Effect of Immunization with Plasmid DNA Encoding for Rinderpest Virus Matrix Protein on Systemic Rinderpest Virus Infection in Rabbits

Plasmid vaccine pBK-CMVMP1LC113 expressing the matrix (M) gene of rinderpest virus was assessed for its potential to protect rabbits against a lethal viral challenge. Rabbits immunized with plasmids expressing the M gene were not protected when challenged with lapinized rinderpest virus, despite the production of anti-M antibodies, while rabbits immunized with rinderpest tissue culture vaccine were completely protected from a lethal challenge with lapinized rinderpest virus. The plasmid vaccine also had no significant effect on the lymphopenia in challenged rabbits. The results indicate that rinderpest M protein does not have a protective role in rinderpest infection.     

A Comparison of The Viruses of Infectious Bovine Rhinotracheitis (IBR), Infectious Pustular Vulvovaginitis (IPV), and Rinderpest Part II. Plaque Assay

A plaque assay procedure was used successfully for studying the viruses of infectious bovine rhinotracheitis (IBR), infectious pustular vulvovaginitis (IPV), and rinderpest. The plaques produced by the IBR and IPV viruses were indistinguishable, but differed from those of rinderpest. The viruses were neutralized by their respective antisera as indicated by plaque inhibition. Plaques formed by the IBR and IPV viruses were inhibited by homologous and heterologous antisera but not by rinderpest antisera, while those of rinderpest were inhibited by the rinderpest antisera only.     

The risk of rinderpest re-introduction in post-eradication era

In 2011, ten years after the last reported outbreak, the eradication of rinderpest was declared. However, as rinderpest virus stocks still exist, there remains a risk of rinderpest re-introduction.     

“后牛瘟时代”的全球牛瘟研究

2011年，联合国粮食及农业组织(FAO)和世界动物卫生组织(WOAH)联合宣布根除牛瘟。这是历史上首个消灭的动物疫病，也是继天花之后全球第二个被消灭的传染病，自此，世界进入“后牛瘟时代”。牛瘟再暴发风险依然存在，维持全球牛瘟无疫状态意义重大。就维持全球牛瘟无疫状态的框架性文件、牛瘟病毒保藏机构以及宣布消灭牛瘟后所发表的实验性研究等进行了综述，为提升公众风险意识、应对牛瘟再暴发提供参考。     

Continuing presence of rinderpest virus as a threat in East Africa, 1983-1985

The re-emergence of rinderpest virus in East Africa in 1979 caused widespread outbreaks of disease and subclinical infection throughout the region until mid-1983. Subsequent massive emergency vaccination campaigns have been successful in eliminating clinical rinderpest from Tanzania and preventing its spread southwards. Unfortunately the virus is still endemic in north-eastern Uganda and has recently caused epidemic outbreaks with high mortality in cattle in that country. In Kenya, buffaloes (Syncerus caffer) in and around the Masai Mara game reserve have developed antibodies to rinderpest virus as recently as late 1984. Although there have been no outbreaks of clinical disease in Tanzania or Kenya from April 1983 to the end of 1985 this serological evidence plus the increasing incidence of clinical outbreaks in Uganda indicate that rinderpest virus still threatens East Africa. The substantial aid which has been provided to the region for rinderpest control must be maintained.     

Reverse phase passive haemagglutination test for the detection of rinderpest antigen

Reverse phase passive haemagglutination [RPHA] test was applied for the detection of rinderpest antigen in various organs of rinderpest infected cattle. The results of RPHA were compared with counter immunoelectrophoresis [CIE] and single radial haemolysis [SRH] test. RPHA was as sensitive as CIE and SRH in detecting rinderpest antigen.     

Diagnosis of Rinderpest in Tanzania by a Rapid Chromatographic Strip-test

A simple chromatographic strip-test based on Clearview technology, is under development as a pen-side test for the detection of rinderpest antigen in eye swabs taken from cattle in the field. An outbreak of rinderpest occurred in the northern zone of Tanzania from late February to June 1997. The affected cattle exhibited very mild clinical signs, which made clinical diagnosis difficult. One hundred and seven eye swabs were collected from cattle suspected of infection with rinderpest. These were tested in the field using a prototype of the pen-side test and 13 (12.15%) of the samples were found to be positive for the presence of rinderpest antigen. These were confirmed by ICE. The positive cases were predominantly found in the Ngorongoro district. This demonstrates the usefulness of such a simple, rapid pen-side diagnostic assay, particularly when clinically `mild' strains of rinderpest are present.     

A reassessment of the dual vaccine against rinderpest and contagious bovine pleuropneumonia

In the light of the recent outbreaks of rinderpest in Africa a further assessment of the efficacy of the simultaneous inoculation of rinderpest virus vaccine and contagious bovine pleuropneumonia vaccine was undertaken. Groups of cattle were inoculated with a dual preparation of rinderpest vaccine virus and Mycoplasma mycoides subspecies mycoides or M mycoides alone. These groups were then challenged with M mycoides, first unsuccessfully by an in-contact challenge method and then by subcutaneous challenge. All animals were examined clinically after challenge for evidence of contagious bovine pleuropneumonia and serologically for rinderpest virus and M mycoides mycoides antibodies. There was no evidence that the serological response to the dual vaccine was in any way less than that to either agent given alone and no clinical disease was detected in these animals after in-contact challenge. However, after subcutaneous challenge, the dual vaccinated groups reacted similarly to an unvaccinated control group and unlike the group vaccinated only with M mycoides. This would indicate that the rinderpest virus component of the dual vaccine interfered with the ability of the M mycoides component to induce a fully effective immune response. In the pan African rinderpest campaign the use of the dual vaccine in areas where contagious bovine pleuropneumonia occurs should be carefully considered; in areas where the disease does not occur it is contraindicated.     

Studies on the methods of preparation of rinderpest hyperimmune sera in rabbits

The procedures for the preparation of the rinderpest hyperimmune sera in rabbits were studied by comparing the sera from rabbits immunised by three different schedules of inoculations. The best sera for use in immunodiffusion tests were obtained from rabbits inoculated first with rinderpest hyperimmune serum and lapinised virus, and then with lapinised virus mixed with oil adjuvant twice at weekly intervals. Those rabbits which received additional one or two intravenous inoculations with lapinised virus yielded satisfactory sera for use in the diagnosis of rinderpest by immunodiffusion technique.     

Rinderpest Antibody Detected in Sheep and Goats Before an Outbreak of Rinderpest Reported in Cattle in Northern Tanzania

In January 1997, serum samples from 1346 adult sheep and goats were tested by a competitive ELISA to determine the prevalence of rinderpest in the northern zone of Tanzania. Seroconversion rates of 20%, 13%, 9%, 7% and 3% in sheep and goats were recorded in Ngorongoro, Monduli, Hai, Arumeru and Simanjiro districts, respectively. The low profile and insidious nature of the rinderpest virus involved caused very mild disease in cattle in some of these area. The mild signs associated with this outbreak of rinderpest resulted in difficulty in its diagnosis. In these circumstances, the presence of rinderpest antibody in sheep and goats served as a valuable and effective indicator of the rinderpest outbreak in cattle.     

Detection of rinderpest virus antigens in vitro and in vivo by direct immunofluorescence

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.     

Rinderpest in the landhi dairy colony

Earlier diagnostic reports of rinderpest in buffaloes in the Landhi Dairy Colony were discounted by most veterinarians in Pakistan. Four recent investigations have shown beyond doubt that the affliction was indeed rinderpest.     

A model of lineage-1 and lineage-2 rinderpest virus transmission in pastoral areas of East Africa

The development of a stochastic, state-transition model of rinderpest transmission dynamics is described using parameter estimates obtained from both laboratory and participatory research. Using serological data, the basic reproduction numbers for lineage-1 rinderpest virus in southern Sudan and for lineage-2 rinderpest virus in Somali livestock were estimated as 4.4 and between 1.2 and 1.9, respectively. The model predictions for the inter-epidemic period in Sudan and Somalia (1.2 and 4.2 years, respectively) were in agreement with analysis of livestock-owner reports (1–2 years and 5 years, respectively).     

The production of peste des petits ruminants hyperimmune sera in rabbits and their application in virus diagnosis

Hyperimmune sera were produced by serial inoculation of rabbits with Vero cell-adapted, sucrose gradient-purified Nigerian peste des petits ruminants virus (PPRV) isolate. Two antisera produced, neutralized the homologous PPRV but not the heterologous rinderpest Kabette "O" virus. The antisera gave strong precipitin lines with purified PPRV antigens and were used to detect PPRV and rinderpest virus antigens from ante-mortem secretions and post-mortem tissue homogenates from PPR and rinderpest virus infected goats and cattle by the agar gel precipitation tests (AGPT). The hyperimmune sera gave good titration curves with both purified Nigerian goat and the United Arab Emirate wildlife PPRV isolates in the indirect enzyme linked immunosorbent assay (ELISA). Results of indirect ELISA showed that although there were some cross reactions with the rinderpest, canine-distemper and measles viruses, at 1:100 dilution, the antisera would give a positive signal with only the homologous PPR virus.     

Evaluation of serological protection against cattle rinderpest of bovine livestock in Chad

2,544 bovine sera, sampled during the year 1986 either in the course of five field missions or at Farcha's abattoir, have been studied by seroneutralization against rinderpest. This survey permits the determination of the overall rinderpest immunity rate in Chadian cattle.     

Colostral Transfer of Rinderpest Neutralizing Antibody to Offspring of Våccinated Dams

The transfer of maternal antibodies to Friesian and buffalo calves born of dams vaccinated against rinderpest was through colostrum only. Colostral antibody titers at the time of parturition were higher than the serum titer. Two hours after suckling, a high level of rinderpest neutralizing antibodies was detected in the sera of newborn animals. The half-life of maternal antibodies in buffalo and Friesian calves was found to be approximately 33 and 29 days respectively. By the age of 7-8 months, 60 per cent of buffalo calves and 80 per cent of Friesian calves had no detectable levels of rinderpest neutralizing antibody.     

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.     

Serological studies with peste des petits ruminants and rinderpest viruses in Nigeria

One hundred and ninety-five goat and 67 sheep sera collected from various parts of southern Nigeria were screened for neutralising antibodies to both the peste des petits ruminants (PPR) and rinderpest viruses. Neutralising antibodies against both viruses were found in the sheep and goat sera examined. Parallel titration of samples which neutralised both viruses indicated a primary infection with the PPR virus (PPRV). However, some samples which failed to neutralise PPRV neutralised the rinderpest virus (RV) indicating RV activity in sheep and goats in Nigeria. These findings are discussed in relation to the diagnosis of PPRV infection and the recent reappearance of bovine rinderpest in Nigeria.     

An epidemiological model of rinderpest. I. Description of the model

The development of an epidemiological model of rinderpest in cattle and wildlife populations is described. The model uses a state-transition structure, incorporating a stochastic element through the use of Monte-Carlo methods modified to allow large populations to be simulated. The potential applications include the estimation of "safe" host population immunity rates and the design of cost-effective rinderpest vaccination programmes.