Chronic Q-fever Research Articles

Rare Case of Chronic Coxiella Endocarditis Without Fever or Classic Risk Factors

Background: “Q-fever” is a zoonotic infectious disease caused by Coxiella burnetii which is most commonly transmitted globally through unpasteurized animal products or aerosolized fluid. This zoonosis is not thought to be common in developed countries due to modern utilization of pasteurization but risk for transmission remains high in those with extended contact with livestock and cattle. Acute Q-fever presents with an illness characterized by high fevers, myalgias, and segmental pneumonia, but rarely it may progress to chronic Q-fever. Chronic Q-fever most often presents with a culture-negative endocarditis with or without renal impairment and can be fatal if left untreated. Case Report: In this case report, we present a 72-year-old male with a 3-month history of body pain, cough, and weight loss who was eventually discovered to have an afebrile presentation of Coxiella endocarditis. This patient was found to have a mitral valve vegetation diagnosed through transesophageal echocardiography and had positive serology for chronic Q-fever. Surprisingly, this patient had no classical exposures, no history of valvular dysfunction or prosthesis, and no clinical signs suggesting endocarditis, making his case markedly atypical. He was placed on a 12 -18-month course of antibiotics and was monitored on an outpatient basis. Conclusion: Although chronic Q-fever is rare its variable presentation may cause diagnostic error if it is not kept on the differential. A transesophageal echocardiogram should be strongly preferred due to its superior visualization of heart valves. Serology remains the gold standard for diagnosis of Coxiella. When dealing with culture-negative endocarditis, clinicians should retain a high index of suspicion of Coxiella and obtain serologies for diagnosis

Impact of Q-fever on physical and psychosocial functioning until 8 years after Coxiella burnetii infection: An integrative data analysis.

This study aimed to determine short- and long-term physical and psychosocial impact of Coxiella burnetii infection in three distinct entities: Q-fever fatigue syndrome (QFS), chronic Q-fever, and patients with past acute Q-fever without QFS or chronic Q-fever. Integrative data analysis was performed, combining original data from eight studies measuring quality of life (QoL), fatigue, physical and social functioning with identical validated questionnaires, from three months to eight years after onset infection. Linear trends in each outcome were compared between Q-fever groups using multilevel linear regression analyses to account for repeated measures within patients. Data included 3947 observations of 2313 individual patients (228 QFS, 135 chronic Q-fever and 1950 patients with past acute Q-fever). In the first years following infection, physical and psychosocial impact was highest among QFS patients, and remained high without significant improvements over time. In chronic Q-fever patients, QoL and physical functioning worsened significantly over time. Levels of fatigue and social participation in patients with past acute Q-fever improved significantly over time. The impact differs greatly between the three Q-fever groups. It is important that physicians are aware of these differences, in order to provide relevant care for each patient group.

Long-term impact of a Q-fever outbreak: An evaluation of health symptoms, health-related quality of life, participation and health care satisfaction after ten years

ObjectiveTo assess health symptoms, health-related quality of life, participation, and health care satisfaction in Q-fever patients up to 10 years after infection. MethodsCross-sectional questionnaire survey in the Netherlands. Data on health symptoms, fatigue (CIS), health-related quality of life (EQ-5D), social/work participation, health care providers and health care satisfaction were collected in patients with chronic Q-fever (CQ), Q-fever fatigue syndrome (QFS), and patients who experience QFS-like disease without a post-infection diagnosis (QLD). ResultsA vast majority of the 478 Q-fever patients (response rate 54.3%) face several health problems 10 years after infection. Fatigue was the most prevalent symptom in all groups (91.2%). The median EQ-5D index value differed significantly between the three diagnostic groups (CQ: 0.67; QFS: 0.55; QLD:0.70; p < 0.001). Approximately 50% of all patients had serious problems with work and physical activities, and more than 25% experienced difficulties with leisure time, household and social contacts. Also, more than one third stopped working permanently. Furthermore, GP's, internists, and physical therapists were the most often consulted health care providers. Patients gave low ratings for the overall quality of care for Q-fever, with 75% scoring a 5.0 or lower on a 10-point scale. ConclusionLong-term health consequences are considerable for Q-fever patients, especially for those with QFS. The majority of the patients was unsatisfied with the quality of care for Q-fever. Awareness of the long-term impact of zoonotic diseases like Q-fever is needed to offer optimal health care for these patients.

Cost-effectiveness of Screening Program for Chronic Q Fever, the Netherlands.

In the aftermath of a large Q fever (QF) epidemic in the Netherlands during 2007–2010, new chronic QF (CQF) patients continue to be detected. We developed a health-economic decision model to evaluate the cost-effectiveness of a 1-time screening program for CQF 7 years after the epidemic. The model was parameterized with spatial data on QF notifications for the Netherlands, prevalence data from targeted screening studies, and clinical data from the national QF database. The cost-effectiveness of screening varied substantially among subpopulations and geographic areas. Screening that focused on cardiovascular risk patients in areas with high QF incidence during the epidemic ranged from cost-saving to €31,373 per quality-adjusted life year gained, depending on the method to estimate the prevalence of CQF. The cost per quality-adjusted life year of mass screening of all older adults was €70,000 in the most optimistic scenario.

Explaining the long-term impact of chronic Q fever and Q fever fatigue syndrome on psychosocial functioning: A comparison with diabetes and the general population

ObjectiveAfter Q fever infection, 1–5% of patients develop chronic Q fever, while about 20% develops Q fever fatigue syndrome (QFS). This study examines whether these two conditions have a long-term impact on psychosocial functioning compared to the general population and patients with type 2 diabetes (DM) and investigate which mediating factors influence outcomes. MethodsCross-sectional study was performed, measuring psychosocial functioning including quality of life (depression and satisfaction with life), anxiety, social functioning and relationship satisfaction in patients with proven or probable chronic Q fever or QFS, 5–9 years after acute Q fever infection. Multivariate linear regression was used to analyse differences between groups, correct for confounders and identify relevant mediators (fatigue, physical or cognitive functioning, illness perception). ResultsQuality of life and social functioning of chronic Q-fever and QFS patients was significantly lower and anxiety significantly higher compared to DM patients and the general population. The impact was completely mediated by fatigue in both Q fever groups. Physical and cognitive functioning and illness perception partially mediated the impact. ConclusionsHealth care workers need to be aware of the long-term impact of chronic Q fever and QFS on psychosocial functioning of patients in order to provide proper guidance.

Q fever in Spain: Description of a new series, and systematic review.

BackgroundForms of presentation of Q fever vary widely across Spain, with differences between the north and south. In the absence of reported case series from Galicia (north-west Spain), this study sought to describe a Q-fever case series in this region for the first time, and conduct a systematic review to analyse all available data on the disease in Spain.MethodsPatients with positive serum antibodies to Coxiella burnetii from a single institution over a 5-year period (January 2011-December 2015) were included. Patients with phase II titres above 1/128 (or documented seroconversion) and compatible clinical criterial were considered as having Q fever. Patients with clinical suspicion of chronic Q-fever and IgG antibodies to phase I-antigen of over 1/1024, or persistently high levels six months after treatment were considered to be cases of probable chronic Q-fever. Systematic review: We conducted a search of the Pubmed/Medline database using the terms: Q Fever OR Coxiella burnetii AND Spain. Our search yielded a total of 318 studies: 244 were excluded because they failed to match the main criteria, and 41 were discarded due to methodological problems, incomplete information or duplication. Finally, 33 studies were included.ResultsA total of 155 patients, all of them from Galicia, with positive serological determination were located during the study period; 116 (75%) were deemed to be serologically positive patients without Q fever and the remaining 39 (25%) were diagnosed with Q fever. A potential exposure risk was found in 2 patients (5%). The most frequent form of presentation was pneumonia (87%), followed by isolated fever (5%), diarrhoea (5%) and endocarditis (3%). The main symptoms were headache (100%), cough (77%) and fever (69%). A trend to a paucisymptomatic illness was observed in women. Hospital admission was required in 37 cases, and 6 patients died while in hospital. Only 2 patients developed chronic Q-fever. Systematic review: Most cases were sporadic, mainly presented during the winter and spring, as pneumonia in 37%, hepatitis in 31% and isolated fever in 29.6% of patients. In the north of Spain, 71% of patients had pneumonia, 13.2% isolated fever and 13% hepatitis. In the central and southern areas, isolated fever was the most frequent form of presentation (40%), followed by hepatitis (38.4%) and pneumonia (17.6%). Only 31.7% of patients reported risk factors, and an urban-environment was the most frequent place of origin. Overall mortality was 0.9%, and the percentage of patients with chronic forms of Q-fever was 2%.ConclusionsThis is the first study to report on a Q-fever case series in Galicia. It shows that in this region, the disease affects the elderly population -even in the absence of risk factors- and is linked to a higher mortality than reported by previous studies. While pneumonia is the most frequent form of presentation in the north of the country, isolated fever and hepatitis tend to be more frequent in the central and southern areas. In Spain, 32% of Q-fever cases do not report contact with traditional risk factors, and around 58% live in urban areas.

Should Acute Q-Fever Patients be Screened for Valvulopathy to Prevent Endocarditis?

Echocardiographic screening of acute Q-fever patients and antibiotic prophylaxis for patients with cardiac valvulopathy is considered an important approach to prevent chronic Q-fever-related endocarditis. During a large Q-fever epidemic in the Netherlands, routine screening echocardiography was discontinued, raising controversy in the international literature. We followed a cohort of acute Q-fever patients to estimate the risk for developing chronic Q-fever, and we evaluated the impact of screening in patients who were not yet known to have a valvulopathy. The study population consisted of patients diagnosed with acute Q-fever in 2007 and 2008. We retrospectively reviewed all screening echocardiographs and checked for development of chronic Q-fever 8 years after the acute episode. Risks of developing chronic Q-fever in relation to the presence or absence of valvulopathy were analyzed with logistic regression. The cohort included 509 patients, of whom 306 received echocardiographic screening. There was no significant difference (P-value = .22) in occurrence of chronic Q-fever between patients with a newly detected valvulopathy (2/84, 2.4%) and those with no valvulopathy (12/202, 5.9%). Two patients with a newly detected valvulopathy, who did not receive antibiotic prophylaxis, developed chronic Q-fever at a later stage. We found no difference in outcome between patients with and without a valvulopathy newly detected by echocardiographic screening. In retrospect, the 2 above-mentioned patients could have benefitted from antibiotic prophylaxis, but its omission must be weighed against the unnecessary large-scale and long-term use of antibiotics that would have resulted from universal echocardiographic screening.

A Case of Primary Aortoduodenal Fistula and Abdominal Aortic Aneurysm in a Patient with Chronic Q-fever

A Case of Primary Aortoduodenal Fistula and Abdominal Aortic Aneurysm in a Patient with Chronic Q-fever

Endovascular Chronic Q Fever with Contiguous Psoas Abscess and Spondylitis

Vascular chronic Q fever (CQF) is a severe form of Q fever, a ubiquitous zoonosis, with non-specific symptoms, challenging diagnosis and that can lead to several complications associated with a poor prognosis. Here, we present the case of a 68 years-old patient that first presented pygalgia, fatigue and weight loss, ultimately diagnosed with vascular chronic Q fever, more than 6 months after the beginning of the symptoms, leading to his death despite appropriate but late antibiotic course and surgical intervention. This case raises the question about the interest of evoking this diagnosis in a systematic way when confronted to new onset of non-specific general symptoms in a context of known aortic aneurysm.

Altered interferon-γ response in patients with Q-fever fatigue syndrome

Whether immunological mechanisms underlie Q-fever fatigue syndrome (QFS) remains unclear. For acute Q-fever, the antigen-specific interferon-γ (IFNγ) response may be a useful tool for diagnosis, and the IFNγ/interleukin(IL)-2 production ratio may be a marker for chronic Q-fever and treatment monitoring. Here we explored the specific IFNγ production and IFNγ/IL-2 ratio in QFS patients. IFNγ and IL-2 production were tested in ex-vivo stimulated whole blood of QFS patients (n = 20), and compared to those previously determined in seropositive controls (n = 135), and chronic Q-fever patients (n = 28). Also, the correlation between patient characteristics and IFNγ, IL-2, and IFNγ/IL-2 ratio was determined. QFS patients were younger (p < 0.001), but gender distribution was similar to seropositive controls and chronic Q-fever patients. Coxiella burnetii Nine Mile stimulation revealed a higher IFNγ production in QFS (median 319.5 pg/ml) than in seropositive controls (120 pg/ml, p < 0.01), but comparable to chronic Q-fever (2846 pg/ml). The IFNγ/IL-2 ratio was similar to that in seropositive controls, but lower than in chronic Q-fever patients (p < 0.01). Symptom duration was positively correlated with IL-2 production, and negatively correlated with the IFNγ/IL-2 ratio. These results point to an altered cell-mediated immunity in QFS, and suggest a different immune response than in chronic Q-fever.

Chronic Q-Fever (Coxiella burnetii) Causing Abdominal Aortic Aneurysm and Lumbar Osteomyelitis: A Case Report.

Coxiella burnetii is a rare cause of chronic infection that most frequently presents as endocarditis. We report a case of C burnetii causing an infected abdominal aortic aneurysm with contiguous lumbar osteomyelitis resulting in spinal cord compromise. The diagnosis was established by serologic studies consistent with chronic Q-fever (ratio of C burnetii immunoglobulin [Ig]G phase II titer to IgG phase I titer <1) and was confirmed by positive C burnetii polymerase chain reaction of vertebral tissue in addition to pathology of vertebral bone showing intracellular Gram-negative coccobacillary bacteria. The patient clinically improved after surgical decompression and prolonged treatment with doxycycline and hydroxychloroquine.

Long-Term Serological Follow-Up of Acute Q-Fever Patients after a Large Epidemic.

BackgroundSerological follow-up of acute Q-fever patients is important for detection of chronic infection but there is no consensus on its frequency and duration. The 2007–2009 Q-fever epidemic in the Netherlands allowed for long-term follow-up of a large cohort of acute Q-fever patients. The aim of this study was to validate the current follow-up strategy targeted to identify patients with chronic Q-fever.MethodsA cohort of adult acute Q-fever patients, diagnosed between 2007 and 2009, for whom a twelve-month follow-up sample was available, was invited to complete a questionnaire and provide a blood sample, four years after the acute episode. Antibody profiles, determined by immunofluorescence assay in serum, were investigated with a special focus on high titres of IgG antibodies against phase I of Coxiella burnetii, as these are considered indicative for possible chronic Q-fever.ResultsOf the invited 1,907 patients fulfilling inclusion criteria, 1,289 (67.6%) were included in the analysis. At any time during the four-year follow-up period, 58 (4.5%) patients were classified as possible, probable, or proven chronic Q-fever according to the Dutch Q-fever Consensus Group criteria (which uses IgG phase I ≥1:1,024 to as serologic criterion for chronic Q-fever). Fifty-two (89.7%) of these were identified within the first year after the acute episode. Of the six patients that were detected for the first time at four-year follow-up, five had an IgG phase I titre of 1:512 at twelve months.ConclusionsA twelve-month follow-up check after acute Q-fever is recommended as it adequately detects chronic Q-fever in patients without known risk factors. Additional serological and clinical follow-up is recommended for patients with IgG phase I ≥1:512, as they showed the highest risk to progress to chronic Q-fever.

Population Screening for Chronic Q-Fever Seven Years after a Major Outbreak.

IntroductionFrom 2007 through 2010, the Netherlands experienced a large Q-fever epidemic, with 4,107 notifications. The most serious complication of Q-fever is chronic Q-fever.MethodIn 2014, we contacted all 2,161 adult inhabitants of the first village in the Netherlands affected by the Q-fever epidemic and offered to test for antibodies against Coxiella burnetii using immunofluorescence assay (IFA) to screen for chronic infections and assess whether large-scale population screening elsewhere is warranted.ResultsOf the 1,517 participants, 33.8% were IFA-positive. Six IFA-positive participants had an IgG phase I titer ≥1:512. Two of these six participants were previously diagnosed with chronic Q-fever. Chronic infection was diagnosed in one of the other four participants after clinical examination.ConclusionsSeven years after the initial outbreak, seroprevalence remains high, but the yield of screening the general population for chronic Q-fever is low. A policy of screening known high-risk groups for chronic Q-fever in outbreak areas directly following an outbreak might be more efficient than population screening. A cost-effectiveness analysis should also be performed before initiating a population screening program for chronic Q-fever.

Primary aortoduodenal fistula and Q-fever

Patients with abdominal aortic aneurysm (AAA) are prone to vascular infection with chronic Q-fever. There is a rising incidence of up to 8% of chronic Q-fever in The Netherlands. Increased vascular aortic aneurysm infection with chronic Q-fever is reported. This report shows two rare cases of primary aortoduodenal fistulae in patients with chronic Q-fever and an AAA. We describe the clinical symptoms, diagnostic tools for detection of Coxiella burnetii infection and treatment.

Strategies for early detection of chronic Q‐fever: a systematic review

Chronic Q-fever, a condition with high morbidity and mortality, may develop after an acute infection with Coxiella burnetii (acute Q-fever). Several strategies have been suggested for early detection of chronic Q-fever, focusing on follow-up of known acute Q-fever patients and detection of asymptomatic or unknown chronic infections. As there is no international standard or consensus, the aims of this study were to summarise the available literature and assess the evidence for different follow-up and screening strategies. We conducted a systematic review by searching PubMed and Embase. Twenty articles were included, of which fourteen only provided information on follow-up of known acute Q-fever cases, four presented data on identification of previously unknown C. burnetii infections, and two had information on both topics. The conversion rate of acute to chronic Q-fever ranged from 0 to 5.0%. Most studies advised serological follow-up of acute Q-fever patients, but without consistent advice on optimum timing and duration. The recommendation to use echocardiography for all acute Q-fever patients to detect valvular damage remains controversial. Screening of high-risk patients in an outbreak setting is advised by studies investigating such strategy. There is sufficient evidence to support serological follow-up of all known acute Q-fever patients at least once during the first year following the acute infection, and more frequently in patients with known risk factors for chronic disease, such as heart valve- or vascular prosthesis. Screening of risk groups should be considered in outbreaks of Q-fever.

Q-fever presenting as an autoimmune disease: case report and review

AbstractQ fever is a worldwide zoonosis caused by the intracellular bacterium Coxiella burnetti. Autoimmune phenomena associated with the disease may obscure the clinical picture, and in many reports mislead physicians to an initial diagnosis of an autoimmune disease. We present a case of chronic Q-fever, complicated by myocarditis/pericarditis, where patient’s initial signs, symptoms and laboratory findings (i.e., protracted fever, oligoarthritis, erythema nodosum, positive antineutrophil cytoplasmic antibodies, monoclonal gammopathy) seemed to suggest an autoimmune disease. We also review the literature for autoimmune phenomena associated with Q-fever.

DNA microarray-chip based diagnosis of Q-fever (Coxiella burnetii)

Coxiella burnetii is an obligate intracellular bacterium causing Q-fever, a zoonotic disease that is ubiquitous throughout the world with the exception of New Zealand. Cattle, goats, sheep and ticks are the primary reservoirs, but many other species, including fish, birds, rodents and cats, are known to become infected. Especially in small ruminants, infection can lead to abortion associated with exceptionally high amounts of C. burnetii in amniotic fluids and the placenta. Furthermore, C. burnetii may be excreted in milk, urine and faeces of infected animals. Human infections frequently follow contact with infected sheep, especially during lambing, or via the inhalation of dried tick faeces during shearing. Most cases of human infection with C. burnetii are self-limiting, associated with fever, fatigue, headache and myalgia. Acute Q-fever is frequently accompanied by atypical pneumonia and ⁄ or hepatitis. Persistence of infection exceeding 6 months in duration is regarded as chronic Q-fever. Commonly, endocarditis is seen, but chronic hepatitis, osteomyelitis, septic arthritis or infection of aneurysm and vascular grafts can also occur. During pregnancy, Q-fever has been associated with premature birth, abortion and neonatal death. Diagnosis mostly relies on serology, but, especially in the early clinical stages, PCR offers substantial benefits for the identification of C. burnetii infection [1]. In our study, we investigated the suitability of a new rapid ‘low cost and density’ (LCD) DNA microarray chip for the detection of C. burnetii (Coxiella 2.5). Besides the commonly used IS1111 genomic target (Genebank accession number: M80806), we coated a recently described genomic marker proposed to be diagnostic of acute Q-fever (acute disease antigen A (adaA), CBU_0952, GenBank ID AAO90475.1) on the chip [2]. The results were compared with those of both conventional, gel-based and a real-time LightCyclerHyprobe– PCR assay in terms of specificity and sensitivity. Clinical materials of both human and animal origin were also used for evaluation.

Asymptomatic Malaria Associated with Protection: Not Causal

An otherwise healthy 44-year-old woman (a resident of a mountainous region of Switzerland) presented to the emergency department with acute onset of fever myalgia and disorientation. On physical examination she was in shock without an evident infectious source. Laboratory analyses revealed leukocytosis (WBC count 27000_109 cells/L) and an elevated C-reactive protein level (260 mg/ L). The patient had a history of congenital left ventricular inflow and outflow tract obstruction that was surgically corrected at the age of 15 years. In 1986 and 1996 she had infectious endocarditis of the aortic valve due to Staphylococcus aureus; the aortic valve was replaced by a homograft in 1990. Transesophageal echocardiography showed vegetations on the aortic valve and possibly also on the mitral valve with severe aortic and moderate mitral regurgitation. Therapy with vancomycin gentamicin and rifampicin was initiated. Blood cultures grew methicillin-sensitive S. aureus supporting a diagnosis of S. aureus prosthetic valve endocarditis and treatment was changed to flucloxacillin and rifampicin. The clinical course was complicated by acute renal failure severe thrombopenia and multiple septic emboli (in the brain skin retina and spleen). After 4 weeks of antibiotic therapy the aortic and mitral valves were replaced by mechanical prostheses. Cultures of the aortic valve were sterile but broad-range eubacterial PCR had results positive for Coxiella burnetii. Serologic results confirmed chronic Q-fever (phase 1 IgG titer 1:6400; phase 1 IgA titer 1: 200; phase 2 IgG titer 1:12800; and phase 2 IgA titer 1:400); analysis of stored serum samples from the patient revealed that the infection had been acquired in the previous 12 months. Thus the final diagnosis was chronic Q-fever prosthetic valve endocarditis complicated by acute S. aureus prosthetic valve endocarditis. The postoperative course was uncomplicated. S. aureus prosthetic valve endocarditis was treated for a total of 6 weeks with flucloxacillin and rifampicin. For Q-fever endocarditis therapy with doxycycline and hydroxychloroquine was introduced and will be continued until the phase 1 IgG titer is !1:400 with a minimum treatment duration of 18 months. At the most recent follow-up visit 10 months after the initial presentation the patient was asymptomatic and titers of anti-Coxiella antibodies were decreasing (phase 1 IgG titer 1:3200; phase 1 IgA titer 1:50; phase 2 IgG titer 1: 6400; phase 2 IgA titer 1:100). This case is remarkable for the simultaneous implication of two different bacterial species in the pathogenesis of infective endocarditis with one of the pathogens being discovered incidentally. Reports in the literature on dual-pathogen endocarditis are scarce; 2 cases with concomitant streptococcal and Q-fever endocarditis have been previously described in a large prospective French study [1]. Our patient had underlying cardiac abnormalities predisposing her to C. burnetii endocarditis and resided in an area of Switzerland with a seroprevalence of Coxiella species infection up to 30% [2]. Nevertheless C. burnetii infection was not suspected because all clinical manifestations were compatible with staphylococcal prosthetic valve endocarditis. The diagnosis of Q-fever endocarditis was thus a lucky strike which is disconcerting given the poor prognosis of unrecognized chronic Coxiella infection. In view of our experience we believe that C. burnetii serologic analysis or PCR testing of heart valve tissue are worth performing in all patients with infective endocarditis who have a preexisting valvulopathy and live in a region in which Q-fever is endemic regardless of whether another etiological agent has been identified or not. (full-text)

High throughput detection of Coxiella burnetii by real-time PCR with internal control system and automated DNA preparation

BackgroundCoxiella burnetii is the causative agent of Q-fever, a widespread zoonosis. Due to its high environmental stability and infectivity it is regarded as a category B biological weapon agent. In domestic animals infection remains either asymptomatic or presents as infertility or abortion. Clinical presentation in humans can range from mild flu-like illness to acute pneumonia and hepatitis. Endocarditis represents the most common form of chronic Q-fever. In humans serology is the gold standard for diagnosis but is inadequate for early case detection. In order to serve as a diagnostic tool in an eventual biological weapon attack or in local epidemics we developed a real-time 5'nuclease based PCR assay with an internal control system. To facilitate high-throughput an automated extraction procedure was evaluated.ResultsTo determine the minimum number of copies that are detectable at 95% chance probit analysis was used. Limit of detection in blood was 2,881 copies/ml [95%CI, 2,188–4,745 copies/ml] with a manual extraction procedure and 4,235 copies/ml [95%CI, 3,143–7,428 copies/ml] with a fully automated extraction procedure, respectively. To demonstrate clinical application a total of 72 specimens of animal origin were compared with respect to manual and automated extraction. A strong correlation between both methods was observed rendering both methods suitable. Testing of 247 follow up specimens of animal origin from a local Q-fever epidemic rendered real-time PCR more sensitive than conventional PCR.ConclusionA sensitive and thoroughly evaluated real-time PCR was established. Its high-throughput mode may show a useful approach to rapidly screen samples in local outbreaks for other organisms relevant for humans or animals. Compared to a conventional PCR assay sensitivity of real-time PCR was higher after testing samples from a local Q-fever outbreak.

Bartonella and Coxiella antibodies in 334 prospectively studied episodes of infective endocarditis in Sweden.

Bartonella spp. have been identified as aetiological agents in culture-negative infective endocarditis (IE). Coxiella burnetii may cause chronic Q-fever with endocarditis, 334 blood samples collected from 329 patients (334 episodes) with IE diagnosed between 1984 and 1996 in Göteborg, Sweden, were investigated for antibodies to Bartonella spp. and C. burnetii. 71 of the episodes (21%) were blood culture negative. A microimmunofluorescence assay revealed immunoglobulin G (IgG) antibodies to Bartonella in 13 of the culture verified episodes and in 2 of the culture-negative episodes. Three of the patients had IgG antibodies to > or = 200 in the blood culture-verified group, but none had a titre > or = 800, the cut-off level for Bartonella endocarditis. One patient had elevated antibodies to C. burnetii, diagnosing chronic Q-fever endocarditis. In conclusion, serologically verified Bartonella endocarditis is not prevalent in western Sweden and Q-fever endocarditis is rare.