The application of new techniques to the improved detection of persistently infected cattle after vaccination and contact exposure to foot-and-mouth disease

• Published in: Vaccine Vol. 23; no. 44; pp. 5186 - 5195
• Main Authors: Parida, S., Cox, S.J., Reid, S.M., Hamblin, P., Barnett, P.V., Inoue, T., Anderson, J., Paton, D.J.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 25.10.2005; Elsevier; Elsevier Limited
• Subjects: Animals; Antigens; Applied microbiology; Biological and medical sciences; Carrier State - diagnosis; Carrier State - immunology; Carrier State - veterinary; Carrier State - virology; Cattle; Cattle Diseases - diagnosis; Cattle Diseases - immunology; Cattle Diseases - transmission; Cattle Diseases - virology; Cell culture; Disease detection; DIVA; Foot & mouth disease; Foot-and-Mouth Disease - diagnosis; Foot-and-Mouth Disease - immunology; Foot-and-Mouth Disease - transmission; Foot-and-mouth disease virus; Foot-and-Mouth Disease Virus - immunology; Foot-and-Mouth Disease Virus - isolation & purification; Fundamental and applied biological sciences. Psychology; Genomes; Immunization; Infections; Livestock housing; Microbiological Techniques - methods; Microbiology; Miscellaneous; Proteins; Serologic Tests; Vaccination - veterinary; Vaccine differentiation; Vaccines; Vaccines, antisera, therapeutical immunoglobulins and monoclonal antibodies (general aspects); Virology; Virus persistence; Europe; Vaccine differentiation; DIVA; Virus persistence; Foot-and-mouth disease virus; Foot and mouth disease; Bovine; Picornaviridae; Vaccination; Vaccine; Virus; Infection; Aphthovirus; Vertebrata; Mammalia; Viral disease; Artiodactyla; Veterinary; Detection; Ungulata
• ISSN: 0264-410X; 1873-2518
• DOI: 10.1016/j.vaccine.2005.06.012

Detection of antibodies to the non-structural proteins (NSP) of foot-and-mouth disease virus (FMDV) was compared with conventional serological and virological methods and with RT-PCR for the identification of FMDV carrier animals obtained after experimental contact challenge of vaccinated cattle. Transmission from carriers to sentinels was also monitored. Twenty FMDV vaccinated and five unvaccinated cattle were challenged by direct contact with five donor cattle excreting FMDV and monitored until 28 days post challenge-exposure [1]. Twelve vaccinated and three unvaccinated animals were retained up to 24 weeks post exposure to FMDV in order to monitor viral persistence, transmission and antibody responses. In nine vaccinated animals, infection persisted beyond 28 days post exposure, virus being detected more frequently and for longer in oesophagopharyngeal samples from these animals when examined by RT-PCR rather than by virus isolation. Although recovery of FMDV RNA became increasingly sporadic over time, the number of RNA copies detected in positive samples declined only slowly. Two naïve sentinel cattle housed with the persistently infected animals between 93 and 168 days after the latter had been challenge-exposed to FMDV did not become infected. There were differences in the ability of commercially available serological tests to detect antibodies to FMDV non-structural proteins (NSP) in vaccinated and subsequently challenged cattle. Although no single test could identify all of the vaccinated cattle that became persistently infected, the most poorly recognised animals were those with the least evidence of virus replication based on other tests. The potential of the detection of antibodies to the 2B NSP of FMDV for diagnosing persistent FMDV infection was demonstrated.