Seroprevalence and Risk Factors Associated with Chlamydia abortus Infection in Sheep and Goats in Eastern Saudi Arabia

Seroprevalence of Chlamydia abortus infection in Tibetan sheep in Qinghai Province, China

Chlamydia abortus (C. abortus) is an obligate intracellular, Gram-negative bacterium, causing ovine enzootic abortion (OEA). No data about C. abortus infection are available in Tibetan sheep in Qinghai, China. A total of 1043 Tibetan sheep serum samples were collected from 8 regions in Qinghai, China, and for specific antibodies against C. abortus using a commercial ELISA Kit. The results showed that the overall seroprevalence of C. abortus in Tibetan sheep was 153/1043 (14.7 %, 95 % confidence interval [CI] 12.5-16.8). The prevalence in female and male Tibetan sheep was 58/421 (13.8 %, 95 % CI 10.5-17.1) and 95/622 (15.3 %, 95 % CI 18.6-26.6), respectively with no significant difference (P > 0.05). The seroprevalence of antibodies to C. abortus in Tibetan sheep ranged from 10.0 to 21.7 % among the eight different areas, and the difference was also without statistical significance. The prevalence among different age groups ranged from 14.0 to 16.5 %, with a higher prevalence among 1 to 1.5 years age category. The results demonstrate the presence of C. abortus infection in Tibetan sheep in Qinghai and its potential impact on public health and the local Tibetan economy. To our knowledge, this is the first seroprevalence survey of C. abortus in Tibetan sheep in Qinghai, China.

A six-year epidemiological study of selected zoonotic abortifacient agents in ovine and caprine foetuses in Türkiye

Abortion is one of the major threats to the livestock industry, and it also poses significant threats to public health since some of the abortifacient agents are considered zoonotic. Chlamydia abortus (C. abortus), Coxiella burnetii (C. burnetii), Listeria monocytogenes (L. monocytogenes), and Cache Valley virus (CVV) are recognized as important zoonotic and abortifacient agents of reproductive failure in small ruminants. This study determined the prevalence of these agents in ovine and caprine foetuses in Türkiye. A total of 1 226 foetuses were collected from the sheep (n = 1 144) and goats (n = 82) from different flocks between 2012 and 2017. Molecular detection methods were used to detect C. abortus, C. burnetii, and L. monocytogenes DNA and CVV RNA in aborted foetuses. In this study, C. abortus was the most prevalent abortifacient agent among the investigated ovine (264/1144) and caprine (12/82) foetuses, followed by C. burnetii with a frequency of 2.8% (32/1144) and 8.5% (7/82) in ovine and caprine foetuses, respectively. L. monocytogenes DNA was detected in 28 (2.4%) and 2 (2.4%) of the ovine and caprine foetuses, respectively. However, CVV RNA was not detected. Although the predominant mixed infection was C. abortus and C. burnetii, mixed infection of C. abortus and L. monocytogenes, and C. burnetii and L. monocytogenes were also found. The information presented in this study contributes to the understanding of the roles of C. abortus, C. burnetii, L. monocytogenes, and CVV in abortions in small ruminants, and could be beneficial for developing more effective control strategies.

Toxoplasmosis and Chlamydophilosis in Small Ruminant Farms in Cameroon: Knowledge, Attitudes, Practices, and Perception of Zoonotic Risks of Farmers

Zoonotic abortive diseases represent a significant health and economic risk for national public health. This cross-sectional survey was conducted from April to October 2021 among 200 selected small ruminant farmers in the three northern regions of Cameroon. Data collection was done through questionnaires administered by exchange with the herder, and responses were coded and recorded on an Excel spreadsheet. The data were then analyzed with R software, version 2.13.0. An ANOVA test was used to assess significant differences in mean of Knowledge, Attitudes, Practices, and Perception of zoonotic risks (KAPP) scores between regions. Pearson correlations were used to calculate the association between KAPP scores within regions. Small ruminant farmers surveyed had low mean scores for knowledge of abortive toxoplasmosis and chlamydophilosis (0.1 ± 0.2), desirable attitude (0.32 ± 0.07), appropriate practice (0.36 ± 0.13) in managing abortion, and positive perception of zoonotic risks of toxoplasmosis and chlamydophilosis in small ruminants (0.12 ± 0.33), respectively. KAPP was significantly (P < 0.01) and positively associated with knowledge (r = 0.98) and risk perception (r = 0.99). However, attitudes (r = 0.06), practices (r = 0.05), and risk perception of toxoplasmosis (r = 0.07) and chlamydophilosis (r = 0.08) were not associated with farmers' knowledge. This study revealed significant knowledge gaps, low levels of desired attitudes, and high-risk behavioral practices. These results therefore call for capacity building of health professionals and farmers to better integrate the One Health concept in the management of neglected zoonotic diseases.

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.

The Importance of the Slaughterhouse in Surveilling Animal and Public Health: A Systematic Review

From the point of public health, the objective of the slaughterhouse is to guarantee the safety of meat in which meat inspection represent an essential tool to control animal diseases and guarantee the public health. The slaughterhouse can be used as surveillance center for livestock diseases. However, other aspects related with animal and human health, such as epidemiology and disease control in primary production, control of animal welfare on the farm, surveillance of zoonotic agents responsible for food poisoning, as well as surveillance and control of antimicrobial resistance, can be monitored. These controls should not be seen as a last defensive barrier but rather as a complement to the controls carried out on the farm. Regarding the control of diseases in livestock, scientific research is scarce and outdated, not taking advantage of the potential for disease control. Animal welfare in primary production and during transport can be monitored throughout ante-mortem and post-mortem inspection at the slaughterhouse, providing valuable individual data on animal welfare. Surveillance and research regarding antimicrobial resistance (AMR) at slaughterhouses is scarce, mainly in cattle, sheep, and goats. However, most of the zoonotic pathogens are sensitive to the antibiotics studied. Moreover, the prevalence at the slaughterhouse of zoonotic and foodborne agents seems to be low, but a lack of harmonization in terms of control and communication may lead to underestimate its real prevalence.

Chlamydia abortus Isolation and Identification in Aborted Ovine Fetus in Mari El Republic of Russia

Reproductive disorders, presumably caused by Chlamydia abortus, are common among the ovine population of the Mari El Republic, Russia. C. abortus infection was determined by serologic testing or isolation and detection of the organism by PCR and direct immunofluorescence in tissue samples. Rams, ewes, and lambs (10 individuals each) were randomly chosen for serological testing by the complement fixation test and 7 of 30 (23%) animals tested were positive. Tissue samples were collected from ewes and aborted fetuses for isolation by inoculating chicken embryo yolk sacs (n = 41). The same samples were analyzed by PCR using commercial and in-house PCR kits and by direct immunofluorescence. C. abortus was detected in 58.5% of samples using PCR and in 60.9% of the samples by direct immunofluorescence. Five Chlamydia isolates were cultured in egg yolk sacs and adapted for growth in cell cultures. Phylogenetic analysis showed no substantial difference between Russian isolates and those from other parts of the world. The results of the study further demonstrate the usefulness of PCR for detection of C. abortus as a faster, simpler, and more reliable approach in comparison to culturing the organism and underscoring the necessity of screening for chlamydiosis as a cause of ovine abortion.

Recent advances and public health implications for environmental exposure to Chlamydia abortus: from enzootic to zoonotic disease

Environmental transmission of Chlamydia abortus as a result of enzootic disease or disease outbreaks and the threats posed by this pathogen has been previously reported, however a state-of-the-science review of these reports and the identification of future research priorities in this area is still lacking. This study provides an overview of the current knowledge of host–pathogen–environment interactions, addressing public health risks and identifying critical questions and research gaps. We performed a systematic PubMed and Web of Science search for publications related to Chlamydia abortus in the past four decades, and we reviewed and combined the evidence critically discussing and commenting the results. A total of 182 studies, 5 chapters of specific books and the “OIE terrestrial manual” were included in this review. There were substantial variations between the studies in topic addressed and experimental design. Overall, the literature largely supports the crucial role played by environmental exposure on the acquisition of zoonotic disease caused by Chlamydia abortus. We also identify the paucity of information related to interspecies transmission and pathogen adaptation in relation to environmental dissemination and zoonotic risk. This analysis further highlights the need for additional research given that environmental transmission represents a serious risk not only to susceptible patients (pregnant women and immunocompromised individuals), but also for other species including wildlife.