Department: Production and Population Health
Research Centres: Veterinary Epidemiology, Economics and Public Health
Julian is a Lecturer in Veterinary Epidemiology and a European Veterinary Specialist in Zoological Medicine. He is particularly interested in finding out how diseases transmit between wildlife, domestic animals and humans.
2010 DipECZM (Wildlife Population Health), European College of Zoological Medicine
2009 PhD in Veterinary Epidemiology, University of Cambridge
2004 MSc (Wild Animal Health), Institute of Zoology and Royal Veterinary College
2004 CertZooMed, Royal College of Veterinary Surgeons
2001 BVetMed, Royal Veterinary College London
2012-date Lecturer in Veterinary Epidemiology, RVC
2010-2012 Project leader for SERVAL surveillance evaluation framework, RVC/AHVLA
2009-2010 Research Fellow in Veterinary Epidemiology, RVC, London
2005-2008 PhD, Cambridge
2001-2005 Veterinary surgeon in general practice, UK and South Africa
I graduated from the Royal Veterinary College in 2001 and then spent two years working in a mixed practice in Norfolk. Patients included farm animals, horses, pets and exotic animals. I spent a very interesting year working as a locum vet in the UK and South Africa in private practices, a wildlife hospital, in industry and in a zoo.
During 2004 I undertook the MSc in Wild Animal Health at the Institute of Zoology in London, and completed my RCVS Certificate in Zoological Medicine at the same time. It was during this time that I developed a particular interest in diseases of wildlife and the impacts that infectious diseases may have on animal populations.
From 2005 to 2009 I did my PhD at the University of Cambridge where I studied the role of social interactions in the transmission of tuberculosis between wild meerkats. This research involved a substantial fieldwork component which I undertook in the beautiful Kalahari Desert in South Africa.
I started at the RVC in February 2009 and became a European Veterinary Specialist in Zoological Medicine in the field of Wildlife Population Health in 2010.
I am particularly interested in diseases that spread between humans, domestic animals and wildlife and am an advocate of interdisciplinary research (that which brings together people with different areas of expertise to tackle disease problems together).
I am currently working with colleagues at the Animal Health and Veterinary Laboratories Agency (AHVLA) to research novel ways for detecting TB (tuberculosis) in badgers. This is important because the same form of TB is found in cattle. You can read details about this project here.
My main research Interests are:
- Cleverer use of diagnostic tests at the individual and group level to better inform the management of diseases in animal populations.
- Identifying animals or groups that are responsible for a disporoportionate amount of disease transmission. Targeting these individuals can result in much more effective disease control.
- Use of social network analysis to help understand the role of social interactions in spreading disease.
- Understanding and managing risks of infectious disease transmission to/from humans, livestock and wildlife.
To hear more about the research I am involved in, you can listen to two podcasts (links at the bottom of this page).
In addition to working with colleagues at the RVC, I am involved in collaborative research projects with scientists at the University of Cambridge, UK (TB in meerkats), Animal Health and Veterinary Laboratories Agency, UK (disease surveillance evaluation), Animal Health and Veterinary Laboratories Agency, UK (diseases in wildlife, particularly TB in badgers) and the University of Cape Town, South Africa (diseases in wild baboons).
For a full list of my publications together with citation metrics please have a look at my Google Scholar account.
20. Drewe, J.A., Haesler, B., Rushton, J. and Staerk, K.D.C. (2014) Assessing the expenditure distribution of animal health surveillance: the case of Great Britain. Veterinary Record 174: 16. doi:10.1136/vr.101846. Highlights: We developed an inventory of livestock health surveillance programmes in GB in 2011. We found livestock health surveillance funding to be unevenly distributed between species: the vast majority (approximately 94 per cent) was spent on cattle diseases (tuberculosis surveillance accounted for most of this expenditure). Consequently, surveillance an effort in GB appears heavily skewed towards regions with high cattle densities, particularly high-prevalence tuberculosis areas such as the southwest. Also see this editorial in the same edition of Vet Record which discusses the importance of this paper's findings.
19. Parsons, S.D.C., Drewe, J.A., Gey van Pittius, N.C., Warren, R.M. and van Helden, P.D. (2013) Novel cause of tuberculosis in meerkats, South Africa. Emerging Infectious Diseases 19: 2004-2007. Highlights: The organism that causes tuberculosis in meerkats (Suricata suricatta) has been poorly characterised. Our genetic analysis showed it to be a new species of bacteria which is epidemiologically and genetically unique. We name this new species as Mycobacterium suricattae.
18. Kukielka, E., Barasona, J.A., Cowie, C.E., Drewe, J.A., Gortazar, C., Cotarelo, I. and Vicente, J. (2013) Spatial and temporal interactions between livestock and wildlife in South Central Spain assessed by camera traps. Preventive Veterinary Medicine 112: 213–221. Highlights: Camera traps were used to record interactions between livestock (cattle and domestic pigs) and wildlife (red deer and wild boar) over 12 months in south-central Spain. Direct contacts between wildlife and livestock were rare but indirect interactions were far more common, which reflects what has been found in other countries (e.g. badgers and cattle in UK: see reference 16 below). Areas near water were a hotspot for interactions between species which suggests that preventing animals from aggregating at such areas might reduce transmission risks of diseases such as bovine tuberculosis.
17. Hoinville, L.J., Alban, L., Drewe, J.A., Gibbens, J., Gustafson, L., Häsler, B., Saegerman, C., Salman, M. and Stärk, K.D.C. (2013) Proposed terms and concepts for describing and evaluating animal health surveillance systems. Preventive Veterinary Medicine 112: 1-12.
Highlights: Widespread movement of animals and their products around the world increases the risk of international disease spread. There is, therefore, a need for exchange between countries of comparable information about disease incidence; the exchange must be based on a common understanding of surveillance approaches and how surveillance systems are designed and implemented. This paper establishes agreed-upon definitions of surveillance terms as a first step in achieving this standardisation, to enhance transparency and confidence in international animal health surveillance.
16. Drewe, J.A., O’Connor, H., Weber, N., McDonald, R.A. and Delahay, R.J. (2013) Patterns of direct and indirect contact among cattle and badgers naturally infected with tuberculosis. Epidemiology and Infection 141: 1467–1475. Highlights: We investigated interactions between badgers and cattle using automated proximity loggers. Direct contacts between badgers and cattle at pasture were very rare despite ample opportunity for interactions to occur. Indirect interactions (visits to badger latrines by badgers and cattle) were much more frequent than direct contacts. Our findings suggest that indirect contacts might be more important than direct contacts in terms of transmission of diseases such as TB. See also this feature in The Ecologist magazine.
15. Drewe, J.A., Hoinville, L.J., Cook, A.J.C., Floyd, T., Gunn, G. and Stärk, K.D.C. (2013) SERVAL: A new framework for the evaluation of animal health surveillance. Transboundary and Emerging Diseases (online early edition, doi: 10.1111/tbed.12063). Highlights: Animal health surveillance protects animal and human health. Surveillance systems should be regularly evaluated to determine if they are providing useful information and to identify needed improvements. This paper introduces SERVAL, a SuRveillance EVALuation framework developed at RVC and AHVLA. SERVAL is novel and generic which makes it suitable for the evaluation of any animal health surveillance system. For more information and to download the SERVAL framework free of charge, visit the accompanying website here.
14. Abeyesinghe, S.M., Drewe, J.A., Asher, L., Wathes, C.M. and Collins, L.M. (2013)
Do hens have friends? Applied Animal Behaviour Science 143: 61-66. Highlights: We investigated the possibility that domesticated egg-laying hens form distinct 'friendships' by examining whether or not individual chickens were particular about who they spent most time with. This is not so odd a question as might be thought: in humans and other species, friendships have been shown to enrich life positively, buffer against stressful experiences and even improve reproductive success. However, we found no evidence to suggest that modern hens reared in commercial conditions form such friendships, even when they are housed in small groups where it is possible to know every other bird. So the answer to the question "do hens have best friends?" is: "it seems not"!
13. Drewe, J.A., Weber, N., Carter, S.P., Bearhop, S., Harrison, X.A., Dall, S.R.X., McDonald, R. A. and Delahay, R.J. (2012) Performance of proximity loggers in recording intra- and interspecies interactions: a laboratory and field-based validation study. PLoS One 7: e39068. Highlights: Automated proximity loggers are increasingly being used to record interactions between animals but their accuracy and reliability remained largely un-assessed until now. We assessed the performance of these devices in the lab and in the field by fitting them to cattle and badgers and using static base stations. We demonstrate how data can be manipulated to ensure it accurately reflects real life. We make five recommendations for the effective use of proximity loggers in future studies.
12. Drewe, J.A., O’Riain, J., Beamish, E., Currie, H. and Parsons, S. (2012) Survey of infections transmissible between baboons and humans in Cape Town, South Africa.
Emerging Infectious Diseases 18: 298-301. Highlights: Baboons on South Africa’s Cape Peninsula come in frequent contact with humans. To determine potential health risks for both species, we screened 27 baboons from 5 troops for 10 infections of public health importance. Most (56%) baboons had antibodies reactive or cross-reactive to human viruses. We conclude that spatial overlap between these species poses low but potential health risks. Read more about this study here.
11. Drewe, J.A., Hoinville, L.J., Cook, A.J.C., Floyd, T. and Stärk, K.D.C. (2012) Evaluation of animal and public health surveillance systems: a systematic review Epidemiology and Infection 140: 575-590. Highlights: We reviewed how epidemiologists around the world evaluate disease surveillance for human and animal health conditions. We found most could do better, for example by assessing more attributes and choosing the ones they do assess more systematically. We discovered that economic assessment is rarely done. We make recommendations to improve surveillance evaluation.
10. Drewe, J.A., Eames, K.T.D., Madden, J.R. and Pearce, G.P. (2011) Integrating contact network structure into tuberculosis epidemiology in meerkats in South Africa: implications for control Preventive Veterinary Medicine 101: 113-120. Highlights: We studied how social interactions between wild meerkats affect tuberculosis transmission in the Kalahari desert. We found that grooming was more risky than aggressive interactions. These results are rather neat because they offer an explanation as to why not all animals in a group become infected and why socially dominant individuals can by their behaviour be effectively protected from becoming infected.
9. Madden, J.R., Drewe, J.A., Pearce, G.P. and Clutton-Brock, T.H. (2011) The social network structure of a wild meerkat population: 3. Position of individuals within networks Behavioral Ecology and Sociobiology 65: 1857-1871. Highlights: We examined social networks in and between groups of wild meerkats. Despite some patterns in who grooms whom, who competes for food against whom, and who is aggressive to whom, we found considerable variation between groups. We conclude that researchers should be cautious about treating individuals with similar attributes as functionally similar. This is relevant to studies of disease transmission where we often generalise or make conclusions on disease risk based on attributes such as age, sex and dominance status.
8. Drewe, J.A., Tomlinson, A.J., Walker, N.J. and Delahay, R.J. (2010) Diagnostic accuracy and optimal use of three tests for tuberculosis in live badgers PLoS ONE 5(6): e11196. Highlights: Accurate diagnosis of tuberculosis (TB) is notoriously difficult in live animals. We used a Bayesian approach to determine how best to use three TB tests in live-sampled badgers. We devised a way to combine results from each test leading to an estimated diagnostic accuracy of 93% meaning approximately 13 out of 14 animals had their true infection status correctly classified from samples collected on a single capture. This method represents a marked improvement on the current procedure for diagnosing TB in live badgers and could be applied to improve accuracy of TB diagnosis in other species.
7. Drewe, J.A. (2010) Who infects whom? Social networks and tuberculosis transmission in wild meerkats Proceedings of the Royal Society B 277: 633-642.
Highlights: Transmission of infectious diseases is strongly influenced by who contacts whom. Here, I use a social network approach to examine the relative importance of a range of social interactions in spreading disease between meerkats. Contrary to predictions, the most socially interactive animals were not at highest risk of acquiring infection, indicating that in addition to contact frequency, the type and direction of interactions must be considered when quantifying disease risk.
6. Asher, L., Collins, L.M., Ortiz-Pelaez, A., Drewe, J.A., Nicol, C.J. and Pfeiffer, D.U. (2009) Recent advances in the analysis of behavioural organization and interpretation as indicators of animal welfare Journal of the Royal Society Interface 6: 1103-1119.
Highlights: While the incorporation of mathematical and engineering methods has greatly advanced in other areas of the life sciences, they have been under-utilised in the field of animal welfare. In this review we explore the scope of such analytical methods as behavioural indicators of welfare. We discuss four classes of analyses that can be used to quantify aspects of behavioural organization: fractal analysis, temporal methods, social network analysis, and agent-based modelling and simulation. We highlight the potential applications and limitations of these methods in the assessment of animal welfare.
5. Madden, J.R., Drewe, J.A., Pearce, G.P. and Clutton-Brock, T.H. (2009) The social network structure of a wild meerkat population: 2. Intra-group interactions Behavioral Ecology and Sociobiology 64: 81-95. Highlights: Knowledge of the how animals interact is important for understanding the evolution of cooperation, transmission of disease, and patterns of social learning, yet little is known of how environmental, ecological, or behavioural factors relate to such structures within groups. Here, we investigate these factors in groups of wild meerkats. We found that the pattern of interactions between group members is not consistent but instead depends on general attributes of the group, the influence of specific individuals, and ecological factors such as parasite load.
4. Drewe, J.A., Madden, J.R. and Pearce, G.P. (2009) The social network structure of a wild meerkat population: 1. Inter-group interactions Behavioral Ecology and Sociobiology 63: 1295-1306. Highlights: We test whether social network analysis is useful for understanding patterns of contact between groups of animals. We looked at how stable interactions are over time and how different types of interactions between groups differ and relate this to risk of disease transmission. Spatial analysis of meerkat social networks reveals that roving male meerkats preferentially visit nearby groups rather than better groups (those with more females) further away.
3. Drewe, J.A., Dean, G.S., Michel, A.L., Lyashchenko, K.P, Greenwald, R. and Pearce, G.P. (2009) Accuracy of three diagnostic tests for determining Mycobacterium bovis infection status in live-sampled wild meerkats (Suricata suricatta) Journal of Veterinary Diagnostic Investigation 21: 31-39. Highlights: We use a Bayesian mathematical approach to work out the diagnostic accuracy of tests for TB in meerkats. Individually the tests were not particularly useful but using them in combination increased the accuracy of diagnosis to a level high enough to be valuable. [This approach has subsequently been adopted by other researchers working on TB in other species.]
2. Drewe, J.A., Foote, A.K., Sutcliffe, R.L. and Pearce, G.P. (2009) Pathology of Mycobacterium bovis infection in wild meerkats (Suricata suricatta) Journal of Comparative Pathology 140: 12-24. Highlights: This paper (illustrated with lots of colourful photos) describes a detailed investigation into the pathology of TB in meerkats. The histological characteristics of the tuberculous lesions, together with the gross pathology and the wide range of body systems affected, suggest that TB in meerkats is acquired principally via the respiratory and oral routes, whereas excretion is most likely via the respiratory tract and suppurating skin wounds. The findings of this study provide information on the transmission, pathogenesis and epidemiology of TB in meerkats that is likely to be relevant to the understanding of M. bovis infection in other social mammal species such as the Eurasian badger.
1. Drewe, J.A., Mwangi, D., Donoghue, H. and Cromie, R. (2009) PCR analysis of the presence and location of Mycobacterium avium in a constructed reed bed, with implications for avian tuberculosis control FEMS Microbiology Ecology 67: 320-328. Highlights: Reed beds are increasingly being planted to act as filters of dirty water. We examined if they remove harmful pathogens such as Mycobacterium avium – the agent that causes TB in birds. We discovered that they can effectively remove M. avium from the water through a combination of sedimentation and adsorption onto vegetation stems. The results of this study show that constructed reed beds composed of a settlement lagoon and one or more vegetation beds can act as valuable and ecologically friendly tools in the environmental control of avian TB.
3. Drewe, J.A., Pfeiffer, D.U. and Kaneene, J.B. (2014) Epidemiology of Mycobacterium bovis In: Zoonotic tuberculosis: Mycobacterium bovis and other pathogenic mycobacteria Eds: C.O. Thoen, J.H. Steele and J.B. Kaneene. Wiley Blackwell, Iowa, USA. pp 63-78. Highlights: An up-to-date review of our current knowledge of the epidemiology of TB due to M. bovis in animals. This chapter covers the main host species, routes of transmission, methods of surveillance and disease prevention strategies drawing on a wide range of examples from around the world.
2. Drewe, J.A. and Smith, N.H. (2014) Molecular epidemiology of Mycobacterium bovis In: Zoonotic tuberculosis: Mycobacterium bovis and other pathogenic mycobacteria Eds: C.O. Thoen, J.H. Steele and J.B. Kaneene. Wiley Blackwell, Iowa, USA. pp 79-88. Highlights: A review of the main molecular techniques and their application for gaining hidden insights into the epidemiology of TB due to M. bovis in animals (including humans). Includes examples of investiagtions to trace the geographical origins and transmission of M. bovis, and discusses the use of epigenetics to aid our understanding of potential risks associated with this pathogen.
1. Cross, P.C., Drewe, J.A., Patrek, V., Pearce, G.P., Samuel, M.D. and Delahay, R.J. (2009) Wildlife population structure and parasite transmission: implications for disease management In: Management of disease in wild mammals Eds: R.J. Delahay, G.C. Smith and M.R. Hutchings. Springer Publishing, London. pp 9-29. Highlights: Emerging infectious diseases have become an important challenge for wildlife ecologists and managers. Management actions to control these diseases are usually directed at the parasite, the host population, or the environment. Control methods directed at the host population, however, remain limited (e.g. vaccination, population reduction, test-and-remove) and have often been implemented without due consideration of how host ecology and behaviour may influence disease dynamics. This chapter highlights how host population structure and social organisation affect parasite transmission and prevalence. Future control efforts may be improved by focusing on subsets of individuals, areas, environmental factors, or times of year that are most important in the propagation and persistence of a pathogen.
2. Implications of land use changes on wildlife behaviour and infectious disease transmission to people (April 2014). Highlights: A short interview in which we discuss research we are conducting in Malaysia looking at how land use changes influence the behaviour of wild monkeys and their interactions with humans, with implications for the transmission of infectious diseases such as malaria. This research is funded by a fellowship grant from the London International Development Centre and is being conudcted researchers from the RVC (Julian Drewe and Martha Betson) and the London School of Hygiene and Tropical Medicine (Kimberly Fornace). You can read more about the project here.
1. Wildlife Reservoirs of Disease and Tuberculosis (January 2010, 6.1MB, MPEG-4)
(also available via iTunes or the RVC eMedia website: RVC podcast no. 42).
Highlights: Badgers are often blamed for the persistence of tuberculosis in cattle herds in parts of the UK. Here Dr Julian Drewe describes his research on the dynamics of UK badger populations and meerkat communities in Africa and the potential importance of this for the spread of TB within and between species.
What do epidemiology conferences have in common with wooden elephants and Marmite? Read Epidemiology and the Giant Elephant to find out!
I teach concepts of epidemiology and wildlife disease ecology on these courses:
BSc (Bioveterinary Science)
BSc (Comparative Pathology)
MSc (One Health)
MSc (Veterinary Epidemiology)
MSc (Wild Animal Biology)
MSc (Wild Animal Health)
I deliver workshops in Asia and Africa for MSc Veterinary Epidemiology and Public Health distance learning students.
I run science seminars in local schools to encourage pupils to be interested in careers in science, as part of the RVC outreach programme. Teenagers curious about science can attend interactive masterclasses that I hold periodically at RVC. A typical topic is 'Deadly contacts: how your social network could trigger the next pandemic'. Contact the RVC outreach office if you would like more information.
I am interested in finding out how different people in society perceive the risks of disease from wildlife. I hold question and answer sessions in the UK and South Africa on this topic and use the results to ensure my future research has maximum community benefit. Please click here to read more about one of my recent public engagement events working with baboons and local communities in South Africa.
Three times a year I head eastwards to teach on the Field Epidemiology Training Programme for Veterinarians in China. Recently we held a One Health workshop in Beijing to explore the interface between animal and public health in China and ways to improve collaboration across disciplines. Next workshop will be held later in 2014.
In August 2014 I delivered a workshop on epidemiology at the Faculty of Veterinary Medicine and Animal Science at the University of Peradeniya in Sri Lanka. This was part of the RVC's distance learning MSc course in Veterinary Epidemiology and Public Health.
In 2013 I taught on the second Southern African Centre for Infectious Disease Surveillance (SACIDS) summer school in Morogoro, Tanzania. It was great to meet students who attended from across eastern and southern Africa, including: Tanzania, Malawi, Zimbabwe, Mozambique, Zambia, Botswana and Democratic Republic of the Congo.
We are developing evidence-based practical solutions to help reduce levels of TB in badger populations.
Linking Epidemiology and Laboratory Research on Transboundary Animal Diseases and zoonoses in China and the EU.
A generic framework for the evaluation of animal health surveillance.
The aim of our research is to investigate whether understanding of susceptibilities and social networks in meerkats can be used to selectively target individuals for interventions, and thus enhance disease control.