Risk factors associated with Coxiella burnetii in wild boars: A study in South Korea

Coxiella burnetii is a Gram-negative bacterium that causes the zoonotic disease Q fever. Wild boars serve as reservoirs for C. burnetii. This study aimed to identify the risk factors associated with C. burnetii infection in wild boars. We analyzed the data from 975 wild boar samples collected from June to November 2021 in South Korea. We utilized the indirect ELISA to detect antibodies against C. burnetii. A sample optical density to positive-control optical density value exceeding 50% was classified as positive. We gathered data on the forestation, terrain, weather, agriculture, and animal density of the region where the samples were collected. Continuous variables were categorized into tertiles. We performed a univariate logistic regression analysis and included variables with a p-value < 0.2 in the final multivariable logistic regression model. In our multivariable logistic regression analysis to identify risk factors for C. burnetii infection in wild boars, we used a forward selection method to enter variables based on the order of their significance. We performed the final multivariable logistic regression analyses using either continuous variables or variables categorized into tertiles. The prevalence of C. burnetii was 14.6% (n=142). Locations with the highest maximum wind speeds (3.92-8.24 m/s) showed a 59% increase in infection odds compared to locations with the lowest speeds (1.45-3.25 m/s)(p=0.044). For each 1 m/s increase in maximum wind speed, infection odds increased by 24.1% (p=0.037). Regions with the highest percentage of paddy fields per area (8.3-45%) showed a 76% increase in infection odds compared to regions with the lowest percentage (0-1.5%)(p=0.011). For each 1% increase in the proportion of paddy fields per area, infection odds increased by 3.3% (p=0.003). High maximum wind speed and a high percentage of paddy field were identified as significant risk factors for C. burnetii infection in wild boars.

Molecular detection of Coxiella burnetii in tick and blood samples from small ruminants in northwest of Iran

This survey sought to molecularly detect Coxiella burnetii in Argasidae and Ixodidae ticks attached to small ruminants in the region of West Azerbaijan (Northwest of Iran) and blood samples collected from the same animals. 451 tick samples and 927 blood samples were obtained from sheep (n = 536) and goats (n = 391) and tested by nested PCR for detection of C. burnetii insertion sequence IS1111 or icd gene sequence. The collected ticks were morphologically classified as Rhipicephalus sanguineus, Rhipicephalus turanicus, Hyalomma asiaticum, Hyalomma anatolicum, or Argas reflexus. 14% of ticks (65 in total 43 for IS1111 and 22 for icd gene) tested positive for C. burnetii, none of which were from the Argas genus. Among the 927 blood samples, 218 (23.5%) tested positive for C. burnetii. The positive result from analysis targeting the genes IS1111 and icd were 131 and 87 respectively. As Q fever is a tickborne zoonosis and endemic to Iran, such information is critical for creating effective, coordinated, and strategic tick and pathogen control programs to prevent disease outbreak in domestic animals and humans.

Prevalence and associated risk factors of anti-Coxiella burnetii antibodies in dairy cattle herds using bulk tank milk analysis in Kabylia area, north Algeria

Coxiella burnetii, or Q fever agent, has notable implications for human and livestock health. Infections in cattle primarily manifest through reproductive issues where infected animals shed the bacterium in birth fluids, placental tissues, and milk, serving as potential sources of transmission. Bovine herds become reservoirs, contributing to the environmental contamination of farming areas. Comprehensive studies on the prevalence, transmission routes, and associated risk factors among cattle contribute to the development of effective control strategies, ultimately safeguarding both livestock and public health.Here we determine the prevalence of Coxiella burnetii antibodies against in dairy cattle farms from Kabylia (northern Algeria) and identify the associated risk factors. Bulk tank milk samples from 184 farms were analyzed by indirect ELISA technique, 49 of them were tested positive which corresponds to a prevalence rate of 26.63% (95% CI 20.25-33.01%). Multivariate analysis by logistic regression showed that the risk factors associated with detection of anti-Coxiella burnetii antibodies are: cohabitation of cattle with small ruminants(OR = 3.74 95% CI [1.41-8.92]), exposure to prevailing winds (OR = 5.12 95% CI [2.11-13.45]), and the veterinarian visits frequency(OR = 5.67 95% CI [2.55-13.60]). These findings underscore the susceptibility of dairy cattle to Q fever in the Kabylia region, highlighting practices that pose risks. We recommend the implementation of hygienic measures and adherence to proper farming conditions to mitigate the transmission of Q fever and reduce the associated zoonotic risk.

Coxiella burnetii infection persistence in a goat herd during seven kidding seasons after an outbreak of abortions: the effect of vaccination

Coxiella burnetii infection was monitored during seven kidding seasons (2017-2023) in a dairy goat herd that after an outbreak of Q fever abortions was vaccinated with an inactivated phase I vaccine. Due to the high infection rate just after the outbreak, only the replacement stock was vaccinated during the first three kidding seasons, and when the average herd immunity had decreased (fourth kidding season onwards), the whole herd was vaccinated. Vaginal swabs, feces, and milk were analyzed by PCR to monitor infection, and dust and aerosols were analyzed to measure C. burnetii environmental contamination. One year after the onset of the outbreak, a significant reduction in C. burnetii shedding loads was observed, but the percentage of shedding animals remained high until the third kidding season. By the seventh kidding season, no shedders were detected. The bacterial load excreted was significantly lower in vaccinated compared with unvaccinated animals, and in yearlings compared with multiparous. C. burnetii was detected by PCR in aerosols collected inside the animal premises throughout the study period except in the last season; whereas, aerosols collected outdoors tested negative in the last three kidding seasons. Viable C. burnetii was detectable in environmental dust collected inside the barn until the third kidding season following the outbreak. These results indicate that after an outbreak of Q fever, the risk of infection for humans and susceptible animals can remain high for at least three kidding seasons when the number of C. burnetii animal shedders is still high, even when bacterial excretion is low.

IMPORTANCE

Q fever is a zoonosis distributed worldwide. Ruminants are the main reservoir, and infection can cause high rates of abortion. After entering a farm, Coxiella burnetii infection can persist in the animal population over several lambing/kidding periods. Once infection is established in a herd, vaccination with the inactivated Phase I vaccine significantly reduces bacterial shedding, but although at low levels, excretion may continue to occur for several lambing/kidding seasons. The time that C. burnetii remains viable in the farm environment after an outbreak of Q fever determines the period when risk of infection is high for the people in close contact. This work showed that this period extends at least three kidding seasons after the outbreak. These results provided valuable information on the epidemiology of C. burnetii infection in goat herds and may help to develop guidelines for controlling the disease and reducing infection risk for susceptible people and animals.

The immune response to a Coxiella burnetii vaccine in sheep varies according to their natural pre-exposure

Q fever in humans is caused by Coxiella (C.) burnetii. In 2008 and 2012, cases of Q fever in humans were linked to an infected flock of approximately 650 ewes. Since 2013 gimmers (G'13, G'14, G'15 etc.) were primary vaccinated (two doses) with an inactivated C.burnetii vaccine without any revaccination. In 2013, 30 ewes were primary vaccinated (A'13). Shedding was annually monitored by qPCR-testing of vaginal and nasal swabs collected at lambing. Animals were tested for Phase I- (PhI) and PhII-antibodies (Ab) and for PhII-specific-interferon-γ (IFN-γ) before and after vaccination. The effect of a revaccination was determined in 2018 and 2023. Groups of randomly selected gimmers primary vaccinated in 2015, 2016 and 2017 and a mixed group of older animals (A'13, G'13 and G'14) were revaccinated once in 2018. The trial was repeated in 2023 on groups primary vaccinated in 2019-2023. Major shedding after the outbreak in 2012 ceased in 2014. Thereafter C.burnetii was only sporadically detected at low-level in 2018, 2021 and 2023. Sheep naturally exposed to C.burnetii during the outbreak in 2012 (A'13, G'13) mounted a strong and complete (PhI, PhII, IFN-γ) recall immune response after vaccination. A serological PhI+/PhII+ pattern dominated after vaccination. In contrast, since 2014 a weaker immune response (PhII-titre, IFN-γ) and a dominance of the PhI-/PhII+ pattern was observed in vaccinated gimmers. The number of serologically non-responding gimmers to vaccination increased to 25.0 % in G'16/G'17 and 40.4 % in G'19/G'20. But revaccination even three (G'15 in 2018) and four (G'19 in 2023) years after primary vaccination resulted in a strong and complete immune response. No difference of the immune response nor to more recently primary vaccinated animals (G'23 in 2023) nor to those animals that were present during the outbreak (A'13/G'13/G'14 in 2018) was observed.

Molecular investigation of Coxiella burnetii in aborted fetus of small ruminants in southeast Iran

The domestic animal, known as a main reservoir of Coxiella burnetii, is susceptible to the occurrence of coxiellosis, which can lead to abortions in domestic animals, causing significant economic damage and posing risks to human health. Therefore, the purpose of this study is to investigate C. burnetii as the causative agent of Q fever in abortion samples of small ruminants in southeastern Iran. This study was conducted between 2020 and 2021 in Zarand city, located in Kerman province (southeast Iran). In this study, 50 abomasum swab samples of aborted sheep and goat fetuses were collected and analyzed using molecular methods to identify C. burnetii. The results revealed that 26% (n: 13) of the collected abortion samples were infected with C. burnetii. Among the positive samples, two (50%) belonged to goat abortion samples while 11 (23.9%) belonged to sheep abortion samples. This study demonstrates that C. burnetii is one of the causes of abortion in small ruminants in southeastern Iran. It is recommended to pay more attention to C. burnetii in domestic animals due to its significant economic impact on livestock and its potential implication for human health in Iran.

Molecular detection and MST genotyping of Coxiella burnetii in ruminants and stray dogs and cats in Northern Algeria

Aiming at identifying the reservoir and contamination sources of Coxiella burnetii in Northern Algeria, we investigated the molecular presence of the bacterium in 599 samples (blood, placenta, liver, spleen, and uterus) collected from cattle, sheep, dogs and cats. Our qPCR results showed that 15/344 (4.36%) blood samples and six/255 (2.35%) organ specimens were positive for C. burnetii. In cattle, three (4%) blood and liver samples were positive. In sheep, one blood (1.19%) and 3 (8.57%) placenta samples were positive. At the Algiers dog pound, 8 (10%) and 3 (5%) blood samples were qPCR positivein dogs and cats, respectively. In addition, MST genotyping showed that MST 33 was present in cattle and sheep, MST 20 in cattle,andMST 21 in dogs and cats.

Coxiella burnetii seroprevalence in domestic goat does in the United States: Prevalence, distribution, and associated risk factors

Infection with the bacterium Coxiella burnetii can cause coxiellosis in animals and Q fever in humans. Coxiellosis a consistently underreported infectious disease. The infection can result in reproductive consequences for humans and animals. Ruminants are a reservoir for infection and humans are generally infected via aerosolized secretions, making it a public health concern. Studies of ruminant seroprevalence are generally limited in size and scope. This study determined seroprevalence in a large-scale U.S. population of female goats using serum samples from 7736 does from 24 states. This study identified C. burnetii seroprevalence in the United States domestic goat population. Overall, 14.5 % (SE = 2.3) of does were seropositive and 21.0 % (SE = 2.4) of operations had at least 1 seropositive doe. Further, operation demographics and herd management practices associated with seropositivity were as follows: the suspected or confirmed presence of caprine arthritis encephalitis (CAE), caseous lymphadenitis (CL), Johne's disease, or sore mouth in the herd in the previous 3 years, not cleaning or disinfecting the kidding areas or removing aborting does from other does, allowing visitors to access the kidding areas, and a lower percentage of adult goat inventory that were adult bucks or wethers. Furthermore, goat breed was associated with seropositivity. These data show C. burnetii seroprevalence in the United States and identify operation and animal characteristics and management practices associated with C. burnetii seropositivity. Together, this information can be used to help limit animal transmission, inform public health measures, and help educate and protect individuals working with goats.

Coxiella burnetii infections from animals and ticks in South Africa: a systematic review

Coxiella burnetii is a zoonotic intracellular bacterium that is widely distributed and affects domestic animals, wildlife, humans and non-mammalian species. This systematic review was aimed at synthesizing research findings on C. burnetii in both domestic and wild animals of South Africa. The systematic review protocol was registered with Open Society Foundations of systematic reviews ( https://doi.org/10.17605/OSF.IO/8WS ). PRISMA guidelines were followed to collect and evaluate relevant scientific articles published on C. burnetii infecting domestic and wild animals in South Africa. Published articles were sourced from five electronic databases, namely, Google Scholar, PubMed and ScienceDirect, EBSCO and Scopus. Results showed 11 eligible studies involving four domestic animals, three wild animals and one ectoparasite species from seven provinces across South Africa. The occurrence of C. burnetii infection was high in Ceratotherium simum (white rhinoceros) (53.9%), medium in sheep (29.0%) and low in pigs (0.9%). Limpopo province (26%) had the most recorded infections followed by KwaZulu-Natal (19%) and Free State (3%) had the least reported occurrence of C. burnetii. The current study discovered that there is scarcity of published research on prevalence and distribution of C. burnetii infecting domestic and wild animals in South Africa, and this is of concern as this bacterium is an important zoonotic pathogen of "One Health" importance.

Molecular epidemiology of Coxiella burnetii infection in sheep and goats in Henan province, China

Q fever is a significant zoonotic disease caused by Coxiella burnetii, an obligate intracellular gram-negative bacterium. Although C. burnetii infection has been identified in various animal species, domestic ruminants serve as the primary reservoirs and main sources of human infection. Understanding of the epidemiology of C. burnetii in domestic ruminants is crucial for preventing and controlling of C. burnetii infection in humans. In this study, spleen tissues from sheep and goats were collected in Hennan province, China. Through PCR screening, C. burnetii was detected in sheep and goats in Henan province with an overall infection rate of 6.8 %. Sequence comparison and phylogenetic analysis revealed that all newly identified C. burnetii strains shared a close genetic relationship with those found in humans worldwide. These findings highlight the high risk of C. burnetii infection among slaughterhouse workers and emphasize the importance of epidemiological studies that investigate samples from both humans and animals within the "One Health" framework. Such surveillance will contribute to a better understanding of the epidemic situation and aid in the development of effective prevention and control strategies for C. burnetii infections in humans.

Molecular prevalence of Coxiella burnetii in cheese samples: Systematic review and meta-analysis

BACKGROUND

Cheese is a popular dairy product consumed worldwide, and it has been implicated as a source of Coxiella burnetii infections.

OBJECTIVES

The present study aimed to describe the molecular prevalence and source analysis of C. burnetii in cheese samples.

METHODS

A systematic literature search was conducted using the Medline/PubMed, Science Direct, Web of Science, Scopus, and Google Scholar databases to identify studies reporting the molecular prevalence of C. burnetii in cheese samples. The pooled prevalence of C. burnetii in cheese samples was estimated using a random-effects model.

RESULTS

A meta-analysis was conducted using the mean and standard deviation values obtained from 13 original studies. The overall molecular prevalence of C. burnetii in cheese was estimated to be 25.2% (95% confidence interval [CI]: 13.1%-39.7%). The I2 value of 96.3% (CI95% 94.9-97.3) suggested high heterogeneity, with a τ2 of 0.642 (CI95% -0.141 to 0.881), and an χ2 statistic of 323.77 (p < 0.0001).

CONCLUSIONS

In conclusion, our meta-analysis provides a thorough assessment of the molecular prevalence and source analysis of C. burnetii in cheese samples.

First report of an outbreak of "Q" fever IN an abattoir from Argentina

In late October 2021, one of the veterinarians and the occupational physician of a bovine and swine abattoir from Entre Ríos Province, Argentina were alerted about workers with atypical pneumonia symptoms, raising suspicious of a possible Q fever outbreak. An outbreak epidemiological investigation was carried out. Analysis was based on the description of the study population, according to gender, age, symptoms, and position within the abattoir, as well as on outbreak epidemic curve and its probable origin. Cases of Q fever in the workers were confirmed by serology. Measurements of the association between the evaluated variables and the risk of exposure were investigated and calculated as attack rates. The outbreak occurred between October and November 2021, symptomatically affecting 11 workers, out of a total exposed population of 49 individuals. The index case was a 33-year-old male who started with symptoms on 27 October 2021, and the outbreak extended for at least 17 days. Workers in the clean zone of the slaughter floor had a 4.68 times higher risk of contracting Q fever than people located in other areas. Importantly, two pregnant cows were slaughtered a few days before the outbreak began, which could have been the origin of the outbreak. The present study demonstrates the urgent need to consider Q fever when diagnosing abortive diseases of ruminants in Argentina, as well as in zoonotic disease epidemiological surveillance to inform all actors of the health system.

Genotyping and phylogenetic analysis of Coxiella burnetii in domestic ruminant and clinical samples in Iran: insights into Q fever epidemiology

Coxiella burnetii, a zoonotic pathogen, is the causative agent of Q fever, an endemic disease in Iran. However, there is currently a lack of available data on the genotypes of C. burnetii in the country. Here, we typed 26 C. burnetii isolates detected in milk, abortion, cotylodon, and cardiac valve samples from various geographical areas and hosts (7 cattle, 8 goats, 10 sheep, and 1 human) using Multilocus Variable Number Tandem Repeat Analysis (MLVA/VNTR) with five loci:ms24, ms27, ms28, ms33, and ms34. As IS1111 was observed to be spontaneously inserted in locus ms23 across all of our examined C. burnetii samples, five loci were employed for MLVA/VNTR genotyping. Among the 26 C. burnetii strains, 22 distinct genotypes (A-V) were identified in the discriminative loci. In silico analysis categorized Iranian C. burnetii strains into five genomic groups along with seven singletons, representing 11 exiting clonal complexes worldwide. Clusters 10 and 11 exclusively consisted of Iranian samples. These findings revealed high genotyping diversity among C. burnetii isolates in Iran. The genotypes circulating in Iran differed significantly from those found in other regions worldwide. To gain a comprehensive understanding of Q fever epidemiology in Iran, it is crucial to conduct large-scale studies that assess the distribution of C. burnetii genotypes across different geographical areas, hosts, and sources.

Molecular and serological prevalence of Coxiella burnetii in bovine dairy herds in southern Chile: A PCR and ELISA-based assessment of bulk tank milk samples

Coxiella burnetii (C. burnetii) is a highly resilient zoonotic bacterium responsible for Q fever, a disease which occurs worldwide, with the exception of New Zealand. However, in Chile, the prevalence and impact of C. burnetii in cattle herds remain poorly understood due to limited research. This study aimed to assess the presence of C. burnetii in dairy cattle herds in southern Chile, using two diagnostic methods on bulk tank milk samples. The results of the study revealed a high prevalence of C. burnetii infection in the analyzed herds. Of the 271 milk tank samples tested, 76% (208/271, CI: 71.1-81.5) tested positive using ELISA, while 73% (200/271, CI: 68.0-78.8) tested positive using qPCR. These findings indicate a significant presence of C. burnetii in the cattle herds studied. Despite the high prevalence observed, no new Q fever outbreaks have been reported in the study area. This discrepancy highlights the need for further research to better understand the transmission dynamics, environmental factors, and livestock management practices associated with C. burnetii infection. These studies will contribute to the development of effective prevention and control strategies and promote public health regarding Q fever.

Epidemiological investigation of Coxiella burnetii in cattle and its association with Ixodid tick infestation in different agro-ecological zones of Southwest Ethiopia

Coxiella burnetii is a serious zoonotic disease that causes significant economic losses in cattle production, including abortion, stillbirth, infertility, and reduced milk yield. However, little is known about the epidemiology of C. burnetii in Ethiopia. From November 2020 to November 2021, a cross-sectional study was conducted to estimate the seroprevalence and associated risk factors of C. burnetii in cattle in various agro-ecologies of Southwest Ethiopia. Blood samples were collected from 461 cattle, and the serum samples were tested for the presence of C. burnetii antibodies using an indirect ELISA. To identify potential risk factors for C. burnetii seropositivity, a multivariable mixed-effect logistic regression analysis was used. The study found an overall seroprevalence of 8.68% (95% CI: 6.11-11.25) and 13.57% (95% CI: 9.56-17.58) at the animal and herd levels, respectively, in the study areas. The results of the study indicated that C. burnetii infection was a widespread disease in the study areas. C. burnetii seropositivity at the animal level was significantly associated with age (OR = 4.1, 95%CI: 1.47-10.92), herd size (OR = 3.9, 95%CI: 1.21-12.66), management system (OR = 9.7, 95%CI: 1.27-27.25), cattle access to dogs, cats, and mice (OR = 2.5, 95%CI: 1.21-5.28), accessibility of cattle to wild animals (OR = 4.2, 95%CI: 1.01-17.18), presence of ticks on cattle (OR = 2.3, 95%CI: 1.12-4.83), and history of abortion (OR = 3.8, 95%CI: 1.78-8.23). A herd level analysis identified several risk factors for C. burnetii infection, including the management system (OR = 3.8, 95%CI: 1.59-8.98), agro-ecology (OR = 2.8, 95%CI: 1.43-7.21), herd size (OR = 4.3, 95%CI: 1.69-9.76), and accessibility of cattle to dogs, cats, and mice (OR = 2.6, 95%CI: 1.18-3.96). Therefore, it is important to implement appropriate control methods and raise public awareness about C. burnetii zoonotic transmission. Moreover, further studies should be conducted to isolate and characterize C. burnetii as a cause of reproductive problems and in disease reservoirs such as ticks and wildlife in the study areas.

Detection of Coxiella antibodies in ruminants using a SucB recombinant antigen

The detection of Coxiella burnetii in ruminants remains challenging despite the use of new technology and the accumulation of novel knowledge. Serology tools, the primary methods of infection surveillance in veterinary medicine, have limitations. We used recombinant antigen production to develop an ELISA based on the SucB protein, one of the major immunodominant antigens described in humans and laboratory animals. We produced the antigen successfully in an Escherichia coli heterologous system, confirmed by sequencing and mass spectrometry, and seen as a band of ~50 kDa in SDS-PAGE and on western blot analysis. We compared the performance of the recombinant ELISA with a commercial ELISA. We observed agreement of 83.5% and a substantial Cohen κ value of 0.67 in our pilot study.

Genome-wide epitope mapping across multiple host species reveals significant diversity in antibody responses to Coxiella burnetii vaccination and infection

Coxiella burnetii is an important zoonotic bacterial pathogen of global importance, causing the disease Q fever in a wide range of animal hosts. Ruminant livestock, in particular sheep and goats, are considered the main reservoir of human infection. Vaccination is a key control measure, and two commercial vaccines based on formalin-inactivated C. burnetii bacterins are currently available for use in livestock and humans. However, their deployment is limited due to significant reactogenicity in individuals previously sensitized to C. burnetii antigens. Furthermore, these vaccines interfere with available serodiagnostic tests which are also based on C. burnetii bacterin antigens. Defined subunit antigen vaccines offer significant advantages, as they can be engineered to reduce reactogenicity and co-designed with serodiagnostic tests to allow discrimination between vaccinated and infected individuals. This study aimed to investigate the diversity of antibody responses to C. burnetii vaccination and/or infection in cattle, goats, humans, and sheep through genome-wide linear epitope mapping to identify candidate vaccine and diagnostic antigens within the predicted bacterial proteome. Using high-density peptide microarrays, we analyzed the seroreactivity in 156 serum samples from vaccinated and infected individuals to peptides derived from 2,092 open-reading frames in the C. burnetii genome. We found significant diversity in the antibody responses within and between species and across different types of C. burnetii exposure. Through the implementation of three different vaccine candidate selection methods, we identified 493 candidate protein antigens for protein subunit vaccine design or serodiagnostic evaluation, of which 65 have been previously described. This is the first study to investigate multi-species seroreactivity against the entire C. burnetii proteome presented as overlapping linear peptides and provides the basis for the selection of antigen targets for next-generation Q fever vaccines and diagnostic tests.

Q fever and toxoplasmosis in South African livestock and wildlife: a retrospective study on seropositivity, sporadic abortion, and stillbirth cases in livestock caused by Coxiella burnetii

BACKGROUND

Q fever and toxoplasmosis are economically important zoonoses as they cause considerable losses in livestock (cattle, sheep and goats) and wildlife (antelopes, giraffes, lions, and cheetahs) through reproductive disorders such as abortions and stillbirths. Q fever and toxoplasmosis testing in South Africa is conducted by the Agricultural Research Council-Onderstepoort Veterinary Research (ARC-OVR). However, both zoonoses are understudied and not monitored in South Africa as they are not considered controlled or notifiable diseases in the Animal Disease Act 35 of 1984. A retrospective study was conducted on Q fever (2007-2009) and toxoplasmosis (2007-2017) using diagnostic laboratory data at the ARC-OVR. Also, we report on sporadic abortion and stillbirth cases in livestock from diagnostic tissue samples submitted for Coxiella burnetii polymerase chain reaction (PCR) detection at the ARC-OVR.

RESULTS

During 2007 to 2009, 766 animal samples were tested for C. burnetii antibodies and seropositivity was 0.9% (95%CI: 0.3-1.7) with sheep (1.9%; 95%CI: 0.6-4.4) having the highest seropositivity followed by cattle (0.7%; 95%CI: 0.09-2.6), while all goats (0.0%; 95%CI: 0.0-4.2) and wildlife (0.0%; 95%CI: 0.0-2.5) tested were negative. From 2007 to 2017, 567 sera were tested for T. gondii antibodies; overall seropositivity was 12.2% (95%CI: 9.6-15). Wildlife had highest seropositivity to T. gondii antibodies (13.9%; 95%CI: 9.0-19.7) followed by goats (12.9%; 95%CI: 9.2-17.4) and sheep (12.3%; 95%CI: 5.1-23.8) while seropositivity in cattle was 2.4% (95%CI: 0.06-12.9). Of 11 animals tested by C. burnetii PCR detection (2021-2022), 10 (91.0%) were positive. The amplicon sequences showed similarity to Coxiella burnetii strain 54T1 transposase gene partial coding sequence.

CONCLUSIONS

We have confirmed the occurrence of the causative agents of Q fever and toxoplasmosis in livestock and wildlife in South Africa, with data limitations. These zoonoses remain of importance with limited information about them in South Africa. This study provides baseline information for future studies on Q fever and toxoplasmosis in South African livestock and wildlife, as well other African countries. Due to limited data collection experienced in this study, it is recommended that improvements in data collection samples tested should include associated factors such as sex, age, and breed of the animals.

Molecular investigation of Coxiella burnetii and Francisella tularensis infection in ticks in northern, western, and northwestern Iran

Tularemia and Q fever are endemic diseases in Iran; however, little information is available on the prevalence of the causative agents, Coxiella burnetii and Francisella tularensis, in Iranian ticks. This study investigated C. burnetii and F. tularensis among hard ticks in this country. We collected ticks from livestock and other mammals in Guilan, Mazandaran, Golestan (northern Iran), Kurdistan (western Iran), and West Azerbaijan (northwestern Iran) provinces. Genomic DNA from collected ticks was extracted and screened for C. burnetii and F. tularensis using Real-time PCR. A total of 4,197 ticks (belonging to 12 different species) were collected, and Ixodes ricinus (46.4%), Rhipicephalus turanicus (25%), and Rhipicephalus sanguineus sensu lato (19.1%) were the most collected species. Of 708 pooled tick samples, 11.3% and 7.20% were positive for C. burnetii and F. tularensis, respectively. The genus of Rhipicephalus had the highest (18.3%) C. burnetii infection among the collected tick pools (P<0.001). Furthermore, the most positive pools for F. tularensis belonged to Haemaphysalis spp. (44.4%). Kurdistan had the most significant percentage of C. burnetii-infected ticks (92.5%), and there was a meaningful relationship between the provinces and the infection (P< 0.001). The ticks from Golestan exhibited the highest F. tularensis infection rate (10. 9%), and the infection showed no significant relationship with the provinces (P = 0.19). Ticks collected from grasslands had a higher Coxiella burnetii infection rate than those collected from animals (39.4% vs. 7.9%; p<0.01). However, ticks collected from animal surfaces had a slightly higher rate of Francisella tularensis infection than those collected from grasslands (7.6% vs. 3.9%; p = 0.24). Here, we demonstrated the presence of both pathogens in the north (Guilan, Mazandaran, and Golestan provinces), the west (Kurdistan province), and the northwest (West Azerbaijan province) of Iran. The public health system should pay particular attention to tick bites in veterinary medicine and humans.

Molecular detection of Coxiella burnetii in raw meat samples collected from different abattoirs in districts Kasur and Lahore of Punjab, Pakistan

Coxiella burnetii is the zoonotic pathogen that causes Q fever; it is widespread globally. Livestock animals are its main reservoir, and infected animals shed C. burnetii in their birth products, feces, vaginal mucus, urine, tissues, and food obtained from them, i.e., milk and meat. There were previously very few reports on the prevalence of C. burnetii in raw meat. This study aimed to determine the prevalence of C.burnetii and its molecular characterization in raw ruminant meat from the Kasur and Lahore districts in Punjab, Pakistan, as this has not been reported so far. In this study, 200 meat samples, 50 from each species of cattle, buffalo, goat, and sheep, were collected from the slaughterhouses in each district, Kasur and Lahore in 2021 and 2022. PCR was used for the detection of the IS1111 element of C. burnetii. The data were recorded and univariate analysis was performed to determine the frequency of C. burnetii DNA in raw meat samples obtained from different ruminant species using the SAS 9.4 statistical package. Of the total of 200 raw meat samples, C. burnetii DNA was present in 40 (20%) of them, tested by PCR using the IS1111 sequence. The prevalence of C.burnetii differed among the studied species of ruminants. When species were compared pairwise, the prevalence in cattle was statistically significantly lower than in sheep (P = 0.005). The sequence alignment based on origin implied that the strains are genetically diverse in different districts of Punjab, Pakistan. The findings demonstrated that the prevalence of C. burnetii, especially in raw meat samples, deserves more attention from the health care system and professionals from Punjab, Pakistan, i.e., abattoir workers and veterinarians.

Coxiella burnetii Pathogenesis: Emphasizing the Role of the Autophagic Pathway

Coxiella burnetii (C. burnetii), the etiological agent of the Q fever disease, ranks among the most sporadic and persistent global public health concerns. Ruminants are the principal source of human infections and diseases present in both acute and chronic forms. This bacterium is an intracellular pathogen that can survive and reproduce under acidic (pH 4 to 5) and harsh circumstances that contain Coxiella-containing vacuoles. By undermining the autophagy defense system of the host cell, C. burnetii is able to take advantage of the autophagy pathway, which allows it to improve the movement of nutrients and the membrane, thereby extending the vacuole of the reproducing bacteria. For this method to work, it requires the participation of many bacterial effector proteins. In addition, the precise and prompt identification of the causative agent of an acute disease has the potential to delay the onset of its chronic form. Moreover, to make accurate and rapid diagnoses, it is necessary to create diagnostic devices. This review summarizes the most recent research on the epidemiology, pathogenesis, and diagnosis approaches of C. burnetii. This study also explored the complicated relationships between C. burnetii and the autophagic pathway, which are essential for intracellular reproduction and survival in host cells for the infection to be effective.

A cross-sectional study of Q fever in Camels: Risk factors for infection, the role of small ruminants and public health implications for desert-dwelling pastoral communities

Q fever represents an important 'neglected zoonosis', with high prevalences recorded across the Middle East region. Among rural desert-dwelling communities in the region, camel milk is largely consumed raw, due to perceptions of dromedaries as a uniquely clean livestock species mentioned in the Qur'an and Islamic hadith, while milk from other livestock species is usually boiled. As a result, camels present a unique public health threat among such communities from milk-borne pathogens, including Coxiella burnetii. In view of this, a cross-sectional study was conducted among dromedary herds in southern Jordan between September 2017 and October 2018, including 404 camels from 121 randomly selected herds. In addition, 510 household members associated with these herds were interviewed regarding potential high-risk practices for zoonotic transmission. Weight adjusted camel population seroprevalence for C. burnetii was 49.6% (95% CI: 44.7-54.5), with evidence of maternally derived immunity in calves ≤6 months old. Adjusted herd-level prevalence was 76.0% (95% CI 72.7-80.2). It was estimated 30.4% (144/477) of individuals consumed raw milk from infected herds monthly or more. Following multivariable logistic regression analysis, seropositive status in camels was found to be associated with increasing age, high herd tick burdens, keeping the herd together throughout the year including when calving, and owning larger (>50) sheep and goat flocks, with goats presenting a higher risk than sheep. Racing camel status was found to be protective. Socioculturally appropriate interventions aimed at raising awareness of potential risks associated with drinking raw camel milk, alongside appropriate livestock management interventions, should be considered.

New Genotype of Coxiella burnetii Causing Epizootic Q Fever Outbreak in Rodents, Northern Senegal

In Senegal, Coxiella burnetii, which causes Q fever, has often been identified in ticks and humans near livestock, which are considered to be reservoirs and main sources of infection. We describe the emergence of C. burnetii in rodents, not previously known to carry this pathogen, and describe 2 new genotypes.

Q fever screening among pregnant women with pre-term delivery in northern Israel: An observational study

The relationship between Q fever, caused by Coxiella burnetii, and obstetrical complications is debatable. Since Q fever is endemic in Israel, we aimed to assess its seroprevalence and clinical characteristics in pre-term deliveries. Between 1 August 2017 and 31 December 2019, we conducted serological screening for C. burnetii in pregnant women who presented to Rambam Health Care Campus with pre-term delivery (before 37 weeks of gestation). Anti-C. burnetii antibodies were tested first by enzyme-linked immunosorbent assay for the detection of phase I-IgG, phase II-IgG and phase II-IgM. Positive results were confirmed by indirect immunofluorescence with titre determination. Seropositivity was classified into past, acute and chronic infection. Demographic and clinical data of mothers and neonates were collected and compared between seropositive and seronegative women. Out of 386 pregnant women screened for anti-C. burnetii antibodies, 16 (4.1%) were seropositive, of whom three were diagnosed with past, 12 with acute and one with chronic infection. A higher percentage of seropositive women were immunosuppressed, 2/16 (12.5%) compared with 7/370 (1.9%) in seronegative women, (p = .05). Neonates with small for gestational age were born to 2/16 (12.5%) seropositive women compared with 29/370 (7.8%) to seronegative women, (p = .35). The seroprevalence of Q fever among pregnant women with pre-term birth reached 4% in northern Israel. This high rate in an endemic setting encourages investigating the role of routine screening for Q fever during pregnancy. Special attention should be given to pregnant immunosuppressed women at risk for exposure to Q fever.

MLVA and com1 genotyping of Coxiella burnetii in farmed ruminants in Great Britain

Coxiella burnetii, the causative agent of the zoonotic disease Q fever, has been shown to be endemic in Great Britain, but information on the prevailing genomic lineages or Genomic Groups (GGs) of Coxiella burnetii is limited. The aim of this study was to genotype C. burnetii isolates from infected farmed ruminants by Multiple Locus Variable Number Tandem Repeat Analysis (MLVA) and identify their associated Genomic Group. A total of 51 Coxiella-containing abortion samples from farmed ruminants (sheep, goats, and cattle), which were collected in Great Britain during 2013-2018, were included in the study, 34 of which returned a C. burnetii MLVA genotype. All bovine samples (n = 18), 5/7 of the ovine samples, and 3/9 of the caprine samples belonged to an MLVA cluster which we could link to the MST20 genotype of GG III, whereas 6/9 of the caprine samples and 2/7 of the ovine samples belonged to MLVA clusters which we could link to the MST33 or MST32 genotypes of GG II (7 vs 1 sample(s), respectively). We also noted that the Coxiella-specific com1 gene contained unique mutations that could genomotype isolates, i.e. assign them to a Genomic Group. In conclusion, both goats and sheep in Great Britain (from 2014 onward) were found to carry the same MLVA genotypes (MST33-like; GG II) that were linked to a human Q fever outbreak in the Netherlands. This knowledge in combination with the usage of genotyping/genomotyping methods should prove useful in future surveillance programs and in the management of outbreaks.

The prevalence of Q fever in the Eastern Mediterranean region: a systematic review and meta-analysis

OBJECTIVES

Q fever, caused by the bacterium, is a major zoonotic disease around the world. This disease is common in the Eastern Mediterranean region; therefore, we conducted the first systematic review and meta-analysis on its prevalence in humans, animals, and ticks in the Eastern Mediterranean region.

METHODS

Major Iranian and international databases were searched from 2000 to 2021. We extracted the prevalence of Q fever in blood samples from animals and milk samples from animals, ticks, and humans as the main outcome. We reported the prevalence of seropositivity and molecular positivity as point estimates and 95% confidence intervals (CIs).

RESULTS

In this review, 112 papers were identified. The overall seroprevalence of Q fever was 22.4% (95% CI, 19.8 to 25.1). The pooled prevalence of Q fever in ticks was 17.5% (95% CI, -1.3 to 36.4). The prevalence was 25.5% (95% CI, 16.1 to 34.9) in humans. The prevalence of Q fever in animal blood samples from goats, sheep, camels, cattle, cats, dogs, horses, and buffalo were 28.1%, 25.1%, 25.0%, 20.1%, 9.8%, 8.4%, 6.5%, and 6.3%, respectively. Furthermore, the prevalence of Q fever in milk samples of animals was higher in cattle (20.3%) than in sheep (20.0%), goats (16.4%), and camels (3.3%).

CONCLUSIONS

Coxiella burnetii infections are common in humans and in a wide range of animal species, but they are still not recognized in many countries in the Eastern Mediterranean region, thus presenting a significant threat to human and animal health in the region.

Genotyping of Coxiella burnetii from Cattle by Multispacer Sequence Typing and Multiple Locus Variable Number of Tandem Repeat Analysis in the Republic of Korea

Genotyping of Coxiella burnetii using multispacer sequence typing (MST) and multiple locus variable number tandem repeat analysis (MLVA) was conducted from infected animals for the first time in the Republic of Korea. C. burnetii was detected by real-time PCR, and followed by MST and MLVA genotyping. The result showed that detected C. burnetii all had the same MLVA genotype, 6-13-2-7-9-10 for markers MS23-MS24-MS27-MS28-MS33-MS34, respectively, and genotype group 61 for MST. The same genotypes were previously identified in Poland. Importantly, this MLVA type was detected in humans in France, suggesting that the Korean strain can also potentially cause Q fever in humans. MST and MLVA were very useful tools for analyzing the molecular epidemiology of C. burnetii and helpful for interpreting the epidemiological relationship between isolates from domestic and international resources.

Investigation of the outbreaks of abortions and orchitis in livestock in Namibia during 2016-2018

This study investigated outbreaks of seemingly related abortions and orchitis which occurred in the Khomas, Omaheke and Otjozondjupa regions of Namibia from 2016 to 2018, affecting cattle, sheep and goats. Fifty-nine questionnaires were administered, and 48 were completed giving an 81.4% return. The outbreaks were limited to Namibia's east and central regions, mainly on farms rearing cattle, sheep and goats and on farms with a mixture of these species. There was no significant difference between Khomas and other regions on abortion reporting at the farm level [X2 (1, N = 48) = 0.0002, p = 0.987851]. However, there was a significant difference in the abortions at the animal level among the three regions [X2 (2, N = 6246) = 239.8339, p = .00001]. In addition, the proportions of abortions calculated at the animal level at each farm were significantly different when the Khomas region was compared to the other regions. Seventeen cattle sera, 35 sheep sera, 52 caprine sera, 18 bovine liver samples, one caprine liver, five aborted cattle foetuses, two cattle placentas, 18 testes (one bull, eight bucks and nine rams) and ten bull sheath scrapings were collected and tested. Histopathology, microbiology, serology, immunohistochemistry, real-time PCR and mineral analytical techniques were used to establish the aetiology of the abortion and orchitis outbreaks. The gross and histopathological findings on the 18 testicles were characteristic of chronic orchitis. In aborted foetuses, significant histopathological findings included meconium aspiration, funisitis and cardiomyopathy. Placentitis and endometritis were the primary pathologies observed in cows. The bacteria isolated from microbiological samples included Enterococcus spp. (65.5% [19/29]), Enterobacter spp. (6.9% [2/29]) and Streptococcus spp. (10.3% [3/29]), Trueperella pyogenes (3.4% [1/29]), Stenotrophomonas maltophilia (3.4% [1/29]), Staphylococcus epidermidis (3.4% [1/29]), Providencia rettgeri (3.4% [1/29]) and Acinetobacter lwoffii (3.4% [1/29]), mostly opportunistic bacteria. On mineral analysis, 28%, 33%, 83%, 33% and 17% (n = 18) of cattle livers were low in copper, zinc, manganese, selenium and iron, respectively. Twenty-three percent (12/52) of the caprine sera were positive for Brucella melitensis on the Rose Bengal and complement fixation tests. Thirty-five ovine sera were tested for B. melitensis, B. ovis and Coxiella burnetii, and the prevalence for each was 2.9% (1/35). PCR tests on foetuses were all negative for Brucella spp., Coxiella burnetii, Chlamydia spp., Listeria monocytogenes, Salmonella spp., Campylobacter fetus spp., Leptospira pathogenic strains, bovine viral diarrhoea virus, Rift Valley fever virus, Anaplasma phagocytophilum and bovine herpes virus 4 Campylobacter fetus spp. and Trichomonas foetus spp. The authors concluded that Brucella spp., Enterococcus spp., Escherichia coli, Streptococcus spp., Trueperella pyogenes and Coxiella burnetii could have contributed to this outbreak. Micronutrient imbalances and pathogenic abiotic nanoparticles were also identified as possible contributors to the abortion outbreaks.

Q fever and coxiellosis in Brazil: an underestimated disease? A brief review

Q fever, caused by the γ-proteobacterium Coxiella burnetii, is a zoonosis of great importance and global impact. This agent has high transmissibility and can spread over long distances via wind, in which a small number of aerosolized particles are needed to infect susceptible hosts. The clinical diagnosis of Q fever is difficult owing to the variety of clinical signs shared with other diseases. In Brazil, studies related to C. burnetii are constantly being conducted, and this review aims to increase the number of approaches already studied, leading to the following question: is Q fever an unknown, neglected disease, or does it have a focal occurrence in certain areas (exotic/rare) in the country?

Abattoir-based serological surveillance for transboundary and zoonotic diseases in cattle and swine in Cambodia: a pilot study in Phnom Penh province during 2019 and 2020

A pilot animal disease surveillance program was implemented at four abattoirs in Phnom Penh, Cambodia, between October 2019 and January 2020. A total of 1141 samples were collected from 477 cattle and 664 swine. Serological testing was performed using commercial antibody ELISA kits for zoonotic and high-impact animal diseases, namely brucellosis, Q fever, classical swine fever (CSF), porcine reproductive and respiratory syndrome (PRRS) and African swine fever (ASF). Only two samples tested positive for Brucella antibodies (0.2%, 95% CI 0.4-0.6, n = 1141). The seroprevalence of Q fever was 0.8% (95% CI 0.3-2.1, n = 477) in the cattle samples, while CSF, PRRS and ASF in pigs were 55.4% (95% CI 51.6-59.2, n = 655), 81.2% (95% CI 78.1-84.0, n = 655) and 2.6% (95% CI 1.6-4.1, n = 664), respectively. All 38 doubtful and 17 positive ASF antibody ELISA samples were negative when tested by real-time PCR. Univariate analyses demonstrated that the factor significantly associated with positive results of ASF was the abattoir location (p-value = 0.002). Based on logistic regression models, significant risk factors for CSF were province of origin (p-value = 1.7 × 10-6), abattoir (p-value = 3.6 × 10-11) and PRRS positivity (p-value = 0.004), and for PRRS were province of origin (p-value = 0.0004) and CSF positivity (p-value = 0.001). In conclusion, the seroprevalences of zoonotic diseases in this study were very low. The high prevalence of CSF and PRRS antibodies were most likely the result of vaccination. All ASF seropositive pigs, including those that gave equivocal results, originated from large-scale Cambodian-based commercial farms, as well as Thailand, which raises questions about possible illegal vaccination or low-pathogenicity ASF variants. The pilot abattoir serological surveillance program described here has the potential to provide a sentinel for incursions of novel and endemic pathogens, although further work is required to demonstrate its capacity to provide information on the longitudinal disease trends.

Genetic diversity of wild rodents and detection of Coxiella burnetii, the causative agent of Q fever, in Saudi Arabia

Throughout history, wildlife has been regarded as a major source of infectious diseases. Rodentia, the most speciose order of mammals, whose members are recognised hosts of more than 60 zoonotic diseases, represent a potential threat to human health. Recently, epidemiological data from Saudi Arabia indicated an actual growth in the number of emerging and/or re-emerging cases of several zoonoses. However, there is a lack of studies focusing on the molecular taxonomy of rodents and the pathogens they may harbour in this region. In this study, the first molecular characterisation of six rodent taxa in this region is provided, based on partial Cyt B and 16S genes. The data confirm the spread of rodent-associated C. burnetii strains in Jazan, southwestern Saudi Arabia. The PCR targeting IS111, the multi-copy transposase gene, revealed 17.5% (36/205) positive samples, whereas the second nested PCR, targeting the single-copy Com1 gene, revealed 16.6% (34/205) positive samples. Phylogenetic and network analyses indicated the presence of four haplotypes of C. burnetii within the studied localities. One major haplotype (H-2) was observed in all rodent species and from 18 localities. The infection rates of C. burnetii among studied species, localities and habitats were not significantly different (>0.05). Our results facilitate the assessment of the health risk associated with rodents and the development of strategies to control the increasing impacts of Q fever.

Molecular detection of Coxiella-like endosymbionts and absence of Coxiella burnetii in Amblyomma mixtum from Veracruz, Mexico

Ticks are obligate ectoparasites associated with a wide range of vertebrate hosts, including domestic animals. Moreover, ticks are capable of transmitting many pathogens such as Coxiella. To date, Coxiella burnetii, the etiological agent of coxiellosis or Q fever, is the only valid species of the genera. Nevertheless, a wide range of agents denominated Coxiella-like have been detected in recent studies, mainly associated with ticks. The pathogenicity of these Coxiella-like agents is controversial as some of them can infect both birds and humans. In Mexico, knowledge about Q fever is scarce and limited to historical serological records, and there is an overall lack of molecular proof of any agent of the genus Coxiella circulating in the country. Therefore, the aim of this study was to detect the presence of Coxiella in ticks associated with cattle in all 10 regions of Veracruz, Mexico. To accomplish this objective, first, we identified ticks collected from cattle and horses in Veracruz. Then, for Coxiella detection, DNA extraction from ticks and PCR amplification of the 16S-rDNA of Coxiella was performed. Finally, we performed a phylogenetic reconstruction to determine the Coxiella lineages detected. From the 10 regions sampled we collected 888 ticks grouped in 180 pools, and only five Amblyomma mixtum from the locality of Castán, and one from Los Angeles from Tuxpan were found positive, which represents a frequency of 20% for each locality. This study represents the first attempt at molecular detection of Coxiella in ticks associated with cattle in the state of Veracruz, the major livestock producer in the country. The findings of the present study are relevant as they establish a precedent regarding the circulation of Coxiella-like agents, as well as the absence in three municipalities of the state of Veracruz of C. burnetii, an abortive agent of livestock importance.

Presence of Coxiella burnetii in dairy cattle and farms in the Czech Republic

The aims of this study were to evaluate the prevalence of Coxiella burnetii on both herd and animal level based on ELISA and PCR tests. Antibodies to C. burnetii were detected in 22 out of the 24 bulk tank milk samples (91.6%) tested by ELISA and the IS1111 element of C. burnetii was detected in 10 out of the 24 samples (41.6%) by real-time polymerase chain reaction (PCR). ELISA testing showed individual seropositivity in 67 out of the 165 cows (40.6%) examined in 24 dairy cattle farms in different parts of the Czech Republic. Our study revealed that the prevalence of C. burnetii has increased substantially in the Czech Republic over the past 30 years, and that the causative agent is a potential risk factor for some reproductive problems in dairy farms and a possible risk factor for human infection.

Evaluation of the sensitivity and specificity of three diagnostic tests for Coxiella burnetii infection in cattle and buffaloes in Punjab (India) using Bayesian latent class analysis

Q Fever is a zoonotic disease of significant animal and public health concern, caused by Coxiella burnetii (C. burnetii), an obligate intracellular bacterium. This study was done to evaluate the diagnostic sensitivity (DSe) and diagnostic specificity (DSp) of three diagnostic methods to diagnose C. burnetii infection in cattle and buffaloes in Punjab, India: an indirect ELISA method applied in serum samples and a trans-Polymerase Chain Reaction (trans-PCR) technique applied in milk samples and genital swabs, using a Bayesian latent class analysis. Conditional independence was assumed between the tests, given (i) the different biological principle of ELISA and trans-PCR and (ii) the fact that the trans-PCR was performed on different tissues. The ELISA method in the serum samples showed the highest DSe of 0.97 (95% Probability Intervals (PIs): 0.93; 0.99) compared to the trans-PCR method applied in milk samples 0.76 (0.63; 0.87) and genital swabs 0.73 (0.58; 0.85). The DSps of all tests were high, with trans-PCR in genital swabs recording the highest DSp of 0.99 (0.98; 1), while the DSp of trans-PCR in milk samples and ELISA in serum samples were 0.97 (0.95; 0.99) and 0.95 (0.93; 0.97) respectively. The study results show that none of the applied tests are perfect, therefore, a testing regimen based on the diagnostic characteristic of the tests may be considered for diagnosis of C. burnetii.

Shedding and extensive and prolonged environmental contamination of goat farms of Q fever patients by Coxiella burnetii

BACKGROUND

A majority (>70%) of Q fever patients in South Korea do not have a history of animal contact. Therefore, unconscious environmental exposure is suspected. The aim of this study was to investigate exposure of Q fever patients to environmental contamination and animal shedding.

METHODS

Two goat farmers were enrolled. One was diagnosed with Q fever 3 years ago (Farm 1). Among 20 goats on Farm 1, five were tested randomly and found to be Q fever PCR-positive. Three of the five were Q fever ELISA-positive. Two of five environmental samples taken in 2015 were PCR-positive. In 2018, 17 of 18 environmental samples were PCR-positive. On Farm 2, 54 of the 77 goats were PCR-positive, and 63 were ELISA-positive. Twelve of 14 environmental samples were PCR-positive. Repeat administration of oxytetracycline to goats led to a gradual reduction in PCR-positive tests over a 5-month period. However, PCR-positivity of the farm environment persisted for 5 months.

CONCLUSION

The environment on farms owned by Q fever patients was contaminated extensively and persistently, even after antibiotic treatment of goats and environmental decontamination. Undetected environmental contamination can be a major source of sporadic Q fever infection in South Korea.

First case of Coxiella burnetii infection in Palaemonetes sinensis cultured in Liaoning, China

The Palaemonetes sinensis aquaculture industry in Panjin City, Liaoning Province, China, experienced heavy losses in October 2018. Morbidity of cultured shrimp reached 50% and was characterized by cloudiness of muscle and the gradual spread of disease within the population. When the infection was mild, histopathological examinations revealed that the muscle cells contained a considerable number of microorganisms. In extreme cases, the structure of the hepatopancreatic glandular and muscle fiber was obscured or even vanished. Electron microscope observations revealed the presence of granular cytoplasmic inclusions in cells from hepatopancreas and muscle tissues. The 16S rDNA sequence of the intracytoplasmic organism was 94.7% identity to that of Coxiella burnetii. This is the first report of infection by C. burnetii in P. sinensis.

Q fever expertise among human and veterinary health professionals in Germany - A stakeholder analysis of knowledge gaps

Q fever is a zoonosis caused by Coxiella burnetii. In Germany, the common sources of human infections include small ruminants that excrete the pathogen. Q fever in humans can be asymptomatic or nonspecific. However, severe disease progression is also possible, which can lead to death. Q fever in small ruminants is usually asymptomatic, although reproductive disorders may occur. To protect humans from Q fever, it is important that human and veterinary health professionals (practitioners/health authority employees) have comprehensive knowledge of the diagnosis, control and prevention of Q fever, and its zoonotic potential. To ensure and enhance this understanding, this stakeholder analysis assessed Q fever expertise in human and veterinary health professionals in Germany and investigated how these knowledge gaps can best be resolved. For this purpose, an online survey and two focus group discussions were conducted with 836 and 18 participants, respectively. Knowledge gaps are due to a lack of awareness of Q fever, especially among human health practitioners. Moreover, colleagues who have heard about Q fever still lack the necessary cross-species knowledge to successfully diagnose, control and prevent this zoonosis. Additionally, differences exist between stakeholders regarding their work context and the region in which they work. In this study, stakeholders in southwestern Germany had slightly better Q fever knowledge than their colleagues in northeastern Germany. In addition, information sources aimed at resolving knowledge gaps involve direct conversations between the stakeholders, as well as reading materials and seminars. Each of these information sources should focus on interdisciplinary resources to strengthen the cooperation between human and veterinary health professionals and to raise awareness of the strengths of each stakeholder group. These results have already been implemented by the Q-GAPS project, with goals of raising awareness of Q fever and filling knowledge gaps.

Sero-epidemiological survey of Coxiella burnetii in livestock and humans in Tana River and Garissa counties in Kenya

Background

Coxiella burnetii is a widely distributed pathogen, but data on its epidemiology in livestock, and human populations remain scanty, especially in developing countries such as Kenya. We used the One Health approach to estimate the seroprevalance of C. burnetii in cattle, sheep, goats and human populations in Tana River county, and in humans in Garissa county, Kenya. We also identified potential determinants of exposure among these hosts.

Methods

Data were collected through a cross-sectional study. Serum samples were taken from 2,727 animals (466 cattle, 1,333 goats, and 928 sheep) and 974 humans and screened for Phase I/II IgG antibodies against C. burnetii using enzyme-linked immunosorbent assay (ELISA). Data on potential factors associated with animal and human exposure were collected using a structured questionnaire. Multivariable analyses were performed with households as a random effect to adjust for the within-household correlation of C. burnetii exposure among animals and humans, respectively.

Results

The overall apparent seroprevalence estimates of C. burnetii in livestock and humans were 12.80% (95% confidence interval [CI]: 11.57–14.11) and 24.44% (95% CI: 21.77–27.26), respectively. In livestock, the seroprevalence differed significantly by species (p < 0.01). The highest seroprevalence estimates were observed in goats (15.22%, 95% CI: 13.34-17.27) and sheep (14.22%, 95% CI: 12.04–16.64) while cattle (3.00%, 95% CI: 1.65–4.99) had the lowest seroprevalence. Herd-level seropositivity of C. burnetii in livestock was not positively associated with human exposure. Multivariable results showed that female animals had higher odds of seropositivity for C. burnetii than males, while for animal age groups, adult animals had higher odds of seropositivity than calves, kids or lambs. For livestock species, both sheep and goats had significantly higher odds of seropositivity than cattle. In human populations, men had a significantly higher odds of testing positive for C. burnetii than women.

Conclusions

This study provides evidence of livestock and human exposure to C. burnetii which could have serious economic implications on livestock production and impact on human health. These results also highlight the need to establish active surveillance in the study area to reduce the disease burden associated with this pathogen.

Q fever caused by Coxiella burnetii is a significant zoonotic disease that affects wildlife, domestic animals and humans. This study determined the prevalence of antibodies to C. burnetii in livestock (cattle, sheep, and goats) and human populations in arid and semi-arid areas of Kenya between December 2013 and February 2014. We also identified potential factors that were associated with exposure among the above-targeted hosts. Results from this study showed considerable exposure in both livestock and human populations. However, human exposure to this pathogen at the household level was not correlated with herd-level seropositivity. Further studies are needed to elucidate the transmission routes of this pathogen among humans.

Detection of Coxiella burnetii DNA in sheep and goat milk and dairy products by droplet digital PCR in south Italy

Coxiella burnetii is a Gram-negative obligate intracellular bacterium that is responsible for Q fever, a common zoonosis which is present virtually worldwide. This microorganism infects a wide range of wild and domestic mammals, but the main reservoirs are cattle, goats and sheep, which also represent sources of human infection. A potential route of transmission of this pathogen to humans is the consumption of C. burnetii-contaminated raw milk or dairy products derived from contaminated raw milk, although the role of these foods as possible infection sources is controversial. The aims of this study were (i) to apply two ddPCR based assays targeting the C. burnetii IS1111 and icd genes for the detection and quantification of C. burnetii DNA, and (ii) to evaluate the occurrence of C. burnetii DNA in raw milk and raw milk products from sheep and goats in Apulia and Basilicata regions of Southern Italy. Of 413 milk and cheese samples tested, 78 were positive for the presence of C. burnetii DNA (18.9%), specifically, 68 of 285 milk samples (23.9%) and 10 of 128 cheese samples (7.8%) The presence of both IS1111 and icd genes was detected in only 2 (2.6%) of the 78 positive samples, while the remaining 76 (97.4%) were positive only for IS1111. C. burnetii DNA was specifically detected by the ddPCR method, whereas no cross-amplification was observed with the DNA of other foodborne bacterial pathogens. The sensitivity of the ddPCR method was determined as 0.35 and 0.56 copies/μL for IS1111 and icd genes, respectively. The findings of this study demonstrate the presence of C. burnetii DNA in a significant proportion of raw milk and dairy products. Although there is no conclusive epidemiological evidence that C. burnetii infection occurs via food, the presence of this organism in raw milk and dairy products made of raw milk should be considered a potential hazard. ddPCR is a useful tool to investigate the quality and safety of food products due to its sensitivity and precision, and could be applied to routine testing.

Seroprevalence of brucellosis, Q fever and Rift Valley fever in domestic ruminants in Guinea in 2017-2019

BACKGROUND

Brucellosis, Q fever and Rift Valley fever are considered as Neglected Zoonotic Diseases (NZDs) leading to socioeconomic losses in livestock globally, and particularly in developing countries of Africa where they are under-reported. In this study, we evaluated the seroprevalence of these 3 zoonotic diseases in domestic ruminants in Guinea from 2017 to 2019. A total of 1357 sera, sampled from 463 cattle, 408 goats and 486 sheep, were collected in 17 Guinean prefectures and analyzed by enzyme-linked immunosorbent assay (ELISA).

RESULTS

Cattle was the species with highest seroprevalence (5 to 20-fold higher than in small ruminants) for the three diseases. The seroprevalence of brucellosis, mostly focused in Western Guinea, was 11.0% (51 of 463) in cattle, 0.4% (2 in 486) in sheep while no specific antibodies were found in goats. Q fever, widespread across the country, was the most frequently detected zoonosis with a mean seroprevalence of 20.5% (95 in 463), 4.4% (18 in 408) and 2.3% (11 in 486) in cattle, goats and sheep, respectively. The mean seroprevalence of RVF was 16.4% (76 in 463) in cattle, 1.0% (4 in 408) in goats and 1.0% (5 in 486) in sheep. Among the samples 19.3% were seropositive for at least one of the three NZDs, 2.5% showed specific antibodies against at least two pathogens and 4 cattle (0.8%) were seropositive for all three pathogens. In cattle, adults over 3-years old and females presented a higher antibody seroprevalence for the three diseases, in congruence with putative exposure risk.

CONCLUSIONS

This study confirms the circulation of these three zoonotic pathogens in Guinea and highlights the need for implementing a syndromic surveillance of ruminant abortions by the Guinean veterinary authorities as well as for the screening of the human population at risk (veterinarians, breeders, slaughterers) in a One Health perspective.

Coxiella burnetii abortion in a dairy farm selling artisanal cheese directly to consumers and review of Q fever as a bovine abortifacient in South America and a human milk-borne disease

Coxiella burnetii is a highly transmissible intracellular bacterium with a low infective dose that causes Q fever (coxiellosis), a notifiable zoonotic disease distributed worldwide. Livestock are the main source of C. burnetii transmission to humans, which occurs mostly through the aerogenous route. Although C. burnetii is a major abortifacient in small ruminants, it is less frequently diagnosed in aborting cattle. We report a case of C. burnetii abortion in a lactating Holstein cow from a dairy farm producing and selling artisanal cheese directly to consumers in Uruguay, and review the literature on coxiellosis as a bovine abortifacient in South America and as a milk-borne disease. The aborted cow had severe necrotizing placentitis with abundant intratrophoblastic and intralesional C. burnetii confirmed by immunohistochemistry and PCR. After primo-infection in cattle, C. burnetii remains latent in the lymph nodes and mammary glands, with milk being a significant and persistent excretion route. Viable C. burnetii has been found in unpasteurized milk and cheeses after several months of maturing. The risk of coxiellosis after the consumption of unpasteurized dairy products, including cheese, is not negligible. This report raises awareness on bovine coxiellosis as a potential food safety problem in on-farm raw cheese manufacturing and sales. The scant publications on abortive coxiellosis in cattle in South America suggest that the condition has probably gone underreported in all countries of this subcontinent except for Uruguay. Therefore, we also discuss the diagnostic criteria for laboratory-based confirmation of C. burnetii abortion in ruminants as a guideline for veterinary diagnosticians.

Coxiella burnetii in 3 Species of Turtles in the Upper Midwest, United States

Coxiella burnetii, the causative bacterium of the zoonotic disease Q fever, has been documented in many different species. We describe documented turtles that were PCR positive for C. burnetii from multiple locations in Illinois and Wisconsin, USA. Assessing the conservation implications, reservoir potential, and zoonotic risk requires further research.

High Coxiella burnetii Seroconversion Rate in Veterinary Students, the Netherlands, 2006-2010

We examined Coxiella burnetii seroconversion rates by measuring C. burnetii IgG among 2 cohorts of veterinary students. During follow-up of 118 seronegative veterinary students, 23 students seroconverted. Although the clinical importance of the presence of antibodies is unknown, veterinary students should be informed about the potential risks for Q fever.

Seroprevalence of Coxiella burnetii in patients presenting with acute febrile illness at Marigat District Hospital, Baringo County, Kenya

Q fever is not routinely diagnosed in Kenyan hospitals. This study reports on Q fever in patients presenting at Marigat District Hospital, Kenya, with febrile illness. ELISA was used to detect Coxiella burnetii phase antigens. Of 406 patients, 45 (11.1%) were judged to have acute disease (phase II IgM or IgG > phase I IgG), 2 (0.5%) were chronic (phase I IgG titer >800 or phase I IgG > phase II IgG), while 26 (6.4%) had previous exposure (phase I IgG titer <800). Age (6–10 years, p = 0.002) and contact with goats (p = 0.014) were significant risk factors. Compared to immunofluorescence antibody test, the sensitivity and specificity for phase I IgG were 84% and 98%, respectfully, 46% and 100% for phase II IgG and 35% and 89% for phase II IgM. It is concluded that the low sensitivity of phase II ELISA underestimated the true burden of acute Q fever in the study population.

Molecular detection of Coxiella burnetii infection in small mammals from Moshi Rural and Urban Districts, northern Tanzania

Coxiella burnetii is an obligate intracellular bacterium that causes Q fever, a zoonotic disease of public health importance. In northern Tanzania, Q fever is a known cause of human febrile illness, but little is known about its distribution in animal hosts. We used a quantitative real-time PCR (qPCR) targeting the insertion element IS1111 to determine the presence and prevalence of C. burnetii infections in small mammals trapped in 12 villages around Moshi Rural and Moshi Urban Districts, northern Tanzania. A total of 382 trapped small mammals of seven species were included in the study; Rattus rattus (n = 317), Mus musculus (n = 44), Mastomys natalensis (n = 8), Acomys wilson (n = 6), Mus minutoides (n = 3), Paraxerus flavovottis (n = 3) and Atelerix albiventris (n = 1). Overall, 12 (3.1%) of 382 (95% CI: 1.6-5.4) small mammal spleens were positive for C. burnetii DNA. Coxiella burnetii DNA was detected in five of seven of the small mammal species trapped; R. rattus (n = 7), M. musculus (n = 1), A. wilson (n = 2), P. flavovottis (n = 1) and A. albiventris (n = 1). Eleven (91.7%) of twelve (95% CI: 61.5-99.8) C. burnetii DNA positive small mammals were trapped within Moshi Urban District. These findings demonstrate that small mammals in Moshi, northern Tanzania are hosts of C. burnetii and may act as a source of C. burnetii infection to humans and other animals. This detection of C. burnetii infections in small mammals should motivate further studies into the contribution of small mammals to the transmission of C. burnetii to humans and animals in this region.

Seroprevalence of Coxiella burnetii in a dairy cattle herd from the Al Ain region, United Arab Emirates

The present study assessed the serostatus of Coxiella burnetii in a dairy cattle herd from the Al Ain region, UAE. In addition, the study evaluated the relationship between C. burnetii seropositivity and history of abortion and cattle age. Blood/sera from 759 cattle were tested by ELISA, and the data analyzed by the Pearson Chi-square test (PCST), odds ratios, and logistic regression. Of the 759 study cattle, 36.5% (277/759) were seropositive while 63.5% (482/759) were seronegative for C. burnetii. Additionally, 19.5% (148/759) of the cattle had ever aborted while 80.5% (611/759) had not. Meanwhile, 34.3% (95/277) of the C. burnetii-seropositive cattle (CBSPos) had history of abortion while 65.7% (182/277) did not. By comparison, only 11.0% (53/482) of the C. burnetii-seronegative (CBSNeg) cattle had history of abortion while 89.0% (429/482) had never aborted. The difference in the conditional probabilities of CBSPos or CBSNeg cattle that had history of abortion was statistically significant (PCST; p value 0.001), as was the association between a CBSPos outcome and history of abortion (p value 0.0001). Moreover, the odds of prior abortion having occurred in CBSPos were 4.3 times higher than in CBSNeg cattle. Similarly, the log of the odds of past abortions was positively correlated with C. burnetii seropositivity and cattle age (p value < 0.001). These data demonstrate apparent C. burnetii infections in cattle from the UAE in which the risk of abortion appears to increase with cattle age. Molecular testing for C. burnetii and comprehensive investigations of other abortigenic pathogens in the study cattle herd are recommended.

Molecular epidemiology of Coxiella Brunetii in small ruminants in Punjab, Pakistan: a novel reporting analytical cross sectional study

Coxiella burnetii, an intracellular zoonotic bacterium, causes query (Q) fever in ruminants. Its role has never been elucidated in small ruminants from Pakistan. The current study is designed to (a) determine the prevalence of coxiellosis in small ruminants, (b) evaluate the association of various potential risk factors and biomarkers in the occurrence of Coxiella burnetii, (c) and determine phylogeny and genetic variability of its various isolates identified during the study. For this purpose, 320 blood samples from sheep (n = 160) and goats (n = 160) were collected from 9 Union Councils of district Kasur, Punjab, and processed for DNA extraction. C. burnetii was confirmed by amplification of IS1111 transposase gene with an amplicon size of 294 bp. The results showed that the overall positive percentage of C. burnetii is 36.87% (sheep: 46.9% and goats: 30%). The phylogenetic tree was also constructed which described the possible origin of this pathogen from environment. Besides, after translation into amino acid, the resultant alignment showed several unique changes at position numbers 18 and 27 in the isolates from goats and at 27 and 66 from those of sheep. These mutations can have major impact on the infectious characteristics of this pathogen. Furthermore, different potential risk factors and clinical biomarkers like age, tick infestation, abortion, mastitis, and infertility were also studied and found that these are significantly (p < 0.05) associated with the occurrence of coxiellosis. It is concluded from the study that C. burnetii is endemic in small ruminants in Punjab, Pakistan. The outcomes of this study are alarming for scientific community as well as for policy makers because coxiellosis is an emerging threat to both humans and animals in this region due to its interspecies transmission ability.

Molecular investigation, isolation and phylogenetic analsysis of Coxiella burnetii from aborted fetus and ticks

Q fever is a zoonotic infection threatening human health, causing abortions in cattle, sheep and goats. Coxiella burnetii (C. burnetii) also causes serious problems such as low birth weight, infertility. This study is the first exemplary for analysis of Q fever around Black Sea region in Turkey. In the study, a total of 270 aborted fetuses (171 cattle, 79 sheep, 20 goats) and 1069 tick samples were aimed to be searched by PCR method. C. burnetii DNA was detected in 8 (2.96 %) of 270 sheep specimens while it could not be found in cattle and goat specimens. 406 sample pools were created from 1069 tick samples (490 male, 579 female) collected from 254 farm animals (187 cattle, 54 sheep, 13 goats) and 11 of these were stated positive. Tick species determined as C. burnetii positive were Hyalomma marginatum, Hyalomma anoliticum excavatum, Hyalomma detritum and Boophilus annulatus. Agent isolation was carried out within embryonated eggs. Agents were stained with Giemsa and was showed. Sequence analysis was performed for TUR/SAM/coxiella_1 (MN917207) isolate and phylogenetic tree was created. This tree, created in compliance with IS1111 transposon gene, did not form different branches in regard to host affiliation (goat, sheep, tick, human) and geographical distribution. As a result, an important zoonotic agent, C. burnetii was diagnosed in sheep aborted fetuses and the infection was proved to have spread among sheep herds in Black Sea region. Besides, 4 separate tick species found in our region hosted the agent and were found important for infection.