English Pig Farmers' Knowledge and Behaviour OPEN ACCESS Towards ASF in Terms of Clinical Suspicion and Reporting
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RESEARCH ARTICLE English Pig Farmers’ Knowledge and Behaviour towards African Swine Fever Suspicion and Reporting Claire Guinat1,2*, Ben Wall1, Linda Dixon2, Dirk Udo Pfeiffer1 1 Veterinary Epidemiology, Economics and Public Health Group, Royal Veterinary College, Hawkshead Lane, Hatfield, Hertfordshire, AL9 7TA, United Kingdom, 2 The Pirbright Institute, Pirbright laboratory, Ash road, Pirbright, Surrey, GU24 0NF, United Kingdom * [email protected] Abstract African swine fever (ASF) is a notifiable, virulent swine disease, and is a major threat to ani- a11111 mal health and trade for many European Union (EU) countries. Early detection of the intro- duction of ASF virus is of paramount importance to be able to limit the potential extent of outbreaks. However, the timely and accurate reporting of ASF primary cases strongly depends on how familiar pig farmers are with the clinical signs, and their motivation to report the disease. Here, an online questionnaire survey was conducted between Decem- ber 2014 and April 2015 to investigate English pig farmers' knowledge and behaviour OPEN ACCESS towards ASF in terms of clinical suspicion and reporting. Multivariable logistic regression Citation: Guinat C, Wall B, Dixon L, Pfeiffer DU analysis was used to identify factors influencing the two variables of interest: 1) farmers (2016) English Pig Farmers' Knowledge and Behaviour towards African Swine Fever Suspicion who ªwould immediately suspect ASFº if they observed clinical signs of fever, lethargy, and Reporting. PLoS ONE 11(9): e0161431. reduced eating and high mortality on their farm and 2) farmers who ªwould immediately doi:10.1371/journal.pone.0161431 report ASFº if they suspected ASF on their farm. The questionnaire was completed by 109 Editor: Odir AntoÃnio Dellagostin, Universidade pig farmers. Results indicate that pig farmers having poor knowledge about ASF clinical Federal de Pelotas, BRAZIL signs and limited concern about ASF compared with other pig diseases are less likely to Received: October 23, 2015 consider the possibility of an outbreak of ASF on their farm. In addition, pig farmers lacking Accepted: August 5, 2016 awareness of outbreaks in other countries, having a perception of the negative impact on them resulting from false positive reporting and the perceived complexity of reporting pro- Published: September 29, 2016 cedures are less likely to report an ASF suspicion. These findings indicate important areas Copyright: 2016 Guinat et al. This is an open © for educational campaigns targeted at English pig farmers to focus on in an attempt to access article distributed under the terms of the Creative Commons Attribution License, which increase the likelihood of a rapid response in the event of an ASF outbreak. permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Data Availability Statement: Data are available on Figshare (DOI: 10.6084/m9.figshare.3504098). Introduction Funding: The authors received no specific funding The circulation of African swine fever virus (ASFV; family Asfarviridae) in Eastern Europe for this work. since 2007 and more recently in European Union (EU) countries has caused considerable con- Competing Interests: The authors have declared cern over the potential for ASFV to spread into Western Europe[1, 2]. ASFV causes a highly that no competing interests exist. virulent disease in domestic pigs with significant economic impact for the pig industry due to a PLOS ONE | DOI:10.1371/journal.pone.0161431 September 29, 2016 1 / 13 English Pig Farmers and African Swine Fever fatality rate of up to 100% and the culling measures and movement bans necessary to control the virus[1, 3]. Containing the ongoing ASF epidemic in Eastern Europe remains a challenge, particularly due to the absence of vaccines or treatment, the stability of the virus in the environ- ment, potential illegal movements of live pigs and pig products, the relatively large number of low-biosecurity farms, the commonplace use of swill feeding, and frequent interactions between domestic and wild swine[4]. In ASF-free European countries, early detection of ASFV introduction is therefore crucial to protect pig health, maintain access to global trade in pigs and pig products, and thereby limit the economic impact of an ASF epidemic. In England, ASF could potentially be introduced through legal and illegal movement of contaminated pig prod- ucts which may then also subsequently be used for swill feeding. Around 23% of pig farmers interviewed in England have reported using swill to feed their pigs although this practice was banned in the United Kingdom in 2011 [5]. In a recent study, this risk of introduction was con- sidered to be one of the highest in the EU, due to the large number of ports, airports and travel- lers coming from affected areas [6]. Therefore, the possibility of an ASF epidemic represents a significant economic risk, and preparedness for an ASFV incursion is of high importance to the English pig industry. In England, the current surveillance system for ASFV relies entirely on the immediate and mandatory notification of any clinically suspect animals by pig farmers to their veterinary sur- geon [7], who will then initiate an investigation by local Animal and Plant Health Agency (APHA) veterinary surgeons. Blood and tissue samples are collected for laboratory analysis, and diagnostic results should be available within 24–48 hours. While under investigation, sus- pect farms are placed under movements’ restrictions in order to reduce the risk of ASFV spread via infected pigs, contaminated vehicles or equipment. In the case of ASFV introduction into the country, the compliance of all farmers with this policy should be able to limit the spread of the virus and thereby mitigate the early spread of the epidemic before control strategies can be implemented. However, a number of factors may delay reporting by farmers. Firstly, the symptoms of ASF are not specific, particularly in the early clinical stage of the disease. Fever, lethargy and loss of appetite are generally observed among infected domestic pigs, in association with sudden deaths within 2–3 weeks [8, 9]. Other symptoms can include vomiting, diarrhoea and haemor- rhages. This is similar to other pig diseases, particularly classical swine fever (CSF), or porcine reproductive and respiratory syndrome (PRRS) which is endemic in England[10, 11]. The dis- ease can also express itself in some domestic pigs in more unusual clinical manifestations, such as with neurological symptoms, and in some cases may even be asymptomatic [12, 13]. Previ- ous surveys have concluded that farmers’ awareness is biased towards diseases which occur at higher prevalence [14], such as PRRS. Since an ASF outbreak has never been confirmed in England, it is unlikely that farmers will have much awareness of the disease, if any. This view is supported by the fact that the Agriculture and Horticulture Development Board (AHDB Pork) recently had to cancel seminars on ASF and porcine epidemic diarrhoea virus due to a lack of interest from the pig industry [15]. Farmers’ awareness of specific clinical signs is essential for early detection of any disease by state authorities [16]. In addition, even if farmers are aware of a particular disease, whether and when they decide to report suspected cases will depend on a variety of factors. A previous study suggested that the main reasons for German, Russian and Bulgarian pig farmers not to imme- diately report suspected ASF cases included lack of knowledge of reporting procedures, the per- ceived impact a notification could have on their reputation, expectation that laboratory confirmation would take a long time, and the belief they could handle the outbreak themselves without the involvement of veterinary services [17]. These behavioural and motivational fac- tors have not yet been investigated among English pig farmers. PLOS ONE | DOI:10.1371/journal.pone.0161431 September 29, 2016 2 / 13 English Pig Farmers and African Swine Fever This study was conducted to investigate pig farmers’ knowledge and behaviour in relation to ASF suspicion and reporting in England, using an online questionnaire survey. Materials and Methods Data collection A questionnaire was developed to collect data on pig farmers’ knowledge of ASF clinical dis- ease, and behaviour in relation to ASF suspicion and reporting. The questionnaire contained 19 questions and was estimated to take around 10 minutes to complete. To maximise compara- bility between respondents, the questions were closed (i.e. questions were in a format that restricts respondents to a range of possible options from which they must choose) or semi- closed (i.e. allowing respondents to express their opinion) [18]. The questionnaire was piloted on one English pig farmer and two interviewers from AHDB Pork and the Royal Veterinary College (RVC) to ensure that questions and pre-defined answers were sufficiently clear and rel- evant, and it was modified based on their feedback. A short introduction explained the reason for the study, and it was emphasised that answers were anonymous and confidential. The ques- tionnaire was divided into four sections. Section 1collected data on farm characteristics and practices, including herd size, production and housing type, number of animal workers and fre- quency of pig monitoring. Section 2 collected data on the farmers’ knowledge about ASF epide- miology including recent outbreaks, description of clinical signs,