A consolidation of our knowledge of the transmission of tick-borne diseases

Abstract

(1) Ticks concerned in the transmission of Babesia spp., Aegyptianella sp., Theileria sp., Gonderia spp., Anaplasma spp., Borrelia spp., viruses and "toxins" responsible for diseases in livestock have been enumerated. (2) This information is presented in a series of tables. (3) An attempt has been made to determine the correct names of various ticks. (4) The vectors of Babesia major, B. taylori, B. foliata, B. perroncitoi, B. felis and Gonderia hirci need to be determined. (5) In all diseases stage to stage transmission within the same generation has been established in one or more of the transmitters, except in those concerned with the transmission of tick paralysis and sweating sickness. (6) Transovarial transmission has been established in one or more of the vectors except in those concerned with the transmission of Theileria parva, Gonderia mutans, G. lawrencei, G. ovis, Rickettsia ruminantium, R. bovis, R. ovina, tick-borne fever, louping ill, Czecho-Slovakian tick encephalitis and Kisenyi sheep disease. (7) From this it is deduced that ticks do not only act as vectors but that they can also serve as reservoirs of certain infectious agents. (8) Vectors, other than ticks, which are capable of transmitting the western type of equine encephalomyelitis, St. Louis encephalitis and Borrelia anserina are referred to in the text. (9) Attention has been drawn to the fact that potential vectors of certain diseases (canine biliary fever, heartwater, louping ill, Nairobi and Kisenyi sheep diseases) do occur beyond the boundaries of the known enzootic areas. The danger associated with the introduction of affected animals into such regions is self-evident.