Preliminary studies on transmission of Chlamydia to cattle by ticks (Ornithodoros coriaceus)
McKercher, D.G.; Wada, E.M.; Ault, S.K.; Theis, J.H.
American Journal of Veterinary Research 41(6): 922-924
1980
ISSN/ISBN: 0002-9645 PMID: 7436080 Document Number: 162729
Preliminary studies in California indicated that Ornithodoros coriaceus Koch can harbour Chlamydia for long periods and are able to transmit the agent to cattle. Field-collected examples of O. coriaceus that were infected experimentally with a bovine chlamydial agent from an aborted foetus transmitted the agent 25 and 48 days later to 3 pregnant heifers. Two of these heifers aborted and the third delivered a term calf. The control heifer also aborted after intradermal (simulated tick) exposure. Also, a chlamydial agent was isolated from O. coriaceus collected from an area where epizootic bovine abortion (EBA) was enzootic when the ticks were held for at least 6 months. In the same enzootic area, a chlamydial agent was isolated from a prematurely delivered calf during a severe EBA outbreak. Seemingly this species is a cause, if not the cause, of EBA.