Molecular diagnosis of Coxiella burnetii in culture negative endocarditis and vascular infection in South Korea.

BACKGROUND: Q fever endocarditis is a major cause of culture-negative endocarditis. The role of Coxellia burnetii is underestimated because it is difficult to diagnose. We investigated the significance of C. burnetii as the cause of culture-negative endocarditis and vascular infection by examining blood and tissue specimens using serological testing and polymerase chain reaction (PCR). METHODS: All patients with infective endocarditis or large vessel vasculitis were prospectively enrolled at a tertiary-care hospital from May 2016 through September 2020. Q fever endocarditis and vascular infection were diagnosed based on: (1) positive PCR for a cardiac valve or vascular tissue, (2) positive PCR for blood or phase I immunoglobulin G (IgG) ≥ 6400, or (3) phase I IgG ≥ 800 and < 6400 with morphologic abnormality. PCR targeted C. burnetii transposase gene insertion element IS1111a. RESULTS: Of the 163 patients, 40 (25%) had culture-negative endocarditis (n = 35) or vascular infection (n = 5). Of the 40 patients, 24 (60%) were enrolled. Eight (33%) were diagnosed with Q fever endocarditis or vascular infection. Of these 8 patients, 6 had suspected acute Q fever endocarditis or vascular infection with negative phase I IgG. Six patients were not treated for C. burnetii, 4 were stable after surgery. One patient died due to surgical site infection after 5 months post-operatively and one died due to worsening underlying disease. CONCLUSIONS: Approximately one-third of patients with culture-negative endocarditis and vascular infection was diagnosed as Q fever. Q fever endocarditis and vascular infection may be underestimated in routine clinical practice in South Korea.KEY MESSAGEQ fever endocarditis and vascular infection may be underestimated in routine clinical practice, thus, try to find evidence of C. burnetti infection in suspected patients by all available diagnostic tests including PCR.

Partial DnaK protein expression from Coxiella-like endosymbiont of Rhipicephalus annulatus tick.

Q fever is one of the most important zoonotic diseases caused by the obligate intracellular bacteria, Coxiella burnetii. This bacterial infection has been frequently reported in both humans and animals, especially ruminants. Ticks are important ectoparasite and serve as reservoir hosts of Coxiella-like endosymbionts (CLEs). In this study, we have attempted to express chaperone-coding genes from CLEs of Rhipicephalus annulatus ticks collected fromcow path. The partial DnaK coding sequence has been amplified and expressed by Escherichia coli. Amino acid sequences have been analyzed by MS-MS spectrometry and the UniProt database. Despites nucleotide sequences indicating high nucleotide variation and diversity, many nucleotide substitutions are synonymous. In addition, amino acid substitutions compensate for the physicochemical properties of the original amino acids. Immune Epitope Database and Analysis Resource (IEDB-AR) was employed to indicate the antigenicity of the partial DnaK protein and predict the epitopes of B-and T-cells. Interestingly, some predicted HLA-A and B alleles of the MHC-I and HLA-DR alleles belonging to MHC-II were similar to T-cell responses to C. burnetii in Q fever patients. Therefore, the partial DnaK protein of CLE from R. annulatus could be considered a vaccine candidate and immunogenic marker with future prospects.

Primary aortoduodenal fistula and chronic Q fever infection.

We report a case of chronic Q fever presenting with catastrophic bleeding from an infected abdominal aortic aneurysm causing a primary aortoduodenal fistula in an 80-year-old retired farmer. This presentation is rarely reported in literature and only through case reports. Early diagnosis and definitive surgery were critical to a successful outcome. Serological diagnosis of Q fever was initiated on the patient's past exposure to animal reservoirs. Complicating the case was ongoing gastrointestinal bleeding postsurgery, with multiple endoscopies undertaken before a culprit remnant fistula was found. This case highlights the value in considering Coxiella burnetii as an underlying cause in patients with known risk factors presenting with primary aortoduodenal fistulas. Though rare, it represents a readily treatable cause.

First molecular detection of Coxiella burnetii in Brazilian artisanal cheese: a neglected food safety hazard in ready-to-eat raw-milk product

ABSTRACT Background: Global publications on Q fever have increased after the 2007 epidemic in the Netherlands. However, the epidemiology of Q fever/coxiellosis in Brazil is still poorly understood. Accordingly, there have been few studies investigating the presence of Coxiella burnetii in dairy products around the world, especially in Brazil, where consumption of fresh cheese made from raw-milk is very high. Objective: This study was a random survey to assess the prevalence of C. burnetii by PCR in traditional Minas artisanal cheese from the Serro microregion, Brazil, which is manufactured from bovine raw-milk. Methods: DNA extracted from 53 cheese samples were analyzed by nested PCR with C. burnetii-specific primers and the products confirmed by DNA sequencing. Results: Out of the 53 cheese samples five (9.43%) were C. burnetii DNA-positive, each coming from one of the respective randomly selected manufacturing agroindustries.Based on our results, it is estimated that 1.62 tons/day of ready-to-eat cheese made from raw-milk from a total of 16.2 tons produced daily in the study region are contaminated with C. burnetii. Conclusion: To our knowledge, this is the first report of highly heat-resistant zoonotic pathogen in raw-milk Brazilian artisanal cheese. This food safety hazard has been completely neglected in ready-to-eat raw-milk Brazilian artisanal cheese and could imply potential threats to consumers, since C. burnetii survives in artisanal cheese submitted to long ripening periods. Thus, this work established random and representative baseline prevalence of C. burnetii in this food product in Brazil. Further epidemiological studies, monitoring trends and setting control targets are warranted. Finally, these results point out the importance of including C. burnetii in animal and public health surveillance programs.

Vertebral Osteomyelitis or Infected Abdominal Aortic Endograft? A Rare Case of Q Fever.

Coxiella burnetii is the etiological agent of Q fever, a zoonosis. Vascular infections are associated with significant morbidity and mortality. Osteoarticular Q fever infections are rare. We describe a case of vertebral osteomyelitis with associated infection of an abdominal aortic endograft, caused by C. burnetii. Most probably, an initial pyogenic vertebral osteomyelitis extended locally to the endograft. Treatment consisted of antibiotic therapy and surgical resection of the infected aortic endograft and in situ reconstruction with autogenous superficial femoral vein grafts.

Q-fever prosthetic valve endocarditis in a patient with SLE and antiphospholipid antibody syndrome.

Q fever prosthetic valve endocarditis in association with antiphospholipid antibody syndrome (APS) in systemic lupus erythematosus (SLE) has not been previously reported. Here, we report a 22-year-old Saudi female diagnosed with SLE and APS. She had mitral valve replacement with bio-prosthesis five years earlier for Libman-Sack endocarditis. She presented with two months' history of fever, cough, palpitations, and progressive shortness of breath. A transthoracic echocardiogram showed a degenerative mitral valve prosthesis with a large mass causing severe obstruction. Open heart surgery revealed multiple masses on the mitral valve. PCR from the resected tissues was positive for Coxiella burnetii DNA. Q fever serology showed phase two IgG 1:2048, phase one IgG 1:512, and IgM 1:1024. The valve was replaced with a bio-prosthesis. She was well at 12 months of follow-up.

Tick-borne pathogens in dogs, wild small mammals and their ectoparasites in the semi-arid Caatinga biome, northeastern Brazil.

Caatinga is a biome exclusive to the semiarid zone of Brazil, where studies on ticks and tick-borne diseases are scarce. Herein, we investigated the occurrence of Rickettsia, Ehrlichia, and Coxiella in wild mammals, domestic dogs and their ectoparasites using molecular and serological techniques. During 2014-2016, blood samples and ectoparasites were collected from 70 small mammals (51 rodents, 18 marsupials, 1 wild canid) and 147 domestic dogs in three areas of the Caatinga. Through serological analyses of domestic dogs of the three areas, 8 to 11 % were seropositive for Rickettsia rickettsii, 9 to 37 % for Rickettsia amblyommatis, 61 to 75 % for Ehrlichia canis, and 0-5% for Coxiella burnetii. All wild mammals were seronegative for Rickettsia spp. and C. burnetii, except for one rodent (Wiedomys pyrrhorhinos) and one marsupial (Didelphis albiventris) that were seroreactive to C. burnetii, one wild canid (Cerdocyon thous) for R. amblyommatis, and two Rattus rattus for Rickettsia spp. Through PCR targeting DNA of Rickettsia, Ehrlichia or Coxiella, all blood samples were negative, except for the presence of Ehrlichia canis DNA in 8.8 % of the domestic dogs, and a recently reported novel agent, Ehrlichia sp. strain Natal, in one marsupial (Gracilinanus agilis). A total of 222 ticks, 84 fleas, and six lice were collected. Ticks were mostly Rhipicephalus sanguineus sensu lato, some Ixodes loricatus, Ornithodoros rietcorreai, Haemaphysalis sp., and Amblyomma spp.; fleas were Ctenocephalides felis felis, Pulex sp. and Polygenis (Polygenis) bohlsi jordani; and lice were Polyplax sp. and Gyropus sp. Through molecular detection of microorganisms, 9% of C. felis felis contained Rickettsia felis, 20 % of A. auricularium contained R. amblyommatis and 13 % of A. parvum contained 'Candidatus Rickettsia andeanae', whereas Ehrlichia canis DNA was detected in at least 6% of the R. sanguineus s.l. from one area. We report a variety of ectoparasites infesting small mammals and domestic dogs in the Caatinga biome, where these ectoparasites probably act as vectors of rickettsiae, ehrlichial agents (E. canis and Ehrlichia sp. strain Natal) and C. burnetii. Our results highlight to the potential risks of human infection by these tick-borne agents in the Caatinga biome.

Comparison of two new in-house Latex Agglutination Tests (LATs), based on the DnaK and Com1 synthetic peptides of Coxiella burnetii, with a commercial indirect-ELISA, for sero-screening of coxiellosis in bovines.

The in-house developed DnaK and Com1 synthetic peptide-based Latex Agglutination Tests (LATs) were comparatively evaluated with commercial indirect-ELISA kit, to provide a rapid, economical and onsite field applicable test for seroscreening of coxiellosis in bovines.

Persistent Coxiella burnetii cardiovascular infection on Bentall-De Bono prosthesis.

Coxiella burnetii cardiovascular prosthetic infections are associated with high morbidity and mortality and represent a major health problem due to the lack of standardized management. We were confronted with a C. burnetii infection on Bentall-De Bono prosthesis characterized by a history of vascular infection with relapse that prompted us to screen for cases of C. burnetii on Bentall-De Bono vascular prosthesis monitored in our center. We screened patients between 1991 and 2019, from the French national reference center for Q fever. A microbiological criterion in addition to a lesional criterion was necessary to diagnose C. burnetii persistent vascular infection. Two thousand five hundred and eighty two patient were diagnosed with Coxiella burnetii infection and 160 patients with persistent C. burnetii vascular infection prosthesis, 95 of whom had a vascular prosthesis, including 12 with Bentall-De Bono prosthesis. Among patients with persistent C. burnetii prosthetic vascular infection, patients with Bentall-De Bono prostheses were significantly more prone to develop complications such as aneurysm, fistula, and abscess (62 versus 32%, two-sided Chi-square test, p = 0.04). All but one patient were treated with doxycycline and hydroxychloroquine for a mean (± standard deviation) period of 29.4 ± 13.6 months. Among the 12 patients, 5 had cardio-vascular complications, and 5 had prolonged antibiotherapy with doxycycline and hydroxychloroquine. Patients with C. burnetii vascular infection on Bentall-De Bono tend to be at high risk of developing complications (fistula, aneurysm, abscess, death). Surgery is rarely performed. Clinical, serological, and PET scanner imaging follow-up is recommended.

New insights in Coxiella burnetii infection: diagnosis and therapeutic update.

Introduction: Coxiella burnetii infection is still challenging physicians, mainly because no international coordination has been stated to standardize the therapeutic strategy and improve the clinical outcomes.Areas covered: Based on the recent knowledge on Q fever, we review here the clinical practices from Q fever diagnosis to therapy. We searched PubMed and Google Scholar to perform the qualitative synthesis.Expert opinion: Four major critical points are highlighted in this review. The first point is that Q fever diagnosis has been reviewed in the light of the new diagnosis tools, including molecular biology, transthoracic echocardiography, and 18F-FDG-PET/CT-scan imaging. Q fever diagnosis results from the presence of a microbiological criterion in addition to a lesional criterion. Second, the identification of the anticardiolipin antibodies as a novel biological predictive marker for acute Q fever complications (hemophagocytic syndrome, acute Q fever endocarditis, alithiasic cholecystitis, hepatitis, and meningitis). Third, the observation of a coincidence between Q fever and non-Hodgkin lymphoma that has made persistent C. burnetii infection a risk of non-Hodgkin lymphoma. Finally, we expose here the close follow-up we proposed from the French National Reference Center for patients with Q fever infection to detect relapse and complications.

A travel-loving woman in her eighties with lower back pain and weight loss. / En reiseglad 80-åring med ryggsmerter og vekttap.

BACKGROUND: This case report presents one of the first documented incidents of chronic Q-fever (C. burnetii) in Norway. A comprehensive workup resulted in an unexpected finding. CASE PRESENTATION: A Norwegian woman in her eighties presented to a district general hospital with lower back pain, decreased general condition and weight loss. Computer tomography (CT) revealed a large thoracic aortic aneurysm presumed to be of mycotic origin, and later magnetic resonance imaging (MRI) scans revealed osteomyelitis in the surrounding vertebrae. Conventional diagnostic workup did not identify the causative agent. After more than 6 months of different examinations, surgery, exhausting invasive procedures and antimicrobial treatment, we were ultimately successful in determining the microbial cause of chronic mycotic aneurism and osteomyelitis to be C. Burnetii (Q-fever) through serological and PCR analysis. INTERPRETATION: An increasing proportion of the population in all age groups travel abroad, and clinicians should be aware of the increasing incidence of imported infectious diseases. Obtaining a thorough medical history is still an important tool in the diagnostic process.

Development of the Com1 synthetic peptide-based Latex Agglutination Test (LAT) and its comparative evaluation with commercial indirect-ELISA for sero-screening of coxiellosis in cattle.

A novel Com1 synthetic peptide-based latex agglutination test (LAT) was developed and evaluated against commercial ELISA kit for sero-screening of coxiellosis in cattle. The developed test is economical, has field applicability and can serve as an important rapid tool for sero-screening of coxiellosis in cattle.

Unusual presentation of Q fever in a kidney-pancreas transplant recipient.

Q fever is uncommon in solid organ transplant (SOT) recipients. We describe a case of granulomatous lung disease as an unusual presentation of chronic Q fever in a kidney-pancreas transplant recipient.

Coxiella burnetii e a febre Q no Brasil, uma questão de saúde pública / Coxiella burnetii and Q fever in Brazil: a public health issue

Resumo A Febre Q é uma zoonose de ampla distribuição mundial, apesar dos poucos relatos associados a sua ocorrência no Brasil. "Coxiella burnetii", agente etiológico da Febre Q, é um cocobacilo gram-negativo, parasita intracelular obrigatório da ordem Legionellales. O microrganismo geralmente está presente na urina e fezes de animais infectados, podendo ser encontrado em grande quantidade nos restos placentários de animais nascidos a termo ou produtos de aborto. A inalação de células bacterianas suspensas no ar ou aerossóis contaminados é a forma mais comum de entrar em contato com a bactéria. A febre Q é uma doença autolimitada e, geralmente, evolui de forma benigna. Nos casos onde a doença evolui de forma crônica, a endocardite é a manifestação mais frequente. O diagnóstico clínico é difícil, visto que os sintomas assemelham-se a várias outras doenças. Nos casos confirmados a antibioticoterapia é o tratamento indicado. Diante da sintomatologia pouco específica e dificuldade de diagnóstico, acredita-se que no Brasil a doença seja mais comum do que se pensa.

Abstract Q fever is a zoonosis that is broadly distributed worldwide, despite few reports associated with its occurrence in Brazil. Coxiella burnetii, namely the causative agent of Q fever is a gram-negative coccobacillus and an obligate intracellular bacterial parasite of the order of Legionellales. The microorganism is generally present in the urine and feces of infected animals and can be found in large quantities in placental membranes of at-term or aborted animals. The inhalation of particles suspended in the air or contaminated aerosols is the most common form of bacterial contact. Q Fever is a self-limited disease, and often progresses in a benign way. In cases where the disease progresses to the chronic form, endocarditis is the most prevalent manifestation. Clinical diagnosis is difficult since the symptoms are similar to many other diseases. In confirmed cases, antibiotic therapy is the treatment indicated. Given the lack of knowledge about the disease and the difficulty of diagnosis, it is believed that Q fever is more common than generally believed in Brazil.

Serological evidence of exposure to some zoonotic microorganisms in cattle and humans with occupational exposure to livestock in Antioquia, Colombia.

Bacteria belonging to Anaplasma, Ehrlichia, Rickettsia and Coxiella genera are considered emerging pathogens and livestock is one of the contexts where the transmission of these microorganisms can occur. The goal of this study was to determine serological evidence for the exposure to these bacteria in cattle and humans with occupational exposure to livestock in the subregions North and Magdalena Medio, Antioquia, Colombia, and to explore related factors. A cross-sectional study was conducted in 48 livestock farms distributed in six municipalities from both subregions: Belmira, Entrerríos and San Pedro de los Milagros (North), and Puerto Berrío, Puerto Nare and Puerto Triunfo (Magdalena Medio). Blood samples from 332 people and 384 bovines were evaluated by serology (IgM and IgG) screening for bacteria from the Anaplasma, Ehrlichia, Rickettsia, and Coxiella genera. Seropositivity in humans from both regions was 42.4% (95%CI: 31.2-55.1) for Anaplasma, 74.2% (95%CI: 66.0-84.4) for Ehrlichia, 72.5% (95%CI: 62.1-82.0) for Rickettsia, and 60.7% (95%CI: 59.7-69.1) for Coxiella burnetii. In cattle, seropositivity was 31.6% (95%CI: 19.9-44.2), 66.8% (95%CI: 55.2-78.1), 64.6% (95%CI: 53.8-74.5), and 61.6% (95%CI: 51.9-69.2), respectively. History of biting by ticks, milking, vaccination, having dogs and hens in the residence, as well as the consumption of raw milk derivatives were some factors associated with the infection by the bacteria studied. The results suggest a previous and recent exposure to these zoonotic bacteria genera in people with occupational exposure to livestock, as well as in cattle in the two studied subregions.

Serological evidence of exposure to some zoonotic microorganisms in cattle and humans with occupational exposure to livestock in Antioquia, Colombia / Evidencia serológica de exposición a algunos microorganismos zoonóticos en bovinos y humanos con exposición ocupacional a ganadería en Antioquia, Colombia / Evidências sorológicas de exposição a alguns microrganismos zoonóticos em bovinos e em humanos com exposição ocupacional ao gado na Antióquia, Colômbia

Bacteria belonging to Anaplasma, Ehrlichia, Rickettsia and Coxiella genera are considered emerging pathogens and livestock is one of the contexts where the transmission of these microorganisms can occur. The goal of this study was to determine serological evidence for the exposure to these bacteria in cattle and humans with occupational exposure to livestock in the subregions North and Magdalena Medio, Antioquia, Colombia, and to explore related factors. A cross-sectional study was conducted in 48 livestock farms distributed in six municipalities from both subregions: Belmira, Entrerríos and San Pedro de los Milagros (North), and Puerto Berrío, Puerto Nare and Puerto Triunfo (Magdalena Medio). Blood samples from 332 people and 384 bovines were evaluated by serology (IgM and IgG) screening for bacteria from the Anaplasma, Ehrlichia, Rickettsia, and Coxiella genera. Seropositivity in humans from both regions was 42.4% (95%CI: 31.2-55.1) for Anaplasma, 74.2% (95%CI: 66.0-84.4) for Ehrlichia, 72.5% (95%CI: 62.1-82.0) for Rickettsia, and 60.7% (95%CI: 59.7-69.1) for Coxiella burnetii. In cattle, seropositivity was 31.6% (95%CI: 19.9-44.2), 66.8% (95%CI: 55.2-78.1), 64.6% (95%CI: 53.8-74.5), and 61.6% (95%CI: 51.9-69.2), respectively. History of biting by ticks, milking, vaccination, having dogs and hens in the residence, as well as the consumption of raw milk derivatives were some factors associated with the infection by the bacteria studied. The results suggest a previous and recent exposure to these zoonotic bacteria genera in people with occupational exposure to livestock, as well as in cattle in the two studied subregions.

Las bacterias pertenecientes a los géneros Anaplasma, Ehrlichia, Rickettsia y Coxiella son consideradas patógenos emergentes y la ganadería es uno de los contextos donde se puede producir la transmisión de este tipo de microorganismos. El objetivo de este estudio fue determinar la evidencia serológica, debida a la exposición a estas bacterias en bovinos y humanos con exposición ocupacional a ganadería en las subregiones Norte y Magdalena Medio, Antioquia, Colombia, además de estudiar los factores relacionados. Se realizó un estudio transversal en 48 fincas ganaderas, distribuidas en seis municipios de ambas subregiones: Belmira, Entrerríos y San Pedro de los Milagros (Norte), y Puerto Berrío, Puerto Nare y Puerto Triunfo (Magdalena Medio). Las muestras de sangre de 332 personas y 384 bovinos fueron evaluadas mediante tamización serológica (IgM e IgG) para la detección de bacterias de los géneros Anaplasma, Ehrlichia, Rickettsia, y Coxiella. La seropositividad en humanos de ambas regiones fue 42,4% (IC95%: 31,2-55,1) en el caso de Anaplasma, un 74,2% (IC95%: 66,0-84,4) en Ehrlichia, un 72,5% (IC95%: 62,1-82,0) en Rickettsia, y un 60,7% (IC95%: 59,7-69,1) en Coxiella burnetii. En los bovinos, la seropositividad fue 31,6% (IC95%: 19,9-44,2), 66,8% (IC95%: 55,2-78,1), 64,6% (IC95%: 53,8-74,5), y 61,6% (IC95%: 51,9-69,2), respectivamente. El antecedente de haber sido mordido por garrapatas, ordeñar, vacunación, tener perros y gallinas en la residencia, así como el consumo de derivados de leche cruda fueron algunos de los factores asociados con la infección por las bacterias estudiadas. Los resultados sugieren la exposición previa y reciente a estas bacterias en personas con una exposición ocupacional a la ganadería, así como a los bovinos en las dos subregiones estudiadas.

As bactérias dos gêneros Anaplasma, Ehrlichia, Rickettsia e Coxiella são considerados patógenos emergentes, e a transmissão desses microrganismos pode ocorrer no contexto da pecuária. O estudo teve como objetivos determinar as evidências sorológicas de exposição a essas bactérias em bovinos e em humanos com exposição ocupacional ao gado nas sub-regiões Norte e Magdalena Médio, Antióquia, Colômbia, e explorar fatores associados. Foi realizado um estudo transversal em 48 fazendas de gado bovino distribuídas em seis municípios nas duas sub-regiões: Belmira, Entrerríos e San Pedro de los Milagros (Norte) e Puerto Berrío, Puerto Nare e Puerto Triunfo (Magdalena Médio). Amostras de sangue de 332 humanos e 384 bovinos foram analisadas com sorologia (IgM e IgG) para bactérias dos gêneros Anaplasma, Ehrlichia, Rickettsia e Coxiella. Os níveis de sorologia positiva em humanos das duas regiões foram de 42,4% (IC95%: 31,2-55,1) para Anaplasma, 74,2% (IC95%: 66,0-84,4) para Ehrlichia, 72,5% (IC95%: 62,1-82,0) para Rickettsia e 60,7% (IC95%: 59,7-69,1) para Coxiella burnetii. Nos bovinos, os níveis foram 31,6% (IC95%: 19,9-44,2), 66,8% (IC95%: 55,2-78,1), 64,6% (IC95%: 53,8-74,5) e 61,6% (IC95%: 51,9-69,2), respectivamente. Os fatores associados às bactérias estudadas foram: história de picada de carrapato, ordenha, vacinação, presença de cães e galinhas no domicílio e consumo de laticínios feitos com leite cru, entre outros. Os resultados sugerem exposição prévia e recente a esses gêneros bacterianos zoonóticos em pessoas com contato ocupacional com gado, assim como nos próprios animais, nas duas sub-regiões estudadas.

Coxiella burnetii: A Hidden Pathogen in Interstitial Lung Disease?

We report 7 patients with interstitial lung disease seen at computed tomographic scan review. Coxiella burnetii infection was diagnosed in situ in 1 lung biopsy specimen. Q fever may be a cofactor of interstitial lung disease, especially in endemic areas.

Seroprevalence of Coxiella burnetii antibodies and chronic Q fever among post-mortal and living donors of tissues and cells from 2010 to 2015 in the Netherlands.

BackgroundAfter a large Q fever outbreak in the Netherlands in the period from 2007 to 2010, the risk of Q fever transmission through tissue and cell transplantation from undiagnosed chronic Q fever cases became a potential issue. Aim: We aimed to evaluate the risk of Q fever transmission through tissue and cell transplantation. Methods: We performed a retrospective observational cohort study among 15,133 Dutch donors of tissues and stem cells from 2010 to 2015 to assess seroprevalence of Coxiella burnetii antibodies, to identify factors associated with presence of C. burnetii antibodies, and to assess the proportion of undiagnosed chronic Q fever cases. Results: The study population consisted of 9,478 (63%) femoral head donors, 5,090 (34%) post-mortal tissue donors and 565 (4%) cord blood donors. Seroprevalence of C. burnetii antibodies gradually decreased after the outbreak, from 2.1% in 2010 to 1.4% in 2015, with a significant trend in time (p < 0.001). Of 301 seropositive donors, seven (2.3%) were newly detected with chronic Q fever (0.05% of all screened donors). Conclusion: This study shows that seroprevalence of C. burnetii antibodies among donors of tissues and cells in the Netherlands after 2014 was similar to pre-outbreak levels in the general population. The proportion of newly detected chronic Q fever patients among donors of tissues and cells was smaller than 0.1%. This study may prompt discussion on when to terminate the screening programme for chronic Q fever in donors of tissues and cells in the Netherlands.

Coxiella burnetii endocarditis on bioprosthetic aortic valve, with peripheral arterial embolism.

Acute limb ischemia related to Coxiella burnetii endocarditis is rare. We report an original case of a 68-year-old man hospitalized for recurrent acute left limb ischemia in a context of atrial flutter, which revealed C. burnetii endocarditis. This case illustrates that even if embolic events are uncommon, septic embolisms must be systematically searched for in case of C. burnetii endocarditis. Conversely, extensive etiologic explorations must be performed in case of systemic embolism. New molecular techniques represent a major step forward in infective endocarditis diagnosis. Finally, diagnosis must be suspected in case of unexplained fever, inflammatory syndrome, or embolic event, especially in patients at risk. Conversely, in case of chronic Q fever, an immunodeficiency cause must be researched.