Roadmap for Vector Transmission Control (VTC)

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

To decrease vector challenge through control in the environment
To evaluate the impact of climate change on the tick-host-biotope interface and possible interventions to mitigate eventual new problems brought about by climate change

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

• Need to establish vector niches to target Environmental toxicity
• Define the different vector host: competition who are the vectors feeding on outside the domestic animals; wild versus domestic (buffalo-cattle; bats-cattle)
• Need to understand competition – could influence spread of different species – leading to displacement, outcompeting, faster breeding (important in relation to climate change).
• Need to understand hybridisation – could be difference in level of transmission/specificity to pathogen
• Socio-economic studies to understand farmers perceptions of vector-borne diseases and preference of control methods – link to acaricide choices, farm management strategies
• Hybridization between different species of ticks can lead to the emergence of new tick-borne diseases or the spread of existing diseases to new areas. It is important to monitor for hybridization events and to study the genetic makeup of tick populations in order to better understand their potential for disease transmission.
• Researchers are currently using molecular techniques such as DNA sequencing to identify hybridization events and track the spread of tick-borne diseases.
• Changing husbandry systems could also be a way to reduce the risk of tick infestations in livestock. For example, keeping cattle indoors or using local breeds that are better adapted to the local environment could help reduce exposure to ticks. Harvesting grass by machine could also help reduce the risk of ticks by reducing the amount of vegetation available for ticks to live on; rotational grass management/rotational grazing
• Need to understand the role of climate change on ectotherm ticks and their biology (number of generations/year, host preferences, etc.)
• Need to understand the role of pastures, agrosilvopastoral systems (that produce the shade that vectors prefer, as do their entomopathogens, but reduce host heat stress), fires and flooding on persistence of vectors in biotope
• Need to understand the role of vector-borne pathogens on resistance of ticks to desiccation and the role of climate on the vectorial capacity of vectors
• Need to understand the role of species of pasture on persistence of ticks in environment and if species that have a negative impact on tick biology (e.g., molasses grass, Melinis minutiflora) can be bred for desirable agronomical traits without losing their negative impact on tick biology
• Need to understand the role of heat stress on the host’s immunity and on its responses to vectors and what are the interventions to mitigate negative impacts.
• Animal movement big factor of tick resistance spreading.
• While mosquito feeding is known to play a role in disease transmission, our understanding of the impact of environmental factors like temperature, humidity, and host behaviour on this process is still limited. Further research is needed to identify the environmental factors that contribute to disease transmission and how they may be mitigated.
• How environmental factors may impact microbiome composition.
• Research is needed to determine how environmental factors like temperature, humidity, and host behaviour may impact tick microbiomes.
• There is a need for a dedicated Vector Control Agency that focuses on developing and implementing strategies for controlling ticks and other disease-carrying vectors. This agency could work with local communities, government agencies, and other stakeholders to develop integrated pest management strategies that incorporate both chemical and non-chemical control methods. The agency could also conduct research on new control methods and technologies.

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

Use of vector attractants and anti-vector chemicals
Pasture management and/or agro-silvo-pastoral systems
Push-pull mechanism (into traps) – doesn’t address repopulation, long term control
Brugger K, Rubel F. Tick maps on the virtual globe: First results using the example of Dermacentor reticulatus. Ticks Tick Borne Dis. 2023 Mar;14(2):102102.

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

• Improved understanding of environmental needs of the vector and the impact of climate changes in host physiology and how changes in host physiology will relate to vector biology
• Renew atlas of vector subspecies – project on this for Tsetse -could participatory science be used to help understand spread of different species
• Environmental control needs to be coordinated otherwise new population will fill gap
• VectorNet mapping for vector diseases (ticks, mosquitoes), in Europe and neighbouring countries (when funding available from EFSA) – maps available on website – also support capacity building in blank spots to collect samples (e.g. Syria, Iceland)

Existing knowledge including successes and failures