An outbreak of Q fever associated with parturient cat exposure at an animal refuge and veterinary clinic in southeast Queensland

Prevalence and risk factors of coxiellosis in meat goat herds: an epidemiological investigation in Northeastern Thailand

Q fever/coxiellosis poses a significant threat to both human and animal health, with goats serving as important reservoirs for disease transmission. This study aimed to evaluate the prevalence of coxiellosis and identify associated risk factors within meat goat herds in northeastern Thailand. A total of 39 meat goat herds were examined, with 84.61% of these herds experiencing reproductive disorders suggestive of Coxiella burnetii infection. Serum samples (n = 513) and vaginal swabs (n = 334) were collected from 522 goats for serological and molecular analyses, respectively. Results unveiled an overall herd prevalence of 74.35% (29/39), with a within-herd prevalence of 15.49% (95% CI: 10.86-20.12). Univariate analysis indicated that knowledge about the transmission of coxiellosis in herd owners serves as a protective factor against C. burnetii infection at the herd level (OR: 0.10; 95% CI: 0.01-0.92; p = 0.04). Multivariable analysis identified two significant risk factors associated with C. burnetii infection at the herd level, including herd establishment exceeding 5 years (OR: 7.14; 95% CI: 1.05-48.4; p = 0.04), as well as reproductive failures including abortion, infertility, and weak offspring (OR: 17.65; 95% CI: 1.76-177.45; p = 0.01). Individual-level risk factors included female gender (OR: 8.42; 95% CI: 1.14-62.42; p = 0.03), crossbreeding (OR: 2.52; 95% CI: 1.32-4.82; p = 0.005), and clinical signs of anaemia (OR: 1.63; 95% CI: 1.01-2.64; p = 0.04). These findings underscore the widespread prevalence of Q fever in meat goat herds within the study area and emphasize the necessity of implementing targeted control strategies.

A systematic review of global Q fever outbreaks

Q fever is an important zoonotic disease with a worldwide distribution. Outbreaks of Q fever are unpredictable and can affect many people, resulting in a significant burden on public health. The epidemiology of the disease is complex and substantial efforts are required to understand and control Q fever outbreaks. The purpose of this study was to systematically review previous investigations of outbreaks and summarise important epidemiological features. This will improve knowledge of the factors driving the occurrence of Q fever outbreaks and assist decision makers in implementing mitigation strategies. A search of four electronic databases identified 94 eligible articles published in English between 1990 and 2022 that related to 81 unique human Q fever outbreaks. Outbreaks were reported across 27 countries and mostly in industrialised nations. Documented Q fever outbreaks varied in size (2 to 4107 cases) and duration (4 to 1722 days). Most outbreaks (43/81) occurred in communities outside of traditional at-risk occupational settings and were frequently associated with living in proximity to livestock holdings (21/43). Indirect transmission via environmental contamination, windborne spread or fomites was the most common route of infection, particularly for large community outbreaks. Exposure to ruminants and/or their products were confirmed as the principal risk factors for infection, with sheep (28/81) as the most common source followed by goats (12/81) and cattle (7/81). Cooperation and data sharing between human and animal health authorities is valuable for outbreak investigation and control using public health and veterinary measures, but this multisectoral approach was seldom applied (14/81). Increased awareness of Q fever among health professionals and the public may facilitate the early detection of emerging outbreaks that are due to non-occupational, environmental exposures in the community.

Coxiella burnetii Infection in Cats

Q fever is a zoonotic disease caused by Coxiella burnetii, with farm ruminants being considered the main sources of infection for humans. However, there have been several cases of the disease in people that have been related to domestic cats as well. Cats can become infected through various routes, including ingestion of raw milk, hunting and consuming infected rodents and birds, consumption of contaminated pet food, inhalation of contaminated aerosols and dust, and bites from hematophagous arthropods. Infected cats typically do not show symptoms, but pregnant queens may experience abortion or give birth to weak kittens. Accurate diagnosis using serological and molecular methods is crucial in detecting infected cats, allowing for prompt action with appropriate treatments and preventive measures. Breeders, cattery personnel, veterinarians, and owners should be informed about the risks of C. burnetii infections associated with cats experiencing reproductive disorders.

Educational intervention to improve infection prevention and control practices in four companion animal clinics in Switzerland

BACKGROUND

Infection prevention and control (IPC) practices vary among companion animal clinics, and outbreaks with carbapenemase-producing Enterobacterales (CPE) have been described.

AIM

To investigate the effect of an IPC intervention (introduction of IPC protocols, IPC lectures, hand hygiene campaign) in four companion animal clinics.

METHODS

IPC practices, environmental and hand contamination with antimicrobial-resistant micro-organisms (ARM) and hand hygiene (HH) were assessed at baseline, and 1 and 5 months after the intervention.

RESULTS

Median IPC scores (% maximum score) improved from 57.8% (range 48.0-59.8%) to 82.9% (range 81.4-86.3%) at 1-month follow-up. Median cleaning frequency assessed by fluorescent tagging increased from 16.7% (range 8.9-18.9%) to 30.6% (range 27.8-52.2%) at 1-month follow-up and 32.8% (range 32.2-33.3%) at 5-month follow-up. ARM contamination was low in three clinics at baseline and undetectable after the intervention. One clinic showed extensive contamination with ARM including CPE before and after the intervention (7.5-16.0% ARM-positive samples and 5.0-11.5% CPE-positive samples). Mean HH compliance improved from 20.9% [95% confidence interval (CI) 19.2-22.8%] to 42.5% (95% CI 40.4-44.7%) at 1-month follow-up and 38.7% (95% CI 35.7-41.7%) at 5-month follow-up. Compliance was lowest in the pre-operative preparation area at baseline (11.8%, 95% CI 9.3-14.8%) and in the intensive care unit after the intervention (28.8%, 95% CI 23.3-35.1%). HH compliance was similar in veterinarians (21.5%, 95% CI 19.0-24.3%) and nurses (20.2%, 95% CI 17.9-22.7%) at baseline, but was higher in veterinarians (46.0%, 95% CI 42.9-49.1%) than nurses (39.0%, 95% CI 36.0-42.1%) at 1-month follow-up.

CONCLUSION

The IPC intervention improved IPC scores, cleaning frequency and HH compliance in all clinics. Adapted approaches may be needed in outbreak situations.

Coxiella burnetii in Dogs and Cats from Portugal: Serological and Molecular Analysis

Dogs and cats are potential sources of infection for some zoonotic diseases such as Q fever, caused by Coxiella burnetii, a multiple host pathogen. Q fever outbreaks in dogs and cats have been related with parturition and abortion events, and ticks have a potential role in the transmission of this pathogen. This study aimed to screen for C. burnetii in dogs and cats, and in ticks collected from infested animals. An observational descriptive study was conducted in Portugal at two time points nine years apart, 2012 and 2021. Sera obtained from dogs and cats (total n = 294) were tested for C. burnetii antibodies using a commercial ELISA adapted for multi-species detection. C. burnetii DNA was screened by qPCR assay targeting IS1111 in uterine samples and in ticks. A decrease in the exposure to C. burnetii was observed in cats from 17.2% (95% CI: 5.8−35.8%) in 2012 to 0.0% in 2021, and in dogs from 12.6% (95% CI: 7.7−19.0%) in 2012 to 1.7% (95% CI: 0.3−9.1%) in 2021 (p < 0.05). Overall, and despite differences in the samples, rural habitat seems to favour the exposure to C. burnetii. The DNA of C. burnetii was not detected in ticks. The low seropositivity observed in 2021 and the absence of C. burnetii DNA in the tested samples, suggest that dogs and cats from Portugal are not often exposed to the pathogen. Nevertheless, the monitoring of C. burnetii infection in companion animals is an important tool to prevent human outbreaks, considering the zoonotic potential for owners and veterinarians contacting infected animals, mainly dogs and cats from rural areas which often come into contact with livestock.

Profiling Risk Factors for Household and Community Spatiotemporal Clusters of Q Fever Notifications in Queensland between 2002 and 2017

Q fever, caused by the bacterium Coxiella burnetii, is an important zoonotic disease worldwide. Australia has one of the highest reported incidences and seroprevalence of Q fever, and communities in the state of Queensland are at highest risk of exposure. Despite Australia’s Q fever vaccination programs, the number of reported Q fever cases has remained stable for the last few years. The extent to which Q fever notifications cluster in circumscribed communities is not well understood. This study aimed to retrospectively explore and identify the spatiotemporal variation in Q fever household and community clusters in Queensland reported during 2002 to 2017, and quantify potential within cluster drivers. We used Q fever notification data held in the Queensland Notifiable Conditions System to explore the geographical clustering patterns of Q fever incidence, and identified and estimated community Q fever spatiotemporal clusters using SatScan, Boston, MA, USA. The association between Q fever household and community clusters, and demographic and socioeconomic characteristics was explored using the chi-squared statistical test and logistic regression analysis. From the total 2175 Q fever notifications included in our analysis, we found 356 Q fever hotspots at a mesh-block level. We identified that 8.2% of Q fever notifications belonged to a spatiotemporal cluster. Within the spatiotemporal Q fever clusters, we found 44 (61%) representing household clusters and 20 (27.8%) were statistically significant with an average cluster size of 3 km radius. Our multivariable model shows statistical differences between cases belonging to clusters in comparison with cases outside clusters based on the type of reported exposure. In conclusion, our results demonstrate that clusters of Q fever notifications are temporally stable and geographically circumscribed, indicating a persistent common exposure. Furthermore, within individuals in household and community clusters, abattoir exposure (a traditional occupational exposure) was rarely reported by individuals.

A cross-sectional survey of risk factors for the presence of Coxiella burnetii in Australian commercial dairy goat farms

The largest Australian farm‐based outbreak of Q fever originated from a dairy goat herd. We surveyed commercial dairy goat farms across Australia by testing bulk tank milk (BTM) samples using a commercial indirect enzyme‐linked immunosorbent assay and two quantitative polymerase chain reactions (PCRs). Of the 66 commercial dairy goat herds on record, managers from 61 herds were contacted and 49 provided BTM samples. Five of the surveyed herds were positive on at least one of the diagnostic tests, thus herd‐level apparent prevalence was 10% (95% confidence interval [CI] 4 to 22). True prevalence was estimated to be 3% (95% credible interval: 0 to 18). Herd managers completed a questionnaire on herd management, biosecurity and hygiene practices and risk factors were investigated using multivariable logistic regression. Herds with >900 milking does (the upper quartile) were more likely to be Coxiella burnetii positive (odds ratio = 6.75; 95% CI 1.65 to 27.7) compared with farms with ≤900 milking does. The odds of BTM positivity increased by a factor of 2.53 (95% CI 1.51 to 4.22) for each order of magnitude increase in the number of goats per acre. C. burnetii was not detected in samples from the majority of the Australian dairy goat herds suggesting there is an opportunity to protect the industry and contain this disease with strengthened biosecurity practices. Intensification appeared associated with an increased risk of positivity. Further investigation is required to discriminate the practices associated with an increased risk of introduction to disease‐free herds, from practices associated with maintenance of C. burnetii infection in infected dairy goat herds.

Serological Prevalence of and Risk Factors for Coxiella burnetti Infection in Women of Punjab Province, Pakistan

Background: Coxiella burnetii, the etiological agent of Q (query) fever, provokes abortions in ruminants and is suspected to cause adverse pregnancy outcomes in women. Infection of pregnant women is linked with high mortality and morbidity of the fetus and the mother is at high risk to acquire chronic Q fever. This research was conducted to evaluate the prevalence of Q fever in women and to detect associated risk factors in four districts of Punjab Province, Pakistan. Methods: A total of 297 blood samples were obtained from 147 pregnant and 150 non-pregnant women of the districts Okara, Jhang, Chiniot and Faisalabad of Punjab, Pakistan. Data related to risk factors and demographic parameters were collected using a questionnaire. Serum samples were screened for phase I and phase II specific IgG antibodies for antigens of phase I and phase II using ELISA tests. Univariate and binary regression were used to analyze important risk factors of Q fever. Results: Twenty-five serum samples (8.4%) were found seropositive for Q fever. Seventeen women were positive for Phase-I and twenty-one were positive for phase-II antibodies. Highest and statistically significant (p < 0.05) seroprevalence of 17.1% was observed in Faisalabad. Age, urbanicity, living status, pregnancy status, abortion history, occupation, and consumption of tap water were positively correlated (p < 0.05) with Q fever, while being aged, urbanity, low income, contact with animals and consumption of tap water was identified as potential risk factors. Conclusions: Q fever is prevalent in women of Pakistan. There is a need for an awareness program about the importance of C. burnetii infections and prevention strategies in women during pregnancy to minimize adverse pregnancy outcomes.

Illuminating the bacterial microbiome of Australian ticks with 16S and Rickettsia-specific next-generation sequencing

Next-generation sequencing (NGS) studies show that mosquito and tick microbiomes influence the transmission of pathogens, opening new avenues for vector-borne pathogen control. Recent microbiological studies of Australian ticks highlight fundamental knowledge gaps of tick-borne agents. This investigation explored the composition, diversity and prevalence of bacteria in Australian ticks (n = 655) from companion animals (dogs, cats and horses). Bacterial 16S NGS was used to identify most bacterial taxa and a Rickettsia-specific NGS assay was developed to identify Rickettsia species that were indistinguishable at the V1-2 regions of 16S. Sanger sequencing of near full-length 16S was used to confirm whether species detected by 16S NGS were novel. The haemotropic bacterial pathogens Anaplasma platys, Bartonella clarridgeiae, “Candidatus Mycoplasma haematoparvum” and Coxiella burnetii were identified in Rhipicephalus sanguineus (s.l.) from Queensland (QLD), Western Australia, the Northern Territory (NT), and South Australia, Ixodes holocyclus from QLD, Rh. sanguineus (s.l.) from the NT, and I. holocyclus from QLD, respectively. Analysis of the control data showed that cross-talk compromises the detection of rare species as filtering thresholds for less abundant sequences had to be applied to mitigate false positives. A comparison of the taxonomic assignments made with 16S sequence databases revealed inconsistencies. The Rickettsia-specific citrate synthase gene NGS assay enabled the identification of Rickettsia co-infections with potentially novel species and genotypes most similar (97.9–99.1%) to Rickettsia raoultii and Rickettsia gravesii. “Candidatus Rickettsia jingxinensis” was identified for the first time in Australia. Phylogenetic analysis of near full-length 16S sequences confirmed a novel Coxiellaceae genus and species, two novel Francisella species, and two novel Francisella genotypes. Cross-talk raises concerns for the MiSeq platform as a diagnostic tool for clinical samples. This study provides recommendations for adjustments to Illuminaʼs 16S metagenomic sequencing protocol that help track and reduce cross-talk from cross-contamination during library preparation. The inconsistencies in taxonomic assignment emphasise the need for curated and quality-checked sequence databases.

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Bacterial pathogens identified in ticks from companion animals with 16S NGS.

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Sanger sequencing confirmed novel Coxiellaceae gen. sp. and Francisella.

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“Candidatus Rickettsia jingxinensis” was identified with Rickettsia-specific NGS.

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Comparison of taxonomic assignments in 16S sequence databases revealed errors.

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Modifications to the 16S metagenomic library protocol (Illumina) are provided.

Seroprevalence of Coxiella burnetii in pig-hunting dogs from north Queensland, Australia

The causative agent of Q fever, Coxiella burnetii, is endemic to Queensland and is one of the most important notifiable zoonotic diseases in Australia. The reservoir species for C. burnetii are classically ruminants, including sheep, cattle and goats. There is increasing evidence of C. burnetii exposure in dogs across eastern and central Australia. The present study aimed to determine if pig-hunting dogs above the Tropic of Capricorn in Queensland had similar rates of C. burnetii exposure to previous serosurveys of companion dogs in rural north-west New South Wales. A total of 104 pig-hunting dogs had serum IgG antibody titres to phase I and phase 2 C. burnetii determined using an indirect immunofluorescence assay test. Almost one in five dogs (18.3%; 19/104; 95% confidence interval 9.6%-35.5%) were seropositive to C. burnetii, with neutered dogs more likely to test positive compared to entire dogs (P = 0.0497). Seropositivity of the sampled pig-hunting dogs was one of the highest recorded in Australia. Thirty-nine owners of the pig-hunting dogs completed a survey, revealing 12.8% (5/39) had been vaccinated against Q fever and 90% (35/39) were aware that both feral pigs and dogs could potentially be sources of C. burnetii. Our findings indicate that pig hunters should be aware of the risk of exposure to Q fever during hunts and the sentinel role their dogs may play in C. burnetii exposure.

Seroepidemiologic evidence of Q fever and associated factors among workers in veterinary service laboratory in South Korea

The incidence of Q fever has rapidly increased in South Korea since 2015. This study was undertaken to investigate the seroprevalence and seroreactivity of Q fever and the risk factors associated with its seroprevalence among workers in the veterinary service laboratory (VSL) in South Korea. This seroepidemiologic study was conducted in a total of 661 human subjects out of 1,328 subjects working in 50 VSL existing in South Korea between July 15 and July 29, 2019. Data were collected by administering survey questionnaires and by analyzing collected blood samples to determine the presence of antibodies against Coxiella burnetii. The seroprevalence and seroreactivity of C. burnetii infection were determined based on serum titers as (phase II IgG ≥1:256 and/or IgM ≥1:16) and (phase II IgG ≥1:16 and/or IgM ≥1:16) as determined by indirect immunofluorescent assay. Work, work environment, behavioral risk and protective factors associated with seroprevalence of Q fever were assessed by employing multivariable logistic regression analysis. Among the 661, the seroprevalence and seroreactivity of C. burnetii infection were 7.9% and 16.0%, respectively. Multivariate logistic regression analysis showed the risk factors significantly associated with seroprevalence were the antemortem inspection of cattle, goats, or sheep (APR (adjusted prevalence ratio), 2.52; 95% CI, 1.23–4.70)), animal blood splashed into or around eyes (APR, 2.24; 95% CI, 1.04–4.41), and contact with animals having Q fever (APR, 6.58; 95% CI, 3.39–10.85) during the previous year. This study suggests the need for precautions when contact with cattle, goats, or sheep is expected, especially during the antemortem inspection, when dealing with C. burnetii infected animals, or when there is a risk of ocular contact with animal derivatives. Therefore, we recommend the consistent use of appropriate personal protective equipment and other protective measures including PPE treatment and washing of body surfaces after work to prevent C. burnetii infections among VSL staff in South Korea.

Multispecies Q Fever Outbreak in a Mixed Dairy Goat and Cattle Farm Based on a New Bovine-Associated Genotype of Coxiella burnetii

A Q fever outbreak on a dairy goat and cattle farm was investigated with regard to the One Health concept. Serum samples and vaginal swabs from goats with different reproductive statuses were collected. Cows, cats, and a dog were investigated with the same sample matrix. The farmer's family was examined by serum samples. Ruminant sera were analyzed with two phase-specific enzyme-linked immunoassays (ELISAs). Dominant immunoglobulin G (IgG) phase II levels reflected current infections in goats. The cows had high IgG phase I and II levels indicating ongoing infections. Feline, canine, and human sera tested positive by indirect fluorescent antibody test (IFAT). Animal vaginal swabs were analyzed by qPCR to detect C. burnetii, and almost all tested positive. A new cattle-associated C. burnetii genotype C16 was identified by the Multiple-Locus Variable-number tandem repeat Analysis (MLVA/VNTR) from ruminant samples. Additionally, a possible influence of 17ß-estradiol on C. burnetii antibody response was evaluated in goat sera. Goats in early/mid-pregnancy had significantly lower levels of phase-specific IgGs and 17ß-estradiol than goats in late pregnancy. We conclude that the cattle herd may have transmitted C. burnetii to the pregnant goat herd, resulting in a Q fever outbreak with one acute human case. The influence of placentation and maternal pregnancy hormones during pregnancy on the immune response is discussed.

SEROLOGICAL EVIDENCE OF COXIELLA BURNETII INFECTION IN THE WHITE RHINOCEROS (CERATOTHERIUM SIMUM) IN SOUTH AFRICA

Coxiellosis, or Query (Q) fever, a disease caused by the intracellular bacteria Coxiella burnetii, was recently described in a managed breeding herd of white rhinoceros (Ceratotherium simum) in the southeastern United States. Clinical disease often results in abortion and could represent a conservation challenge for this species. In addition to the reproductive and herd management consequences, coxiellosis is also a zoonotic disease. Infection or clinical disease in any free-ranging rhinoceros species in a national park setting has not been previously described. In this study, evidence of prior infection was measured by immunofluorescent antibody titers in 89 serum samples collected from white rhinoceros within private reserves and a national park in South Africa. Total seropositivity was 48/89 (53.9% [95% CI, 43.6-63.9%]). Animals on private reserves had a seropositivity of 21/51 (41.1% [95% CI, 27.1-55.2%]), and national park rhinoceros had a higher rate of seropositivity at 71.0% [95% CI, 55.9-86.2%] (27/38; P= 0.004). Adults had a higher seropositivity compared with subadults (P= 0.03). There was no difference in seropositivity between sexes (P > 0.05). Results demonstrate that South African white rhinoceros populations are exposed to Coxiella, which could result in underrecognized reproductive consequences. Further studies should investigate potential implications for public health and conservation management of this species.

Parturient Cat As a Potential Reservoir for Coxiella burnetii: A Hidden Threat to Pet Owners

Background: Q fever is a worldwide zoonosis caused by Coxiella burnetii. This study was carried out to investigate the occurrence of C. burnetii among apparently healthy pregnant, parturient, and postparturient dogs and cats to highlight their role in the transmission of such disease to humans. Materials and Methods: A total of 88 apparently healthy pet animals (48 dogs and 40 cats) were enrolled in this study, vaginal swabs were obtained from pregnant and postparturient animals while birth fluids were collected from parturient ones. All samples were subjected to DNA extraction followed by nested PCR for molecular detection of C. burnetii. Results: Out of 40 cats, 3 were positive for C. burnetii with an overall prevalence of 7.5%, all positive samples were birth fluids of parturient queens with a prevalence of 15.8% (3/19) while all pregnant and postparturient animals were negative. In contrast, none of 48 dogs yielded positive result. Moreover, the phylogenetic analysis and sequence identity matrix of the obtained sequence from a parturient cat showed high genetic relatedness to strains derived from human cases rather than those of ruminants to indicate the public health burden of such strain. Conclusion: This study underscores the occurrence of C. burnetii among parturient cats to point out the possible zoonotic transmission to human contacts.

Citizens' juries give verdict on whether private practice veterinarians should attend unvaccinated Hendra virus suspect horses

BACKGROUND

Hendra virus (HeV) is endemic in Australian flying foxes, posing a threat to equine and human health. Equine vaccination remains the most effective risk mitigation strategy. Many horses remain unvaccinated - even in higher-risk regions. Debate surrounding the vaccine's use is characterised by conflicting perspectives, misunderstanding and mistrust. Private veterinary practitioners are critical to early identification of public health risk through recognition, sampling and management of suspect-equine-HeV-cases. However, managing such cases can be burdensome, with some veterinarians opting not to attend unvaccinated horses or to abandon equine practice because of risk posed by HeV disease and liability.

OBJECTIVE

Ascertain the perspectives of informed citizens on what obligations (if any) private veterinarians have to attend unvaccinated horses with HeV or HeV-like disease.

METHODS

Three citizens' juries were tasked with considering approaches to managing HeV risk in Australia, including (reported here) roles and obligations of private veterinarians in responding to HeV-suspect-cases.

RESULTS

Jurors acknowledged that HeV management posed an important challenge for private veterinarians. A clear majority (27 of 31 jurors) voted that veterinarians should not be obliged to attend unvaccinated horses. All recognised that greater support for veterinarians should be a priority.

CONCLUSIONS

When informed of HeV risks and strategies for control and management, citizens appreciated the need to support veterinarians performing this critical 'One Health' role for public benefit. The current governance framework within which zoonotic disease recognition and response operates limits the contingency and scope for increasing support and efficacy of these important veterinary public health practices.

New insights on the epidemiology of Coxiella burnetii in pet dogs and cats from New South Wales, Australia

Q fever is considered one of the most important zoonoses in Australia. Whilst ruminants are the primary reservoirs for Coxiella burnetii, and the major source of human infection, human cases have also been reported following contact with pet dogs and cats. This study aimed to estimate the prevalence of seropositivity to, and bacterial shedding of, C. burnetii by pet dogs and cats in a region with a high human Q fever incidence and explore risk factors for C. burnetii exposure. Samples (serum, whole blood, reproductive tissue, reproductive swabs) and questionnaires (completed by the pet's owner) were collected from dogs and cats from eight communities across remote New South Wales (NSW), Australia. Overall 86/330 dogs (26.1%, 95% CI 21.3-30.8%) and 19/145 cats (13.1%, 95% CI 7.6-18.6%) were seropositive to C. burnetii. Seroprevalence varied significantly between communities and was highest in communities within 150 km of a 2015 human Q fever outbreak. Feeding raw kangaroo was identified as a risk factor for seropositivity (adjusted OR 3.37, 95% CI 1.21-9.43). Coxiella burnetii DNA was not detected from any dog or cat whole blood, reproductive tissue or vaginal/preputial swab using qPCR targeting the IS1111 and com1 genes. Our findings suggest that companion animals are frequently exposed to C. burnetii in western NSW. Geographical variation in C. burnetii seroprevalence amongst companion animals - which corresponds with a human Q fever outbreak - suggests a shared environmental source of infection is likely with important consequences for public and animal health. The lack of detection of C. burnetii DNA from healthy companion animals suggests that pet dogs and cats are not an important reservoir for human Q fever infection outside a narrow periparturient window.

Molecular detection of Coxiella burnetii in raw meat intended for pet consumption

The discovery of antibodies against Coxiella burnetii in cattery-confined breeding cats indicating prior or current exposure (Shapiro et al., 2015) prompted an investigation into possible sources of infection. One hypothesis was that raw meat diets containing reservoir species may provide a source of C. burnetii transmission. The aim of this pilot study was to determine whether C. burnetii DNA was present in raw meat sold exclusively for companion animal consumption. The sample population consisted of raw meat packages (n = 58) of primarily kangaroo origin, with three to four aliquots (50-120 mg) randomly selected from each package. Genomic DNA was extracted from whole tissue in each of these aliquots using a modified protocol. Three quantitative PCR assays were used for the detection of C. burnetii targeting the IS1111 gene, the heat shock operon htpAB and the C. burnetii outer membrane protein-coding gene, com1. Coxiella burnetii DNA was detected in 25/58 samples (43%) using the IS1111, htpAB and/or com1 PCR assays and confirmed by DNA sequencing. All samples amplifying a product in the com1 assay also amplified a product in the htpAB and IS1111 assays. A total of 17/58 (29%) packets were positive with all three genes, 4/58 (7%) were positive with two genes (IS1111 and htpAB) and 4/58 (7%) were positive with the IS1111 gene only. Coxiella burnetii DNA was five times more likely to be found in offal than skeletal muscle meat samples. All meat samples in which C. burnetii DNA was found were from kangaroo tissues, while samples labelled as non-kangaroo meat (n = 4) were negative. Multi-locus variable number of tandem repeat analysis (MLVA) identified three different genotypes of C. burnetii that have all been identified previously from Australian human clinical Q fever cases. Further investigations are required to determine the potential role of certain raw meats in the transmission of C. burnetii to cats and humans.

A Q fever outbreak associated to courier transport of pets

On August 3rd, 2017, a Q fever outbreak alert was issued at a courier company that in addition to urgent freight transport offered pet delivery services. The epidemiological investigation set the exposition period between June 1 and August 8. In this period, 180 workers from two operational platforms for parcel distribution located in two provinces of the Basque Country (Bizkaia and Araba) were exposed; 64 filled a questionnaire and provided blood samples for serological testing, resulting in 10 confirmed cases (15.6%) and six (9.4%) probable cases. Nine workers (8 confirmed and 1 probable) showed Q fever symptoms, including pneumonia (five cases), and required medical care services, including one hospital admission. The attack rate was 25% (16/64), being higher among workers that visited the Bizkaia platform. This suggested that the origin of the outbreak was in the Bizkaia platform, where animals in transit waited at a pet holding site until being moved to their destination. Environmental samples consisting on 19 surface dust and two aerosol samples were collected at the Bizkaia platform to investigate the presence of C. burnetti DNA. All dust samples were positive by real time PCR, the lowest Ct values being found in dust collected at the pet holding facilities, and therefore suggesting that contamination originated at the pet holding site. The genotype identified in dust was SNP1/MST13, one of the most commonly identified genotypes in goats and sheep in the Basque Country. During the exposure period, two deliveries of miniature goats were made, of which only one could be investigated and tested negative. Although the contamination source could not be unequivocally identified, transport of ruminants was banned at the company, and Q fever was included among the occupational-associated health risks.

Coxiella burnetii seroprevalence in unvaccinated veterinary workers in Australia: Evidence to support Q fever vaccination

Q fever (caused by Coxiella burnetii) is a serious zoonotic disease that occurs almost worldwide. Occupational contact with animals increases the risk of exposure, and Q fever vaccination is recommended for veterinary workers in Australia. This study aimed to investigate C. burnetii seroprevalence among unvaccinated veterinary workers in Australia and determine factors associated with a positive serological result. During 2014 and 2015, convenience sampling at veterinary conferences and workplace vaccination clinics was undertaken. Participants completed a questionnaire and provided a blood sample for C. burnetii serology. Participants were predominantly veterinarians (77%), but veterinary support staff, animal scientists, and administration workers also participated. Blood samples (n = 192) were analysed by an immunofluorescence assay and considered positive where the phase I or phase II IgG titre was ≥1/50. Seroprevalence was 19% (36/192; 95% CI 14%-25%). A positive serological result was significantly associated with (a) working in outer regional/remote areas (odds ratio [OR] 6.2; 95% CI 1.9-20.8; reference = major cities; p = .009) and (b) having spent more than 50% of total career working with ruminants (OR 4.8; 95% CI 1.7-13.5; reference = <15% of career; p = .025). These findings confirm an increased risk of exposure to C. burnetii compared to the general population, providing new evidence to support Q fever vaccination of veterinary workers in Australia.

Current perspectives on the transmission of Q fever: Highlighting the need for a systematic molecular approach for a neglected disease in Africa

Q fever is a bacterial worldwide zoonosis (except New Zealand) caused by the Gram-negative obligate intracellular bacterium Coxiella burnetii (C. burnetii). The bacterium has a large host range including arthropods, wildlife and companion animals and is frequently identified in human and livestock populations. In humans, the disease can occur as either a clinically acute or chronic aetiology, affecting mainly the lungs and liver in the acute disease, and heart valves when chronic. In livestock, Q fever is mainly asymptomatic; however, the infection can cause abortion, and the organism is shed in large quantities, where it can infect other livestock and humans. The presence of Q fever in Africa has been known for over 60 years, however while our knowledge of the transmission routes and risk of disease have been well established in many parts of the world, there is a significant paucity of knowledge across the African continent, where it remains a neglected zoonosis. Our limited knowledge of the disease across the African sub-continent have relied largely upon observational (sero) prevalence studies with limited focus on the molecular epidemiology of the disease. This review highlights the need for systematic studies to understand the routes of C. burnetii infection, and understand the disease burden and risk factors for clinical Q fever in both humans and livestock. With such knowledge gaps filled, the African continent could stand a better chance of eradicating Q fever through formulation and implementation of effective public health interventions.