Infectious abortions in small domestic ruminants in the Iberian Peninsula: Optimization of sampling procedures for molecular diagnostics

Seroprevalence and Risk Factors Associated with Chlamydia abortus Infection in Sheep and Goats in North-Western Italy

Chlamydia abortus, although poorly recognized as a human pathogen, is a zoonotic microorganism that can cause many different symptoms in humans, including subclinical infection and fatal illnesses in pregnant women. C. abortus is one of the most common causes of ovine and caprine infectious abortion worldwide, known as the causative agent of the enzootic abortion of ewes (EAE) or ovine enzootic abortion (OEA). To estimate C. abortus seroprevalence and the risk factors related to C. abortus in small ruminants, the sera from 3045 animals (both sheep and goat) belonging to 202 herds were tested and a questionnaire investigating flock management was administered. At the herd level, the true seroprevalence was 56.6% (CI95%: 46.9-66.3%), at sheep-farm and goat-farm level, the true seroprevalence was 71.4% (CI95%: 54.6-88.3%) and 44.8% (CI95%: 41.3-57.0%), respectively. The true seroprevalence was significantly higher among the sheep than the goats. The logistic regression model identified four factors associated with Chlamydia seropositivity: flock size (i.e., farms with >50 heads), contact with cattle, introduction of animals, and Coxiella seropositivity. The study evidenced a high seroprevalence of Chlamydia abortus in small ruminant farms in the Piedmont region. Considering its zoonotic potential and the health consequences in humans, communication to farmers on the importance of vaccination, as well as the sensibilization of farm vets, seem to be strategical.

Sero-epidemiological study of zoonotic bacterial abortifacient agents in small ruminants

Abortion is one of the leading causes of economic losses in the livestock industry worldwide. Chlamydia abortus, Coxiella burnetii, and Brucella spp. are the leading cause of late fetal loss in small ruminants. This study determined the seroprevalence of these agents in small ruminants in district Jhang. A total of 385 serum samples were taken from the sheep and goats from different flocks with a history of abortion and subjected to i-ELISA. Further, samples were analysed for liver enzymes and total serum protein using a semi-automated chemistry analyzer. The result of indirect commercial ELISA showed 13.0, 4.2 and 11.2% prevalence for Coxiella burnetii, Chlamydia abortus, and Brucella spp., respectively. Values of different serum parameters (ALT, AST, and total protein) of seropositive animals were also determined. There was a significant rise in AST and ALT values of infected animals (p ≤ 0.05). Total protein decreased for all three infections, but a significant drop was noted in Brucella positive sheep serum samples. Various risk factors were studied. Binary logistic regression proved a significant role of ticks for coxiellosis and brucellosis. Age, parity, and species did not impact the prevalence of diseases studied.