Burnetii Infection Research Articles

Coxiella burnetii Nine Mile phase I primary infection derived protective immunity against C. burnetii reinfection in mice depends on both B and T cells, but T cells play a critical role.

Coxiella burnetii is an obligate intracellular Gram-negative bacterium that causes acute and chronic Q fever in humans. Acute Q fever is usually a flu-like, self-limiting or treatable illness, but some infections can turn into a severe and sometimes fatal chronic disease. There is currently no FDA-approved vaccine available for the prevention of human Q fever in the US, development of a safe and effective vaccine for the prevention of human Q fever remains an important goal for public health. However, there is a fundamental gap in knowledge regarding the mechanism of protective immunity against C. burnetii infection. To understand the mechanism of C. burnetii infection induced protective immunity, we examined if C. burnetii Nine Mile phase I (NMI) infection induces protection against C. burnetii reinfection in mice. Our results indicate that NMI-infected mice conferred significant protection against C. burnetii reinfection. We also found that NMI infection derived protection did not depend on the routes of infection and antibodies are required for NMI infection derived protection. In addition, NMI infection elicited a comparable level of protection in Wild type, CD4+ T cell deficient, and CD8+ T cell deficient mice, partial protection in B cell deficient mice but no protection in T cell deficient mice. These results suggest that both B cells and T cells are required for NMI-infection derived protection, but T cells may play a critical role. Therefore, the new generation vaccine for the prevention of human Q fever should be focused on boosting both humoral and T cell immune responses.

A first insight into seropositivity and risk factors for Brucella spp. and Coxiella burnetii in free-roaming dogs in Ecuador

Brucellosis and Q fever are two bacterial zoonoses caused by Brucella spp. and Coxiella burnetii, respectively. Dogs are reservoirs of these pathogens and play an important role in their spread. In this research, we determined the seroprevalence of antibodies against Brucella spp. and C. burnetii in free-roaming dogs from Ecuador and conducted a statistical analysis based on geographical variables. Serum samples were collected from 397 free-roaming dogs between November 2018 and May 2019 and analyzed with commercial ELISA tests for Brucella spp. and Q fever. An overall seroprevalence of 2.8 % (CI: 95 %, 0.0–6.2 %) and 1.8 % (CI: 95 %, 0.0–5.6 %) was found for Brucella spp. and C. burnetii, respectively. No statistical differences in seroprevalence values were found between geographical regions in Ecuador or between dogs from rural or urban settings, except for the association of C. burnetii infection with the Coastal Region. This is the first study of this kind in Ecuador and points out the need for a One Health approach for control and surveillance of zoonotic diseases like brucellosis and Q fever including feral and stray dogs as reservoirs to spread those pathogens to cattle, humans, or wildlife.

Molecular detection of Coxiella burnetii in ticks infesting wild and domestic animals in the Eastern region of Punjab, Pakistan.

Tick-borne pathogens are significant for human, veterinary, and wildlife health. Coxiella burnetii is an example that is widely distributed across various hosts and can cross species boundaries. In Pakistan, there is a scarcity of data regarding C. burnetii at the intersection of wildlife and livestock. Ticks were collected from ruminants and wildlife from the districts of Kasur, Pakpattan, and Okara in Pakistan. Five tick species totaling 571 ticks were collected, with the following distribution: 56.4% Hyalomma anatolicum, 22.4% Rhipicephalus microplus, 10.5% Hyalomma marginatum, 7.9% Rhipicephalus sanguineus, and 2.8% Rhipicephalus turanicus. Fifty tick pools were screened for C. burnetii to amplify a segment of the IS1111 using real-time PCR assays. Ticks collected from sheep and goats had a greater rate of positivity for C. burnetii (40% and 38%, respectively) compared to Indian long-eared hedgehogs with a prevalence of 2%. Coxiella burnetii was prominent in Rhipicephalus microplus (92.3%) and Hyalomma anatolicum (88.9%), followed by Rhipicephalus turanicus (66.6%), Rhipicephalus sanguineus (33.3%), and Hyalomma marginatum (25.0%). Ticks from Pakpattan district displayed the highest prevalence of C. burnetii (88.9%), whereas the lowest was observed in ticks from Kasur district (77.3%). There was no significant association between tick gender and C. burnetii infection. Female host animals were more likely to harbor ticks containing C. burnetii, with a prevalence rate of 81.8%. The research underscores the urgent need for comprehensive studies on C. burnetii in Pakistan, especially at the interface of wildlife and livestock. The high prevalence rates observed in certain tick species and geographic regions emphasize the importance of targeted public health interventions. Future research should focus on elucidating the transmission dynamics and implementing effective control measures to mitigate the impact of these pathogens on human, veterinary, and wildlife health in the region.

First Insight into the Prevalence of Coxiella burnetii Infection among Veterinary Medicine Students in Bulgaria.

The aim of this study was to assess the prevalence of Coxiella burnetii infection among veterinary medicine students from two Bulgarian Universities, located in Sofia and Stara Zagora. Blood samples were collected from a total of 185 veterinary students for the detection of C. burnetii phase II antibodies and presence of DNA using an enzyme-linked immunosorbent assay (ELISA) and end-point PCR test. Out of all samples, 29.7% were positive for at least one C. burnetii phase II antibody marker or by the result of the PCR test. Veterinary students from Stara Zagora showed a significantly high seropositivity for Q fever (33.6%), as compared to the students in Sofia (23%; p < 0.05). Evidence of recent exposure with detection of anti-C. burnetii phase II IgM (+) antibodies was observed in 14.6% of the students under study. Seroprevalence among students in Stara Zagora was higher (15.3%). Anti-C. burnetii phase II IgG antibodies were detected in 21.6% of examined samples. Our study revealed a higher seropositivity among the male students (32.8%) as compared to females (16.0%; p < 0.05). The end-point PCR assay detected 5.9% blood samples as positive. The relative risk (RR) of Q fever exposure for male students was 40.7%, whereas it was 24.6% in females (p < 0.05). The findings from this study indicate that the C. burnetii infection is widely distributed amongst veterinary students in Bulgaria. This study emphasizes the need for improved safety protocols and infection control measures in veterinary training programs.

Molecular and serological screening of coxiellosis in bovines with reproductive disorders in dairy farms

Coxiella burnetii infection is an emerging/re-emerging public health problem affecting several countries worldwide. In India, the disease is mainly underdiagnosed, creating hindrances in its effective control. This study investigated the occurrence of C. burnetii among apparently healthy cattle and cattle with a history of reproductive disorders by both PCR and indirect-ELISA. A total of 731 clinical samples (serum: 531, and vaginal swabs as well as blood: 100 each) from 531 cattle were screened for coxiellosis. The serum, blood, and vaginal swabs each collected from 100 cattle with a history of reproductive disorders were screened using Com1-PCR, Trans-PCR, and indirect-ELISA. Conversely, serum samples obtained from apparently healthy cattle were exclusively screened using indirect ELISA. None of the samples tested could detect C. burnetii in PCR assays, while 13.37 % of serum samples were found to be seropositive in i-ELISA. Seropositivity noted among clinically healthy and those suffering from reproductive disorders were 12.76 % and 16 %, respectively, exhibiting a non-significant difference observed between these two categories. The obtained results suggested that the occurrence of coxiellosis did not differ significantly between clinically healthy animals and those with reproductive disorders; hence, in farms affected with C. burnetii infection, screening healthy and symptomatic animals is crucial to implement appropriate preventive measures.

Coxiella burnetii: A Brief Summary of the Last Five Years of Its Presence in the Abruzzo and Molise Regions in Italy.

Coxiella burnetii is the causative agent of Q fever. The main reservoirs for this bacterium, which can lead to human infection, in our region are typically cattle, goats, and sheep. In animals, C. burnetii infection is often detected due to reproductive problems. European Member States are required to report confirmed cases annually, but the lack of uniform reporting methods makes the data rather inconsistent. The Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise is involved in official controls to identify the causes of abortions, monitor suspected or positive herds, evaluate suspected infections in pets and humans, monitor the spread in wildlife, etc. In this paper, we summarize the presence of C. burnetii over the last five years (2019-2023). Additionally, a detailed overview of C. burnetii infection in wild and domestic animals is provided. Five hundred sixty animals-including cattle; goats; sheep; wild animals, such as deer, boars, wolves, roe deer, owls, and otters; buffalo; dogs; horses; cats; and a donkey-and six human samples were tested by real-time PCR on the transposase gene IS1111 to detect C. burnetii. The MST profile was identified in some of the samples. Outbreaks of C. burnetii occurred in four herds. In one of them, it was possible to follow the outbreak from inception to eradication by evaluating the effect of vaccination on real-time PCR Ct values. A total of 116 animals tested positive for C. burnetii, including 73 goats, 42 sheep, and one bovine. None of the other samples tested positive. The strains for which the ST was performed were identified as ST79, a strain that has been present in the area for more than ten years. The effect of vaccination on the reduction of positive samples and the variation of real-time PCR Ct values was evaluated in strict correlation.

Clinical Coxiella burnetii infection in sable and roan antelope in South Africa.

Various zoonotic microorganisms cause reproductive problems such as abortions and stillbirths, leading to economic losses on farms, particularly within livestock. In South Africa, bovine brucellosis is endemic in cattle, and from 2013-2018, outbreaks ofBrucella melitensisoccurred in sable.Coxiella burnetii, the agent responsible for the zoonotic disease known as Q-fever and/or coxiellosis, also causes reproductive problems and infects multiple domestic animal species worldwide, including humans. However, little is known of this disease in wildlife. With the expansion of the wildlife industry in South Africa, diseases like brucellosis and coxiellosis can significantly impact herd breeding success because of challenges in identifying, managing and treating diseases in wildlife populations. This study investigated samples obtained from aborted sable and roan antelope, initially suspected to be brucellosis, from game farms in South Africa using serology tests and ruminant VetMAX™ polymerase chain reaction (PCR) abortion kit. The presence ofC. burnetiiwas confirmed with PCR in a sable abortion case, while samples from both sable and roan were seropositive forC. burnetiiindirect enzyme-linked immunosorbent assay (iELISA). This study represents the initial report ofC. burnetiiinfection in sable and roan antelope in South Africa. Epidemiological investigations are crucial to assess the risk ofC. burnetiiin sable and roan populations, as well as wildlife and livestock in general, across South Africa. This is important in intensive farming practices, particularly as Q-fever, being a zoonotic disease, poses a particular threat to the health of veterinarians and farm workers as well as domestic animals.Contribution:A report of clinicalC. burnetiiinfection in the wildlife industry contributes towards the limited knowledge of this zoonotic disease in South Africa.

A sero-epidemiological analysis of Coxiella burnetii infection and its risk factors in livestock from Addis Ababa, Adama, and Modjo abattoirs and pastoral areas of Oromia, Ethiopia.

Coxiella burnetii is causing infections in both humans and animals, resulting in Q fever and Coxiellosis, respectively. Information on the occurrence of C. burnetii infection is scarce in Ethiopia. This study estimated the sero-prevalence of C. burnetii infection and associated risk factors in four common livestock species from Addis Ababa, Adama, and Modjo abattoirs and pastoral areas of Oromia, Ethiopia. Sera samples were analyzed for the presence of anti-C. burnetii antibodies using an indirect Enzyme Linked Immunosorbent Assay kit. Out of the 4140 serum samples tested, 777 (18.77%; 95% CI: 17.59, 19.99) were found positive for C. burnetii. The sero-prevalence estimate was 27.17% at Addis Ababa abattoir, 19.41% at Adama abattoir, 19.13% at Modjo abattoir and 12.1% in animals tested from pastoral areas. Sera analysis at the animal species level showed that cattle exhibited the lowest sero-prevalence estimate (11.83%; 95% CI, 10.27-13.53%), while the highest was observed in camels (28.39%; 95% CI, 25.16-31.80%). The sero-prevalence estimate was 21.34% (95% CI, 18.86-23.99%) in goats and 20.17% (95% CI, 17.49-23.07%) in sheep. The results of multivariable logistic regression analysis showed that species, age, sex of animals and tick infestation were important risk factors for C. burnetii infection. The odds of infection were 3.22 times higher in camels and almost twice as high in goats and sheep compared to cattle. Adult animals were infected more likely (OR = 3.23) than young ones. Interestingly, a significant difference was observed in the sero-prevalence of infection between animals that were infested with ticks (OR = 16.32) and those which were tick-free. This study provides valuable insights into the sero-epidemiology of C. burnetii infection in four common livestock species at major abattoirs and pastoral areas of Ethiopia. The findings highlight the need for further studies and implementing surveillance and biosecurity measures to prevent the spread of the disease in both humans and livestock to safeguard the economical and public health aspects.

Molecular surveillance of zoonotic pathogens from wild rodents in the Republic of Korea.

Rodents are recognized as major reservoirs of numerous zoonotic pathogens and are involved in the transmission and maintenance of infectious diseases. Furthermore, despite their importance, diseases transmitted by rodents have been neglected. To date, there have been limited epidemiological studies on rodents, and information regarding their involvement in infectious diseases in the Republic of Korea (ROK) is still scarce. We investigated rodent-borne pathogens using nested PCR/RT-PCR from 156 rodents including 151 Apodemus agrarius and 5 Rattus norvegicus from 27 regions in eight provinces across the ROK between March 2019 and November 2020. Spleen, kidney, and blood samples were used to detect Anaplasma phagocytophilum, Bartonella spp., Borrelia burgdorferi sensu lato group, Coxiella burnetii, Leptospira interrogans, and severe fever with thrombocytopenia syndrome virus (SFTSV). Of the 156 rodents, 73 (46.8%) were infected with Bartonella spp., 25 (16.0%) with C. burnetii, 24 (15.4%) with L. interrogans, 21 (13.5%) with A. phagocytophilum, 9 (5.8%) with SFTSV, and 5 (3.2%) with Borrelia afzelii. Co-infections with two and three pathogens were detected in 33 (21.1%) and 11 rodents (7.1%), respectively. A. phagocytophilum was detected in all regions, showing a widespread occurrence in the ROK. The infection rates of Bartonella spp. were 83.3% for B. grahamii and 16.7% for B. taylorii. To the best of our knowledge, this is the first report of C. burnetii and SFTSV infections in rodents in the ROK. This study also provides the first description of various rodent-borne pathogens through an extensive epidemiological survey in the ROK. These results suggest that rodents harbor various pathogens that pose a potential threat to public health in the ROK. Our findings provide useful information on the occurrence and distribution of zoonotic pathogens disseminated among rodents and emphasize the urgent need for rapid diagnosis, prevention, and control strategies for these zoonotic diseases.

Molecular identification of Coxiella burnetii in raw milk samples collected from farm animals in districts Kasur and Lahore of Punjab, Pakistan

Coxiella burnetii is the worldwide zoonotic infectious agent for Q fever in humans and animals. Farm animals are the main reservoirs of C. burnetii infection, which is mainly transmitted via tick bites. In humans, oral, percutaneous, and respiratory routes are the primary sources of infection transmission. The clinical signs vary from flu-like symptoms to endocarditis for humans’ acute and chronic Q fever. While it is usually asymptomatic in livestock, abortion, stillbirth, infertility, mastitis, and endometritis are its clinical consequences. Infected farm animals shed C. burnetii in birth products, milk, feces, vaginal mucus, and urine. Milk is an important source of infection among foods of animal origin. This study aimed to determine the prevalence and molecular characterization of C. burnetii in milk samples of dairy animals from two districts in Punjab, Pakistan, as it has not been reported there so far. Using a convenience sampling approach, the current study included 304 individual milk samples from different herds of cattle, buffalo, goats, and sheep present on 39 farms in 11 villages in the districts of Kasur and Lahore. PCR targeting the IS1111 gene sequence was used for its detection. Coxiella burnetii DNA was present in 19 of the 304 (6.3%) samples. The distribution was 7.2% and 5.2% in districts Kasur and Lahore, respectively. The results showed the distribution in ruminants as 3.4% in buffalo, 5.6% in cattle, 6.7% in goats, and 10.6% in sheep. From the univariable analysis, the clinical signs of infection i.e. mastitis and abortion were analyzed for the prevalence of Coxiella burnetii. The obtained sequences were identical to the previously reported sequence of a local strain in district Lahore, Sahiwal and Attock. These findings demonstrated that the prevalence of C. burnetii in raw milk samples deserves more attention from the health care system and veterinary organizations in Kasur and Lahore of Punjab, Pakistan. Future studies should include different districts and human populations, especially professionals working with animals, to estimate the prevalence of C. burnetii.

Caspase-8 activity mediates TNFα production and restricts Coxiella burnetii replication during murine macrophage infection.

Coxiella burnetii is an obligate intracellular bacteria that causes the global zoonotic disease Q Fever. Treatment options for chronic infection are limited, and the development of novel therapeutic strategies requires a greater understanding of how C. burnetii interacts with immune signaling. Cell death responses are known to be manipulated by C. burnetii, but the role of caspase-8, a central regulator of multiple cell death pathways, has not been investigated. In this research, we studied bacterial manipulation of caspase-8 signaling and the significance of caspase-8 to C. burnetii infection, examining bacterial replication, cell death induction, and cytokine signaling. We measured caspase, RIPK, and MLKL activation in C. burnetii-infected tumor necrosis factor alpha (TNFα)/cycloheximide-treated THP-1 macrophage-like cells and TNFα/ZVAD-treated L929 cells to assess apoptosis and necroptosis signaling. Additionally, we measured C. burnetii replication, cell death, and TNFα induction over 12 days in RIPK1-kinase-dead, RIPK3-kinase-dead, or RIPK3-kinase-dead-caspase-8-/- bone marrow-derived macrophages (BMDMs) to understand the significance of caspase-8 and RIPK1/3 during infection. We found that caspase-8 is inhibited by C. burnetii, coinciding with inhibition of apoptosis and increased susceptibility to necroptosis. Furthermore, C. burnetii replication was increased in BMDMs lacking caspase-8, but not in those lacking RIPK1/3 kinase activity, corresponding with decreased TNFα production and reduced cell death. As TNFα is associated with the control of C. burnetii, this lack of a TNFα response may allow for the unchecked bacterial growth we saw in caspase-8-/- BMDMs. This research identifies and explores caspase-8 as a key regulator of C. burnetii infection, opening novel therapeutic doors.

Chronic Q fever infective endocarditis: a case report

Abstract Q fever is an epidemic disease caused by the Coxiella burnetii (C. burnetii) infection. It can manifest clinically as an acute or chronic disease, with chronic infections being more common. Q fever endocarditis is the most common manifestation of chronic infection and usually occurs in patients with previous valvular heart disease like in our present study, a case of Q fever endocarditis that occurred in background of Tetralogy of Fallot (TOF) surgical repair. However, Q fever endocarditis is difficult to diagnose clinically and may lead to very serious or even life-threatening outcomes if not diagnosed promptly. In the present study, accurate diagnosis and treatment were achieved by 18F-FDG-PET/CT combined with detection of the Q fever serological antibodies.

Occurrence of Coxiella burnetii in wild lagomorphs and their ticks in Spanish Mediterranean ecosystems.

Coxiella burnetii, the causative agent of Q fever, is a zoonotic multi-host vector-borne pathogen of major public health importance. Although the European Food Safety Authority has recently made the monitoring of this bacterium in wildlife a priority, the role of wild lagomorphs in the transmission and maintenance of C. burnetii is poorly understood. The aims of this study were to determine the prevalence and risk factors associated with C. burnetii circulation in European wild rabbits (Oryctolagus cuniculus) and Iberian hares (Lepus granatensis) and to assess the presence of this pathogen in ticks that feed on them in Mediterranean ecosystems in Spain, the country with the highest number of reported cases of Q fever in Europe. A total of 574 spleen samples were collected from 453 wild rabbits and 121 Iberian hares, and 513 ticks (processed in 120 pools) between the 2017/2018 and 2021/2022 hunting seasons. C. burnetii DNA was detected in 103 (17.9%; 95% CI: 14.8-21.1) of the 574 wild lagomorphs tested. By species, prevalence was 16.3% (74/453; 95% CI: 12.9-19.7) in the European wild rabbit and 24.0% (29/121; 95% CI: 16.4-31.6) in the Iberian hare. At least one positive lagomorph was found on 47.9% of the 96 hunting estates sampled and in every hunting season since 2018/2019. Two risk factors associated with C. burnetii infection were as follows: outbreak of myxomatosis on the hunting estate in the month prior to sampling and high tick abundance observed by gamekeepers on the hunting estate. C. burnetii DNA was also found in 33 of the 120 (27.5%; 95% CI: 19.5-35.5) tick pools tested. The pathogen was detected in 66.7% (4/6), 29.2% (26/89) and 21.4% (3/14) of Haemaphysalis hispanica, Rhipicephalus pusillus and Hyalomma lusitanicum pools respectively. This study provides new epidemiological data on C. burnetii in European wild rabbits and is the first survey on this zoonotic pathogen performed in Iberian hares. Our results indicate widespread endemic circulation of C. burnetii and highlight the importance of both wild lagomorph species as natural reservoirs of this zoonotic bacterium in Mediterranean ecosystems in southern Spain, which may be of public and animal health concern. The high prevalence and wide diversity of positive tick species suggest the possible role of ticks in the epidemiological cycle of C. burnetii, with the potential risk of transmission to sympatric species, including humans.

Acute Q fever revealed by an anti-phospholipid syndrome: A case report

IntroductionQ fever is a zoonosis caused by Coxiella burnetii. Acute infection is mainly asymptomatic. In other cases it mainly causes a flu-like illness, a pneumonia, or an hepatitis. We present an atypical case of an acute Q fever revealed by a massive pleural effusion. Case reportWe report the case of a 43-year-old man referred to our hospital for an acute respiratory distress. Further analyses showed an exudative eosinophilic pleural effusion, associated with a pulmonary embolism and a deep femoral vein thrombosis. Aetiologic explorations revealed an acute Q fever (IgM and IgG against C. burnetii phase II antigens) associated with anti-phospholipids. The outcome was favorable with vitamin K antagonists, doxycycline, and hydroxychloroquine, till the negativation of the anti-phospholipid antibodies. Discussion and conclusionDuring acute C. burnetii infections, anti-phospholipid antibodies are highly prevalent but thrombotic complications are rare. The 2023 ACR/EULAR APS criteria restricts the diagnosis of APS, as in our case of acute severe infection. In front of an atypical pneumonia and/or thrombotic events, screening of C. burnetii and anti-phospholipid antibodies could be useful. Given its low level of evidence, prolongated treatment by doxycycline, hydroxychloroquine ± anticoagulant for C. burnetii's associated anti-phospholipid syndrome is discussed, but succeeded in our case.

Acute Coxiella burnetii Infection: A 10-Year Clinical Experience at a Tertiary Care Center in the United States.

Identifying and treating patients with acute Q fever who are at an increased risk of progressing to persistent disease is crucial for preventing future complications. In this study, we share our decade-long clinical experience with acute Q fever, highlighting the challenges that clinicians encounter from making an initial diagnosis and performing risk stratification to determining the appropriate prophylaxis regimen and duration. We retrieved records of adult Mayo Clinic patients (≥18 years) with positive Coxiella burnetii serology results between 1 January 2012 and 31 March 2022. Patients with Q fever anti-phase II immunoglobulin G ≥1:256 by indirect immunofluorescence were further analyzed. Thirty-one patients were included. Their median age was 58 years (IQR, 50-64), and the majority were men (84%). Acute hepatitis (29%), flu-like illness (25.8%), and pneumonia (16%) were the most common presentations. Thirteen patients (42%) received antibiotic prophylaxis to prevent disease progression, with significant variation in the indications and duration across physicians. The combination of doxycycline and hydroxychloroquine was the preferred regimen. Prophylaxis was administered for a median 333 days (IQR, 168-414). Four patients (13%) progressed to Q fever native valve infective endocarditis, with elevated anticardiolipin immunoglobulin G levels being the sole risk factor in 2 cases. The small sample size precluded drawing conclusions on the impact of prophylaxis in preventing disease progression. Management of acute Q fever is complicated by the lack of comprehensive clinical guidelines leading to varied clinical practices. There is a critical need for randomized trials to establish robust evidence-based protocols for management.

Coxiella burnetii in domestic doe goats in the United States, 2019-2020.

Coxiella burnetii is a bacterial pathogen capable of causing serious disease in humans and abortions in goats. Infected goats can shed C. burnetii through urine, feces, and parturient byproducts, which can lead to infections in humans when the bacteria are inhaled. Goats are important C. burnetii reservoirs as evidenced by goat-related outbreaks across the world. To better understand the current landscape of C. burnetii infection in the domestic goat population, 4,121 vaginal swabs from 388 operations across the United States were analyzed for the presence of C. burnetii by IS1111 PCR as part of the United States Department of Agriculture, Animal Plant Health Inspection Service, Veterinary Services' National Animal Health Monitoring System Goats 2019 Study. In total, 1.5% (61/4121) of swabs representing 10.3% (40/388) (weighted estimate of 7.8, 95% CI 4.4-13.5) of operations were positive for C. burnetii DNA. The quantity of C. burnetii on positive swabs was low with an average Ct of 37.9. Factors associated with greater odds of testing positive included suspected Q fever in the herd in the previous 3 years, the presence of wild deer or elk on the operation, and the utilization of hormones for estrus synchronization. Factors associated with reduced odds of testing positive include the presence of kittens and treatment of herds with high tannin concentrate plants, diatomaceous earth, and tetrahydropyrimidines. In vitro analysis demonstrated an inhibitory effect of the tetrahydropyrimidine, pyrantel pamoate, on the growth of C. burnetii in axenic media as low as 1 μg per mL. The final multivariable logistic regression modeling identified the presence of wild predators on the operation or adjacent property (OR = 9.0, 95% CI 1.3-61.6, p value = 0.0248) as a risk factor for C. burnetii infection.

Coxiella burnetii and Reproductive Disorders in Cattle: A Systematic Review.

Coxiellosis or Q fever is an infectious zoonotic disease caused by the bacterium Coxiella burnetii. A systematic review using bibliographic research was carried out, and the focus was the relationship between C. burnetii infection and reproductive disorders in cattle [abortion/stillbirth/perinatal morality/weak calves (ASPW complex); retained foetal membranes (RFMs); metritis/endometritis; and infertility/sub-fertility]. The bibliographical search yielded 443 results from databases, but only 61 were deemed eligible. For each disorder, summary tables were prepared, and a scientific evidence score was calculated for each study based on four criteria to help assess the level of evidence for the impact of C. burnetii on the reproductive disorders assessed: type of publication (peer-reviewed or other); type of study (case-control/cohort or other); type of C. burnetii test (direct or indirect); and comparative statistical analysis (yes or no). In addition, summary tables also included information on the study population, country, authors and year of publication, key findings and an assessment of the evidence for an association. For the ASPW complex, RFMs, metritis/endometritis and infertility/sub-fertility, 43, 9, 8 and 19 studies provided data, respectively. On a scale of four, nearly 50% of all study citations had evidence scores of three or four. For ASPW, RFMs and infertility/sub-fertility, there is a significant body of evidence to support a deleterious role for Q fever. In contrast, for metritis/endometritis, the evidence is unclear. It is concluded that there is a substantial need for further research, particularly involving larger animal populations in more controlled settings. To provide more consistency, it is recommended that authors follow more precise definitions of reproductive parameters and more robust diagnostic methodologies.

Potential biomarkers of IFN-γ, IL-2 and CXCL9 for diagnosis of Q fever disease

The pathogen responsible for Q fever disease, Coxiella burnetii, is a zoonosis classified as a pathogen due to its airborne transmission. The C. burnetii infection could be both acute or chronic in humans. The main and most common entry of the pathogens to the body is through the breathing of polluted aerosols containing a resistant substance similar to C. burnetii spores. This small cell variant (SCV) or spore-like morphotype is extremely stress-resistant, therefore inadequate treatment causes serious effects even death. Due to the diversity of clinical manifestations of Q fever and the presence of less specific and sensitive diagnoses for other diseases, multiple platforms for exploring Q fever biomarkers are required. Apart from serological studies to determine a biomarker for Q fever, it will be prudent to concentrate on the more appropriate cell-mediated immune response. This article discusses C. burnetii causing Q fever disease and how the host develops humoral and cellular immunity, particularly IFN-γ, IL-2 and CXCL9, as potential biomarkers for the diagnosis of Q fever disease.

Serosurvey of Coxiella burnetii in Police Officers and Working Dogs in Brazil: Case Report and One Health Implications.

Although the Coxiella burnetii infection has been investigated in dogs, its role in human transmission remains to be fully established, particularly in close and daily human-dog contact settings, such as in Police K-9 Units. Accordingly, this study aimed to assess anti-C. burnetii antibodies in clinically healthy police officers by an in-house indirect immunofluorescence assay (IFA), and working dogs by a commercial IFA Kit, from the State Special Operations Battalion, Paraná, Southern Brazil. Overall, 1/18 (5.5%) police officers and 9/30 (30.0%; CI 95% 16.66-47.88) dogs tested seropositive to anti-C. burnetii IgG antibodies. To date, this is the highest prevalence of Q fever seropositivity among military dogs worldwide. Despite the low sampling rate, a statistically significant association was found between seropositivity and female dogs (p = 0.0492). Further studies with larger sample sizes should be conducted to establish the prevalence of Q Fever in other Brazilian K-9 Units. In summary, this study is the first to conduct a concomitant serosurvey of police officers and working dogs, and its findings should be considered a warning for cross-exposure and transmission of Coxiella burnetii among Police K-9 Units in Brazil and worldwide.

Serological investigation of Coxiella burnetii infection (Query fever) in livestock in Makkah Province, Saudi Arabia.

Query fever (Q fever) is an endemic zoonotic disease and ruminants are considered to be the primary source of infection in humans. It is caused by Coxiella burnetii which is an obligate intracellular bacterial pathogen with a worldwide distribution. This study estimated the prevalence of Q fever in livestock with a history of abortion in Makkah Province, Saudi Arabia. Sera from 341 camels, 326 sheep, and 121 goats of either sex from various locations (Makkah, Jeddah, AL-Taif, AL-Qunfudah, AL-Laith, and AL-Kamil) were examined using a Q fever indirect enzyme-linked immunosorbent assay. Among the 788 serum samples, 356 animals had anti-Coxiella burnetii immunoglobulin G antibodies with an overall seroprevalence of 45.4%. Significant differences were observed in seroprevalence between species and locations. Camels had the highest percentage of Q fever-positive sera, with a prevalence of 50.4%, followed by goats (44.6%) and sheep (36.8%), with a high significant difference between animals (p = 0.000). The prevalence was significantly higher in Makkah (65.4%) than in Jeddah (28.8%). C. burnetii infection is prevalent in agricultural animals, especially camels maintained at livestock farms in Makkah province. Therefore, these animals considered as the main source of Q fever infections in Saudi Arabia, which is also a reason for the abortion in these animals. Therefore, there is an urgent need for further studies on Q fever infection with interventional approaches for prevention and control.