Laboratory artificial infection of hard ticks: a tool for the analysis of tick-borne pathogen transmission

Despite its importance, our knowledge of pathogen transmission by ticks is incomplete. Detailed studies on the transmission, maintenance, infectivity, virulence, and pathogenicity of tick-borne microparasites all require the use of large numbers of live ticks raised under controlled conditions and difficulties in rearing ticks in the laboratory could partly explain the current lack of data. The most complex part in maintaining tick colonies doubtlessly lies in their engorgement, as ticks are strict haematophagous arthropods. Indeed, relatively few research teams have worked on artificial feeding systems for ticks due to the long, complex, and poorly understood feeding patterns of these arthropods. It is nonetheless essential to investigate the mechanisms underlying tick infection and infectiousness in order to better understand parasite-host-vector relationships and elaborate new control strategies for transmitted pathogens. The various methods used to date to feed ticks and infect them with their associated pathogens are reviewed here and their advantages and inconveniences are discussed.