Disease Risk Analysis and Health Surveillance

The Disease Risk Analysis and Health Surveillance (DRAHS) project is a collaborative initiative between the Zoological Society of London and Natural England (NE) established to investigate the health and disease implications of interventions carried out for conservation purposes. 

Our Vision

To generate healthy and abundant free-living wildlife populations resulting from conservation interventions.

Our Objectives

  • To assess the risk of disease threats to wildlife populations which may arise from carrying out translocations
  • To detect disease threats to wildlife populations arising from conservation interventions
  • To mitigate against disease threats to wildlife populations through management actions
  • To publish and promote best practice during conservation interventions through dissemination of protocols and reports

Our History

The DRAHS project commenced in 1989 working alongside NE to undertake disease risk analysis and health surveillance for species included in the Species Recovery Programme. We have now worked with over 30 species include threatened and endangered native invertebrates, amphibians, reptiles, birds and mammals and the project continues to expand including overseas.

What is disease risk analysis?

Disease risk analysis (DRA) is qualitative risk assessment method undertaken in the planning stage of a conservation intervention such as a translocation. Translocations such as reintroductions are important conservation tools but they engender risk of disease to the translocated and recipient populations due to changes in wild animal and parasite population dynamics. During a DRA, the risk that infectious and non-infectious hazards will precipitate during or following an intervention, is analysed and mitigating measures proposed. Preventing the introduction of alien parasites to native populations is crucial because parasite invasions have the potential to cause catastrophic mortality outbreaks in potentially immunologically naïve populations.

Why do we carry out pre and post release health surveillance?

Pre and post release health surveillance (PRHS) is undertaken to check the health of animals before, during and after a translocation. Both translocated and recipient wild animal populations are monitored so that known and unknown disease threats can be detected early. 

How do we mitigate against disease?

Disease risk management (DRM) involves developing protocols to mitigate against potential disease threats. These may include enhanced biosecurity recommendations, implementation of quarantine procedures, infectious agent screening and therapeutic regimes. 

What are our outcomes? 

Before the project began methods for assessing the risk of disease to wild animal populations during interventions was rudimentary. In 2012, using methods available for domestic animal movements, a novel disease risk analysis method appropriate for wild animal interventions was developed and published (Sainsbury & Vaughan-Higgins 2012).  This method has since been adopted as part of the International Union for the Conservation of Nature (IUCN) Guidelines for Wildlife Disease Risk Analysis. Using applied research, the DRAHS team continue to develop structured evidence-based approaches to conservation interventions.

What action should you take if planning or undertaking a conservation translocation or reintroduction?

A conservation translocation is defined as the deliberate movement of living organisms from one place to another in order to benefit a population, species or ecosystem. If you are intending to carry out a conservation translocation it is important that you become acquainted with guidelines set out by the International Union for Conservation of Nature (IUCN) for reintroductions and other conservation translocations as early as possible in the planning process. These guidelines can be accessed here: https://portals.iucn.org/library/efiles/documents/2013-009.pdf.

The benefits of a conservation translocation should be carefully weighed against the risks and these risks include the risk of disease to both source and destination populations. Disease risk analysis (DRA) is an important tool through which disease risks can be analysed prior to translocation. Guidelines for conducting a DRA are described by Sainsbury and Vaughan-Higgins (2012) and can be accessed here: https://portals.iucn.org/library/sites/library/files/documents/2014-006.pdf. As part of the planning process a comprehensive disease risk management (DRM) and post-release health surveillance (PRHS) protocol should be written to mitigate against risks highlighted through the DRA.

The disease risk analysis and health surveillance (DRAHS) project provides expertise in conducting DRA, DRM and PRHS for conservation translocations. Please get in touch at DRAHS@zsl.org if you are thinking about carrying out a conservation translocation and would like our help.


Key references:

  • Sainsbury AW, Vaughan-Higgins RJ. 2012. Analysing disease risks associated with translocations. Conservation Biology 26: 442-452.
  • Rideout B, Sainsbury AW, Hudson PJ 2017.  Which Parasites Should We Be Most Concerned About in Wildlife Translocations?  Ecohealth 14: S42-S46
  • Bobadilla Suarez, M, Ewen, JG, Groombridge JJ, Beckmann K, Shotton J, Masters N, Hopkins T, Sainsbury AW 2017.  Using Qualitative Disease Risk Analysis for Herpetofauna Conservation Translocations Transgressing Ecological and Geographical Barriers.  Ecohealth 14: S47-S60

The DRAHS project is part of the WILDCOMS Network

Project Information

Our Core Team

Dr Tony Sainsbury

Dr Tammy Shadbolt

Dr Claudia Carraro

Dr Helen Donald

Georgina Gerard

Dr Sophie Common

Key Collaborators 

Natural England 

People's Trust for Endangered Species 

Amphibian and Reptile Conservation 

Pensthorpe Conservation Trust 

Butterfly Conservation 

Royal Society for the Protection of Birds 

The Wildlife Trusts 

Example Projects

Learn more about our work with threatened and endangered species: