To mark the International Day of Women and Girls in Science (11 February), Emma Snary (Head of Dept of Epidemiological Sciences) talks about the science carried out to underpin policy in the area of animal and public health.
What we do
In the Department of Epidemiological Sciences (DES) disciplines such as epidemiology, risk assessment, mathematical modelling, statistics, geographic information systems, database design and management are applied across many different animal diseases to provide robust evidence and advice to animal health policy makers in order to protect livestock and humans.
Such disciplines are applied across the research and surveillance work carried out within APHA; often providing the important ‘how, why and so what?’ questions or to add value to other scientific outputs and therefore making the results more meaningful.
Expertise with impact
The APHA Science Strategy identifies how the agency is committed to delivering high quality science-based evidence for decision making. Due to its nature, work carried out within the DES has an impact on animal and human health, and therefore the epidemiological sciences are a core capability across all of the 3 strategic themes: threat awareness, threat definition and threat mitigation.
New microbiological threats continue to emerge (e.g. new strains of highly pathogenic avian influenza virus in poultry) and old threats may re-emerge (e.g. bluetongue virus in ruminants); some of which may also pose a threat to humans. We provide input to the identification of the events that might promote such threats and, for specific disease threats, how we might detect them. For example, we provide a weekly input to a cross-Government Horizon Scanning group called the International Forward Look, which reports and analyses new, emerging or deteriorating situations including forecasts of severe weather and volcanoes/landslides.
Surveillance of disease (a key function of the APHA) necessitates collaboration with many scientists and veterinarians including other epidemiologists/quantitative scientists within APHA (Surveillance Intelligence Unit, the National Wildlife Management Centre, Field Epidemiologists and Veterinary Advisors). We provide expertise on the design of surveillance and analysis of the subsequent data across many different diseases. For example, surveillance plans are often needed to detect new threats, as such colleagues have rapidly designed sampling plans and analysed results to enable early detection of bluetongue in England (2016). Working with the Royal Veterinary College and European partners, DES and wider APHA contributed to an EU project called RISKSUR which was part-funded by Defra that developed and validated conceptual and decision support frameworks and associated tools for designing efficient risk-based animal health surveillance systems.
Assessing the threat of disease, including the potential impact such as how it might spread is an important part of our work. For bovine TB, we try to understand the risks to farmers and to help them make informed choices so that they can reduce the risk. There have been previous blogs published by my colleagues in the area of TB looking at both the spread of TB and also how we work with farmers and universities on this important, but complex disease. In addition, the Data Systems Group within the department played a key role in the development of an internet based mapping system called IBTB to put information in the public domain (a Defra priority) so that farmers can make informed biosecurity decisions.
Avian ‘flu is another busy area for the department (and not just because of the current outbreak!). See a previous blog on our surveillance work in this area which focused on tracking bird ‘flu across continents. For both Salmonella and BSE, we manage the data for these diseases, which is a vital job for the reporting of these notifiable diseases. The role of many database managers is often unsung, but the availability of clean data with a thorough understanding of its collection is essential prior to any further analysis of the data, and therefore the backbone to any evidence-based policy.
The fields of risk assessment, modelling and epidemiology can be applied to the identification and assessment of controls for the prevention of animal and human disease. Import risk assessments can be used to compare the efficacy of different control options in the risk of disease incursion. For example, our rabies risk assessment work was a key piece of scientific evidence when adopting the harmonised EU system for the movement of companion animals. Within the UK, epidemiological models can be used to inform disease control policy by simulating transmission across livestock populations and then predicting the impact of potential control measures. As an example, within DES, we are applying such approaches to both bovine TB and foot and mouth disease to ensure that current and future control options can be considered for these diseases.
The success of interventions in reducing disease can be assessed using epidemiological studies such as cohort or longitudinal studies. For example, a recent Salmonella in pigs project considered the use of sow vaccination; it concluded that the use of vaccination would significantly reduce the prevalence of Salmonella on a pig farm after a period of around 14 months. Due to this piece of work the UK is now seeking to licence this vaccine for use in sows.
In conclusion, in the DES we use epidemiology, risk assessment, modelling, statistics and data management to identify, define and mitigate against animal disease threats. Through these disciplines, we provide input to the development of scientifically robust evidence based UK and EU policy and hence – as emphasised by the APHA Science Strategy – we use our expertise with impact!
Emma Snary is Head of Department of Epidemiological Sciences at APHA.
After completing a PhD in mathematical modelling of the HIV/AIDS epidemic, Emma joined the Veterinary Laboratories Agency as a Risk Analyst in 2000.
She specialises in food safety risk assessment and enjoys working with colleagues across the APHA and elsewhere in the UK and Europe.
Emma was the Risk Research Thematic Coordinator for the Med-Vet-Net Network of Excellence and the Leader of the EFSA Salmonella in Pigs risk assessment. She has published over 40 papers in the field of risk assessment and is currently a member of the EFSA BIOHAZ Panel.