Molecular properties of the matrixprotein(M) gene of the lapinized rinderpest virus

The nucleotide sequence of the matrixprotein (M) gene of the lapinized rinderpest virus (RPV-L) was determined. The full-length cDNA of the RPV-L M gene is composed of 1460 base pairs and is supposed to contain an open reading frame of 1005 nucleotides encoding on M protein of 335 amino acids. The homology of the predicted amino acid among congeneric morbilliviruses such as RPV Kabete 'O' strain (wild strain of RPV), RPV RBOK strain (vaccine strain of RPV for cattle), measles virus (MV), and canine distemper virus (CDV), is approximately 94%, 93%, 87% and 77%, respectively. In the present study, all coding regions of the RPV-L strain have been determined.     

利用荧光定量RT-PCR法与间接免疫荧光法比较测定猪瘟兔化弱毒病毒含量

利用荧光定量RT-PCR技术与间接免疫荧光技术(IFA)对12份猪瘟兔化弱毒(ST细胞毒)病毒含量与毒价进行了测定,并与兔体反应热法测定结果进行了比较分析。结果显示:12份猪瘟兔化弱毒(ST细胞毒)可根据兔体感染量分为4组,各组间荧光定量RT-PCR法与IFA法测得的病毒含量间差异极显著(P<0.01);3种方法的检测结果间呈显著正相关性(γ>0.9)。研究结果提示:可用荧光定量RT-PCR技术结合IFA替代传统的兔体反应热法,高通量、快速、准确地测定猪瘟兔化弱毒病毒含量,其有助于简化疫苗检验工作并提高准确度。     

An epidemiological model of rinderpest. II. Simulations of the behaviour of rinderpest virus in populations

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.     

Use of the caprinised strain of rinderpest virus for potency testing an attenuated cell culture rinderpest vaccine

The caprinised strain of rinderpest virus was inoculated into goats to produce a challenge stock. These goats were kept with control animals (goats, sheep, calves). In this trial the caprinised strain was shown to have a mild pathogenicity for goats and it spread to one of two contact goats but not from goats to other species. The caprinised strain was then tested on cattle where a febrile reaction was observed. The caprinised strain also did not spread between cattle. The cattle vaccinated with a freeze-dried vaccine produced from the attenuated Kabete RBKO strain on bovine kidney cells were then challenged with the caprinised strain with good results.     

Protection of goats against peste-des-petits-ruminants with attenuated rinderpest virus

Goats vaccinated with attenuated rinderpest were protected from peste-des-petits-ruminants virus for at least 12 months; vaccinated animals were unable to transmit the challenge virus. Before challenge neutralising antibodies were directed primarily against rinderpest but following exposure to peste-des-petits-ruminants, a high antibody level to both viruses was found.     

Microelisa test for detecting antibodies to rinderpest virus antigens

Summary A microplate enzyme-linked immunosorbent assay (ELISA) was developed which detected antibodies to a soluble antigen prepared from sonicated rinderpest virus-infected cells. The ELISA detected titres of antibody to the virus in the sera of cattle 3 weeks after immunisation with tissue culture rinderpest virus vaccine which were similar to those detected by the virus neutralisation test. The ELISA test shows potential as a rapid and economic technique for screening large numbers of sera for antibody to rinderpest virus.

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La Prueba Micro-Elisa Para Detectar Anticuerpos Producidos Por Antigenos Del Virus De Rinderpest

Resumen Se utilizó la prueba micro-ELISA para detectar anticuerpos producidos por un antígeno soluble preparado con células sonicadasinfectadas con el virus de rinderpest. La prueba ELISA detectó anticuerpos en el suero de bovinos, 3 semanas después de que éstos fueron inmunizados con la vacuna de rinderpest, preparada ésta en cultivos celulares. Los anticuerpos detectados fueron similares a los estudiados mediante la prueba de neutralización viral. La prueba ELISA se perfila como una técnica rápida y económica para trabajar un número apreciable de muestras de suero con el fin de detectar anticuerpos del virus de rinderpest.

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Un Micro-Test Elisa Pour Deceler Les Anticorps Specifiques Du Vir Us Bovipestique

Résumé Un test immuno-enzymatique (ELISA) a été mis au point déceler les anticorps correspondant à un antigène préparé par traitement aux ultra-sons de cellules infectées. Les titres sériques obtenus par cette méthode dans les sérums de bovins immunisés trois semaines auparavant avec du vaccin de culture cellulaire se sont révélés comparables à ceux obtenus par la méthode classique de séroneutralisation. Le test ELISA apparait comme un moyen rapide et économique pour rechercher les anticorps spécifiques du virus bovipestique dans des sérums en grand nombre.

     

Development and distribution of rinderpest virus antigen in experimentally infected goats

Three goats, experimentally infected with rinderpest virus were examined for the development and distribution of precipitating antigens in various tissues and secretions using the agar gel immunodiffusion test. Virus antigens were detected in ocular secretions and lymph node biopsies from the second to the fourth and fifth days of pyrexia, respectively, but were not detected in nasal secretions. Precipitating antigens were demonstrated in various lymphoid organs, the lung and abomasum of a goat killed on the fourth day of pyrexia. These findings are discussed in relation to the epidemiology of rinderpest in goats in Africa.     

Humoral antibody response in animals infected with virulent rinderpest virus

Summary Humoral antibody responses in cattle or rabbits infected with virulent rinderpest virus or lapinised rinderpest virus respectively were assessed. Rinderpest specific antibodies could be first detected 6 days post-infection. No correlation could be established between antibody response and the course of the disease in infected animals during the early stages of infection. The animals with fatal infection either did not respond or had a transient antibody response. A gradual increase in antibody titre from 7 days post-infection was observed in animals which ultimately recovered.

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Respuesta De Anticuerpos Humorales En Animales Infectados Con Virus Virulento De Rinderpest

Resumen Se llevó a cabo un estudio tendiente a captar la respuesta de anticuerpos humorales en bovinos o conejos infectados con virus virulento de rinderpest o virus lapinizado de rinderpest, respectivamente. Los anticuerpos específicos de rinderpest fueron detectados a partir de los 6 días despues de la inoculación. No se pudo establecer correlación entre la respuesta de anticuerpos y el curso de la enfermedad en animales infectados, durante los estadíos iniciales de la enfermedad. Los animales con infecciones fatales o no respondieron o tuvieron una respuesta humoral débil. Los animales que se recuperaron presentaron un alza progresiva en el nivel de anticuerpos desde los 7 días después de la infección.

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Response Immunitaire Humorale Chez Des Animaux Infectes Par Le Virus De La Peste Bovine

Résumé Les réponses immunitaires de bovines ou lapins infectés respectivement par le virus de la peste bovine virulent ou lapinisé ont été évaluées. Des anticorps spécifiques contre la peste bovine ont pu être décelés 6 jours après l'infection. Aucune corrélation n'a pu être établie entre la réponse immunitaire et l'évolution de la maladie chez les animaux durant les premiers stades de l'infection. Les animaux n'ayant pas survécu soit n'ont pas développé une réponse immunitaire soit l'on présentée mais de façon transitoire. Une augmentation graduelle de taux d'anticorps à partir du 7e jour après l'infection a été observée chez les animaux qui ont fini par guérir.

     

Attenuation of a strain of rinderpest virus: potential homologous live vaccine

Peste des petits ruminants (PPR) is a highly contagious disease of small ruminants frequently associated with severe mortality in these hosts. In countries where it occurs, PPR represents an important constraint to the improved productivity of sheep and goats. Until now the only way to combat this plague has been the use of heterologous rinderpest vaccine; all attempts to develop a homologous vaccine have ended in failure. The present communication describes the attenuation of the Nigerian strain PPRV Nig 75/1 by serial passage in Vero cells. The avirulent virus obtained has the same characteristics as Plowright and Ferris' rinderpest vaccine. The virus is advanced as a potential homologous vaccine against PPR.