Chlamydia abortus is a sexually transmitted disease in animals, which has been found in sheep, goats, cattle, pigs, wild pigs, horses, antelope, deer, giraffe, and birds; and has also been shown to cause miscarriages, placenta previa, stillbirths, prematurity, birth defects, weak offspring, and late-term fetal demise. Ewes seldom abort more than once, but remain persistently infected and shed chlamydia abortus, for two to three days before and after ovulation. The male animal can acquire the infection and transmit the infection to female animals, and throughout a herd.
Chlamydia abortus can be transmitted to humans who are exposed to an infected animal or contaminated environment; and has been reported to cause abortion and fetal demise, in humans. Most recognized cases of chlamydia abortus occurred in pregnant women, who developed a life-threatening illness after contact with livestock who had recently given birth, or in a research setting. The United Kingdom has reported one or two cases per year of chlamydia abortus in pregnant women. The fetus survived in only a few cases, after delivery by cesarean section.
Emerging species such as chlamydia abortus are not well studied. More research is needed into emerging species, including improved methods for diagnosis and greater awareness of the risks.
