Clinical and laboratory investigations of the outbreaks of foot-and-mouth disease in southern England in 2007.

A case of foot-and-mouth disease (fmd) on a cattle farm in Normandy, Surrey, was confirmed on Friday August 3, 2007, the first case in the uk since 2001. The infection was detected nearby on a second farm on August 6. On September 12, fmd was confirmed on a farm approximately 20 km from Normandy in Egham, and this was followed by cases on five more farms in that area in the next three weeks. The majority of the infected farms consisted of multiple beef cattle holdings in semi-urban areas. In total, 1578 animals were culled on the infected farms, and fmd virus infection was confirmed in 278 of them by the detection of viral antigen, genome or antibodies to the virus, or by clinical signs. This paper describes the findings from animal inspections on the infected farms, including the estimated ages of the fmd lesions and the numbers of animals infected. It also summarises the test results from samples taken for investigation, including the detection of preclinically viraemic animals by using real-time reverse transcriptase-pcr.

Review: Capripoxvirus Diseases: Current Status and Opportunities for Control.

Lumpy skin disease, sheeppox and goatpox are high-impact diseases of domestic ruminants with a devastating effect on cattle, sheep and goat farming industries in endemic regions. In this article, we review the current geographical distribution, economic impact of an outbreak, epidemiology, transmission and immunity of capripoxvirus. The special focus of the article is to scrutinize the use of currently available vaccines to investigate the resource needs and challenges that will have to be overcome to improve disease control and eradication, and progress on the development of safer and more effective vaccines. In addition, field evaluation of the efficacy of the vaccines and the genomic database available for poxviruses are discussed.

The importance of FMDV localisation in lymphoid tissue.

Foot-and-mouth disease virus, a highly contagious pathogen that can cause lameness, low weight and decreased milk production, is a scourge of agricultural livestock around the world. Although the acute phase of infection is rarely fatal, infection may persist in animals that have apparently recovered, creating a viral reservoir that some fear could contribute to the spread of disease. We have used an array of molecular techniques to search for traces of virus in tissues from the mouths and throats of infected cattle. In a carefully controlled study, we have found evidence of intact, non-replicating virus particles trapped by follicular dendritic cells within the germinal centres of lymph nodes. Strikingly, virus was present for up to 38 days post infection, even though it was undetectable in surrounding tissues. The retention of intact virus within germinal centres is likely to have a role in stimulating the long lasting immune response that is characteristic of viral infections. Our data suggests that this capture may also be responsible for preserving intact viruses capable of infecting susceptible cells as they come into contact with germinal centres. African buffalo (Syncerus caffer) are typically infected with all three South African Territories types of FMDV by 2 years of age and these viruses can be transmitted to farmed livestock. Buffalo harbour persistent virus in greater amounts and for longer periods than cattle and thus provided us with further opportunities to define the sites of viral localisation.

The pathogenesis of foot-and-mouth disease I: viral pathways in cattle.

In 1898, foot-and-mouth disease (FMD) earned a place in history as the first disease of animals shown to be caused by a virus. Yet, despite over a century of active investigation and elucidation of many aspects of FMD pathogenesis, critical knowledge about the virus-host interactions is still lacking. The aim of this review is to provide a comprehensive overview of FMD pathogenesis in cattle spanning from the earliest studies to recently acquired insights emphasizing works which describe animals infected by methodologies most closely resembling natural infection (predominantly aerosol or direct/indirect contact). The three basic phases of FMD pathogenesis in vivo will be dissected and characterized as: (i) pre-viraemia characterized by infection and replication at the primary replication site(s), (ii) sustained viraemia with generalization and vesiculation at secondary infection sites and (iii) post-viraemia/convalescence including resolution of clinical disease that may result in long-term persistent infection. Critical evaluation of the current status of understanding will be used to identify knowledge gaps to guide future research efforts.

The pathogenesis of foot-and-mouth disease II: viral pathways in swine, small ruminants, and wildlife; myotropism, chronic syndromes, and molecular virus-host interactions.

Investigation into the pathogenesis of foot-and-mouth disease (FMD) has focused on the study of the disease in cattle with less emphasis on pigs, small ruminants and wildlife. 'Atypical' FMD-associated syndromes such as myocarditis, reproductive losses and chronic heat intolerance have also received little attention. Yet, all of these manifestations of FMD are reflections of distinct pathogenesis events. For example, naturally occurring porcinophilic strains and unique virus-host combinations that result in high-mortality outbreaks surely have their basis in molecular-, cellular- and tissue-level interactions between host and virus (i.e. pathogenesis). The goal of this review is to emphasize how the less commonly studied FMD syndromes and host species contribute to the overall understanding of pathogenesis and how extensive in vitro studies have contributed to our understanding of disease processes in live animals.