Roadmap for Vector Transmission Control (VTC)

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

• To identify which arthropods are the vectors and which samples are optimal for confirming infection in an arthropod vector
• To identify animal pathogens in carrier vector
• To control pathogen replication and/or transmission through elucidation and understanding vector physiology/immunology
• To define vector species and establish the feeding and environmental conditions necessary for survival and long-term maintenance of particular vectors

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

• Molecular based diagnostics for tick resistance to pathogens – test needs to be rapid, field appropriate – lots of associated challenges; molecular understanding of tick resistance to pathogen
• Determine whether and which bacteria trigger the immune system of vector
• Gain understanding of vector innate and acquired immune responses.
• Determine which physiological and immunological processes can influence the presence/replication of the pathogen, microbiome, etc.
• Population genomics: resistance, vector competence, infested/infected
• Mosquitos have an ability to encapsulate parasites. They have components of an immune system that experimentally can influence virus infection
• Collection of pathogen-infested vectors and their breeding

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

• NGS on various vector samples to determine the pathogens they carry
• The microbiota of ticks is another area of research that could provide new insights into tick biology and control. Understanding how the microbiota interacts with the tick’s immune system and affects its ability to transmit pathogens could lead to new approaches for controlling tick-borne diseases.
• What are the mechanism of losing the immunity after acquiring it from infection with babesia or malaria?
• Sterile male technique (Lead 4a)
• Female uninfected can only mate with uninfected males (Tsetse) (Lead 4a)

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

Improved understanding of pathogen replication and transfer between compartments in the vector.
Techniques to study physiology and immunology of vectors

Existing knowledge including successes and failures

Molecular detection of tick-borne pathogens in bovine blood and ticks from Khentii, Mongolia (2019)
Microbial control of arthropod-borne disease (2017)
Engineered symbionts activate honeybee immunity and limit pathogens (2020)
Mosquito transgenics – Denge virus when infected chain response to kill mosquito – Uni Sao Paulo

Van den Hurk, A.F., Hall-Mendelin, S., Pyke, A.T., Frentiu, F.D., McElroy, K., Day, A., Higgs, S. & O’Neill, S.L. (2012). Impact of Wolbachia on infection with chikungunya and yellow fever viruses in the mosquito vector Aedes aegypti. PloS Neglected Tropical Diseases 6(11): e1892.
Vector potential and population dynamics for Ambylomma inornatum (2015)
Liu WL, Hsu CW, Chan SP, Yen PS, Su MP, Li JC, Li HH, Cheng L, Tang CK, Ko SH, Tsai HK, Tsai ZT, Akbari OS, Failloux AB, Chen CH. Transgenic refractory Aedes aegypti lines are resistant to multiple serotypes of dengue virus. Sci Rep. 2021 Dec 13;11(1):23865.

Yen PS, James A, Li JC, Chen CH, Failloux AB. Synthetic miRNAs induce dual arboviral-resistance phenotypes in the vector mosquito Aedes aegypti. Commun Biol. 2018 Feb 8;1:11.