Investigation of pre-natal Chlamydophila abortus (Chlamydia psittaci) exposure of female lambs and the outcome of their first pregnancy

摘要

Chlamydophila abortus (formerly Chlamydia psittaci), is responsible for enzootic abortion of ewes, the most commonly diagnosed cause of abortion in UK sheep, and is also capable of causing a serious zoonosis. The most obvious clinical sign is abortion but the birth of live, often weakly, lambs is also common. In all cases, large numbers of chlamydiae are shed in the fetal membranes and fluids and in vaginal discharges for a short time after parturition. The most important route of transmission is from the ingestion or inhalation of chlamydiae from fetal membranes or fluid around lambing time. The newly infected ewes remain latendy infected until the subsequent pregnancy, during which the organisms are mobilized from an unknown site, causing clinical signs about a year after the ewes became infected. Other routes of infection may also be important, one of which is pre-natal infection, on which there is little published evidence. Wilsmore et al. (1990) experimentally infected 16 ewes with chlamydiae during pregnancy, eight of which showed clinical signs and lesions of enzootic abortion. Five ewe-lambs that were produced by these ewes, two of which were from ewes showing lesions, were mated at eight months old. The two lambs that came from ewes with lesions excreted chlamydiae at parturition and one aborted, whereas the other three lambs did not.