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1.
Vaccine ; 34(47): 5736-5743, 2016 11 11.
Artigo em Inglês | MEDLINE | ID: mdl-27742221

RESUMO

The measurement of virus-specific neutralising antibodies represents the "gold-standard" for diagnostic serology. For animal morbilliviruses, such as peste des petits ruminants (PPRV) or rinderpest virus (RPV), live virus-based neutralisation tests require high-level biocontainment to prevent the accidental escape of the infectious agents. In this study, we describe the adaptation of a replication-defective vesicular stomatitis virus (VSVΔG) based pseudotyping system for the measurement of neutralising antibodies against animal morbilliviruses. By expressing the haemagglutinin (H) and fusion (F) proteins of PPRV on VSVΔG pseudotypes bearing a luciferase marker gene, neutralising antibody titres could be measured rapidly and with high sensitivity. Serological responses against the four distinct lineages of PPRV could be measured simultaneously and cross-neutralising responses against other morbilliviruses compared. Using this approach, we observed that titres of neutralising antibodies induced by vaccination with live attenuated PPRV were lower than those induced by wild type virus infection and the level of cross-lineage neutralisation varied between vaccinates. By comparing neutralising responses from animals infected with either PPRV or RPV, we found that responses were highest against the homologous virus, indicating that retrospective analyses of serum samples could be used to confirm the nature of the original pathogen to which an animal had been exposed. Accordingly, when screening sera from domestic livestock and wild ruminants in Tanzania, we detected evidence of cross-species infection with PPRV, canine distemper virus (CDV) and a RPV-related bovine morbillivirus, suggesting that exposure to animal morbilliviruses may be more widespread than indicated previously using existing diagnostic techniques.


Assuntos
Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Monitorização Imunológica/métodos , Peste dos Pequenos Ruminantes/diagnóstico , Vírus da Peste dos Pequenos Ruminantes/imunologia , Vírus da Peste Bovina/imunologia , Peste Bovina/diagnóstico , Vacinas Atenuadas/imunologia , Vírus da Estomatite Vesicular Indiana/imunologia , Animais , Bovinos , Reações Cruzadas/imunologia , Vírus Defeituosos/imunologia , Vírus da Cinomose Canina/imunologia , Cães , Cabras , Células HEK293 , Humanos , Peste dos Pequenos Ruminantes/sangue , Peste dos Pequenos Ruminantes/prevenção & controle , Vírus da Peste dos Pequenos Ruminantes/genética , Estudos Retrospectivos , Peste Bovina/imunologia , Peste Bovina/prevenção & controle , Vírus da Peste Bovina/genética , Tanzânia , Vacinação/veterinária , Vírus da Estomatite Vesicular Indiana/genética , Vacinas Virais/imunologia
2.
J Virol ; 90(10): 5152-5162, 2016 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-26984722

RESUMO

UNLABELLED: Although rinderpest virus (RPV) has been eradicated in the wild, efforts are still continuing to restrict the extent to which live virus is distributed in facilities around the world and to prepare for any reappearance of the disease, whether through deliberate or accidental release. In an effort to find an alternative vaccine which could be used in place of the traditional live attenuated RPV strains, we have determined whether cattle can be protected from rinderpest by inoculation with vaccine strains of the related morbillivirus, peste des petits ruminants virus (PPRV). Cattle were vaccinated with wild-type PPRV or either of two established PPRV vaccine strains, Nigeria/75/1 or Sungri/96. All animals developed antibody and T cell immune responses to the inoculated PPRV. However, only the animals given wild-type PPRV were protected from RPV challenge. Animals given PPRV/Sungri/96 were only partially protected, and animals given PPRV/Nigeria/75/1 showed no protection against RPV challenge. While sera from animals vaccinated with the vaccine strain of RPV showed cross-neutralizing ability against PPRV, none of the sera from animals vaccinated with any strain of PPRV was able to neutralize RPV although sera from animals inoculated with wild-type PPRV were able to neutralize RPV-pseudotyped vesicular stomatitis virus. IMPORTANCE: Rinderpest virus has been eradicated, and it is only the second virus for which this is so. Significant efforts are still required to ensure preparedness for a possible escape of RPV from a laboratory or its deliberate release. Since RPV vaccine protects sheep and goats from PPRV, it is important to determine if the reverse is true as this would provide a non-RPV vaccine for dealing with suspected RPV outbreaks. This is probably the last in vivo study with live RPV that will be approved.


Assuntos
Doenças dos Bovinos/prevenção & controle , Vírus da Peste dos Pequenos Ruminantes/imunologia , Vírus da Peste Bovina/imunologia , Peste Bovina/prevenção & controle , Vacinas Virais/imunologia , Animais , Anticorpos Antivirais/imunologia , Bovinos , Doenças dos Bovinos/virologia , Reações Cruzadas , Ensaio de Imunoadsorção Enzimática , Peste dos Pequenos Ruminantes/imunologia , Vírus da Peste dos Pequenos Ruminantes/genética , Vírus da Peste dos Pequenos Ruminantes/patogenicidade , Peste Bovina/virologia , Vacinação/veterinária , Vacinas Atenuadas/administração & dosagem , Vacinas Atenuadas/imunologia , Vacinas Virais/administração & dosagem
3.
J Virol Methods ; 227: 40-6, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26506137

RESUMO

Peste des petits ruminants (PPR) is a contagious and often fatal transboundary animal disease affecting mostly sheep, goats and wild small ruminants. This disease is endemic in most of Africa, the Middle, Near East, and large parts of Asia. The causal agent is peste des petits ruminants virus (PPRV), which belongs to the genus Morbillivirus in the family Paramyxoviridae. This genus also includes measles virus (MV), canine distemper virus (CDV) and rinderpest virus (RPV). All are closely related viruses with serological cross reactivity. In this study, we have developed a Luciferase Immunoprecipitation System (LIPS) for the rapid detection of antibodies against PPRV in serum samples and for specific differentiation from antibodies against RPV. PPR and rinderpest (RP) serum samples were assayed by PPR-LIPS and two commercially available PPR cELISA tests. The PPR-LIPS showed high sensitivity and specificity for the samples tested and showed no cross reactivity with RPV unlike the commercial PPR cELISA tests which did cross react with RPV. Based on the results shown in this study, PPR-LIPS is presented as a good candidate for the specific serosurveillance of PPR.


Assuntos
Anticorpos Antivirais/sangue , Ensaio de Imunoadsorção Enzimática/métodos , Cabras/imunologia , Vírus da Peste dos Pequenos Ruminantes/imunologia , Vírus da Peste Bovina/imunologia , Ovinos/imunologia , Animais , Anticorpos Antivirais/imunologia , Cabras/sangue , Cabras/virologia , Imunoprecipitação , Luciferases , Peste dos Pequenos Ruminantes/diagnóstico , Peste dos Pequenos Ruminantes/imunologia , Peste dos Pequenos Ruminantes/virologia , Sensibilidade e Especificidade , Ovinos/sangue , Ovinos/virologia
4.
Nature ; 499(7458): 264-5, 2013 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-23868239
5.
Science ; 337(6100): 1309-12, 2012 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-22984063

RESUMO

Rinderpest is only the second infectious disease to have been globally eradicated. In the final stages of eradication, the virus was entrenched in pastoral areas of the Greater Horn of Africa, a region with weak governance, poor security, and little infrastructure that presented profound challenges to conventional control methods. Although the eradication process was a development activity rather than scientific research, its success owed much to several seminal research efforts in vaccine development and epidemiology and showed what scientific decision-making and management could accomplish with limited resources. The keys to success were the development of a thermostable vaccine and the application of participatory epidemiological techniques that allowed veterinary personnel to interact at a grassroots level with cattle herders to more effectively target control measures.


Assuntos
Erradicação de Doenças/métodos , Monitoramento Ambiental/métodos , Vírus da Peste Bovina , Peste Bovina/prevenção & controle , Vacinação/métodos , Vacinas Virais/administração & dosagem , África/epidemiologia , Animais , Bovinos , Monitoramento Epidemiológico , Temperatura Alta , Programas de Imunização , Peste Bovina/epidemiologia , Peste Bovina/imunologia , Vírus da Peste Bovina/imunologia , Vírus da Peste Bovina/isolamento & purificação , Vírus da Peste Bovina/patogenicidade , Vacinas Virais/química , Vacinas Virais/imunologia
6.
Vet Immunol Immunopathol ; 148(1-2): 12-5, 2012 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-22748234

RESUMO

The global eradication of rinderpest was declared in 2011. This is the second infectious disease to have been eradicated from the world after smallpox, for which eradication was declared in 1980. From a scientific aspect, smallpox eradication was achieved by improvements in the Jenner vaccine, originally developed in the 18th century. Developments in vaccine technology and virological techniques during the 20th century have contributed to the eradication of rinderpest. The scientific background to rinderpest eradication is briefly reviewed vis-à-vis that of smallpox eradication.


Assuntos
Doenças dos Bovinos/história , Doenças dos Bovinos/prevenção & controle , Vírus da Peste Bovina/imunologia , Peste Bovina/história , Peste Bovina/prevenção & controle , Vacinas Virais/história , Animais , Bovinos , Doenças dos Bovinos/imunologia , Doenças dos Bovinos/virologia , Erradicação de Doenças , História do Século XVIII , História do Século XIX , História do Século XX , História do Século XXI , Peste Bovina/imunologia , Vacinas Virais/imunologia
7.
Curr Opin Virol ; 2(3): 330-4, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22709518

RESUMO

In 2011 the Food and Agriculture Organization formally announced that rinderpest was eradicated from the globe. Rinderpest virus had long been associated with huge disease outbreaks among cattle. The disease not only had a devastating effect on cattle herds world-wide, but also on human populations that depended on them. Rinderpest virus - a member of the genus Morbillivirus of the family Paramyxoviridae - is a close relative of measles virus. Both viruses are highly infectious and share many other biological properties. Although no formal goal or timeframe has been set, plans are currently being developed to eradicate measles. Here, we discuss how lessons learned from the global eradication of rinderpest may help in the future eradication of measles.


Assuntos
Erradicação de Doenças/métodos , Sarampo/epidemiologia , Sarampo/prevenção & controle , Peste Bovina/epidemiologia , Peste Bovina/prevenção & controle , Animais , Bovinos , Saúde Global , Humanos , Vírus do Sarampo/imunologia , Vírus do Sarampo/patogenicidade , Vírus da Peste Bovina/imunologia , Vírus da Peste Bovina/patogenicidade , Nações Unidas
8.
Vaccine ; 30(11): 1927-35, 2012 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-22265946

RESUMO

The eradication of rinderpest virus (RPV) from the globe was possible through the availability of a safe and effective live attenuated vaccine and a suitable companion diagnostic test. However, the inability to serologically 'Differentiate between naturally Infected and Vaccinated Animals' (DIVA) meant that both the time taken to complete the eradication programme and the economic burden on countries involved was significantly greater than if a vaccine and companion diagnostic test that fulfilled the DIVA concept had been available. During the RPV eradication campaign serosurveillance for RPV was primarily based on a competitive ELISA using a RPV specific (C1) monoclonal antibody (mAb) directed against the viral haemagglutinin (H) protein but this test was not able to meet DIVA requirements. To provide proof of concept for the generation of novel morbillivirus DIVA vaccines we have identified, by phage display, and mutated residues critical for C1 mAb binding and assessed the functionality of mutants in an in vitro fusion assay. Finally we have incorporated mutated epitopes into a full length clone and rescued recombinant RPV using reverse genetics techniques. Here we describe a novel mechanism of marking morbillivirus vaccines, using RPV as a proof of concept, and discuss the applicability of this method to the development of marked vaccines for peste des petits ruminants virus (PPRV).


Assuntos
Anticorpos Monoclonais/imunologia , Epitopos/imunologia , Hemaglutininas Virais/imunologia , Vacinas de DNA/biossíntese , Vacinas Virais/biossíntese , Sequência de Aminoácidos , Animais , Sítios de Ligação de Anticorpos , Chlorocebus aethiops , Ensaio de Imunoadsorção Enzimática , Hemaglutininas Virais/genética , Dados de Sequência Molecular , Mutação , Biblioteca de Peptídeos , Peste dos Pequenos Ruminantes/prevenção & controle , Vírus da Peste dos Pequenos Ruminantes/imunologia , Vírus da Peste dos Pequenos Ruminantes/patogenicidade , Estrutura Terciária de Proteína , Peste Bovina/prevenção & controle , Vírus da Peste Bovina/genética , Vírus da Peste Bovina/imunologia , Vírus da Peste Bovina/patogenicidade , Vacinas de DNA/imunologia , Células Vero , Vacinas Virais/imunologia
9.
Rev Sci Tech ; 31(3): 729-46, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23520729

RESUMO

In 2011, the 79th General Session of the World Assembly of the World Organisation for Animal Health (OIE) and the 37th Food and Agriculture Organization of the United Nations (FAD) Conference adopted a resolution declaring the world free from rinderpest and recommending follow-up measures to preserve the benefits of this new and hard-won situation. Eradication is an achievable objective for any livestock disease, provided that the epidemiology is uncomplicated and the necessary tools, resources and policies are available. Eradication at a national level inevitably reflects national priorities, whereas global eradication requires a level of international initiative and leadership to integrate these tools into a global framework, aimed first at suppressing transmission across all infected areas and concluding with a demonstration thatthis has been achieved. With a simple transmission chain and the environmental fragility of the virus, rinderpest has always been open to control and even eradication within a zoosanitary approach. However, in the post-1945 drive for more productive agriculture, national and global vaccination programmes became increasingly relevant and important. As rinderpest frequently spread from one region to another through trade-related livestock movements, the key to global eradication was to ensure that such vaccination programmes were carried out in a synchronised manner across all regions where the disease was endemic - an objective to which the European Union, the United States Agency for International Development, the International Atomic Energy Agency, the African Union-Interafrican Bureau of Animal Resources, FA0 and OIE fully subscribed. This article provides a review of rinderpest eradication, from the seminal work carried out by Giovanni Lancisi in the early 18th Century to the global declaration in 2011.


Assuntos
Controle de Doenças Transmissíveis/história , Peste Bovina/história , Peste Bovina/prevenção & controle , África/epidemiologia , Animais , Ásia/epidemiologia , Bovinos , Controle de Doenças Transmissíveis/legislação & jurisprudência , Controle de Doenças Transmissíveis/métodos , Europa (Continente)/epidemiologia , História do Século XVI , História do Século XVII , História do Século XVIII , História do Século XIX , História do Século XX , História do Século XXI , Pandemias/história , Pandemias/prevenção & controle , Pandemias/veterinária , Peste Bovina/epidemiologia , Vírus da Peste Bovina/imunologia , Vacinação/história , Vacinação/veterinária , Vacinas Virais/história , Vacinas Virais/normas
10.
Virus Res ; 162(1-2): 63-71, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21982973

RESUMO

The mononegaviruses include a number of highly contagious and severe disease-causing viruses of both animals and humans. For the control of these viral diseases, development of vaccines, either with classical methods or with recombinant DNA virus vectors, has been attempted over the years. Recently reverse genetics of mononegaviruses has been developed and used to generate infectious viruses possessing genomes derived from cloned cDNA in order to study the consequent effects of viral gene manipulations on phenotype. This technology allows us to develop novel candidate vaccines. In particular, a variety of different attenuation strategies to produce a range of attenuated mononegavirus vaccines have been studied. In addition, because of their ideal nature as live vaccines, recombinant mononegaviruses expressing foreign proteins have also been produced with the aim of developing multivalent vaccines against more than one pathogen. These recombinant mononegaviruses are currently under evaluation as new viral vectors for vaccination. Reverse genetics could have great potential for the preparation of vaccines against many mononegaviruses.


Assuntos
Antígenos Virais/imunologia , Leishmaniose/prevenção & controle , Peste Bovina/prevenção & controle , Vacinação , Vacinas Atenuadas/genética , Vacinas Combinadas/genética , Vacinas Sintéticas/genética , Vacínia/prevenção & controle , Animais , Antígenos Virais/genética , Bovinos , Doenças dos Bovinos/imunologia , Doenças dos Bovinos/virologia , Proteção Cruzada/imunologia , DNA Complementar/genética , DNA Complementar/imunologia , Doenças do Cão/imunologia , Doenças do Cão/parasitologia , Cães , Leishmania major/imunologia , Leishmaniose/imunologia , Leishmaniose/parasitologia , Poxviridae/imunologia , Genética Reversa , Peste Bovina/imunologia , Peste Bovina/virologia , Vírus da Peste Bovina/imunologia , Transgenes , Vacinas Atenuadas/administração & dosagem , Vacinas Atenuadas/biossíntese , Vacinas Combinadas/administração & dosagem , Vacinas Combinadas/biossíntese , Vacinas Sintéticas/administração & dosagem , Vacinas Sintéticas/biossíntese , Vacínia/imunologia , Vacínia/virologia
11.
Prev Vet Med ; 102(2): 98-106, 2011 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-21783268

RESUMO

This paper describes the demise of rinderpest, focussing on the 20th Century and especially the period of the Global Rinderpest Eradication Programme, before proceeding to describe the process of accreditation of rinderpest freedom which is now virtually complete.


Assuntos
Doenças dos Bovinos/história , Doenças dos Bovinos/prevenção & controle , Surtos de Doenças/veterinária , Vírus da Peste Bovina/imunologia , Peste Bovina/história , Peste Bovina/prevenção & controle , Vacinação/veterinária , Vacinas Virais/história , Animais , Bovinos , Doenças dos Bovinos/epidemiologia , Surtos de Doenças/história , Surtos de Doenças/prevenção & controle , História do Século XIX , História do Século XX , Peste Bovina/epidemiologia , Vacinação/história , Vacinas Virais/imunologia
12.
Hybridoma (Larchmt) ; 30(3): 291-5, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21707365

RESUMO

Peste des petits ruminant (PPR) is an acute, febrile, viral disease of small ruminants with great economic importance. PPR and rinderpest (RP) viruses are antigenically related and need to be differentiated serologically. The use of monoclonal antibodies (MAbs) in ELISA for specific diagnostics and separation of PPR and RPV is important. For this purpose, six Balb/c mice were immunized with inactivated antigen from the Nijeria strain. Fusion cloning was performed 3 months later by directly using cloning plates, selecting the hybridoma colonies at an early stage with an inverted microscope, and transferring the colonies into 96-well plates with a micropipette. From 300 wells, nearly 56 hybridoma clones were found, from which, after testing in ELISA, 11 with higher titer were selected. Among these, only two clones were placed for limiting dilution (1H1, 6A12). Only one clone (6A12L1F12) had no cross-reactivity with RP, reacted with the N protein, and was of IgG2 isotype.


Assuntos
Anticorpos Monoclonais/imunologia , Vírus da Peste dos Pequenos Ruminantes/imunologia , Vírus da Peste Bovina/imunologia , Testes Sorológicos/métodos , Animais , Chlorocebus aethiops , Ensaio de Imunoadsorção Enzimática , Immunoblotting , Camundongos , Camundongos Endogâmicos BALB C , Vírus da Peste dos Pequenos Ruminantes/genética , Vírus da Peste Bovina/genética , Ovinos , Células Vero
13.
J Virol ; 85(12): 6038-48, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21450819

RESUMO

The presentation of viral peptide epitopes to host cytotoxic T lymphocytes (CTLs) is crucial for adaptive cellular immunity to clear the virus infection, especially for some chronic viral infections. Indeed, hosts have developed effective strategies to achieve this goal. The ideal scenario would be that the peptide epitopes stimulate a broad spectrum of CTL responses with diversified T-cell receptor (TCR) usage (the TCR repertoire). It is believed that a diversified TCR repertoire requires a "featured" peptide to be presented by the host major histocompatibility complex (MHC). A featured peptide can be processed and presented in a number of ways. Here, using the X-ray diffraction method, the crystal structures of an antigenic peptide derived from rinderpest virus presented by bovine MHC class I N*01801 (BoLA-A11) have been solved, and two distinct conformations of the presented peptide are clearly displayed. A detailed analysis of the structure and comparative sequences revealed that the polymorphic amino acid isoleucine 73 (Ile73) is extremely flexible, allowing the MHC groove to adopt different conformations to accommodate the rinderpest virus peptide. This makes the peptide more featured by exposing different amino acids for T-cell recognition. The crystal structures also demonstrated that the N*01801 molecule has an unusually large A pocket, resulting in the special conformation of the P1 residue at the N terminus of the peptide. We propose that this strategy of host peptide presentation might be beneficial for creating a diversified TCR repertoire, which is important for a more-effective CTL response.


Assuntos
Epitopos de Linfócito T/química , Antígenos de Histocompatibilidade Classe I/imunologia , Fragmentos de Peptídeos/química , Conformação Proteica , Vírus da Peste Bovina/imunologia , Sequência de Aminoácidos , Animais , Bovinos , Cristalografia por Raios X , Epitopos de Linfócito T/imunologia , Epitopos de Linfócito T/metabolismo , Antígenos de Histocompatibilidade Classe I/química , Antígenos de Histocompatibilidade Classe I/metabolismo , Modelos Moleculares , Dados de Sequência Molecular , Fragmentos de Peptídeos/imunologia , Fragmentos de Peptídeos/metabolismo , Alinhamento de Sequência , Análise de Sequência de DNA , Relação Estrutura-Atividade , Linfócitos T Citotóxicos/imunologia
14.
J Virol Methods ; 174(1-2): 42-6, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21419802

RESUMO

This paper describes the improvement of a rapid diagnostic test for the detection of rinderpest virus (RPV) at pen-side and the development of a similar test for the detection of another Morbillivirus, peste de petits ruminants virus (PPRV). Using the Svanova Biotech format, prototype chromatographic strip test devices were developed for RPV and PPRV detection. For the RP device, the incorporation of a monoclonal antibody (Mab), which recognises additional RPV strains of RPV lineage 2, enhanced the range of reactivity of the rapid diagnostic test. The device detected antigen in animals infected experimentally with different RPV strains. It also showed detection levels similar to the RP Clearview™ device reported previously. In addition, RPV was also detected under field conditions in Pakistan. A PPRV specific Mab (C77) was used for the development of the PPR test. This Mab recognised a wide range of PPRV isolates and did not show any cross-reactivity with any other virus tested. In animal experiments the device was able to detect viral antigen in eye swabs taken from the animals. The PPRV test should be invaluable for future PPR control eradication programs.


Assuntos
Antígenos Virais/isolamento & purificação , Técnicas de Laboratório Clínico/métodos , Peste dos Pequenos Ruminantes/veterinária , Vírus da Peste dos Pequenos Ruminantes/isolamento & purificação , Vírus da Peste Bovina/isolamento & purificação , Peste Bovina/diagnóstico , Virologia/métodos , Animais , Anticorpos Monoclonais , Anticorpos Antivirais , Antígenos Virais/imunologia , Imunoensaio/métodos , Paquistão , Peste dos Pequenos Ruminantes/diagnóstico , Peste dos Pequenos Ruminantes/imunologia , Vírus da Peste dos Pequenos Ruminantes/imunologia , Peste Bovina/imunologia , Vírus da Peste Bovina/imunologia , Sensibilidade e Especificidade
16.
Rev Sci Tech ; 29(3): 497-511, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21309450

RESUMO

A cross-sectional sero-survey, using a two-stage cluster sampling design, was conducted between 2002 and 2003 in ten administrative regions of central and southern Somalia, to estimate the seroprevalence and geographic distribution of rinderpest (RP) in the study area, as well as to identify potential risk factors for the observed seroprevalence distribution. The study was also used to test the feasibility of the spatially integrated investigation technique in nomadic and semi-nomadic pastoral systems. In the absence of a systematic list of livestock holdings, the primary sampling units were selected by generating random map coordinates. A total of 9,216 serum samples were collected from cattle aged 12 to 36 months at 562 sampling sites. Two apparent clusters of RP seroprevalence were detected. Four potential risk factors associated with the observed seroprevalence were identified: the mobility of cattle herds, the cattle population density, the proximity of cattle herds to cattle trade routes and cattle herd size. Risk maps were then generated to assist in designing more targeted surveillance strategies. The observed seroprevalence in these areas declined over time. In subsequent years, similar seroprevalence studies in neighbouring areas of Kenya and Ethiopia also showed a very low seroprevalence of RP or the absence of antibodies against RP. The progressive decline in RP antibody prevalence is consistent with virus extinction. Verification of freedom from RP infection in the Somali ecosystem is currently in progress.


Assuntos
Anticorpos Antivirais/sangue , Doenças dos Bovinos/epidemiologia , Vírus da Peste Bovina/imunologia , Peste Bovina/epidemiologia , Agricultura/métodos , Animais , Bovinos , Doenças dos Bovinos/sangue , Doenças dos Bovinos/virologia , Análise por Conglomerados , Estudos Transversais , Ecossistema , Modelos Logísticos , Peste Bovina/sangue , Peste Bovina/imunologia , Fatores de Risco , Estudos Soroepidemiológicos , Somália/epidemiologia , Migrantes
17.
Trop Anim Health Prod ; 40(7): 521-7, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18716909

RESUMO

Monoclonal antibody-based competitive ELISA (C-ELISA) has been used for the specific measurement of antibodies to peste des petits ruminants (PPR) viruses in sheep, goats, cattle and buffalo. Serum samples from sheep (n = 232), goats (n = 428), cattle (n = 43), buffalo (n = 89) were tested. The animals had not been vaccinated against rinderpest or PPR. Findings suggested that the sero-positive cases were significantly higher in sheep (51.29%) than in goats (39.02%) (P = 0.002). The overall sero-prevalence of PPRV in small ruminants was 43.33%. The PPR antibodies seroprevalence was 67.42% in buffalo and 41.86% in cattle which was significantly higher in buffalo (P = 0.005). The overall sero-prevalence of PPRV in large ruminants was 59.09%. Cattle and buffalo sera showed a high prevalence of antibody against PPR virus which may explain the difficulty experienced in achieving high post-vaccination immunity levels against rinderpest. Because antibodies against PPR virus are both cross-neutralizing and cross-protective against rinderpest virus, further vaccination in the presence of antibodies against PPR virus may be a waste of national resources. It was also suggested that antibodies to PPR virus could prevent an immune response to the rinderpest vaccine. This paper presents serological evidence for the transmission of PPR virus from sheep and goats to cattle and buffalo and highlights the need to include PPR serology in the sero-monitoring programme to give a better indication of national herd immunity of sheep and goats against PPR.


Assuntos
Anticorpos Antivirais/sangue , Búfalos/virologia , Doenças dos Bovinos/epidemiologia , Doenças das Cabras/epidemiologia , Peste dos Pequenos Ruminantes/veterinária , Vírus da Peste dos Pequenos Ruminantes/imunologia , Doenças dos Ovinos/epidemiologia , Animais , Bovinos , Reações Cruzadas , Ensaio de Imunoadsorção Enzimática/métodos , Ensaio de Imunoadsorção Enzimática/veterinária , Feminino , Cabras , Masculino , Paquistão/epidemiologia , Peste dos Pequenos Ruminantes/epidemiologia , Peste Bovina/epidemiologia , Vírus da Peste Bovina/imunologia , Estudos Soroepidemiológicos , Ovinos , Especificidade da Espécie , Vacinação/veterinária
19.
Can J Microbiol ; 53(6): 720-6, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17668032

RESUMO

A competitive enzyme-linked immunosorbent assay (C-ELISA) has been developed and standardized for the detection of antibodies to the rinderpest virus (RPV) in sera from cattle, sheep, and goats. The test is specific for rinderpest because it does not detect antibodies to peste-des-petits-ruminants virus (PPRV). The test depends on the ability of the monoclonal antibody (MAb) directed against the hemagglutinin (H) protein of RPV to compete with the binding of RPV antibodies in the positive serum to the H protein of this virus. This MAb recognized a region from amino acids 575 to 583 on the H protein of RPV that is unique to the RPV H protein and is not present on the hemagglutinin-neuraminidase protein of PPRV. Another C-ELISA (peptide C-ELISA) was set up using this specific region as an antigen. A threshold value of 64.4% inhibition was established for the RPV C-ELISA, with 90 known RPV-negative and 30 RPV-positive serum samples. Using common serum samples, a cutoff value of 43.0% inhibition for the peptide C-ELISA was established. Based on statistical analysis, the overall sensitivity and specificity of the RPV C-ELISA, relative to those of a commercial kit, were found to be 90.00% and 103.33%, respectively. However, the sensitivity and specificity of the peptide C-ELISA were found to be 180.00% and 73.33%, respectively. Although a common MAb in 2 new C-ELISA systems was used, variation in their percent inhibition, due to the use of different antigens, was observed. Taking into consideration the difference in percent inhibition of the 2 described assays and the commercial kit (50%), it was found that the RPV C-ELISA and the peptide C-ELISA are more specific and sensitive tools than the commercial kit for assessing herd immune status and for epidemiologic surveillance.


Assuntos
Anticorpos Monoclonais/imunologia , Anticorpos Antivirais/imunologia , Hemaglutininas/imunologia , Vírus da Peste Bovina/imunologia , Anticorpos Antivirais/análise , Western Blotting , Ensaio de Imunoadsorção Enzimática/métodos , Reprodutibilidade dos Testes
20.
Cell Immunol ; 246(1): 17-25, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17582390

RESUMO

The relay hypothesis [R. Nayak, S. Mitra-Kaushik, M.S. Shaila, Perpetuation of immunological memory: a relay hypothesis, Immunology 102 (2001) 387-395] was earlier proposed to explain perpetuation of immunological memory without requiring long lived memory cells or persisting antigen. This hypothesis envisaged cycles of interaction and proliferation of complementary idiotypic B cells (Burnet cells) and anti-idiotypic B cells (Jerne cells) as the primary reason for perpetuation of immunological memory. The presence of peptidomimics of antigen in anti-idiotypic antibody and their presentation to antigen specific T cells was postulated to be primary reason for perpetuation of T cell memory. Using a viral hemagglutinin as a model, in this work, we demonstrate the presence of peptidomimics in the variable region of an anti-idiotypic antibody capable of functionally mimicking the antigen derived peptides. A CD8+ CTL clone was generated against the hemagglutinin protein which specifically responds to either peptidomimic synthesizing cells or peptidomimic pulsed antigen presenting cells. Thus, it appears reasonable that a population of activated antigen specific T cells is maintained in the body by presentation of peptidomimic through Jerne cells and other antigen presenting cells long after immunization.


Assuntos
Anticorpos Anti-Idiotípicos/imunologia , Apresentação de Antígeno , Memória Imunológica , Mimetismo Molecular , Linfócitos T Citotóxicos/imunologia , Animais , Antígenos Virais/imunologia , Células Clonais/imunologia , Epitopos de Linfócito T/imunologia , Hemaglutininas Virais/imunologia , Imunização , Região Variável de Imunoglobulina , Camundongos , Camundongos Endogâmicos BALB C , Peptídeos/análise , Peptídeos/imunologia , Vírus da Peste Bovina/imunologia
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