Linda J Hoinville

Department for Environment, Food and Rural Affairs | DEFRA · Epidemiology, Surveillance and Risk Group (ESRG)

Animal health surveillance programmes may change in response to altering requirements or perceived weaknesses but are seldom subjected to any formal evaluation to ensure that they provide valuable information in an efficient manner. The literature on the evaluation of animal health surveillance systems is sparse, and those that are published may be...

Disease surveillance programmes ought to be evaluated regularly to ensure they provide valuable information in an efficient manner. Evaluation of human and animal health surveillance programmes around the world is currently not standardized and therefore inconsistent. The aim of this systematic review was to review surveillance system attributes an...

As part of an EU-wide programme to reduce the prevalence of Salmonella in commercial egg-laying holdings, the EU has set for the UK an annual target of 10% reduction in the prevalence of Salmonella Enteritidis and Salmonella Typhimurium in commercial egg-laying holdings. To assist in demonstrating such a reduction, it is very important to obtain an...

It has been known for many years that the offspring of scrapie affected ewes are at increased risk of developing scrapie but whether this is simply the result of an increased genetic susceptibility or transmission of infection has always been unclear. To contribute to clarify this we analysed the data collected in a detailed study of scrapie occurr...

An accurate estimate of the prevalence of scrapie infection in the Great Britain (GB) sheep flock is essential when assessing any potential risk to human health through exposure to sheep transmissible spongiform encephalopathies (TSEs). One method for assessing the prevalence is to sample sheep intended for human consumption using a diagnostic test...

Susceptibility to clinical scrapie is associated with polymorphisms in the PrP gene. The 'ARR' allele of this gene reduces susceptibility to clinical disease caused by all known strains of the transmissible spongiform encephalopathy (TSE) agent. The British government proposes to use a ram-genotyping scheme to breed genetic resistance to clinical s...

In 1997/1998, an abattoir survey was conducted to determine the likely exposure of the human population to transmissible spongiform encephalopathy (TSE) infection in sheep submitted for slaughter in Great Britain. The survey examined brain material from 2809 sheep processed through British abattoirs. Sampling was targeted by age: 45% of animals tes...

A postal survey of British sheep farmers provided information on the proportion of farms that experienced their first case of scrapie in each year between 1962 and 1998. We found no evidence of a large increase in the proportion of scrapie-affected farms prior to, during or following the epidemic of BSE in British cattle. After correcting for betwe...

The experimental transmission of bovine spongiform encephalopathy (BSE) to sheep1 raised the possibility that some sheep in the United Kingdom could have been infected during the 1980s after exposure to BSE-contaminated feed. In contrast to new diseases that have appeared in a number of feline species and wild ungulates2, the symptoms of BSE in she...

In 1998, a questionnaire was sent to 11,554 British sheep farmers to determine how many believed that scrapie cases had occurred in their flock; 61.4 per cent of them responded anonymously. The results indicated that 14.9 per cent of farmers with more than 30 breeding ewes thought that they had ever experienced scrapie in their flock and 2.7 per ce...

A randomised sample of 2,809 apparently healthy sheep, 55 per cent of them less than 15 months of age, which were slaughtered for human consumption at abattoirs in Great Britain in 1997/98, was taken to establish the prevalence of scrapie infection. The medulla oblongata of each sheep was examined histopathologically at the level of the obex, and f...

Responses to an anonymous postal survey concerning scrapie are analysed. Risk factors associated with farms that have had scrapie are identified as size, geographical region, lambing practices and holding of certain breeds. Further analysis of farms that have scrapie only in bought-in animals reveals that such farms tend to breed a smaller proporti...

Nature 382, 779-788 (1996). In Table 2 of this Letter, the reported number of cases saved for policy 9 was erroneously given for 1996 to 2001 rather than for 1997 to 2001. The number should be 584 rather than 797. Thus, the number of cases saved in policies 11-14 should be reduced by 213. Also, the culling policy description for policy 6 should beg...

The aim of this review is to summarise and evaluate the data available about the aetiology of scrapie in naturally affected sheep flocks, particularly data concerning the possible transmission of infection between related animals. The author examines data taken from various relevant studies carried out over the last thirty years. The main conclusio...

A comprehensive analysis of the bovine spongiform encephalopathy (BSE) epidemic in cattle in Great Britain assesses past, present and future patterns in the incidence of infection and disease, and allows a critical appraisal of different culling policies for eradication of the disease.

Bovine spongiform encephalopathy (BSE) occurred in cattle in Great Britain after the inclusion of protein derived from infected tissues in their feed, and the incidence of the disease has been reduced by the introduction of legislation to prevent the inclusion of such protein in ruminant feed. This paper describes a case-control study designed to i...

A standard questionnaire was used to record the presence of specific clinical signs reported for histopathologically confirmed cases of bovine spongiform encephalopathy observed before June 30, 1990, and the frequencies of these signs were analysed. The signs most frequently recorded were apprehension, hyperaesthesia and ataxia, and there were vari...

Following the identification of bovine spongiform encephalopathy (BSE) in the British cattle population in 1986 epidemiological studies were launched. This paper provides an updated account of the epidemiological features of BSE from 1985, when the first cases, based on clinical histories, occurred, until 1990. The number of cases up to December 19...