Serological evidence of Coxiella burnetii infection in dogs in a regional centre

Molecular Detection of Tick-Borne Pathogens in Kumasi: With a First Report of Zoonotic Pathogens in Abattoir Workers

Tick-borne pathogens continue to infect humans and animals worldwide. By adapting to the movement of livestock, ticks facilitate the spread of these infectious pathogens. Humans in close contact with animals that could be amplifying hosts are especially at risk of being infected with tick-borne pathogens. This study involved the collection of dry blood spots (DBSs) to determine tick-borne pathogens occurring in slaughtered livestock and abattoir workers in Kumasi. This study employed the use of conventional PCR, RT-PCR, and Sanger sequencing to detect and identify the tick-borne pathogens. The resulting data was analysed using Stata version 13. A total of 175 DBSs were collected from goats (76), cattle (54), and sheep (45) in the Kumasi abattoir (130, 74.29%) and Akwatia Line slaughter slab (45, 25.71%). The pathogens identified were mostly bacterial including Anaplasma capra (9.71%), Anaplasma phagocytophilum (1.14%), and Rickettsia aeschlimannii (0.57.%). The only parasite identified was Theileria ovis (9.14%). A significant association was seen between A. capra (p < 0.001) infection and female sheep sampled from the Akwatia Line slaughter slab. Again, there was a significant association between T. ovis (p < 0.001) infections and female sheep from the Kumasi abattoir. From the human DBS (63) screened, the pathogens identified were all bacterial including Coxiella burnetii (1.89%), Rickettsia africae (1.89%), and R. aeschlimannii (1.89%). This study reports the first detection of R. aeschlimannii in livestock as well as the occurrence of the above-mentioned pathogens in humans in Ghana. Animals can serve as amplifying hosts for infectious pathogens; hence, there is an increased risk of infections among the abattoir workers. Continuous surveillance effort is essential, and abattoir workers need to protect themselves from tick bites and infectious tick-borne pathogens.

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

BACKGROUND

Although the Coxiella burnetii infection has been investigated in dogs, its role in human transmission remains to be fully established, particularly in close and daily human-dog contact settings, such as in Police K-9 Units.

METHODS

Accordingly, this study aimed to assess anti-C. burnetii antibodies in clinically healthy police officers by an in-house indirect immunofluorescence assay (IFA), and working dogs by a commercial IFA Kit, from the State Special Operations Battalion, Paraná, Southern Brazil.

RESULTS

Overall, 1/18 (5.5%) police officers and 9/30 (30.0%; CI 95% 16.66-47.88) dogs tested seropositive to anti-C. burnetii IgG antibodies.

CONCLUSIONS

To date, this is the highest prevalence of Q fever seropositivity among military dogs worldwide. Despite the low sampling rate, a statistically significant association was found between seropositivity and female dogs (p = 0.0492). Further studies with larger sample sizes should be conducted to establish the prevalence of Q Fever in other Brazilian K-9 Units. In summary, this study is the first to conduct a concomitant serosurvey of police officers and working dogs, and its findings should be considered a warning for cross-exposure and transmission of Coxiella burnetii among Police K-9 Units in Brazil and worldwide.

Q fever awareness in Australia: A scoping review

OBJECTIVE

To investigate the level of Q fever awareness in Australia.

METHODS

A scoping review was conducted by searching the electronic databases Medline, PubMed and Web of Science using keywords for Q fever, awareness, knowledge, and Australian locations. The search was initially limited to articles published in the 10 years prior to June 2022 and then extended up to and including August 2023; yielding 387 records.

RESULTS

Fifteen articles were assessed as being eligible. These articles reported on surveys and interviews conducted with farmers, veterinary practitioners and nurses, medical practitioners, policy makers, researchers, industry representatives, animal science students, cat breeders, wildlife rehabilitators, and agriculture show attendees. Farmers were the largest group represented. Level of Q fever awareness amongst these communities, including those at high-risk, was generally low. The need for increased awareness was recognised. General practitioner awareness levels were low and recognised to be so by high-risk groups. Awareness of preventive measures including vaccination was greater among those with greater awareness and risk.

CONCLUSION

With the availability of a highly effective vaccine in Australia, there is a need to increase Q fever knowledge and awareness among high-risk groups and primary health care practitioners.

IMPLICATIONS FOR PUBLIC HEALTH

Strategies to increase awareness and knowledge of Q fever risks and prevention strategies may assist with reducing Q fever burden in Australia.

Occurrence of Rickettsia spp. and Coxiella burnetii in ixodid ticks in Kassena-Nankana, Ghana

Ticks are arthropods of veterinary and medical importance which spread zoonotic pathogens that link animal and human health. In this study, ticks were collected from 448 livestock between February and December 2020 in the Kassena-Nankana Districts of Ghana and screened for the presence of zoonotic pathogens DNA using PCR and sequencing approaches. In total, 1550 ticks were collected and morphologically identified. Three tick genera were identified with Amblyomma variegatum (63%) as the predominant tick species collected. DNA was extracted from 491 tick pools and screened for the presence of DNA of Rickettsia spp. based on the 115 bp fragment of the 17 kDa surface protein and 639 bp of the Outer membrane protein A (ompA) gene and the 295 bp fragment of the transposase gene of Coxiella burnetii IS1111a element. From the 491 pools screened, the DNA of Rickettsia spp. and C. burnetii was detected in 56.8 and 3.7%, respectively. Coinfections were identified in 2.4% of the tick pools. Characterization of the Rickettsia spp. in this study based on the ompA gene showed that the DNA of Rickettsia africae and Rickettsia aeschlimannii accounted for 39.7 and 14.7%, respectively, and were 100% similar to sequences in GenBank. Most R. africae and C. burnetii infections occurred in ticks collected in the wet season, whereas R. aeschlimannii occurred mostly in the dry season. These pathogens are potential public health threats, thus there is a need to implement control measures to reduce the risk of infections in vulnerable populations.

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.

•

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

•

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

•

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

•

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

•

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.

Evaluation of three immunological assays to mitigate the risk of transboundary spread of Coxiella burnetii by alpacas

Coxiella burnetii causes coxiellosis in animals and Q fever in humans, a potentially debilitating zoonotic disease commonly transmitted through domestic ruminants. To prevent transboundary spread of C. burnetii, animals may be tested prior to export. In alpacas, this process is complicated by the lack of scientific evidence for C. burnetii infection in the species, and the unique composition of camelid antibodies, which may cause false-positive results in assays developed for ruminants. We evaluated a complement fixation test (CFT; currently recommended for alpacas in New Zealand), an enzyme-linked immunosorbent assay (ELISA) and an immunofluorescence assay (IFA). Positive analytical control samples were generated through vaccination of alpacas with a human Q fever vaccine, whereas negative analytical control samples were sourced from New Zealand (deemed free of C. burnetii). Immunological assays were conducted on 131 alpaca sera submitted for export testing. Test characteristics (sensitivity, specificity, positive and negative predictive values) for CFT, ELISA and IFA were determined using Bayesian latent class analysis. Due to anticomplementary activity, 37 (28.2%) of the CFT results were inconclusive, making CFT unsuitable for routine use. Of the remaining 94 samples, 10.6%, 0% and 7.4% were positive for C. burnetii antibodies based on CFT, ELISA and IFA, respectively, yielding estimated sensitivities of 58%, 26% and 78%, and estimated specificities of 95%, 98% and 95%, with the estimates for sensitivity being imprecise, as evidenced by wide 95% credible intervals. Positive predictive values were similar across assays, albeit very low at the estimated seroprevalence of 5%. Our results indicate that, of the tests available, IFA appears to be the most appropriate for use in alpacas. Higher sensitivity of antibody detection, use of antigen detection assays and availability of samples from individuals with evidence of infection could provide additional insight into the risk of transboundary spread of C. burnetii by alpacas.

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.

Seroprevalences of Rickettsia conorii, Ehrlichia canis and Coxiella burnetii in Dogs from Montenegro

PURPOSE

The incidence of vector-borne zoonoses has been increasing in Europe as a result of global climate change, and rickettsioses are a significant etiologic entity among these infections. The objective of this study was to investigate the seroprevalences of Rickettsia conorii, Ehrlichia canis and Coxiella burnetii in dogs in Montenegro.

METHODS

The seroepidemiological study covered 259 dogs, of which 155 were owned dogs suspected of infection with agents of rickettsial aetiology from the continental (Podgorica) or five coastal municipalities of Montenegro (Budva, Herceg Novi, Kotor, Ulcinj and Bar), and 104 dogs were from a public shelter in Podgorica. The presence of specific IgG antibodies against R. conorii was analysed using a commercial indirect enzyme-linked immunosorbent assay (ELISA) test, and the presence of antibodies against E. canis and C. burnetii was analysed using commercial indirect immunofluorescence tests (IFAT).

RESULTS

Seroprevalences of 73.36, 19.3 and 1.16% were determined for R. conorii, E. canis and C. burnetii, respectively. R. conorii was significantly more prevalent (χ² = 14.53; p < 0.001) in owned dogs (81.93%) than in dogs from the public shelter (60.6%), while E. canis was more prevalent (χ² = 12.31; p < 0.001) in dogs from the public shelter (29.81%) than in owned dogs (12.26%). Coinfection with two pathogens was determined in 40 (15.44%) dogs, and the prevalence of R. conorii/E. canis (χ² = 4.23; p < 0.05) was greater in dogs from the public shelter (20.19%) than in owned dogs (10.97%).

CONCLUSION

The prevailing evidence from this study shows that dogs from Montenegro are exposed to pathogens of veterinary and public health importance. This calls for the One Health approach to sensitise the public on the risks of zoonoses from dogs and to formulate policies and strategies to mitigate their spread and safeguard public health.

Dairy goat producers' understanding, knowledge and attitudes towards biosecurity and Q-fever in Australia

The Australian dairy goat sector is an emerging animal industry undergoing rapid expansion. Limited information is available within this industry in relation to socio-demographic characteristics and biosecurity implementation. Q-Fever, caused by the bacterium Coxiella burnetii, is a zoonotic disease endemic in Australia, with a range of domestic and wild-animal reservoir species, including goats, with infected pregnant goats posing a significant public health risk. The aim of the current study was to investigate the socio-demographics of Australian dairy goat producers, their biosecurity implementation and levels of understanding, knowledge and attitudes towards Q-Fever. To achieve this aim, a cross-sectional study was conducted, using an online survey and follow-up semi-structured interviews among dairy goat producers. A total of 106 goat producers participated in the online survey (35.3% response rate) and 14 participated in the semi-structured interviews. Findings from this study suggest that most goat producers implement biosecurity practices related to direct animal husbandry, such as separating sick goats (86%), vaccinations (79%) and providing separate kidding space (75%); and, practices minimizing the risk of disease introduction, such as maintaining boundary fences (86%) and isolating incoming animals (67%). However, implementation of other biosecurity practices, such as keeping records of visitors and visitor biosecurity requirements, was inadequate. Furthermore, this study identifies a deficit of knowledge and understanding surrounding Q-Fever in the Australian dairy goat sector, and a disconnect between producers' perception of risk and implementation of known appropriate biosecurity measures. The research has identified that producers rely on 'trusted' community networks to provide advice on biosecurity implementation, due to a perceived absence of industry-specific, reputable information sources. Producers identified those outside of these networks as the 'other'. The creation of this other allows producers to deflect responsibility for individual biosecurity on to the other. A multifaceted approach is necessary to increase knowledge, understanding and perception of risk surrounding Q-fever, and promote positive uptake of biosecurity measures, for improved outcomes for animal and human health.

Genetic characterization of tick-borne pathogens in ticks infesting cattle and sheep from three South African provinces

Ticks are involved in the transmission of many public health and veterinary important pathogens. Although tick-borne pathogens are widely distributed in South Africa, information on tick-pathogen relationship needs to be updated particularly using modern molecular techniques. This study used PCR and sequencing to confirm the identity of the tick species collected from cattle and sheep from KwaZulu-Natal, Free State and Eastern Cape. Furthermore, presence of Babesia spp., Theileria spp., Anaplasma marginale, Rickettsia spp., Ehrlichia ruminantium and Coxiella burnetii was detected from tick DNA using species-specific PCR or nested PCRs. The study samples consisted of 390 adult ticks (male and female) which were pooled according to species, host animal and sampling site (three ticks per pool) for DNA extraction. The PCR results revealed that out of 130 tick DNA pools, 30 (23.1%) were positive for at least one pathogen. The most frequent pathogen was C. burnetii (9.2%), followed by Rickettsia spp. (7.7%), A. marginale (3.8%), T. mutans (3.1%), T. taurotragi (2.3%) and E. ruminantium (1.5%). The highest prevalence of pathogens was observed in ticks collected from cattle in Eastern Cape (16/42) and the lowest was in ticks obtained from sheep in Free State (1/21). Infected ticks were identified as Rhipicephalus evertsi evertsi (n = 13), R. appendiculatus (n = 3), R. decoloratus (n = 7) and Amblyomma hebraeum (n = 7). Coinfection with two pathogens was found in 21% of pathogen-positive pools. Analysis of Theileria taurotragi 18S rRNA, T. mutans 18S rRNA, C. burnetii htpB, Rickettsia spp. gltA, Rickettsia spp. ompA, E. ruminantium pCS20 and A. marginale Msp5 sequences showed that the pathogens detected in this study were genetically related to isolates previously reported in Africa. These findings provide important information on distribution of ticks and tick-borne pathogens of ruminants and will contribute in the formulation of future control strategies in South Africa.

Airborne geographical dispersal of Q fever from livestock holdings to human communities: a systematic review and critical appraisal of evidence

BACKGROUND

Q fever is a zoonotic disease caused by Coxiella burnetii. This bacterium survives harsh conditions and attaches to dust, suggesting environmental dispersal is a risk factor for outbreaks. Spatial epidemiology studies collating evidence on Q fever geographical contamination gradients are needed, as human cases without occupational exposure are increasing worldwide.

METHODS

We used a systematic literature search to assess the role of distance from ruminant holdings as a risk factor for human Q fever outbreaks. We also collated evidence for other putative drivers of C. burnetii geographical dispersal.

RESULTS

In all documented outbreaks, infective sheep or goats, not cattle, was the likely source. Evidence suggests a prominent role of airborne dispersal; Coxiella burnetii travels up to 18 km on gale force winds. In rural areas, highest infection risk occurs within 5 km of sources. Urban outbreaks generally occur over smaller distances, though evidence on attack rate gradients is limited. Wind speed / direction, spreading of animal products, and stocking density may all contribute to C. burnetii environmental gradients.

CONCLUSIONS

Q fever environmental gradients depend on urbanization level, ruminant species, stocking density and wind speed. While more research is needed, evidence suggests that residential exclusion zones around holdings may be inadequate to contain this zoonotic disease, and should be species-specific.

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

OBJECTIVE

To determine the source of a Q fever outbreak in humans at an animal refuge and veterinary clinic in southeast Queensland from October to December 2016.

METHODS

Case interviews and a retrospective cohort study of animal refuge and veterinary clinic staff using a self-administered questionnaire related to clinical history of Q fever, Q fever vaccination status and workplace activities during the exposure period.

RESULTS

Seven cases (six confirmed, one probable) were identified. Forty-three questionnaires were completed (92% response rate). Workplace activities associated with the greatest risk of illness were the disposal of deceased cats or dogs (RR, 14.0; 95%CI, 1.9-104.1) and participating in euthanasia of cats or dogs (RR, 4.6; 95%CI, 1.3-16.9). Five feline birthing events occurred at the animal refuge from 25 September to 19 October 2016, each with subsequent euthanasia of the queen cat and litter. All cases had likely exposure to a specific queen cat and her litter that were euthanised the same day as the birthing event.

CONCLUSIONS

A parturient cat was the most likely source of the outbreak. Implications for public health: Occupational groups and others with regular exposure to feline or canine parturient products should receive Q fever vaccine.

Rethinking Coxiella infections in Australia

Coxiellaburnetii is the causative agent of coxiellosis in animals and Q fever in humans. Despite being a vaccine preventable disease, Q fever remains a frequently reported zoonotic infection in Australia. Recently, a Coxiella species was identified in brown dog ticks (Rhipicephalus sanguineus) in urban and rural regions of Australia. Further molecular characterisation revealed that it is genetically identical to ‘Candidatus Coxiella massiliensis’ (KM079627) described in R. sanguineus ticks removed from humans with eschars in France and serologic cross-reactivity among ‘Ca. Coxiella massiliensis’ and C.burnetii may occur. This report highlights the need for molecular testing of seropositive companion animals and humans to determine which species of Coxiella they are infected with, in order to further assess Coxiella species associated with Coxiella infections in Australia.

Occurrence of <i>Coxiella burnetii</i>, <i>Ehrlichia canis</i>, <i>Rickettsia</i> species and <i>Anaplasma phagocytophilum</i>-like bacterium in ticks collected from dogs and cats in South Africa

Ticks are major vectors of arthropod-borne infections and transmit a wide variety of zoonotic pathogens. This study was conducted mainly to determine the occurrence of canine tick-borne bacterial and rickettsial pathogens especially those with zoonotic potential. We examined 276 Rhipicephalus sanguineus, 38 Haemaphysalis elliptica and 4 Amblyomma hebraeum ticks from 90 dogs and 4 cats from the Free State, KwaZulu-Natal, North West and Mpumalanga provinces. DNA of Coxiella burnetii (41%), Ehrlichia or Anaplasma (18%), Rickettsia spp. (37%), Anaplasma phagocytophilum-like bacterium (18%) and Ehrlichia canis (19%) was detected by polymerase chain reaction (PCR) from a total of 147 pooled DNA samples. All samples were negative for the presence of Borrelia burgdorferi DNA. Ehrlichia canis was detected in samples from all the provinces except the North West; A. phagocytophilum was absent in KwaZulu-Natal samples, whereas Rickettsia species and C. burnetii were detected in all sampled provinces. The PCR-positive samples were confirmed by direct sequencing of the product. Data from this study calls for a joint effort by both veterinary and medical sectors to conduct epidemiological studies of the zoonotic pathogens in both animals and humans.

Trends and risk factors for human Q fever in Australia, 1991-2014

Australian abattoir workers, farmers, veterinarians and people handling animal birthing products or slaughtering animals continue to be at high risk of Q fever despite an effective vaccine being available. National Notifiable Diseases Surveillance System data were analysed for the period 1991-2014, along with enhanced risk factor data from notified cases in the states of New South Wales and Queensland, to examine changes in the epidemiology of Q fever in Australia. The national Q fever notification rate reduced by 20% [incident rate ratio (IRR) 0·82] following the end of the National Q fever Management Program in 2006, and has increased since 2009 (IRR 1·01-1·34). Highest rates were in males aged 40-59 years (5·9/100 000) and 87% of Q fever cases occurred in New South Wales and Queensland. The age of Q fever cases and proportion of females increased over the study period. Based on the enhanced risk factor data, the most frequently listed occupation for Q fever cases involved contact with livestock, followed by 'no known risk' occupations. More complete and comparable enhanced risk factor data, at the State/Territory and national levels, would aid in further understanding of the epidemiology of Q fever.

Molecular investigation into the presence of a Coxiella sp. in Rhipicephalus sanguineus ticks in Australia

Q fever is an infectious disease with a global distribution caused by the intracellular bacterium, Coxiella burnetii, which has been detected in a large number of tick species worldwide, including the brown dog tick, Rhipicephalus sanguineus. Recent reports of a high seroprevalance of C. burnetii in Australian dogs, along with the identification of additional Coxiella species within R. sanguineus ticks, has prompted an investigation into the presence and identification of Coxiella species in R. sanguineus ticks in Australia. Using a combination of C. burnetii species-specific IS1111a transposase gene and Coxiella genus-specific 16S rRNA PCR assays, a Coxiella sp. was identified in 100% (n=199) of R. sanguineus ticks analysed, and C. burnetii was not detected in any R. sanguineus ticks studied. Phylogenetic analysis of the 16S rRNA gene revealed the Coxiella sequences were closely related to Coxiella sp. identified previously in R. sanguineus and R. turanicus ticks overseas. This study illustrates the value of using genus specific PCR assays to detect previously unreported bacterial species. Furthermore, the presence of an additional Coxiella sp. in Australia requires further investigation into its potential for contributing to serological cross-reactions during Q fever testing.

Multiple Pathogens Including Potential New Species in Tick Vectors in Côte d'Ivoire

BACKGROUND

Our study aimed to assess the presence of different pathogens in ticks collected in two regions in Côte d'Ivoire.

METHODOLOGY/PRINCIPAL FINDINGS

Real-time PCR and standard PCR assays coupled to sequencing were used. Three hundred and seventy eight (378) ticks (170 Amblyomma variegatum, 161 Rhipicepalus microplus, 3 Rhipicephalus senegalensis, 27 Hyalomma truncatum, 16 Hyalomma marginatum rufipes, and 1 Hyalomma impressum) were identified and analyzed. We identified as pathogenic bacteria, Rickettsia africae in Am. variegatum (90%), Rh. microplus (10%) and Hyalomma spp. (9%), Rickettsia aeschlimannii in Hyalomma spp. (23%), Rickettsia massiliae in Rh. senegalensis (33%) as well as Coxiella burnetii in 0.2%, Borrelia sp. in 0.2%, Anaplasma centrale in 0.2%, Anaplasma marginale in 0.5%, and Ehrlichia ruminantium in 0.5% of all ticks. Potential new species of Borrelia, Anaplasma, and Wolbachia were detected. Candidatus Borrelia africana and Candidatus Borrelia ivorensis (detected in three ticks) are phylogenetically distant from both the relapsing fever group and Lyme disease group borreliae; both were detected in Am. variegatum. Four new genotypes of bacteria from the Anaplasmataceae family were identified, namely Candidatus Anaplasma ivorensis (detected in three ticks), Candidatus Ehrlichia urmitei (in nine ticks), Candidatus Ehrlichia rustica (in four ticks), and Candidatus Wolbachia ivorensis (in one tick).

CONCLUSIONS/SIGNIFICANCE

For the first time, we demonstrate the presence of different pathogens such as R. aeschlimannii, C. burnetii, Borrelia sp., A. centrale, A. marginale, and E. ruminantium in ticks in Côte d'Ivoire as well as potential new species of unknown pathogenicity.

Q Fever Knowledge, Attitudes and Vaccination Status of Australia's Veterinary Workforce in 2014

Q fever, caused by Coxiella burnetii, is a serious zoonotic disease in humans with a worldwide distribution. Many species of animals are capable of transmitting C. burnetii, and consequently all veterinary workers are at risk for this disease. An effective Q fever vaccine has been readily available and used in Australia for many years in at-risk groups, and the European Centre for Disease Prevention and Control has recently also called for the use of this vaccine among at-risk groups in Europe. Little is known about attitudes towards this vaccine and vaccine uptake in veterinary workers. This study aimed to determine the Q fever vaccination status of veterinarians and veterinary nurses in Australia and to assess and compare the knowledge and attitudes towards Q fever disease and vaccination of each cohort. An online cross-sectional survey performed in 2014 targeted all veterinarians and veterinary nurses in Australia. Responses from 890 veterinarians and 852 veterinary nurses were obtained. Binary, ordinal and multinomial logistic regression were used to make comparisons between the two cohorts. The results showed that 74% of veterinarians had sought vaccination compared to only 29% of veterinary nurses. Barriers to vaccination among those not vaccinated did not differ between cohorts, and included a lack of perceived risk, financial expense, time constraints, and difficulty in finding a vaccine provider. Poor knowledge and awareness of Q fever disease and vaccination were additional and notable barriers for the veterinary nursing cohort, suggesting veterinary clinics and veterinarians may not be meeting their legal responsibility to educate staff about risks and risk prevention. Further evaluation is needed to identify the drivers behind seeking and recommending vaccination so that recommendations can be made to improve vaccine uptake.

Client knowledge, attitudes and practices regarding zoonoses: a metropolitan experience

OBJECTIVE

To assess knowledge, attitudes and practices in relation to zoonoses among pet owners.

METHODS

Questionnaire completed by 81 clients attending a small animal practice in Sydney, Australia.

RESULTS

Most (64.5%) clients reported that they were not concerned about contracting a disease from their pet, but 7.9% and 3.9% of clients were a little or very concerned, respectively; 23.7% of clients stated that they had not considered the possibility. Although respondents indicated that they had heard of a number of zoonoses, knowledge of animal sources and exposure pathways was generally low, particularly for the more important zoonoses in Australia such as toxoplasmosis, psittacosis and Q fever. Only 37.0%, 12.3% and 11.1%, respectively, of clients had heard of these diseases. Most respondents (84.1%) indicated that they viewed veterinarians as having the primary responsibility for providing information about zoonoses, yet less than half (48.1%) recalled ever getting information from their veterinarian. Likewise, many respondents (48.1%) indicated that medical professionals played a role in providing information about zoonoses, yet less than one-quarter (23.5%) recalled ever getting information from their doctor.

CONCLUSION

The low level of knowledge among pet owners about sources and exposure pathways indicates a need to strengthen communication between veterinarians, doctors and their clients around the possible risks of zoonoses and appropriate prevention strategies.

Molecular detection of zoonotic tick-borne pathogens from ticks collected from ruminants in four South African provinces

Ticks carry and transmit a remarkable array of pathogens including bacteria, protozoa and viruses, which may be of veterinary and/or of medical significance. With little to no information regarding the presence of tick-borne zoonotic pathogens or their known vectors in southern Africa, the aim of our study was to screen for Anaplasma phagocytophilum, Borrelia burgdorferi, Coxiella burnetii, Rickettsia species and Ehrlichia ruminantium in ticks collected and identified from ruminants in the Eastern Cape, Free State, KwaZulu-Natal and Mpumalanga Provinces of South Africa. The most abundant tick species identified in this study were Rhipicephalus evertsi evertsi (40%), Rhipicephalus species (35%), Amblyomma hebraeum (10%) and Rhipicephalus decoloratus (14%). A total of 1634 ticks were collected. DNA was extracted, and samples were subjected to PCR amplification and sequencing. The overall infection rates of ticks with the target pathogens in the four Provinces were as follows: A. phagocytophilum, 7%; C. burnetii, 7%; E. ruminantium, 28%; and Rickettsia spp., 27%. The presence of B. burgdorferi could not be confirmed. The findings of this study show that zoonotic pathogens are present in ticks in the studied South African provinces. This information will aid in the epidemiology of tick-borne zoonotic diseases in the country as well as in raising awareness about such diseases in the veterinary, medical and tourism sectors, as they may be the most affected.

Serosurvey and observational study of US Army Veterinary Corps officers for Q fever antibodies from 1989 to 2008

Since World War II, the military has experienced outbreaks of Q fever among deploying units including recent case reports of Q fever in US military personnel returning from serving in the Middle East during Operation Iraqi Freedom and Operation Enduring Freedom. Occupational exposure and prevalence of Q fever among US Army Veterinary Corps officers have not been examined. A retrospective serosurvey and observational study of 500 military veterinarians were conducted using archived serum specimens from military veterinarians who entered and served between 1989 and 2008 and were tested for exposure to Coxiella burnetii. Corresponding longitudinal health-related, demographic, medical and deployment data were examined. A total of 69 (13.8%) individuals at military entry and 85 (17%) had late career positive titres. A total of 18 (3.6%) individuals showed seroconversion. Women were more likely to be seropositive after military service [prevalence ratio (PR) 1.96; 95% confidence interval (CI) 1.15–3.35] and were also more likely to seroconvert (incidence rate ratio 3.55; 95% CI 1.19–12.7). Women who deployed to Operation Iraqi Freedom were more likely to be seropositive (PR 3.17; 95% CI 1.03–9.71). Veterinarians with field service and pathology specialties had the highest incidence rates (7.0/1000 PY; 95% CI 4–12 and 3–19, respectively). This is the first report documenting US military veterinarians' exposure to C. burnetii. Military veterinarians are at risk prior to service, with moderate number of new cases developing during service and most maintaining titres for long periods of time. Women consistently demonstrated higher seroprevalence and incidence levels. As increasing numbers of women enter the veterinary profession and subsequently the US Army, this may warrant close monitoring. This study likely underestimates exposure and risk and does not address chronic health effects, which may be valuable to explore in future health studies.

Seroprevalence and risk factors for Rickettsia felis exposure in dogs from Southeast Queensland and the Northern Territory, Australia

Background

The recent detection of Rickettsia felis DNA in dogs in Australia suggests that dogs are potential mammalian reservoir hosts for this emerging rickettsia. To date, there is no published report addressing the seroprevalence of R. felis in dogs in Australia.

Methods

Antigens for R. felis were produced by inoculating confluent XTC-2 monolayer cell cultures with three pools of cat flea (Ctenocephalides felis) homogenates. Infection was confirmed by real-time (qPCR), conventional or nested PCRs targeting the ompB, gltA, 17 kDa and ompA genes. Two hundred and ninety-two dogs from Southeast Queensland and the Northern Territory were tested for the presence of R. felis antibodies using a microimmunofluorescence (IF) test and the seroprevalence and associated risk factors for exposure were determined using both uni- and multi-variate analyses.

Results

Rickettsia felis was successfully isolated in cell culture from all three cat-flea pools. One hundred and forty-eight dogs (50.7%) showed seropositivity with titres ≥64 and 54 (18.5%) with titres ≥128. At antibody titres ≥64, dogs with active ectoparasite control were less likely to be seropositive to R. felis (OR: 2.60; 95% CI: 1.20 - 5.56).

Conclusions

This first reported isolation of R. felis in cell culture in Australia allowed for the production of antigen for serological testing of dogs. Results of this serological testing reflects the ubiquitous exposure of dogs to R. felis and advocate for owner vigilance with regards to ectoparasite control on domestic pets.

Coxiella burnetii associated reproductive disorders in domestic animals--a critical review

The bacterium Coxiella burnetii has been detected in the fetal membranes, birth fluids and vaginal mucus, as well as in the milk and other excretions of several domestic mammals. The finding of C. burnetii in association with abortion, parturition and in the postpartum period has led to the hypothesis that C. burnetii causes a range of reproductive diseases. This review critically evaluates the scientific basis for this hypothesis in domestic mammals.The review demonstrates a solid evidence for the association between C. burnetii infection and sporadic cases of abortion, premature delivery, stillbirth and weak offspring in cattle, sheep and goats. C. burnetii induced in-herd epidemics of this complete expression of reproductive failure have been reported for sheep and goats, but not for cattle. The single entities occur only as part of the complex and not as single events such as generally increased stillbirth rate. Studies show that C. burnetii initially infects the placenta and that subsequent spread to the fetus may occur either haematogenous or by the amniotic-oral route. The consequences for the equine, porcine, canine and feline conceptus remains to the elucidated but that infection of the conceptus may occur is documented for most species. There is no solid evidence to support a hypothesis of C. burnetii causing disorders such as subfertility, endometritis/metritis, or retained fetal membranes in any kind of domestic animal species.There is a strong need to validate non-pathology based methods such as polymerase chain reaction for their use in diagnostic and research in relation to establishing C. burnetii as the cause of abortion and to adapt an appropriate study design and include adequate control animals when linking epidemiological findings to C. burnetii or when evaluating effects of vaccination in production herds.