Browsing by Author "Rossiter, P.B."

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Anaesthesia of Wildlife
(1985) Rossiter, P.B.; East African Veterinary Research Organisation, P.O Box 32, Kikuyu, Kenya.
Of two leopards of similar age and weight, one that received ketamine alone (5 mg/kg) recovered completely after 60 min, while the other received the ketamine dose plus xylazine (0.3 mg/kg) and took 9 hours. In the wild, the second animal would be at risk from predation or aggression. For the same reason, the author does not use acepromazine plus etorphine in ungulates. Acepromazine should not be used 2-3 hours before dusk. Xylazine, which causes vomiting in cats, should not be given simultaneously with ketamine to these animals.
Antibodies to Malignant Catarrhal Fever Virus Antigens in the Sera of Normal and Naturally Infected Cattle in Kenya
(1980) Rossiter, P.B.; Jessett, D.M.; Mushi, E.Z.; Karstad, L.; Kenya Agricultural Research Institute, Muguga, PO Box 32, Kikuyu, Kenya; Veterinary Research Laboratory, PO Kabete, Nairobi, Kenya
Six different serological tests were used to examine Kenyan cattle sera for antibodies to the herpesvirus of malignant catarrhal fever. Significantly higher levels of indirect immunofluorescent antibody to early and late virus antigens and of complement fixing antibody were found in the sera of 13 naturally infected cattle than in 482 sera collected from four different groups of normal cattle. Virus neutralising and immunoprecipitating antibodies were also found in some infected cattle sera but not in normal cattle sera. Many non-specific reactions occurred using counterimmunoelectrophoresis. These preliminary results indicate that the serological diagnosis of wildebeest-associated malignant catarrhal fever may be possible.
Antigens and Antibodies of Malignant Catarrhal Fever Herpesvirus Detected by Immunodiffusion and Counter-Immunoelectrophoresis
(1980) Rossiter, P.B.; Veterinary Research Department, Muguga, Kenya Agricultural Research Institute, P.O. Box 32, Kikuyu, Kenya
Using hyperimmune rabbit and cattle sera, immunodiffusion (ID) and counter-immunoelectrophoresis (CIEP) tests detected three or four and two or three malignant catarrhal fever (MCF) virus antigens, respectively, in infected cells. The ID test detected precipitating antibodies to MCF virus in 39 experimentally infected rabbits, 014 experimentally infected cattle, 113 naturally infected cattle, 62176 wildebeest and 320 hartebeest. The CIEP test detected specific antibodies in 39 rabbit sera, but non-specific reactions prevented its use with bovine sera. The CIEP test was 2 to 4 times more sensitive than ID for detecting antibodies to MCF virus, but both tests were less sensitive than indirect immunofluorescence. The ID test demonstrated an antigenic relationship between wildebeest and hartebeest strains of MCF virus. Neither ID nor CIEP detected MCFV antigens in tissues infected with MCF virus.
Attempts to Protect Rabbits against Challenge with Virulent, Cell-Associated, Malignant Catarrhal Fever Virus
(1982) Rossiter, P.B.; Division of Virology, Veterinary Research Department
Rabbits hyperimmunized with inactivated malignant catarrhal fever virus (MCFV) infected rabbit lymph node cells did not develop specific antibodies to the virus and succumbed to challenge with live MCFV-infected lymphoid cells. Rabbits hyperimmunized with either inactivated or live, cultured bovine kidney cells infected with MCFV developed antibodies to the virus, but also succumbed to challenge with live MCFV-infected rabbit lymphoid cells. Rabbits hyperimmunized with live cultured rabbit kidney cells infected with MCFV developed antibodies to the virus and resisted challenge with live MCFV infected rabbit lymphoid tissues 47 weeks later. However, rechallenge of this group at 90 weeks post immunization resulted in the death of 2/4 rabbits suggesting a waning immunity.
Detection of Rinderpest Virus Antigens In Vitro and In Vivo by Direct Immunofluorescence
(1982) Rossiter, P.B.; Jessett, D.M.; Veterinary Research Department, Kenya Agricultural Research Institute, Muguga, PO Box 32, Kikuyu, Kenya
Cell-culture attenuated and virulent strains of rinderpest virus (RV) were inoculated on to bovine kidney cell cultures. A direct immunofluorescent antibody test detected RV antigens in cell cultures within one to three days after inoculation whereas RV cytopathic effects usually took three to nine days to develop. Cells containing RV antigens were also detected in impression smears and frozen sections of tissues collected from RV infected animals at post mortem examination, and in smears of lymph node biopsies taken from cattle with clinical rinderpest. These techniques may offer additional methods for rapid diagnosis of rinderpest.
An Epidemiological Model of Rinderpest. II. Simulations of the Behavior of Rinderpest Virus in Populations
(1989) Rossiter, P.B.; James, A.D.
Fixed parameters for different hypothetical strains of rinderpest virus (RV) and different susceptible populations are described together with details of their derivation. Simulations were then carried out in a computer model to determine the effects that varying these parameters would have on the behaviour of RV in the different populations. The results indicated that virulent strains of RV are more likely to behave in epidemic fashion whereas milder strains tend towards persistence and the establishment of endemicity. High herd immunity levels prevent virus transmission and low herd immunity levels encourage epidemic transmission. Intermediate levels of immunity assist the establishment of endemicity. The virus is able to persist in large populations for longer than in small populations. Different vaccination strategies were also investigated. In areas where vaccination is inefficient annual vaccination of all stock may be the best policy for inducing high levels of herd immunity. In endemic areas and in herds recovering from epidemics the prevalence of clinically affected animals may be very low. In these situations veterinary officers are more likely to find clinical cases by examining cattle for mouth lesions rather than by checking for diarrhoea or high mortalities.
Growth of Rinderpest and Bovine Virus Diarrhea Viruses in Theileria Parva Infected Iympho blastoid Cell Lines
(1988) Rossiter, P.B.; Wafula, J.S.; Gumm, I. D.
CO-Cultivation of lymphoid cells from infected cattle on feeder monolayers of bovine spleen or thymus is a routine technique for establishing continuous lines of lymphoblastoid cells transformed and infected by the protozoan Theileria parva (Malmquist and Brown 1977, Kurtti and others 1981). Recently several viruses, including bovme herpesvlfus-3 (also classified as bovid herpesvirus-4) and rinderpest vaccine virus have been isolated from such cultures following development of cytopathic effects in the monolayers (P. B. ROSSISTER and others, m preparation). It would have been interesting to know whether these viruses originated from the monolayers or the transformed Iympho blasts or other cells in the culture but it was not possible to determine this. A small study was subsequently made to investigate whether two lympho tropic viruses, rinderpest virus and Bovine virus diarrhoea virus (BVDV) could infect and grow in T parvaI~ infected Iympho blastoid cell lines which, once established, grow continuously in suspension without a requirement for feeder layers.
Immunofluorescence and Immunoperoxidase Techniques for Detecting Antibodies to Malignant Catarrhal Fever in Infected Cattle
(1981) Rossiter, P.B.; Kenya Agricultural Research Institute, Muguga, PO Box 32, Kikuyu, Kenya
The indirect immunoperoxidase and immunofluorescent antibody techniques were compared for their ability to detect antibodies to malignant catarrhal fever virus in experimentally and naturally infected cattle. The immunoperoxidase test detected titres of antibody 8-fold higher than those detected by immunofluorescence. The immunoperoxidase technique detected antibodies in all of 23 naturally infected cattle whereas immunofluorescence only detected antibodies in 19. The immunoperoxidase test gave good definition of intracellular virus antigens.
Immunoglobulin response of rabbits infected with malignant catarrhal fever virus
(1982) Rossiter, P.B. ; Division of Virology, Veterinary Research Department
Using an indirect immunoperoxidase test the sera from five rabbits infected with malignant catarrhal fever virus were assayed for total Ig, IgM and IgG antibodies to the virus. All rabbits developed IgM and IgG antibody titres to virus antigens and these increased four times or more during the infection. The onset and initial development of IgM and IgG antibodies were similar, but IgG antibodies were present in higher titre than IgM antibodies during clinical disease and comprised most of the total antibody. Total serum IgM and IgG concentrations did not change during the course of the disease
Malignant Catarrhal Fever in Cattle Experimentally Inoculated With a Herpesvirus Isolated From a Case of Malignant Catarrhal Fever in Minnesota USA
(1991) Mirangi, P.K.; Rossiter, P.B.; National Veterinary Research Centre: Kenya Agricultural Research Institute, Muguga,
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 ofMCF 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.
Microtitre Techniques for the Assay of Rinderpest Virus and Neutralising Antibody
(1982) Rossiter, P.B.; Jessett, D.M.; Veterinary Research Department, Kenya Agricultural Research Institute, Muguga, PO Box 32, Kikuyu, Kenya
Microtitre techniques were compared with conventional tube techniques for their ability to assay rinderpest virus and neutralising antibody to the virus. The microtitre technique was as sensitive and reliable for assaying the virus as the recommended tube technique, using cell suspensions. Both of these methods, however, were less sensitive than tube titrations on preformed cell monolayers. The microtitre test was as sensitive as the tube test for detecting and assaying virus neutralising antibody and more robust in that it was less sensitive to variations in virus dose.
Neutralising Antibodies to Rinderpest Virus in Wild Animal Sera Collected in Kenya Between 1970 and 1981
(1983) Rossiter, P.B.; Karstad, L.; Jessett, D.M.; Yamamoto, T.; Dardiri, A.H.; Mushi, E.Z.; Veterinary Research Department, Muguga, P.O. Box 32, Kikuyu Kenya; Veterinary Research Laboratories, Kabete, P.O. Kabete Kenya; On leave from the University of Alberta, Edmonton Canada; Plum Island Animal Disease Centre, U.S.D.A., Greenport, New York, NY 11944 U.S.A.
Four hundred and twenty-five sera were collected from 18 species of wild mammals in Kenya between 1970 and 1981. Neutralising activity to rinderpest virus (RV) was detected in 35 samples from 13 species. This activity appeared to be specific antibody to RV since it did not neutralise the virus of peste des petits ruminants. It was associated with the serum globulin fraction and it blocked the staining of a rabbit immunofluorescent antibody conjugate to RV. Positive sera were not restricted to any particular area of Kenya. It is possible that strains of RV with low pathogenicity and low transmissibility are still present in wildlife in East Africa, a fact which must be considered when studying the epidemiology and control of rinderpest.
Notes on Immunoprecipitin Reactions with Rinderpest Virus
(1985) Rossiter, P.B.; Kenya Agricultural Research Institute, Muguga, Kenya.
Clear precipitin lines in counterimmunoelectrophoresis could be detected within 25 min if the distance between antigen and antibody wells was reduced to 3 mm. The test was most sensitive between 30° and 50°C. The microslide test was considered too slow for routine use, but was sensitive in detecting and separating different precipitins. Inclusion of 2 mm of phenylmethyl-sulphonylfluoride with the positive control antigens helps to maintain potency, particularly when refrigeration is inadequate.
Notes on Immunoprecipitin Reactions with Rinderpest Virus.
(1985) Rossiter, P.B.; Division of Virology, Veterinary Research Department, Kenya Agricultural Research Institute. Muguga
The standard agar gel immunodiffusion (AGID) test for detecting rinderpest virus antigens with hyperimmune sera (Scott, 1967) has recently been adapted to electrophoretic and micro-systems (Rossiter and Mushi, 1980; Foreman, Rowe and Taylor, 1983). This report summarises some additional findings which may prove useful with these tests. Counterimmunoelectrophoresis (CIEP) was carried out as described (Rossiter and Mushi, 1980) and the effect of temperature and distance between wells examined. Positive antigens were prepared from infected cell cultures and lymph nodes; an antiprotease agent, 2mM phenylmethyl-sulphonylfluoride (PMSF) was added to aliquots of antigen which were then stored on a sunny window-ledge. Some aliquots also received sodium azide (NaN3). Micro-dou}'le diffusion tests were made using the microscope slide-template method (Tyrell, 197 8). Rabbits were hyperimmunised with washed precipitin lines of rinderpest virus antigen and rabbit antibody formed in routine AGID tests. Complexes formed between different ratios of antigen and antibody were used and were administered to rabbits in two intramuscular inoculations of Freund's Complete Adjuvant three weeks apart. Sera were collected four weeks later. Clear positive precipitin lines could be detected within 25 min if the distance between antigen and antibody wells was reduced to 3 mm in the CIEP test. Results from two repeated teries of experiments using a temperature-controlled plate showed that the CIEP test was most sensitive between 30 and 500C, the titres of cell culture and lymph node antigen being two-fold higher than at 20 and 6000. Two precipitin lines were routinely detected up to 300C after which the faster migrating antigen was less easily detectable at 40 to 500C and absent at 6000. Using a portable petro: electricity generator the CIEP test worked at maximum sensitivity in the t 'idday sun at an altitude of 1,000m above sea level in northern Kenya the gel temperature being 45 0C.
Preliminary Observations on Rinderpest in Pregnant Cattle
(1989) Wafula, J.S.; Rossiter, P.B.; Wamwayi, H.M.; Scott, G.R.; Kenya Agricultural Research Institute, National Veterinary Research Centre, PO Box 32, Kikuyu, Kenya. University of Edinburgh, Centre for Tropical Veterinary Medicine, Easter Bush, Roslin, Midlothian, Scotland
A Kabete 'O' strain of rinderpest virus enhanced in virulence was inoculated subcutaneously into four cows which were between six and eight months pregnant. All the cows developed clinical signs of rinderpest from the third day after inoculation and shed high titres of virus in their ocular and vaginal secretions during the course of the clinical disease. Three of the cows died of rinderpest on the third day after the onset of fever but no virus was isolated from their fetuses which were examined post mortem. The fourth cow showed complete clinical and virological recovery by the eighth day after the onset of fever and aborted an eight-and-a-half-month-old fetus on the 12th day after it recovered. Rinderpest virus was demonstrated in a wide range of the aborted fetal tissues. Virus was also detected in the maternal vaginal discharges up to 24 hours after abortion. The only gross pathological change observed was a severe necrotising placentitis.
Proliferation of T Lymphoblasts in Rabbits Fatally Infected with the Herpes Virus of Malignant Catarrhal Fever
(1983) Rossiter, P.B. ; Kenya Agricultural Research Institute, Muguga, Kikuyu, Kenya
Lymphoid cell suspensions prepared from tissues collected from rabbits infected with malignant catarrhal fever virus, a herpes virus causing fatal lymphoproliferative disease in cattle and rabbits, were examined for various properties. The majority of the proliferating cells did not adhere to plastic, phagocytose opsonized bacteria or carry surface immunoglobulin. On the basis of their morphology, high incorporation of ³H-thymidlne and ability to form non-immune rosettes with rabbit erythrocytes it is probable that these cells are T lymphoblasts.
Re-emergence of Rinderpest as a Threat in East Africa since 1979
(1983) Rossiter, P.B.; Jessett, D.M.; Wafula, J.S.; Karstad, L.; Chema, S.; Taylor, W.P.; Rowe, L.; Nyange, J.C.; Otaru, M.; Mumbala, M.; Veterinary Research Department, Kenya Agricultural Research Institute, Muguga, P PO Box 32, Kikuyu, Kenya. Veterinary Research Laboratories, PO Box Kabere, Kenya. Animal Virus Research Institute, Pirbright, Woking. Veterinary Investigation Centre, PO Box 1068, Arusha, Tanzania. Ministry of Animal Industry and Fisheries, Kampala, Uganda. Centre for Tropical Veterinary Medicine, Easter Bush, Roslin, Midlothian, Scotland
The evidence for the recent re-emergence of rinderpest as a threat in East Africa is reviewed. East Africa was free from rinderpest in domestic and wild animals from 1966 to 1979 apart from isolated outbreaks of the disease in unvaccinated nomadic cattle and wildlife. However, in July 1979, rinderpest was diagnosed in East African zebu cattle in northeastern Uganda and the disease spread rapidly before being brought under control in November 1981. In July 1980 the disease was confirmed by virus isolation and specific antigen detection among unvaccinated grade and Boran cattle in Muguga, and serological surveys reported in 1982 and 1983 indicated that the virus had infected goats, sheep and wild ungulates in Kenya. In Tanzania, in March 1982, the disease affected buffaloes in the Serengeti National Park and later that year many buffaloes and also giraffes, warthogs and eland in the Ngorongoro Crater area were killed by what is thought to have been the same disease. Serum samples subsequently collected from buffaloes in these latter two areas had a high prevalence of neutralizing antibody to rinderpest virus. In September 1982 detection of virus neutralizing antibody in cattle, sheep and goats in northern Tanzania where a disease resembling rinderpest had been active since 1981 indicated that the rinderpest virus was responsible for this outbreak which was spreading slowly in 1983. It is concluded that the worldwide recession and resultant decrease in the level of vaccination cover have facilitated re-entry of rinderpest to East Africa. Immediate provision of resources to prevent the disease regaining endemic status is called for.
Re-emergence of Rinderpest as a Threat in East Africa since 1979.
(1983) Rossiter, P.B.; Jessett, D.M.; Wafula, J.S.; Karstad, L.; Chema, S.; Taylor, W.P.; Rowe, L.; Nyange, J.C.; Otaru, M.; Mumbala, M.; Veterinary Research Department, Kenya Agricultural Research Institute, Muguga, PO Box 32, Kikuyu, Kenya. Veterinary Research Laboratories, PO Box Kabete, Kenya. Animal Virus Research Institute. Veterinary Investigation Centre, PO Box 1068, Arusha, Tanzania. Ministry of Animal Industry and Fisheries, Kampala, Uganda. Centre for Tropical Veterinary Medicine, Easter Bush, Roslin. Midlothian, Scotland
Following the success of the JP15 scheme and subsequent annual vaccination campaigns, East Africa was virtually free of rinderpest after the mid 1960s and the disease was considered beaten. However, economic difficulties have recently reduced the expensively maintained vaccine cover and the disease has reappeared throughout much of the region. In 1979 rinderpest was diagnosed in cattle in north eastern Uganda and caused considerable losses until finally brought under control in 1981. No field outbreaks of the disease in cattle have been seen in Kenya but there is serological evidence that the virus has recently infected unvaccinated sheep and goats and wild ungulates in that country. In 1982 rinderpest was confirmed in the laboratory as the cause of death of large numbers of buffaloes in northern Tanzania and implicated as the cause of a rinderpest-like disease of cattle which is reported to be still active in that area. Substantial aid is essential for further control and research if the virus is not again to become endemic in the region.
Role of Wildebeest Fetal Membranes and Fluids in the Transmission of Malignant Catarrhal Fever Virus
(1983) Rossiter, P.B.; Jessett, D.M.; Karstad, L.; Veterinary Research Department, Kenya Agricultural Research Institute, Muguga, PO Box 32, Kikuyu, Kenya; Veterinary Research Laboratories, PO Box Kabete, Kenya
Malignant catarrhal fever virus was not isolated from samples of fetal membranes or fluid collected from 93 calving wildebeest (Connochaetes taurinus) in Kenya Maasai land. Cell-free strains of malignant catarrhal fever virus were very rapidly inactivated when exposed to the sun under field conditions, at least 3.0 log10 units/25 microliter being lost per hour at midday. It is suggested that wildebeest fetal membranes and fluids act as visual markers for areas of pasture which are particularly heavily contaminated with malignant catarrhal fever virus in oculonasal secretions of wildebeest calves. It is possible that starting to graze cattle one to two hours later each morning may be a useful measure for helping to protect cattle from malignant catarrhal fever in areas where they are forced to share pastures with calving wildebeest.
Simple Techniques for Increasing the Batch Size of Rinderpest Cell Culture Vaccine
(1985) Rossiter, P.B.; Jessett, D.M.; Veterinary Research Department, Kenya Agricultural Research Institute, Muguga, PO Box 32, Kikuyu, Kenya
Vaccine production could be increased by culturing monolayers around the complete circumference of the flask, by seeding with three times the usual amount of cells and virus followed by continuous rolling, and by pooling two harvests. Increasing the volume of medium threefold before harvest caused a two-fold decrease in titre. Only very high titre harvests should be stored at -70°C before freeze drying, otherwise short-term storage at 4°C is recommended.

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Browsing by Author "Rossiter, P.B."

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