Coxiella burnetii Infections in Small Ruminants and Humans in Switzerland

Seroprevalence of Q fever (Coxiella burnetii) in sheep in the Kwahu West municipality, Eastern Region, Ghana

Query fever, also known as Q fever, is a zoonotic disease caused by Coxiella burnetii. It is a cause of abortion in livestock and presents as a febrile illness in humans. A correlation between the incidence of the disease in humans and abortion in goats and sheep farms has been reported in countries such as the Netherlands and Australia. In Ghana, the occurrence of Q fever in both livestock and humans has not been fully explored. This study sought to determine the seroprevalence of Q fever in livestock in Nkawkaw, in the Eastern Region of Ghana. Sera obtained from 92 sheep from 12 farms were tested using the indirect multi-species ELISA for the detection of anti-Coxiella burnetii antibodies. Animal demographics, farms' proximity to human settlement and history of abortion in relation to the Q fever status were assessed. The overall prevalence of Q fever was 13.0 % [95 % CI 6.9-21.6] (12/92). Both sexes were equally affected, with a sex-specific prevalence of 13.0 % each. The farm-specific prevalence was 50 %. Abortions were reported on eight (8) of the 12 farms, and all farms were located less than 200 m from human habitation. Only proximity of farm to human settlement showed statistical significance. Q fever is prevalent in Nkawkaw and requires the attention of both animal and health authorities, using the One- Health approach to nip any future epidemics in its bud.

Global and regional seroprevalence of coxiellosis in small ruminants: A systematic review and meta-analysis

BACKGROUND

Coxiellosis is a neglected zoonosis for occupationally exposed people in many parts of the world. Sheep and goats are two important small ruminants that act as reservoirs for human contamination; however, there is a lack of comprehensive data on the epidemiological aspects of coxiellosis in sheep and goats at regional and global levels. The aim of this study was to systematically review the available articles on seroprevalence of coxiellosis in sheep and goats and estimate the overall seroprevalence in different regions.

METHODS

A systematic search strategy was performed in five electronic repositories for articles published until December 2021. Relevant data were extracted from the selected articles based on the inclusion criteria. A random effect meta-analysis model was used to analyse the data. Results are presented as the prevalence of seropositivity as a percentage and 95% confidence intervals.

RESULTS

The global pooled seroprevalence of coxiellosis in sheep was 17.38% (95% confidence interval [CI]: 15.59%-19.17%). Overall, the regional level pooled prevalence estimates in sheep ranged from 15.04% (95% CI: 7.68%-22.40%) to 19.14% (95% CI: 15.51%-22.77%), depending on region. The global pooled seroprevalence of coxiellosis in goats was 22.60% (95% CI: 19.54%-25.66%). Overall, the regional level pooled prevalence estimates in goats ranged from 6.33% (95% CI: 2.96%-9.71%) to 55.13% (95% CI: 49.61%-60.65%), depending on the region. The prevalence estimates also varied significantly in both sheep and goats depending on age, sex, and rearing systems of the animals (p < 0.001).

CONCLUSION

Seroprevalence of coxiellosis in both sheep and goats is considerable. Routine monitoring of the sheep and goat populations is needed to prevent spillover infection in other livestock and humans.

Two Years after Coxiella burnetii Detection: Pathogen Shedding and Phase-Specific Antibody Response in Three Dairy Goat Herds

The infection dynamics of Coxiella (C.) burnetii were investigated in three dairy goat herds (A, B, and C) 2 years after the first pathogen detection. A total of 28 and 29 goats from herds A and B, and 35 goats from herd C, were examined. Sera were analyzed on three sampling dates using phase-specific serology. Pathogen shedding was assessed using post-partum vaginal swabs and monthly bulk tank milk (BTM) samples. Dust samples from a barn and milking parlor were also collected monthly. These samples were analyzed with PCR (target IS1111). In herd A, individual animals tested seropositive, while vaginal swabs, BTM, and most dust samples tested negative. Herds B and C exhibited high IgG phase I activity, indicating a past infection. In herd B, approximately two-thirds of the goats shed C. burnetii with vaginal mucus, and irregular positive results were obtained from BTM. Herd C had two positive goats based on vaginal swabs, and BTM tested positive once. Dust samples from herds B and C contained C. burnetii DNA, with higher quantities typically found in samples from the milking parlor. This study highlights the different infection dynamics in three unvaccinated dairy goat herds and the potential use of dust samples as a supportive tool to detect C. burnetii at the herd level.

A review of coxiellosis (Q fever) and brucellosis in goats and humans: Implications for disease control in smallholder farming systems in Southeast Asia

Coxiella burnetii and Brucella spp. are pathogenic bacteria that can cause large-scale outbreaks in livestock. Furthermore, these infectious agents are capable of causing zoonotic infections and therefore pose a risk to the close relationship between farm households and their livestock, especially goats. A review of seroprevalence studies of Coxiella burnetii and Brucella spp. in domestic goats demonstrated large differences in the total number of samples tested in different regions and countries. This review aims to provide information on coxiellosis (Q fever in humans) and brucellosis in goats concerning the characteristics of the causative agent, surveillance, and available prevention and control measures at a global level. Implications for Coxiella burnetii and Brucella spp. infections in domesticated goats in Southeast Asia are discussed.

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

Introduction

Infectious abortions have a major impact on small domestic ruminant farms, i.e., sheep and goats, both in terms of profitability and health status. Therefore, rapid and sensitive diagnosis is essential to minimize losses. Currently, molecular techniques, such as qPCR, are routinely used for their diagnosis, which imply the need to manipulate all abortive material, with consequent biosafety risks. Here, we evaluate the frequency of the main abortifacient pathogens in small domestic ruminants in the Iberian Peninsula and also assess an alternative approach for the optimization of sampling for molecular diagnosis.

Results

A total of 392 clinical cases were analyzed from April 2020 to May 2021, evidencing that the main causative agents of abortion detected were Coxiella burnetii (49.0%), Chlamydia abortus (38.3%) and, to a lesser extent, Toxoplasma gondii (10.2%), Salmonella enterica (7.1%) and Campylobacter spp. (6.1%). An uneven distribution of these pathogens was observed between ruminant species, with a higher frequency (p &lt; 0.05) of T. gondii, S. enterica and Campylobacter spp. in sheep than goat abortions, and among geographic areas, highlighting the higher frequency (p &lt; 0.05) of T. gondii and Campylobacter spp. in the north compared to southeastern Spain. The alternative sampling method, consisting on the use of fetal tongues and placental swabs in replacement of the whole fetus and placental tissue, offered a very good agreement with the classical method for all pathogens, except for low concentrations of C. burnetii, which seems to have a doubtful role in abortion when its concentration in the abortifacient material is low.

Conclusions

This study reveals a high frequency of infectious etiology in abortions of small domestic ruminants in the Iberian Peninsula and validates for the first time an alternative sampling method for molecular diagnosis that will help to provide rapid and accurate results while minimizing biosafety risks.

Role of Goats in the Epidemiology of Coxiella burnetii

Since its first description in the late 1930s, Q fever has raised many questions. Coxiella burnetii, the causative agent, is a zoonotic pathogen affecting a wide range of hosts. This airborne organism leads to an obligate, intracellular lifecycle, during which it multiplies in the mononuclear cells of the immune system and in the trophoblasts of the placenta in pregnant females. Although some issues about C. burnetii and its pathogenesis in animals remain unclear, over the years, some experimental studies on Q fever have been conducted in goats given their excretion pattern. Goats play an important role in the epidemiology and economics of C. burnetii infections, also being the focus of several epidemiological studies. Additionally, variants of the agent implicated in human long-term disease have been found circulating in goats. The purpose of this review is to summarize the latest research on C. burnetii infection and the role played by goats in the transmission of the infection to humans.

Causes of Abortions in South American Camelids in Switzerland-Cases and Questionnaire

Over the last decade, South American camelids (SAC) have gained increasing popularity in Switzerland. They are used for several purposes such as fiber and meat production, as companion or guard animals and for trekking activities. The purpose of this study was to investigate the frequency and reasons for pregnancy loss and perinatal death in SAC herds. Within the scope of this study, early embryonic losses could not be identified, as pregnancy examinations by ultrasonography are not performed routinely. Aborted and stillborn fetuses were collected, necropsied and analyzed for infectious abortifacients. A nationwide survey among breeders was carried out. During a 1.5-year period, only eight cases of aborted or stillborn alpaca and llama (out of a population of 6550 animals) were reported by the breeders, and their causes were subsequently analyzed. In half of the cases, Coxiella burnetii was identified in the fetoplacental material. Abortions and stillbirths were reported to be rare in Swiss herds. As a conclusion, recording of embryonic losses through ultrasound training of veterinarians should be impaired and breeders motivated to have abortions and perinatal mortality examined. Special focus should be laid on C. burnetii due to its zoonotic risk.

Serological survey of Coxiella burnetii infections in dairy cattle, sheep, goats and zoo animals in Hungary - Short communication

Q fever is a disease of high zoonotic potential, but interest in its causative agent is rather low although it causes some public health problems in Hungary. The prevalence of Q fever is highly variable by country. The main reservoirs of the disease are the same domestic ruminant species everywhere, but the epidemiological profile depends on the features of the specific reservoir. The aim of this large-scale study was to demonstrate the importance of Q fever in different species as a possible source for human infection in most regions of Hungary. A total of 851 serum samples from 44 dairy farms, 16 sheep flocks, 4 goat farms and 3 zoos located in different parts of Hungary were tested. The presence of antibodies to Coxiella burnetii was surveyed in dairy cattle (n = 547), goats (n = 71), sheep (n = 200) and zoo animals (n = 33). The animal species tested in Hungary showed different seroprevalence values of C. burnetii infection. Seropositivity by the enzyme-linked immunosorbent assay was found in 258 out of 547 (47.2%) cows and in 69 out of 271 (25.5%) small ruminants, among them in 47 out of 200 (23.5%) sheep and in 22 out of 71 (31.0%) goats. Antibodies to C. burnetii were not detected in zoo animals. Seropositivity was demonstrated in 44 out of 44 (100%) dairy cattle farms, with at least one serum sample found to be positive on each farm. The seropositivity rate of small ruminant farms was 55.0% (11 positive out of 20 tested), with 9 out of 16 (56.3%) sheep flocks and 2 out of 4 (50.0%) goat herds showing seropositivity.

Molecular detection of Coxiella burnetii infection in aborted samples of domestic ruminants in Iran

BACKGROUND

Coxiella burnetii is the causative agent of Q fever which is a highly infectious zoonotic disease. C. burnetii has become one of the most important causes of abortion in livestock, which can lead to widespread abortions in these animals. There are very limited studies on the prevalence of C. burnetii infection in cases of animal abortion in Iran. The aim of this study was to investigate the occurrence of C. burnetii in ruminant abortion samples in Iran.

METHODS

Abortion samples from cattle, sheep and goats were collected from different parts of Iran and were tested using Real-time PCR targeting the IS1111 element of C. burnetii.

RESULTS

In this study, 36 samples (24.7%) of the 146 collected samples were positive for C. burnetii. The prevalence of C. burnetii was 21.3% (20 of 94 samples) in sheep samples. Also, 10 of 46 cattle samples (21.7%) were positive. All six goat abortion samples were positive for C. burnetii.

CONCLUSIONS

The findings of the study demonstrate that C. burnetii plays an important role in domestic ruminant abortions in Iran, suggesting that more attention should be paid to the role of C. burnetii in domestic animal abortions by veterinary organizations. The risk of transmitting the infection to humans due to abortion of animals should also be considered.

Prevalence and Molecular Characterization of Coxiella burnetii in Cattle, Goats, and Horses in the Republic of Korea

Coxiella burnetii is an obligate intracellular zoonotic bacterium with a global distribution. This study was conducted to investigate the prevalence of C. burnetii in different animals and to assess the potential role of these species as reservoirs of infection and transmission to humans. A total of 592 blood samples (105 beef cattle, 61 dairy cattle, 110 Korean native goats, 83 Boer goats, and 233 horses) were collected in the Republic of Korea (ROK). The C. burnetii DNA was detected from blood samples using the transposon-like repetitive region (IS1111) by PCR method. The results showed that 22.7% of the Korean-native goats, 16.4% of the dairy cattle, 15.2% of the beef cattle, 6.0% of the Boer goats, and 5.2% of the horses were positive for C. burnetii. Significant differences were found between the animal species. The univariable binary logistic regression analysis revealed that the risk of contracting C. burnetii was significantly high by 5.4-fold in Korean-native goats (95% confidence interval [CI]: 2.60%-11.27%, p = 0.000), 3.6-fold in dairy cattle (95% CI: 1.48%-8.82%, p = 0.005), and 3.3-fold in beef cattle (95% CI: 1.51%-7.28%, p = 0.003) compared with horses. A phylogenetic tree based on the IS1111 gene revealed that our sequences had 92.2%-99.9% similarity and were clustered with those detected in humans, cattle, goats, dogs, rodents, and ticks. C. burnetii circulating in the ROK exhibits genetic variation. To the best of our knowledge, this is the first study to identify C. burnetii DNA in a horse in the ROK. These results suggest that cattle, goats, and horses can be potential reservoirs for C. burnetii and play an important role in the transmission of infection. Further studies should assess the pathogenicity of C. burnetii circulating in the ROK.

Sero-detection of Coxiella burnetii infection in cattle, sheep and goats in selected regions of Nepal

Coxiella burnetii, a Gram‐negative bacterium is a zoonotic agent causing coxiellosis in animals. Small ruminants and cattle are the primary reservoirs for human infection. This study was aimed to estimate the sero‐prevalence of C. burnetii in the ruminants of the selected region in Nepal. Field visits were carried out at four sites in different geographical regions of Nepal. A total of 522 sera samples were collected from 118 sheep, 242 goats and 162 cattle with the history of abortion, anoestrus and infertility. Sera were tested for the presence of antibodies against C. burnetii using a commercially available ready‐to‐use ELISA test kit. The overall true sero‐prevalence was 1.89% (95% CI: 0.33–3.45), the prevalence ranged between 4.35% and 23.21% in goats. Sero‐prevalence in goat was higher than that of cattle and sheep which ascertained that total freedom from coxiellosis cannot be confirmed in Nepal. This could complement the impacts of other infectious causes of the infertility in the farm animals as well as the public health of the farming households.

Development of a Rapid and Sensitive Colorimetric Loop-Mediated Isothermal Amplification Assay: A Novel Technology for the Detection of Coxiella burnetii From Minimally Processed Clinical Samples

Q fever is an important zoonotic disease caused by the bacterium Coxiella burnetii. The agent is considered as a potential agent for bioterrorism because of its low infectious dose, aerial route of transmission, resistance to drying, and many commonly used disinfectants. Humans are largely infected by the inhalation of aerosols that are contaminated with parturition products of infected animals as well as by the consumption of unpasteurized milk products. Thus, rapid and accurate detection of C. burnetii in shedders, especially those that are asymptomatic, is important for early warning, which allows controlling its spread among animals and animal-to-human transmission. In the present study, a colorimetric loop-mediated isothermal amplification (LAMP) assay was developed to confirm the presence of IS1111a gene of C. burnetii in sheep vaginal swabs. The sensitivity of this assay was found to be very comparable to the quantitative PCR (qPCR) assay, which could detect three copies of the gene, which corresponds to a single cell of C. burnetii. The applicability of the colorimetric LAMP assay in the disease diagnosis was assessed by evaluating 145 vaginal swab samples collected from the sheep breeding farms with a history of stillbirth and repeated abortions. Compared to qPCR, colorimetric LAMP had a sensitivity of 93.75% (CI, 69.77–99.84%) and specificity of 100% (CI, 97.20–100%), with a positive (PPV) and negative predictive value (NPV) of 100 and 99.24%, respectively. A very high level of agreement was observed between both colorimetric LAMP and reference qPCR assay. The colorimetric LAMP assay reported here is a rapid and simple test without extensive sample preparation and has a short turnaround time of <45 min. To the best of our understanding, it is the very first study describing the use of colorimetric LAMP assay that detects C. burnetii in vaginal swab samples with minimal sample processing for DNA extraction.

Molecular Detection of Rickettsia Spp. and Coxiella Burnetii in Cattle, Water Buffalo, and Rhipicephalus (Boophilus) Microplus Ticks in Luzon Island of the Philippines

Rickettsia and Coxiella burnetii are zoonotic, tick-borne pathogens that can cause febrile illnesses with or without other symptoms in humans, but may cause subclinical infections in animals. There are only a few reports on the occurrence of these pathogens in cattle and water buffalo in Southeast Asia, including the Philippines. In this study, molecular detection of Rickettsia and C. burnetii in the blood and in the Rhipicephalus (Boophilus) microplus ticks of cattle and water buffalo from five provinces in Luzon Island of the Philippines was done. A total of 620 blood samples of cattle and water buffalo and 206 tick samples were collected and subjected to DNA extraction. After successful amplification of control genes, nested PCR was performed to detect gltA of Rickettsia and com1 of C. burnetii. No samples were positive for Rickettsia, while 10 (cattle = 7, water buffaloes = 3), or 1.6% of blood, and five, or 1.8% of tick samples, were C. burnetii-positive. Sequence analysis of the positive amplicons showed 99-100% similarity to reported C. burnetii isolates. This molecular evidence on the occurrence of C. burnetii in Philippine ruminants and cattle ticks and its zoonotic nature should prompt further investigation and surveillance to facilitate its effective control.

First molecular and serological evidence of Coxiella burnetti infection among sheep and goats of Jammu province of India

The epidemiology and prevalence of Q fever in India is largely unknown. There are very few serologic and molecular reports of Q fever in India and these are old reports. The objective of this study was to investigate, for the first time, the presence of Coxiella burnetii infection in sheep and goat flocks of Jammu province of Jammu and Kashmir, India. A total of 148 milk (110 sheep and 38 goats) samples, 282 sera (170 sheep and 112 goats), and 152 vaginal swabs (123 sheep and 29 goats) were collected from farms with incidences of repeated abortion. The LSI Q fever ruminant serum/milk ELISA kit was used to identify anti-C. burnetii antibodies and nested PCR was employed to detect DNA in vaginal swabs. Overall, 42 (38.2%; 95% CI: 29.2-47.9) sheep and 9 (23.7%; 95% CI: 12.0-40.6) goat milk samples, and 21 (12.4%; 95% CI: 8.0-18.5) sheep and 11 (9.8%; 95% CI: 5.2-17.3) goat sera were ELISA positive. In addition, nine (7.3%; 95% CI: 3.6-13.8) vaginal swabs from sheep tested positive by nested PCR; however, C. burnetii could not be found in any of the vaginal swabs from goat. These results indicate that sheep seem to be a more important reservoir of C. burnetii than goats posing a risk for human infection in this area.

Prevalence of Anaplasma phagocytophilum and Coxiella burnetii in Ixodes ricinus ticks in Switzerland: an underestimated epidemiologic risk

Ticks are vectors of several microorganisms responsible for infectious diseases in human and animals, such as Anaplasma phagocytophilum and Coxiella burnetii. In this study, we investigated the prevalence of these two bacteria in 62 889 Ixodes ricinus ticks in selected regions covering all Switzerland. A high prevalence of 11.9% of A. phagocytophilum DNA was observed by real-time PCR on 8534 pools of ticks. This pool prevalence corresponds to an estimated prevalence of 1.71% in individual tick. A total of 144 of the 171 collection sites (84.2%) were positive for the presence of A. phagocytophilum, and these sites were homogenously distributed throughout Switzerland. Such prevalence and geographical distribution underline the risk of human and animal exposure to A. phagocytophilum and highlight the need to assess the epidemiology and clinical diagnosis of human and animal anaplasmosis in Switzerland. However, DNA of C. burnetii was never found in any tick pool. This absence suggests a very low role of I. ricinus ticks as vector and reservoir of C. burnetii in Switzerland, and it supports previous reports demonstrating the role of sheep and goats in the epidemiology of Q fever. However, considering its pathogenic potential, it is necessary to keep monitoring for the possible reemergence of this bacterium in ticks in the future.

Estimation of the frequency of Q fever in sheep, goat and cattle herds in France: results of a 3-year study of the seroprevalence of Q fever and excretion level of Coxiella burnetii in abortive episodes

A study was carried out, from 2012 to 2015, in 10 French départements to estimate the serological prevalence of Q fever and the frequency of abortive episodes potentially related to Coxiella burnetii in a large sample of cattle, sheep and goat herds. The serological survey covered 731 cattle, 522 sheep and 349 goat herds, randomly sampled. The frequency of abortive episodes potentially related to C. burnetii was estimated by investigating series of abortions in 2695 cattle, 658 sheep and 105 goat herds using quantitative polymerase chain reaction analyses and complementary serological results when needed. The average between-herd seroprevalence was significantly lower for cattle (36·0%) than for sheep (55·7%) and goats (61·0%) and significantly higher for dairy herds (64·9% for cattle and 75·6% for sheep) than for meat herds (18·9% for cattle and 39·8% for sheep). Within-herd seroprevalence was also significantly higher for goats (41·5%) than for cattle (22·2%) and sheep (25·7%). During the study period, we estimated that 2·7% (n = 90), 6·2% (n = 48) and 16·7% (n = 19) of the abortive episodes investigated could be ‘potentially related to C. burnetii’in cattle, sheep and goat herds, respectively. Overall, strong variability was observed between départements and species, suggesting that risk factors such as herd density and farming practices play a role in disease transmission and maintenance.

Ex vivo ovine model for head and neck surgical simulation

OBJECTIVE

To evaluate a fresh, ovine/sheep head and neck tissue model to teach otolaryngology-head and neck surgical techniques.

STUDY DESIGN

Observational animal study.

SETTING

A university animal resource facility.

METHODS

Tissue was collected from pre-pubescent sheep (n=10; mean age: 4months; mean mass: 28kg) following humane euthanasia at the end of an in vivo protocol. No live animals were used in this study. The head and neck of the sheep were disarticulated and stored at 5°C for 1-5days. The tissues were tested in a variety of simulated procedures by a medical student and four fellowship-trained otolaryngology faculty. Practicality and similarity to human surgeries were assessed.

RESULTS

While ovine head and neck structures are proportionally different, the consistencies of skin, subcutaneous tissues and bone are remarkably similar to that seen in human dissection. Particularly useful were the eyelids and orbits, facial nerve and parotid gland, mandible, anterior neck and submandibular triangle. Surgeries performed included blepharoplasty, ptosis repair, orbital floor exploration, facial nerve dissection and repair, mandibular plating, tracheotomy, laryngofissure, tracheal resection and laryngectomy. The model was also useful for flexible and microsuspension laryngoscopy.

CONCLUSION

Fresh, ovine tissue provides a readily available, anatomically compatible, affordable, model for training in otolaryngology-head and neck surgery. The use of sheep tissues carries a low risk for disease transmission and is ethically defensible. Structural variations in the sheep temporal bone, paranasal sinuses and skull base anatomy limit the usefulness of the model for surgical training in these areas.

ESCCAR international congress on Rickettsia and other intracellular bacteria

The European Society for the study of Chlamydia, Coxiella, Anaplasma and Rickettsia (ESCCAR) held his triennial international meeting in Lausanne. This meeting gathered 165 scientists from 28 countries and all 5 continents, allowing efficient networking and major scientific exchanges. Topics covered include molecular and cellular microbiology, genomics, as well as epidemiology, veterinary and human medicine. Several breakthroughs have been revealed at the meeting, such as (i) the presence of CRISPR (the "prokaryotic immune system") in chlamydiae, (ii) an Anaplasma effector involved in host chromatin remodelling, (iii) the polarity of the type III secretion system of chlamydiae during the entry process revealed by cryo-electron tomography. Moreover, the ESCCAR meeting was a unique opportunity to be exposed to cutting-edge science and to listen to comprehensive talks on current hot topics.