Tick

POST - Parliamentary Office of Science and Technology

Climate Change and Vector-Borne Disease in Humans in the UK

• Key points: 
  • VBDs are diseases that are transmitted by vectors, organisms that carry and transmit diseases between humans, animals and plants. VBDs account for 17% of infectious diseases and have a significant health impact globally.  
  • Vectors vary in the diseases they transmit. Mosquitoes and ticks are the vectors most concerning to the UK. Mosquitoes recorded in the UK, such as Ae. albopictus are capable of transmitting dengue fever and chikungunya fever. Ticks endemic to the UK can transmit Lyme disease and tick-borne encephalitis, a severe viral infectious disease. 
  • Vector establishment does not always mean spread of the VBDs they can carry, as other factors such as vector biting behaviour, affects their capacity to transmit disease. Currently, no mosquito-borne diseases of humans are circulating in the UK. Lyme disease is the most common VBD in the UK.  
  • Vector distribution is complex and affected by a variety of factors including globalisation and socio-economic factors. Climate change is also thought to be a main contributory factor.  
  • Higher temperatures as a result of climate change impacts mosquito development and affects transmission of VBDs. Infected ticks are less dependent on temperature but are affected by other climate variables such as moisture levels. Modelling predictions suggest that further climate changes coupled with other factors such as globalisation of trade could increase the UK’s susceptibility to other VBDs.  
  • Tick and mosquito surveillance is conducted by Public Health England, but several stakeholders believe that the current level is inadequate and should be expanded.  
  • Expanding citizen science approaches, as well as increasing public awareness and health professional awareness would also help in combating VBD incursion into the UK.  
• POSTnotes are based on literature reviews and interviews with a range of stakeholders and are externally peer reviewed. POST would like to thank interviewees and peer reviewers for kindly giving up their time during the preparation of this briefing, including:
  • Dr Rhian Rees-Owen, Department for Business, Energy and Industrial Strategy
  • British Veterinary Association 
  • Dr Debbie Hemming, Met Office* 
  • Dr Helen Roberts, Dr. Chris Browne, Department for Enviroment, Food & Rural Affairs*
  • Professor Steven Lindsay, Durham University
  • Professor James Logan, London School of Hygiene and Tropical Medicine
  • Dr Jolyon Medlock, Public Health England*
  • Dr Bethan Purse, Centre for Ecology and Hydrology* 
  • Professor Matthew Baylis, University of Liverpool*
  • Professor Heather Ferguson, University of Glasgow*
  • Dr Madeleine Thomson, Columbia University
  • Dr Barbara Tschirren, University of Exeter* 
  • Professor Richard Birtles, University of Salford*
  • Lydia Franklinos, University College London* 
  • Dr Caroline Millins, University of Glasgow 
  • Dr Lauren Cator, Imperial College London*  
  • Dr Simon Carpenter, The Pirbright Institute*
  • Dr Anne Cruickshank, Royal College of General Practitioners* 
  • Lyme Disease Action*
  • Gemma Holmes, Committee on Climate Change
  • Oxitec
• The distribution of these species is changing across Europe, and within the UK.
• The causes of why the distribution is changing are complex and interlinked but climate change plays a key role, especially in mosquito distribution.
• These factors are correlated with the spread of Lyme disease, a major tick-borne disease in the UK.Surveillance coverage and methods vary for different vector species and there is consensus that UK surveillance requires improvement.



POSTnotes POST-PN-0597