Detection of sheep-associated malignant catarrhal fever from clinical cases in Ethiopian cattle.

Mucoid nasal discharge, loss of weight, decreased milk production, diarrhoea, salivation, dyspnoea, fever, lacrimation, bilateral corneal opacity and bloody urine were observed in cattle located in the Arbe Gona district of southern Ethiopia. The disease was associated with a high case fatality rate: diseased cattle died within four to five days after showing clinical signs. The clinical presentation, gross pathological observations, histopathological findings and epidemiological data strongly suggested malignant catarrhal fever. Subsequently, the ovine herpesvirus type 2 (OvHV-2) DNA polymerase (UL30) gene was detected in pathological tissue samples using pan-herpesvirus nested polymerase chain reaction (PCR) and real-time PCR. As far as the authors are aware, this is the first report of a diagnostic investigation resulting in the detection of ovine OvHV-2 in cattle and confirming the existence of sheep-associated malignant catarrhal fever in Ethiopia.

Outbreak of wildebeest-associated malignant catarrhal fever in Ankole cattle.

During an outbreak of malignant catarrhal fever in a herd of Ankole cattle in a zoological collection, two adult cows and one adult bull from a herd of 15 died or were euthanased between July and November 2004. The clinical, gross postmortem and histological findings were typical of the disease in uk native domestic cattle. The diagnosis was confirmed by serology in two animals, and by pcr in all three; the pcr provided evidence of alcelaphine herpesvirus type 1 infection in all three animals and also of ovine herpesvirus type 2 infection in one.

Sheep-associated malignant catarrhal fever involving 3-5-week-old calves in Saudi Arabia.

Between late December 1999 and late April 2000, three locally bred Friesian calves (ageing 25, 28 and 35 days) in a dairy farm, at Al-Ahsa locality of the eastern region of Saudi Arabia showed dullness and inappetence. Their rectal temperatures ranged between 41 and 41.5 degrees C. One to 2 days later and onwards, the calves showed lacrimation, nasal discharge, salivation, oedema of the head, conjunctivitis, exo-ophthalmia and corneal opacity. One calf showed diarrhoea. The superficial lymph nodes were oedematous and swollen. The calves died after 7, 5 and 8 days, respectively, following the onset of the disease. Calves and rabbits were experimentally infected with materials from the naturally infected calves. The rabbits showed fever, mild conjunctivitis and one rabbit showed wet faeces. The experimentally inoculated calves showed rise in temperature and mild symptoms but none of them died. The virus from the naturally infected calves and from the experimentally infected rabbits was identified as malignant catarrhal fever (MCF) virus using both the complement fixation test and the fluorescent antibody test, employing a reference anti-serum against the WC 11 strain of MCF virus. Serological survey for MCF antibodies in cattle, sheep and goats from the affected farm revealed that 54% of the examined animals were positive. The situation of MCF in Saudi Arabia was discussed in relation to sheep and wild game. This paper constitutes the first report of MCF in Saudi Arabia and the Gulf region.

Gamma herpesvirus carrier status of captive artiodactyls.

Between 1998 and 2000, 103 individuals of 19 species of the order Artiodactyla at Whipsnade Wild Animal Park were tested for evidence of infection with gamma herpesviruses in order to distinguish between species which are susceptible to malignant catarrhal fever (MCF), caused by alcelaphine herpesvirus-1 (AlHV-1) of wildebeest (Connochaetes sp.) or ovine herpesvirus-2 (OvHV-2) of domestic sheep, and species which carry related viruses sub-clinically. Gamma herpesvirus DNA was detected in the known, or suspected, carrier species: roan antelope (Hippotragus equinus), scimitar-horned oryx (Oryx dammah), gemsbok (Oryx gazella), musk ox (Ovibos muschatus) and mouflon (Ovis musimon). In six other species: lowland anoa (Bubalus depressicornis) yak (Bos grunniens), sitatunga (Tragelaphus spekei), greater kudu (Tragelaphus strepsiceros), waterbuck (Kobus ellipsiprymnus) and Nile lechwe (Kobus megaceros), DNA was present in some newborn calves and over 30% of adults, strongly suggesting a carrier state. In contrast five Père David's deer (Elaphurus davidianus) and two swamp deer (Cervus duvauceli) died of MCF during the study. A virus isolated from scimitar-horned oryx calves produced cytopathic effects in scimitar-horned oryx kidney cell-culture and caused MCF in a rabbit.

Deer health and disease.

This paper describes the most significant diseases of farmed deer which have emerged over the last 30 or so years. It describes their characteristic signs, how control measures have evolved, their current status and gives an indication of future diagnostic and control measures. Overall, it shows that wild deer brought into a farming environment have developed some of the production limiting diseases which affect sheep and cattle, such as parasitism and trace element deficiencies. In addition, farmed deer are susceptible to potentially fatal diseases such as tuberculosis, malignant catarrhal fever and yersiniosis. A disease which has recently emerged and has the potential to be more serious than any of the above is Johne's disease. In North America, Chronic Wasting Disease occurs in captive and wild deer in only two states but has the potential to be a serious threat to wild and farmed deer elsewhere if it spreads. The zoonotic risks of diseases affecting deer are discussed, as well as stress, welfare and deer restraint. The productivity of farmed deer can be maximised by using a well-designed deer health programme integrated with good management and feeding.

[Malignant catarrhal fever of cattle (review)]. / Das Bösartige Katarrhalfieber des Rindes (Ubersichtsreferat).

In this review paper of Malignant cattarhal fever a general account is given with reference being made to latest knowledge on aetiology, epidemiology, pathogenesis, clinical symptoms, pathology, general and differential diagnosis, immunity and control.

The detection of Alcelaphine herpesvirus-1 DNA by in situ hybridization of tissues from rabbits affected with malignant catarrhal fever.

Tissue sections and cultured lymphocytes from rabbits clinically affected following experimental infection with Alcelaphine herpesvirus-1 (AHV-1) were assessed for the presence of viral DNA by in situ hybridization with the cloned major HindII repeat sequence of this virus. Small numbers of virus-infected cells were consistently detected only in submandibular lymph nodes, while other tissues showed no evidence of viral DNA. Virus titration in culture suggested that there were higher titres of virus in the lymph nodes, spleen and lung of infected animals than in the kidney or peripheral blood lymphocytes and confirmed the low level of virus in these animals. Substantially more viral DNA was detected by in situ hybridization in lymphocytes following at least 24 h of culture, suggesting that viral replication is normally repressed by the host.

Malignant catarrhal fever in cattle experimentally inoculated with a herpesvirus isolated from a case of malignant catarrhal fever in Minnesota USA.

A malignant catarrhal fever (MCF)-like syndrome was experimentally induced in three steers, which were under immunization trials with a herpesvirus previously isolated from a case of MCF in a cow in Minnesota USA. The clinical signs observed in the three steers, and the pathological and histological lesions observed in two of these steers which succumbed to the disease syndrome were indistinguishable from those described for MCF. Although seroconversion was readily demonstrated in the three animals, virus was not re-isolated from the blood leucocytes, secretions and tissues obtained from the two animals which succumbed to the syndrome during the course of the disease and after death. However, a herpesvirus which showed cell rounding cytopathic effects (cpe) in bovine thyroid cells (Bth), was re-isolated from the one steer which survived the disease.

[The etiology and epidemiology of malignant catarrh--a review]. / Zur Aetiologie und Epidemiologie des bösartigen Katarrhalfiebers--eine Ubersicht.

It is generally accepted that both, the wildebeest-derived malignant catarrhal fever (WD-MCF), and the circumstantially evidenced sheep-associated form of the disease (SA-MCF), may be explained as autoimmune disease of various ruminants, namely cattle and farmed deer. The disease follows infection with related herpesviruses being shed by the respective healthy carrier animals. This has convincingly be shown to apply for WD-MCF (Alcelaphine herpesvirus 1, AlcHV1). SA-MCF, however, remains to be controversial with both respects. In Switzerland, a serological study indicated that a herpesvirus(es) was highly prevalent among cattle and sheep, inducing antibody that cross-react with AlcHV1 and bovine herpesvirus 4 (BHV4). The latter is known as a largely innocuous agent. A relationship can be demonstrated between the presence of MCF in this country and concurrent serological reactions to both viruses. However similar results may be obtained with healthy animals. Healthy cattle and sheep from farms with or without incidences of MCF displayed the same antibody profiles. It is thus not possible to effectuate meaningful diagnostic tests for (SA-)MCF, nor to confirm any relationship between presumed carrier sheep and the appearance of MCF.

Antibody to alcelaphine herpesvirus-1 (AHV-1) in hamsters experimentally infected with AHV-1 and the 'sheep-associated' agent of malignant catarrhal fever.

Malignant catarrhal fever was induced in four groups of hamsters by the inoculation of cells infected with either the C/500 isolate of alcelaphine herpes-virus-1 (AHV-1) or the sheep-associated agent derived from cattle, red deer or Père David's deer. Using an indirect immunofluorescence assay, antibody to AHV-1 was detected in sera of clinically affected animals of all four groups. The reaction of sera from hamsters affected with malignant catarrhal fever induced by AHV-1 caused diffuse cytoplasmic staining while that from sera of hamsters with the sheep-associated form of the disease stained particulate nuclear antigens. Tests employing three other bovid herpesviruses were negative and no reaction was found with sera from normal hamsters. These studies provide convincing evidence that a virus antigenically related to AHV-1 is the cause of sheep-associated malignant catarrhal fever and that the same virus probably causes this form of the disease in both cattle and deer.

Fatal respiratory disease in Nilgiri tahr: possibly malignant catarrhal fever.

Nilgiri tahr (Hemitragus hylocrius) are native to India and are a rare zoo exhibit. This report describes an acute respiratory disease in tahr that caused the death of 15 of 16 animals in an extensive exhibit of about 35 acres where they were housed together with a variety of other exotic species of ruminants. The deaths occurred in two separate outbreaks and were associated with losses from malignant catarrhal fever in other ruminants in the exhibit. The most prominent clinical sign was severe dyspnea, and death occurred within five days. The principal lesions were an acute nonsuppurative inflammation of the respiratory tract and pulmonary vessels, lymphadenopathy and lymphoid cell infiltration in the organs of some animals. It was conjectured that the tahr died of a unique pneumonic form of malignant catarrhal fever. Attempts at viral isolation were negative.

Malignant catarrhal fever.

Malignant catarrhal fever is briefly reviewed and recent findings are described. Initially the disease was observed as a disease of cattle in Europe where, although no cause could be identified, circumstantial evidence implicated sheep as a source of infection and it was thus designated 'sheep-associated' malignant catarrhal fever. Subsequently the disease was observed in Africa where it became evident that a herpesvirus which normally infects wildebeest was the cause. It is now apparent that deer are highly susceptible to both forms of the disease, the sheep-associated form being a serious problem in farmed deer. The wide spectrum of clinical and pathological changes that occur in affected deer are described. A major constraint to studies of sheep-associated malignant catarrhal fever has been the absence of an experimental laboratory system. However, from affected deer it has been possible to transmit the disease to rabbits and thus has allowed detailed pathogenesis studies to be made which are summarised in this paper. It is suggested that the agent of sheep-associated malignant catarrhal fever is a virus and that when a particular subpopulation of T-lymphocytes is infected a profound immunological perturbation results; the lesions of malignant catarrhal fever being explained by a benign T-lymphocyte hyperplasia accompanied by a deregulation of cytotoxic natural killer lymphocytes that gives rise to tissue necrosis.

Pathogenesis of 'sheep-associated' malignant catarrhal fever in rabbits.

Pathogenesis studies of experimentally produced sheep-associated malignant catarrhal fever (MCF) in laboratory rabbits are described. Animals were examined at intervals after inoculation. The principal change was a proliferation of lymphoid cells which began as soon as three days and became quite pronounced by 13 days after inoculation. The appendix, mesenteric lymph node and spleen were most obviously affected. The reason for this was a progressive increase in T-lymphocytes, which appeared to be a hyperplasia rather than neoplasia in T-dependent areas of these organs. Lymphoid cells also accumulated in interstitial spaces of non-lymphoid organs. The use of cyclosporin-A suppressed the lymphoid proliferation but rabbits still developed clinical MCF after a similar incubation period. It is suggested that the agent of MCF might produce its effect by infecting and causing a dysfunction of lymphoregulatory cells, resulting in benign polyclonal T-lymphocyte proliferation. Terminal necrosis could be due to natural killer cell activity.

A cytotoxic T-lymphocyte line propagated from a rabbit infected with sheep associated malignant catarrhal fever.

The propagation of a cell line from a rabbit affected with the sheep associated form of malignant catarrhal fever is described. Immunological and morphological characteristics of the cell indicated that it was a T-lymphocyte and the presence of electron dense cytoplasmic granules suggested that the cell could be further classified as a large granular lymphocyte. The cell line required a feeder layer and was cytotoxic to both primary cell cultures and cell lines, a characteristic of large granular lymphocytes. No evidence of the nature of the agent could be detected but as few as 10(2) cells transmitted the disease. These findings are discussed and the possibility that infection and subsequent dysfunction of large granular lymphocytes may have a central role in the pathogenesis of malignant catarrhal fever is considered. That cells with similar characteristics have been derived from Herpesvirus saimiri and H ateles infected marmoset lymphocytes suggests that the lymphoproliferation associated with infection by these two simian herpes-viruses and malignant catarrhal fever may have a similar pathogenesis.