees of degeneration,

necrosis and epithelial exfoliation. Congestion in thesubmucosal blood vessels and haemorrhages associated withround cell infiltrations in the lamina propria were detected. Thelungs showed proliferative reactions involving the bronchiolarand alveolar epithelia, (epithelization), so that the lesions wereconsidered as atypical interstitial pneumonia. Most of thebronchiolar and alveolar epithelial cells were vacuolated.Intranuclear acidophelic inclusions were detected in the liningalveolar epithelium as shown in Figure 6. Most of the bronchiand alveoli contained a mixture of neutrophils, macrophagesand lymphocytes, with detached epithelial cells and serousexudates which had almost completely blocked the lumina ofthe bronchioles and alveoli with multiple syncytial giant cells.In addition, vasculitis and thrombosis were observed in most ofthe pulmonary blood vessels. Examination of the kidneysrevealed nephritis in the tissue samples collected from all threeinvestigated cattle herds.


a) Duodenum revealing severe necrosis and sloughing of most of the lining epithelium ofthe intestinal villi with inflammatory cells infiltration. Haematoxylin and eosin × 250b) Duodenum showing glandular oedema with separation of the lining epithelium insidetheir lumen. Haematoxylin and eosin × 250

Fig. 4Pathological changes in the intestines

a) Haematoxylin and eosin × 500b) Phloxin and tartrazin × 1,000

Fig. 5Liver showing both intranuclear and intracytoplasmic inclusionbodies in the hepatocytes (arrows)

The hepatic cells showed variable degrees of vacuolardegeneration and multiple focal areas of necrosis associatedwith round cell infiltrations. Both intranuclear andintracytoplasmic acidophilic inclusion bodies, which werepositive with phloxin and tartrazine stain, were seen in most ofthe examined hepatic tissues (Figs 5a and 5b). There wasdegeneration of the epithelial lining the bile ducts and fibrosisin the portal areas. The lymphoid follicles of the bronchial andmesenteric lymph nodes were markedly depleted, with anaccumulation of a large number of macrophages in thesubcapsular zone. The white pulp of the spleen was alsodepleted. There was vasculitis of the small and medium sizedblood vessels.

In Herds 2 and 3, microscopic changes were noticed in therespiratory system and there were changes in the alimentary

Fig. 6Lung showing intranuclear acidophelic inclusion bodies in thelining alveolar epithelium (arrows) associated with massivedegeneration and necrosis of the lining alveolar epithelium.Haematoxylin and eosin × 500

a) b)

a) b)

Virological diagnosisIsolation and identification of bovine viral diarrhoeavirusThe results of the isolation and identification of both cpBVDVand ncpBVDV biotypes using the cell culture method and theimmunofluorescent technique are represented in Table V.Immunofluorescence positive samples were characterised byspecific intracytoplasmic fluorescence.

Detection of parainfluenza-3 virus antigenTable VI shows the results of HA and HI tests which were usedto detect PI-3V antigen in nasal swabs collected from thediseased calves in the three investigated cattle herds.

Demonstration of bovine herpesvirus-1Both the cell culture method and the VN test were used todemonstrate and identify BHV-1 isolates in the collected nasalswabs. Cytopathic effect was observed in MDBK cell cultureafter 36 h post-inoculation; this appeared in the form ofrounding of the cells, shrinkage of cell walls and an increase ingranularity, leading to the formation of a bunch of grapes within72 h-96 h. In the VN test, the isolated virus was neutralised byreference bovine hyperimmune serum against BHV-1. Viruswas only isolated from Herd 3, in which thirty-two out of forty-eight nasal swab samples were positive (Table VII).

Epidemiological studiesIn 2000, there were outbreaks of severe acute BVD, eitheralone, as in Herd 1, or mixed with PI-3V infection, as in Herd 2,or mixed with both PI-3V and BHV-1 infection, as in Herd 3.The current study suggested that the immunosuppressive effectof BVDV predisposed cattle in Herds 2 and 3 to infection withPI-3V or both PI-3V and BHV-1. Herd 3 had been importedfrom Romania just a few weeks before the appearance of clinicalsigns, and the stress of this transportation facilitated theconcurrent infection with both PI-3V and BHV-1. Also, thestudy suggested that the young calves of Herd 3 (ingovernmental quarantine in El-Behira Province) were infected

with BVDV before being imported into Egypt. Morbidity,mortality, case fatality and abortive rates in the three affectedherds are represented in Table VIII.

DiscussionThe BVDV infection in cattle has been reported throughout theworld, and the wide spectrum of clinical syndromes associatedwith this positive-stranded and enveloped RNA virus makes itone of the most important viral pathogens of cattle (17). TheBVDV spreads widely among cattle herds in the world (5, 23,54, 68, 72). The BVDV was isolated for the first time in Egyptin 1972 from a calf suffering from severe enteritis (33). Thepresent study recorded an outbreak of acute BVDV infection in2000 in three cattle herds in Egypt, with clinical manifestations


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Table VIsolation of both cytopathic (CP) and non-cytopathic (NCP) bovine viral diarrhoea virus (BVDV) biotypes

Detection of BVDHerds Nasal BVDV Buffy BVDV Dead BVDV Aborted BVDV

swabs CP NCP coats CP NCP calves CP NCP foetuses CP NCP

1 14 – 5 14 – 9 – – – 5 – 3 (b)

2 16 – 7 16 – 10 – – – 3 – 2 (c)

3 48 16 – 48 21 – 4 4 (a) – – – –

Total 78 16 12 78 21 19 4 4 – 8 – 5

a) tissue samples from the same four calves were also positive by the immune staining techniqueb) from lung and spleenc) from spleen

Table VIDetection of parainfluenza-3 virus antigen in the threeinvestigated herds

Haemagglutination and haemagglutinationHerds inhibition tests

Number of examined nasal swabs Positive %

1 14 – (0)

2 16 10 (62.5)

3 48 28 (58.3)

Total 78 38 (48.7)

Table VIIIsolation of bovine herpesvirus-1 from nasal swabs

Herds Virus neutralisation test

Number of examined nasal swabs Positive %

1 14 – (0)

2 16 – (0)

3 48 32 (66.7)

Total 78 32 (41)

of enteritis and congenital malformations. Isolation andidentification of the causative viruses, as well as the detection ofthe viral antigens by immunohistochemistry, indicated that themain cause of calf mortalities in the three herds was severeacute bovine viral diarrhoea. Concurrent infection with BVDVand PI-3V was observed in Herd 2. In Herd 3, mixed infectionof BVD, PI-3 and BHV-1 was reported. The BVDV waswidespread throughout the country as determined by thedetection of neutralising BVD antibodies in 99 (37.6%) out of263 sheep sera in 24 different localities throughout all theprovinces of Egypt (31). In March 1982, an outbreak due toBVDV infection was reported by Ghaffar and Ata (27) in cattleand buffalo in Fayoum and Qina Governorates. The BVDV andBHV-1 are prevalent in the country as indicated by thedetection of antibodies in bovine and buffalo serum samplescollected from some governmental farms in Lower Egypt (32).

The BVDV seems to be transmitted directly from either acutelyor persistently infected cattle to susceptible cattle. Persistentlyinfected cattle play a more significant role in the transmissionand maintenance of BVDV than acutely infected cattle (13, 67).For a persistent infection to become established, ncpBVDVmust infect the developing embryo or foetus during the firstfour months of gestation (41). Persistently infected-calvesusually have poor viability and suffer early disease and deathwith or without signs of diarrhoea (54). This study suggestedthat Herds 1 and 2 were suffering from persistent BVDVinfection. Animals from Herd 3 may already have been infectedwith BVDV before being imported.

Both CP and NCP biotypes of BVDV are capable of affectingfoetal and neonatal development. The CP biotypes arefrequently associated with embryonic death, abortion, andmalformation; NCP biotypes are associated withimmunotolerance and persistent infection (46). This studysuggested that the malformations observed in newborn calvesin the affected herds were a result of intrauterine infection withcpBVD biotype.

Clinically, fevers, anorexia, depression, salivation, erosivestomatitis, abortion, and profuse watery diarrhoea withdehydration were the most observable signs of acute BVD in the

affected herds. Young calves aged from three to twelve monthswere more susceptible to the infection and showed severeclinical signs. The BVDV infection should be considered wheninvestigating severe acute outbreaks of enteritis (19) andabortion in cattle (38). In addition to the above mentionedclinical signs, severe respiratory and ocular manifestations,including rapid respiration, mucopurulent nasal discharge,dyspnoea, coughing and sneezing and conjunctivitis wereobserved among diseased animals in Herds 2 and 3.

Accurate diagnosis of BVDV infection depends upon isolatingthe virus from nasal swabs or blood or tissue samples fromaffected animals in a diagnostic laboratory (2, 6, 21, 32, 34, 61,71). In this study, laboratory investigations revealed isolationand identification of ncpBVDV biotype from the nasal swabs,buffy coats and tissue samples collected from Herds 1 and 2using the cell culture method and the immunofluorescenttechnique, while the CP biotype was detected in the samplesobtained from Herd 3. The indirect peroxidase stainingtechnique is a practical test for detecting BVDV in infectedherds (43), and has been used previously to diagnose BVDVinfection (34) and IBR (74). In the present study, the ABCimmunoperoxidase method was used as a rapid way ofconfirming the demonstration of BVD, BHV-1 and PI-3 viralantigens in the collected tissue samples. This techniquereflected the involvement of a wide variety of tissues. Thelocation and intensity of BVD, BHV-1 and PI-3 antigens in theexamined organs were similar to the observations of Hosny etal. (36) and Shehab et al. (66). The results of the tissue culturemethod and the avidin biotin complex-immunoperoxidasetechnique for detecting BVDV infection in tissue samplesobtained from 4 dead calves from Herd 3 were correlated.Histopathological findings of severe acute BVD were observed.There was severe congestion and haemorrhages throughout thegastrointestinal tract as seen previously by Ernst et al. (25), Ruth(61), Mebus et al. (42). Massive degenerative changes wereobserved in the liver and kidneys as detected by Barlow et al.(7), Omran (50), Tyler and Ramsey (69).

The BVDV infections in congregated and stressed cattle maylead to severe respiratory or enteric disease (9, 59). The currentstudy suggested that the immunosuppressive effect of BVDV


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Table VIIIMorbidity, mortality, case fatality and abortive rates in the three affected cattle herds

Epidemiological aspects

HerdsTotal number Number of Morbidity Number of Mortality Case fatality Total number Number of Abortive

of calves diseased rate dead calves rate rate of pregnant aborted rate calves (%) (%) (%) cows cows (%)

1 69 35 50.7 21 30.4 60 98 26 26.5

2 112 48 42.9 32 28.6 66.7 70 14 20

3 1,520 74 4.9 26 1.7 35.1 0 0 0

Total 1,701 157 9.2 79 4.6 50.3 168 40 23.8

facilitated the infection of the diseased calves with other viralagents such as BHV-1 and PI-3V. This suggestion coincides withthe findings reported by Potgieter et al. (53). The concurrentinfection with the BVDV, BHV-1 and PI-3V worsened theclinical disease and the economic losses in the three affectedherds. Field outbreaks of mixed infection by BVDV and otherviruses such as malignant catarrhal fever virus (65) and foot andmouth virus (36) have been previously reported.

Respiratory and enteric infections are the most costly andtroublesome disease problems in calves in Egypt (32). Thisstudy revealed that the direct economic losses of BVDVinfection (and the indirect losses due to theimmunosuppressive effect of the virus, which facilitatesinfection with other infectious agents), are considerable. Theseeconomic losses were estimated at US$13,800, US$15,600 andUS$10,400 in Herds 1, 2 and 3 respectively. The economiclosses associated with BVDV infections are due to suboptimalreproductive performance due to infertility and embryonicdeath, abortion, prenatal growth retardation, stillbirths,congenital defects, postnatal growth retardation, and deathfrom mucosal disease (24).

Bovine PI-3V is a common infection of cattle, 60%-90% ofcattle in a herd often having serological evidence of pastinfection (8). The PI-3V was detected in the nasal swabs, whichwere collected from Herds 2 and 3 using HA and HI tests.Subclinical viral pneumonia, which is associated with the PI-3Vand is uncomplicated by secondary infection, is usually ofminor importance (55). However, in the current study, severerespiratory signs were observed among the affected calves ofHerds 2 and 3 as a result of complication of BVDV infectionwith PI-3V, as in Herd 2, or with both PI-3V and BHV-1, as inHerd 3. These findings agree with the experiment of Castrucciet al. (15), who found that simultaneous infection of calves withBVDV and PI-3V induced a clinical response which wasconsidered of moderate intensity. A different situation wasobserved, however, when simultaneous infection was madewith BVDV and BHV-1. In the inoculated calves, BVDV andBHV-1 together induced a severe clinical response characterisedby a wide variety of signs which included mucoid nasaldischarge, profuse salivation and pronounced diarrhoea.

The BHV-1 was found primarily in large, concentrated cattlepopulations, such as feedlots or intensively managed dairyoperations (44). Both the immunosuppressive effect of theBVDV and PI-3V, and the effect of being transported over longdistances, predisposed the imported feedlot calves in Herd 3 toinfection with BHV-1. The BHV-1 can be spread through nasal

secretions or aerosol droplets containing the virus. Closecontact among animals is responsible for the high rate oftransmission (70). The present study also suggested that thecrowdedness and close contact of the 1,520 animals in Herd 3(in the governmental quarantine in Behira Province) played animportant role in rapidly transmitting BHV-1 among the youngimported feedlot calves, which had been imported fromRomania just a few weeks before these investigations.

In cattle infected with BHV-1, the initial lesions whichdeveloped in the upper respiratory tract usually progressed tobroncho and/or lobar pneumonia as a result of secondaryinfection, either a viral infection, such as PI-3V, or a bacterialinfection (49). In the present study, it was evident that BHV-1has a cellular destructive power on the parenchymatous organsand causes necrosis of hepatic cells, as observed previously byShehab et al. (66). The BHV-1 is distributed worldwide, but hasbeen eradicated from Denmark and Switzerland and controlprogrammes have started in some other countries (49).

ConclusionThe present study leads us to conclude that:

– concurrent infection with BVDV, BHV-1 and PI-3V should beconsidered as one of the infectious causes of pneumoenteritisand the subsequent high morbidities and mortalities amongyoung calves in Egypt. Consequently, preventive and controlmeasures against these infectious viral agents should beadopted

– the ABC immunoperoxidase technique is one of the mostrapid and accurate laboratory tests for the diagnosis of differenttypes of mixed viral infections, such as concurrent infectionwith BVDV, BHV-1 and PI-3V

– both BVDV and BHV-1 have an immunosuppressive effectand facilitate secondary infection in diseased calves, whichsubsequently results in high economic losses

– all animals imported into Egypt must be free from BVDVinfection

– control programmes for detecting and removing BVDV-persistent cattle should be applied in cattle herds all over thecountry.


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Cas de diarrhée virale bovine et d’infection à l’herpèsvirus bovin etau virus para-influenza 3 dans trois troupeaux de bovins en Égypteen 2000

N.M. Aly, G.G. Shehab & I.H.A. Abd El-Rahim

RésuméCette étude rapporte la présence de foyers causés par le virus de la diarrhéevirale bovine (BVDV) en Égypte, en 2000. Le virus responsable a été détecté soitseul, soit conjointement avec l’herpèsvirus bovin de type 1 (BHV-1) et/ou le viruspara-influenza de type 3 (PI-3V). En Basse Égypte, des symptômes d’entérite,parfois accompagnés de manifestations respiratoires, ont été observés chez dejeunes veaux dans trois troupeaux, dans les provinces d’El-Minufiya et d’El-Fayoum, ainsi que dans les installations gouvernementales de quarantainede la province d’El-Behira. Les troupeaux contaminés ont été inspectés et lesanimaux atteints soumis à un examen clinique. Un grand nombre d’aspectsépidémiologiques (morbidité, mortalité et létalité, par exemple) ont étédéterminés, dont le taux d’avortement. Des échantillons de sang sur EDTA (acideéthylène diamine tétra-acétique), des frottis nasaux ainsi que des échantillonssériques ont été prélevés à des fins de diagnostic virologique et sérologique. Lesanalyses de laboratoire ont révélé que la principale cause de la mortalitéobservée chez les veaux des trois troupeaux était une infection au seul BVDV(élevage d’El-Minufiya), à la présence simultanée du BVDV et du PI-3V (élevaged’El-Fayoum) ou à la présence conjointe du BVDV, du BHV-1 et du PI-3V (troupeaude la station gouvernementale de quarantaine de la province d’El-Behira). Unexamen post-mortem complet a été réalisé sur neuf veaux issus des troistroupeaux. Des prélèvements de tissus ont été effectués chez les veaux mortsrécemment pour examen immunohistochimique et histopathologique. Lesanalyses histopathologiques ont principalement mis en évidence unedégénérescence massive, accompagnée de nécrose et d’érosion de la paroiépithéliale du tube digestif. La plupart des organes lymphoréticulairesprésentaient un important déficit lymphocytaire. Des signes debronchopneumonie et de pneumonie interstitielle atypique étaient manifestesdans les cas pulmonaires. Selon les auteurs de cette étude, l’effetimmunodépresseur du BVDV aurait prédisposé les animaux à une infectionsecondaire au BHV-1 et PI-3V. Cette étude a permis de conclure qu’une infectionopportuniste à BVDV, BHV-1 et PI-3V devait être envisagée comme l’une descauses de l’infection de pneumoentérite et des taux élevés de morbidité et demortalité observés ultérieurement parmi les jeunes veaux d’Égypte. Il convientdès lors de mettre en place des mesures préventives et de contrôle contre cesagents infectieux. Tous les animaux importés en Égypte devraient être indemnesde toute infection au BVDV. Il convient de mettre en place des programmes decontrôle destinés à dépister et à éliminer les bovins porteurs du BVDV au sein destroupeaux sur l’ensemble du territoire.

Mots-clésDiagnostic virologique – Diarrhée virale bovine – Épidémiologie – Examen pathologique –Immunohistochimie – Rhinotrachéite infectieuse bovine – Sérologie – Symptôme clinique– Virus para-influenza de type 3.�

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Diarrea viral bovina e infección por el herpesvirus bovino y elvirus de la parainfluenza 3 en tres rebaños vacunos de Egipto en elaño 2000

N.M. Aly, G.G. Shehab & I.H.A. Abd El-Rahim

ResumenLos autores describen el estudio de una serie de brotes infecciosos que sedeclararon en 2000 en Egipto, causados por el virus de la diarrea viral bovina(VDVB), ya fuera solo o acompañado del herpesvirus bovino 1 (HVB-1) y/o el virusparainfluenza 3 (VPI-3). En las tierras bajas egipcias, y concretamente en lasprovincias de El-Minufiya y el El-Fayoum y las instalaciones oficiales decuarentena de la provincia de El-Behira, se observaron síntomas de enteritis entres rebaños de jóvenes terneras, que a veces se presentaban solos y otrasveces acompañados de disfunción respiratoria. Se efectuaron inspecciones delos rebaños afectados y análisis clínicos de los animales enfermos. Se calcularonnumerosos parámetros epidemiológicos, tales como las tasas de morbilidad,mortalidad y letalidad y el índice de abortos. Para proceder al diagnósticovirológico y serológico, se recogieron muestras de sangre en ácido etilendiaminotetracético, muestras de exudado nasal en hisopos estériles y muestras de suero.Los análisis de laboratorio revelaron que, en los tres rebaños, la principal causade mortalidad era la infección por el VDVB, ya fuera solo (como en la explotaciónde El-Minufiya) o combinado con el VPI-3 (como en la granja de El-Fayoum) o conéste y el HVB-1 (como en el rebaño de las instalaciones de cuarentena de laprovincia de El-Behira). Un total de nueve terneras de los tres rebaños fueronsometidas a inspección post-mortem exhaustiva. Se extrajeron muestrastisulares de terneras muertas poco tiempo antes para someterlas a análisisinmunohistoquímico e histopatológico. Desde el punto de vista histopatológico,las observaciones más destacadas fueron una degeneración muy extendida,zonas de necrosis y erosión del epitelio de revestimiento del tracto digestivo. Lamayor parte de los órganos linforreticulares habían perdido los linfocitos. Losanimales neumónicos presentaban signos evidentes de bronconeumonía yneumonía intersticial atípica. Del estudio se desprende que los efectosinmunosupresores del VDVB habían predispuesto a los animales a contraerinfecciones secundarias por el HVB-1 y el VPI-3, lo que a su vez lleva a concluirque es preciso tener en cuenta que las infecciones oportunistas por el VDVB, elHVB-1 o el VPI-3 constituyen una de las causas infecciosas de neumoenteritis y,ulteriormente, de las elevadas tasas de morbilidad y mortalidad entre las ternerasjóvenes de Egipto. De ahí la necesidad de adoptar medidas preventivas y decontrol contra esos agentes infecciosos. Todos los animales que Egipto importedeben estar libres de la infección por el VDVB. Por otra parte, los rebañosbovinos de todo el país deben estar sujetos a programas de control para detectary eliminar los ejemplares que presenten infección persistente por el VDVB.

Palabras claveAnálisis patológico – Diagnóstico virológico – Diarrea viral bovina – Epidemiología –Inmunohistoquímica – Rinotraqueítis infecciosa bovina – Serología – Síntomatologíaclínica – Virus de la parainfluenza 3.�

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References1. Abd El-Rahim I.H.A. (1996). – Clinical and laboratory

studies on mucosal disease in cattle. PhD thesis (infectiousdiseases). Faculty of Veterinary Medicine, Assiut University,Egypt, 87-98.

2. Abd El-Rahim I.H.A. & Gründer H.-D. (1996). –Thrombocytopenia in cattle with mucosal disease. Tierärztl.Umsch., 8, 470-478.

3. Abd El-Rahim I.H.A, El-Allawy T.A., Laila S.A. &Gründer H.-D. (1997). – Detection of noncytopathic BVDvirus isolated from clinically mucosal disease affected cattleon the inoculated tissue culture using interference andimmunofluorescent technique. In Proc. 37th Science Week,1-6 November, Damascus, Syria. Vol. 2. Damascus University,Damascus, 523-536.

4. Abo El-Lail T.A. (1992). – Pathological studies on mortality ofcalves with special reference to respiratory affections. M.V.Sc.thesis. Faculty of Veterinary Medicine, Cairo University.

5. Alenius S., Jacobsson S.O. & Cafaro E. (1986). – Frequencyof bovine viral diarrhea virus infections in Sweden amongheifers selected for artificial insemination. In Proc. XIV Worldcongress on diseases of cattle, Dublin, Ireland, 204-207.

6. Baker J.C. (1987). – Bovine viral diarrhea virus: a review.J. Am. vet. med. Assoc., 190, 1449-1458.

7. Barlow R.M., Gardiner A.C. & Nettleton P.F. (1983). – Thepathology of a spontaneous and experimental mucosaldisease-like syndrome in sheep recovered from clinical borderdisease. J. comp. Pathol., 93 (3), 451-461.

8. Bellini W.J., Rota P.A. & Anderson L.J. (1998). –Paramyxoviruses. In Topley and Wilson’s Microbiology andmicrobial infections, 9th Ed., Vol. I: Virology (B.W.J. Mahyand L.H. Collier, eds). Hodder Arnold, London, 435-461.

9. Bolin S.R. (1992). – BVD: what’s the latest. In Proc. XVIIWorld Buiatrics Congress and XXV American Association ofBovine Practitioners Conference (Vol. 2), 31 August-4September, St. Paul, Minnesota, 155-157.

10. Bolin S.R., McClurkin A.W. & Coria M.F. (1985). – Effects ofbovine viral diarrhea virus on the percentages and absolutenumbers of circulating B and T lymphocytes in cattle. Am. J.vet. Res., 46 (4), 884-886.

11. Brown G.B., Bolin S.R., Frank D.E. & Roth J.A. (1991). –Defective function of leukocytes from cattle persistentlyinfected with bovine viral diarrhea virus and the influence ofrecombinant cytokines. Am. J. vet. Res., 52 (3), 381-387.

12. Brownlie J. (1991). – The pathways for bovine virus diarrheavirus biotypes in the pathogenesis of the disease. Arch. Virol.,31 (supplement), 79-96.

13. Brownlie J. & Clarke M.C. (1990). – Bovine virus diarrhoeavirus: speculation and observations on current concepts(J. Brownlie & M.C. Clarke, eds). Rev. sci. tech. Off. int. Epiz.,9 (1), 223-230.

14. Carleton H.M., Drury R.A.B. & Wallington F.A. (1967). –Carleton’s histological technique, 4th Ed. Oxford UniversityPress, New York.

15. Castrucci G., Ferrari M., Traldi V. & Tartaglione E. (1992). –Effects in calves of mixed infections with bovine viral diarrheavirus and several other bovine viruses. Comp. Immunol.Microbiol. Infect. Dis., 15 (4), 261-270.

16. Clarke M.C., Brownlie J. & Howard C.J. (1984). – Isolationof cytopathic and non-cytopathic bovine viral diarrhea virusfrom tissues of infected animals. In Pestivirus infections ofruminants (J.W. Harkness, ed.). Commission of the EuropeanCommunities, Brussels, 3-12.

17. Corapi W.V., French T.W. & Dubovi E.J. (1989). – Severethrombocytopenia in young calves experimentally infectedwith noncytopathic bovine viral diarrhea virus. J. Virol., 63(9), 3934-3943.

18. Dasika G.K. & Letchworth G.J. (2000). – Homologous andheterologous interference requires bovine herpesvirus-1glycoprotein D at the cell surface during virus entry. J. gen.Virol., 81, 1041-1049.

19. David G.P., Gunning R.F., Crawshaw T.R., Hibberd R.C.,Lloyd G.M. & Marsh P.R. (1993). – Fatal BVDV infection inadult cattle. Vet. Rec., 132 (11), 283.

20. Dinter Z. & Bakos K. (1966). – The aetiology and pathologyof pneumonia in calves. Vet. Bull., 36 (5), 259-273.

21. Donis R.O. (1988). – Bovine viral diarrhea: the unraveling ofa complex of clinical presentations. Bovine Proc., 20, 16-22.

22. Dubovi E.J. (1986). – Fatal BVD virus-induced disease: roleof persistently infected animals. Bov. Practit., 20, 20-24.

23. Duffell S.J. & Harkness J.W. (1985). – Bovine virus diarrhoea-mucosal disease infection in cattle. Vet. Rec., 117 (10), 240-245.

24. Duffell S.J., Sharp M.W. & Bates D. (1986). – Financial lossresulting from BVD-MD virus infection in a dairy herd. Vet.Rec., 118 (2), 38-39.

25. Ernst P.B., Baird F.D. & Butler D.G. (1983). – Bovine viraldiarrhea: an update. Compend. cont. Educ. pract. Vet., 5, 5581-5589.

26. Fray M.D., Supple E.A., Morrison W.I. & Charleston B.(2000). – Germinal centre localization of bovine viraldiarrhoea virus in persistently infected animals. J. gen. Virol.,81, 1669-1673.

27. Ghaffar S.A. & Ata F.A. (1982). – Bovine virus diarrhoea inEgypt. Vet. Rec., 110 (24), 566.

28. Gibbs E.P.J. & Rweyemamu M.M. (1977). – Bovineherpesviruses. Part 1. Bovine herpesvirus 1. Vet. Bull., 47,317-343.

29. Gillespie J.H., Lee K.M. & Baker J.A. (1957). – Infectiousbovine rhinotracheitis. Am. J. vet. Res., 18 (68), 530-535.

30. Gründer H.-D. (1990). – BVD-infektion beim Kalb. Tierärztl.Umsch., 45, 258-267.

31. Hafez S.M. (1975). – Geographical distribution of bovine viraldiarrhea-mucosal disease in Egypt determined by thedetection of neutralizing antibodies in sheep sera. J. Egypt. Vet.Med. Assoc., 34, 1-12.

32. Hafez S.M. & Frey H.R. (1973). – Serological evidence for theoccurrence of bovine viral diarrhea-mucosal disease (BVD-MD) and infectious bovine rhinotracheitis (IBR) in Egypt. Bull.epiz. Dis. Afr., 21, 5-10.

33. Hafez S.M. (1975). – Isolation and identification of bovineviral diarrhea-mucosal disease virus in Egypt. J. Egypt. Vet.Med. Assoc., 35, 1-9.

34. Haines D.M., Clark E.G. & Dubovi E.J. (1992). – Monoclonalantibody-based immunohistochemical detection of bovineviral diarrhea virus in formalin-fixed, paraffin-embeddedtissues. Vet. Pathol., 29 (1), 27-32.

35. Hegazy A.A., El-Sanousi A.A., Lotfey M.M., Hamouda M.A. &Abo El-Lail T.A. (1995). – Pathological and virological studieson calf mortality: mortalities associated with bovine viraldiarrhea virus (BVDV) infection. J. Egypt. Vet. Med. Assoc., 55,493-503.

36. Hosny G.A., Omran R.M.A., Shehab G.G., Aly N.M. &Karim I.A. (1996). – Pathological, immunopathological andvirological findings in field outbreak of mixed infection bybovine viral diarrhea (BVD) and foot and mouth (FMD) incattle and buffaloes. Vet. med. J. Giza, 44, 349-369.

37. Jubb K.V.F., Kennedy P.C. & Palmer N. (1993). – Pathology ofdomestic animals, 4th Ed. Academic Press, San Diego.

38. Kahrs R.F. (1968). – The relationship of bovine viral diarrhea-mucosal disease to abortion in cattle. JAVMA, 153, 1652-1655.

39. Lemaire M., Meyer G., Ernst E., Vanherreweghe V.,Limbourg B., Pastoret P.-P. & Thiry E. (1995). – Latent bovineherpesvirus 1 infection in calves protected by colostralimmunity. Vet. Rec., 137 (3), 70-71.

40. Lennette E.D. & Schmidt W.J. (1964). – Diagnosticprocedures for viral and rickettsial diseases, 3rd Ed. AmericanPublic Health Association Inc., New York.

41. McClurkin A.W., Littledike E.T., Cutlip R.C., Frank G.H.,Coria M.F. & Bolin S.R. (1984). – Production of cattleimmunotolerant to bovine viral diarrhea virus. Can. J. comp.Med., 48, 165-161.

42. Mebus C.A., Newman L.E. & Stair E.L. (1975). – Scanningelectron, light, and immunofluorescent microscopy ofintestine of gnotobiotic calf infected with calf diarrhealcoronavirus. Am. J. vet. Res., 36 (12), 1719-1725.

43. Meyling A. (1984). – Detection of BVD virus in viremic cattleby an indirect immunoperoxidase technique. In Recentadvances in virus diagnosis. Martinus Nijhoff, The Hague, 37-46.

44. Miller J.M. (1991). – The effect of IBR virus infection onreproductive function of cattle. Vet. Med., 86 (1), 95-98.

45. Molesworth S.J., Lake C.M., Borza C.M., Turk S.M. &Hutt-Fletcher L.M. (2000). – Epstein-Barr virus gH is essentialfor penetration of B cells but also plays a role in attachment ofvirus to epithelial cells. J. Virol., 74 (14), 6324-6332.

46. Oberst R.D. (1993). – Viruses as teratogens. Vet. Clin. N. Am.(Food Anim. Pract.), 9 (1), 23-31.

47. OIE (World organisation for animal health) (1992). – Bovinevirus diarrhoea. In Manual of standards for diagnostic testsand vaccines for lists A and B diseases of mammals, birds andbees. OIE, Paris, 726-735.

48. OIE (World organisation for animal health) (2000). – Bovineviral diarrhoea. In Manual of standards for diagnostic tests andvaccines: Lists A and B diseases of mammals, birds and bees.OIE, Paris 843-854.

49. OIE (World organisation for animal health) (2000). –Infectious bovine rhinotracheitis/infectious pustularvulvovaginitis. In Manual of standards for diagnostic tests andvaccines: Lists A and B diseases of mammals, birds and bees.OIE, Paris, 381-391.

50. Omran R.M. (1991). – Experimental pathological studies onbovine viral diarrhea infection (BVD) in calves. Ph.D. Thesis,Faculty of Veterinary Medicine, Cairo University, Egypt.

51. Perdrizet J.A., Rebhun W.C., Dubovi E.J. & Donis R.O.(1987). – Bovine virus diarrhea-clinical syndromes in dairyherds. Cornell Vet., 77 (1), 46-74.

52. Potgieter L.N.D., McCracken M.D., Hopkins F.M. &Walker R.D. (1984). – Effect of bovine viral diarrhea virusinfection on distribution of infectious bovine rhinotracheitisin calves. Am. J. vet. Res., 45 (4), 687-690.

53. Potgieter L.N.D., McCracken M.D., Hopkins F.M.,Walker R.D. & Guy J.S. (1984). – Experimental production ofbovine respiratory tract disease with bovine viral diarrheavirus. Am. J. vet. Res., 45 (8), 1582-1585.

54. Radostits O.M. & Littlejohns I.R. (1988). – New concepts inthe pathogenesis, diagnosis and control of diseases caused bythe bovine viral diarrhea virus. Can. vet. J., 29, 513-528.

55. Radostits O.M., Gay C.C., Blood D.C. & Hinchcliff K.W.(2000). – Veterinary medicine: a textbook of the diseases ofcattle, sheep, pigs, goats, and horses, 9th Ed. W.B. SaundersCompany Ltd, London, New York, Philadelphia, SanFrancisco, St Louis, Sydney, 1160-1172.

56. Rijsewijk F.A.M., Kaashoek M.J., Langeveld J.P.M., Meloen R.,Judek J., Bienkowska-Szewczyk K., Maris-Veldhuis M.A. &Van Oirschot J.T. (1999). – Epitopes on glycoprotein C ofbovine herpesvirus-1 (BHV-1) that allow differentiationbetween BHV-1.1 and BHV-1.2 strains. J. gen. Virol., 80, 1477-1483.

57. Roeder P.L. & Drew T.W. (1984). – Mucosal disease of cattle:a late sequel to fetal infection. Vet. Rec., 114 (13), 309-313.

58. Roizmann B., Desrosiers R.C., Fleckenstein B., Lopez C.,Minson A.C. & Studdert M.J. (1992). – The familyherpesviridae: an update. Arch. Virol., 123 (3-4), 425-449.


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59. Roth J.A., Bolin S.R. & Frank D.E. (1986). – Lymphocyteblastogenesis and neutrophil function in cattle persistentlyinfected with bovine viral diarrhea virus. Am. J. vet. Res., 47(5), 1139-1141.

60. Roy J.H.B. (1980). – Factors affecting susceptibility of calvesto disease. J. Dairy Sci., 63 (4), 650-664.

61. Ruth G.R. (1986). – Bovine viral diarrhea: a difficult infectionto diagnose. Vet. Med., 81 (9), 870-874.

62. Schroder C. & Keil G.M. (1999). – Bovine herpesvirus 1requires glycoprotein H for infectivity and direct spreadingand glycoproteins gH (W450) and gB for glycoprotein D-independent cell-to-cell spread. J. gen. Virol., 80, 57-61.

63. Schweizer M. & Peterhans E. (1999). – Oxidative stress incells infected with bovine viral diarrhoea virus: a crucial stepin the induction of apoptosis. J. gen. Virol., 80, 1147-1155.

64. Schwyzer M. & Ackermann M. (1996). – Molecular virologyof ruminant herpesviruses. Vet. Microbiol., 53 (1-2), 17-29.

65. Sharpe R.T., Bicknell S.R. & Hunter A.R. (1987). –Concurrent malignant catarrhal fever and bovine virusdiarrhea virus infection in a dairy herd. Vet. Rec., 120 (23),545-548.

66. Shehab G.G., Hosny G.A., Ahmed L.A. & Sabry A.A. (2001).– Microbiological and pathological studies of an outbreak inimported fattening veal calves suffering from pneumonia.Egypt. J. comp. Pathol. clin. Pathol., 14, 66-83.

67. Shimizu M. & Satou K. (1987). – Frequency of persistentinfection of cattle with bovine viral diarrhea-mucosal diseasevirus in epidemic areas. Jpn. J. vet. Sci., 49 (6), 1045-1051.

68. Shimizu M. (1990). – Current situation of bovine virusdiarrhoea-mucosal disease (BVD-MD) virus infections andtheir antigenic diversity in Hokkaido, Japan. Rev. sci. tech. Off.int. Epiz., 9 (1), 181-194.

69. Tyler D.E. & Ramsey F.K. (1965). – Comparative pathologic,immunologic, and clinical responses produced by selectedagents of the bovine mucosal disease-virus diarrhea complex.Am. J. vet. Res., 26 (113), 903-913.

70. Van Donkersgoed J. & Babiuk L.A. (1991). – Diagnosing andmanaging the respiratory form of infectious bovinerhinotracheitis. Vet. Med., 86, 86-94.

71. Vickers H.L. (1992). – BVD: getting a positive diagnosis. InProc. XVII World Buiatrics Congress and XXV AmericanAssociation of Bovine Practitioners Conference (Vol. 2),31 August-4 September, St. Paul, Minnesota, USA, 158-161.

72. Weiss M., Hertig C., Strasser M., Vogt H.-R. & Peterbans E.(1994). – Bovine virusdiarrhoe/mucosal disease eineÜbersicht. Schweizer Arch. Tierheilkd., 136, 173-185.

73. Wilchek M. & Bayer E.A. (1990). – Applications of avidin-biotin technology: literature survey. Meth. Enzymol., 184, 14-45.

74. Wyler R. (1990). – Infectious bovine rhino-tracheitis/vulvovaginitis (BHV-1). In Herpesviridae of cattle,horse and pigs (G. Whittmann, ed.). Kluwer AcademicPublishers, Boston, Massachusetts, 1-72.


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bovine viral diarrhoea, bovine herpesvirus and ... · both a non-cytopathic (ncp) and an...

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