Roadmap for Vector Transmission Control (VTC)

What are we trying to achieve and why? What is the problem we are trying to solve?

• How can we interact with the biotope to reduce vector population or disease transmission
• Define the natural vector biotope or eco-environment
• Do climate-changes alter the distribution of the vector population
• To identify the potential range of particular vectors and their associated pathogen based on environmental parameters.
• To predict possible spread of particular vectors and their associated pathogen based on climatic conditions
• Impact of climate change on permissiveness of vectors, for example culicoides gut leakiness associated with higher temperatures leading to BTV transmission in ‘non-permissive’ species

What are the scientific and technological challenges (knowledge gaps needing to be addressed)?

• Understanding the vector biotope to help in predictive modelling for determining parameters to control vector populations on the farm or environment
• Changes to vector biotope through habitat/environmental changes (due to climate change, land development) predictive modelling
• Economic impact of vectors
• Socio economics – understanding which production systems will work: animal husbandry – zero grazing; rotational land use – used in Africa – farmers don’t like it in Brazil; rice field then cattle grazing. Integrated management.
• Develop new ways of data mining to describe populations genetics and distributions.
• Mapping of climate change and change in land use (habitat).
• Field sampling of vector in different geographical locations under influence of climate change
• Field sampling at different seasonal periods for cyclical
• Modelling of climate change and associated environmental/habitat/land-use changes and impact on host/vector changes – destroy habitat/preserve habitat
• Also link to preserving/protecting landscape for conservation or changes in land use
• Modelling based on level of antigens/antibodies in milk (when is the largest infestation of cattle with ticks) – help overcoming only identifying ticks when engorged, proxy for tick numbers
• Understanding the ecological drivers of tick populations in different environments can help researchers predict how they may respond to climate change.
• Algorithms that can predict based on temperature, time of year etc, when tick population rise (peak tick season) to id better time interventions – could also include any resistance
• Accurate data on the environmental conditions needed for the survival and maintenance of a particular vector
• When tick/vector season going to occur, could predict when most effective to begin control methods (i.e. more effective during low density than when high density, allow small exposure for natural immunity before control methods)
• Ecological analysis and predictive modelling can be used to better understand the distribution and abundance of tick populations. This information can be used to predict when the tick season will start and to develop more effective tick treatment strategies. By analyzing environmental factors such as temperature, humidity, and vegetation, researchers can gain insights into the ecological drivers of tick populations. Predictive models can then be developed to forecast tick abundance and distribution based on these environmental factors.
• Tick mapping is an important tool for understanding the distribution and abundance of ticks in different regions. In Africa, there is a need for more comprehensive tick mapping efforts in order to better understand the risk of tick-borne diseases in different areas. These efforts could involve field surveys, remote sensing techniques, and citizen science initiatives. By mapping tick populations, researchers can identify areas where disease risk is highest and develop targeted interventions to reduce this risk.

What approaches could/should be taken to address the research question?

Review of literature on changes in the distribution of the vector
Satellite imagery supported by field studies

What else needs to be done before we can solve this need?

Improved understanding of vector ecology

Existing knowledge including successes and failures

Clinglobal Mapping Project (BMGF funded)

• Ecto- and endoparasite frequency and economic impact
• Sampled 7000 cattle from 7 countries in Central and East Africa
• Has 2 publications on ticks and pathogen infections and follow on work around cattle genetics for susceptibility

KENTTEC is a model of control but needs lots of labour. If do long-term may be able to need fewer people as go along. Not research money – more government decision to support. In Europe have 6 people/vector and take literature data and put in a database and map all the vectors. Do capacity building.
GIS modelling – Robert Miller, USDA project using location tracking to trigger surveillance systems and cascade of actions (including lab to carry out testing) and map resistant populations
Probst J, Springer A, Topp AK, Bröker M, Williams H, Dautel H, Kahl O, Strube C. Winter activity of questing ticks (Ixodes ricinus and Dermacentor reticulatus) in Germany – Evidence from quasi-natural tick plots, field studies and a tick submission study. Ticks Tick Borne Dis. 2023 Nov;14(6):102225.
Baylis, M. Potential impact of climate change on emerging vector-borne and other infections in the UK. Environ Health 16 (Suppl 1), 112 (2017).
Sanders CJ, Shortall CR, England M, Harrington R, Purse B, Burgin L, Carpenter S, Gubbins S. Long-term shifts in the seasonal abundance of adult Culicoides biting midges and their impact on potential arbovirus outbreaks. J Appl Ecol. 2019 Jul;56(7):1649-1660.
Climate and emergence of rift valley fever: Anyamba A, Chretien JP, Small J, Tucker CJ, Formenty PB, Richardson JH, Britch SC, Schnabel DC, Erickson RL, Linthicum KJ. Prediction of a Rift Valley fever outbreak. Proc Natl Acad Sci U S A. 2009 Jan 20;106(3):955-9.