The importance of experimental design for studying the vector competence ofOrnithodorosticks for African swine fever virus: a meta-analysis of published evaluations

Abstract

AbstractAfrican Swine Fever (ASF) is a highly economically devastating viral disease for swine. Soft ticks of the genusOrnithodorosare involved in its epidemiology, as vectors and natural reservoirs of African Swine Fever Virus (ASFV). This constitutes a significant problem as it is currently challenging to eliminate endophilous soft ticks living in inaccessible, sheltered habitats. The vector competence ofOrnithodorosticks for ASFV has been mainly studied by mimicking natural tick-to-pig and tick-to-tick transmission pathways through experimental infections in the laboratory. However, experimental designs are anticipated to exert significant influence on the results, owing to inherent technical limitations of the approaches. By reviewing the original research studies dating back to the 1960s on the vector competence ofOrnithodorosfor ASFV, we clarified the processes involved in ASFV maintenance and transmission by ticks, emphasized the extensive range of protocol designs employed and subsequently analysed the all-encompassing factors impacting vector competence. Our study demonstrated that the success of tick infection is primarily impacted by experimental factors, whereas the impact of natural determinants is inconclusive. Our results offer valuable insights into how future trials can be refined by curtailing potential experimental biases. They call for caution when interpreting conclusions drawn from studies on ASFV vector competence.