Exposure and risk factors to Coxiella burnetii, spotted fever group and typhus group rickettsiae, and Bartonella henselae among volunteer blood donors in Namibia

Background: The role of pathogen-mediated febrile illness in sub-Saharan Africa is receiving more attention, especially in Southern Africa where four countries (including Namibia) are actively working to eliminate malaria. With a high concentration of livestock and high rates of companion animal ownership, the influence of zoonotic bacterial diseases as causes of febrile illness in Namibia remains unknown.Methodology/Principal Findings: The aim of the study was to evaluate exposure to Coxiella burnetii, spotted fever and typhus group rickettsiae, and Bartonella henselae using IFA and ELISA (IgG) in serum collected from 319 volunteer blood donors identified by the Blood Transfusion Service of Namibia (NAMBTS). Serum samples were linked to a basic questionnaire to identify possible risk factors. The majority of the participants (64.8%) had extensive exposure to rural areas or farms. Results indicated a C. burnetii prevalence of 26.1% (screening titre 1:16), and prevalence rates of 11.9% and 14.9% (screening titre 1:100) for spotted fever group and typhus group rickettsiae, respectively. There was a significant spatial association between C. burnetii exposure and place of residence in southern Namibia (P0.012), especially cattle (P>0.006), were also significantly associated with C. burnetii exposure. Males were significantly more likely than females to have been exposed to spotted fever (P<0.013) and typhus (P<0.011) group rickettsiae. Three (2.9%) samples were positive for B. henselae possibly indicating low levels of exposure to a pathogen never reported in Namibia.Conclusions/Significance: These results indicate that Namibians are exposed to pathogenic fever-causing bacteria, most of which have flea or tick vectors/reservoirs. The epidemiology of febrile illnesses in Namibia needs further evaluation in order to develop comprehensive local diagnostic and treatment algorithms.Peer reviewedEntomology and Plant Patholog

Comparison Between ESC and Duke Criteria for the Diagnosis of Prosthetic Valve Infective Endocarditis

International audienceObjectives: The primary objective was to assess the value of the European Society of Cardiology (ESC) criteria, including 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG-PET/CT) in prosthetic valve infective endocarditis (PVE). Secondary objectives were: 1) to assess the reproducibility of 18F-FDG-PET/CT; 2) to compare its diagnostic value with that of echocardiography; and 3) to assess the diagnostic value of the presence of a diffuse splenic uptake BACKGROUND: 18F-FDG PET/CT has been added as a major criterion in the ESC 2015 infective endocarditis (IE) guidelines, but the benefit of the ESC criteria has not been prospectively compared with the conventional Duke criteria.Methods: Between 2014 and 2017, 175 patients with suspected PVE were prospectively included in 3 French centers. After exclusion of patients with uninterpretable 18F-FDG PET/CT, 115 patients were evaluated, including 91 definite and 24 rejected IE, as defined by an expert consensus.Results: Cardiac uptake by 18F-FDG PET/CT was observed in 67 of 91 patients with definite PVE and 6 with rejected IE (sensitivity 73.6% [95% confidence interval (CI): 63.3% to 82.3%], specificity 75% [95% CI: 53.3% to 90.2%]). The ESC 2015 classification increased the sensitivity of Duke criteria from 57.1% (95% CI: 46.3% to 67.5%) to 83.5% (95% CI: 74.3% to 90.5%) (p < 0.001), but decreased its specificity from 95.8% (95% CI: 78.9% to 99.9%) to 70.8% (95% CI: 48.9% to 87.4%). Intraobserver reproducibility of 18F-FDG PET/CT was good (kappa = 0.84) but interobserver reproducibility was less satisfactory (kappa = 0.63). A diffuse splenic uptake was observed in 24 (20.3%) patients, including 23 (25.3%) of definite PVE, and only 1 (4.2%) rejected PVE (p = 0.024).Conclusions: 18F-FDG PET/CT is a useful diagnostic tool in suspected PVE, and explains the greater sensitivity of ESC criteria than Duke criteria. However, 18F-FDG PET/CT also presents with important limitations concerning its feasibility, specificity, and reproducibility. Our study describes for the first time a new endocarditis criterion, that is, the presence of a diffuse splenic uptake on 18F-FDG PET/CT

Endocarditis in the elderly: clinical, echocardiographic, and prognostic features

Aims Infective endocarditis (IE) is more and more frequent in elderly persons and it has been associated with various clinical, bacteriological, and prognostic features. The aim of the study was to define the clinical, echographic, and prognostic characteristics of IE in a large population of elderly patients from four European centres (three French, one Italian). Methods and results Three hundred and fifteen consecutive patients with definite IE underwent clinical evaluation, echocardiography, blood cultures, and follow-up. Patients were separated into three groups: group A: 117 patients aged <50 years, group B: 111 patients aged >50 and 70 years. Elderly patients (group C) presented more frequently than other groups with digestive or urinary portal of entry, pacemaker endocarditis, and anaemia. S bovis endocarditis was less frequent and S aureus endocarditis more frequent in younger (group A) patients than in other groups. No difference was observed among groups concerning echocardiographic data as well as the incidence and localization of embolic events. Elderly patients were operated on as frequently as younger patients and their operative risk was similar than in other groups (11%, 3%, and 5% in groups C, B, and A, respectively, P=ns). Overall mortality in elderly patients was low (17%) but significantly higher than in younger patients (10% in group A, 7% in group B, P=0.02). By multivariate analysis, the only risk factors for in-hospital mortality were age (P=0.003), prosthetic valve (P=0.002), and cerebral embolism (P=0.006). Conversely, surgical management was associated with a lower in hospital mortality (P=0.03). Conclusions In this largest series of elderly patients with IE, IE in elderly carries specific features when compared with younger patients, although the echographic characteristics and embolic risk are similar. The overall mortality rate in elderly patients is higher than in younger, but the mortality in operated patients is low and similar than that of younger patient

Echocardiography predicts embolic events in infective endocarditis

The aim of our study was to assess the value of transesophageal echocardiography (TEE) in predicting embolic events (EEs) in a large group of patients with definite endocarditis according to the Duke criteria, including silent embolism. BACKGROUND The value of echocardiography in predicting embolism in patients with endocarditis remains controversial. Some studies reported an increased risk of embolism in patients with large and mobile vegetations, whereas other studies failed to demonstrate such a relationship. METHODS Multiplane transesophageal echocardiograms of 178 consecutive patients with definite infective endocarditis (IE) were analyzed. The incidence of embolism was compared with the echocardiographic characteristics (localization, size and mobility) of the vegetations. To detect silent embolism, cerebral and thoraco-abdominal scans were performed in 95% of patients. RESULTS Among 178 patients, 66 (37%) had one or more EEs. There was no difference between patients with and without embolism in terms of age, gender and left valve involved. On univariate analysis, Staphylococcus infection, right-side valve endocarditis and vegetation length and mobility were significantly related to EEs. A significant higher incidence of embolism was present in patients with vegetation length .10 mm (60%, p , 0.001) and in patients with mobile vegetations (62%, p , 0.001). Embolism was particularly frequent among 30 patients with both severely mobile and large vegetations (.15 mm) (83%, p , 0.001). On multivariate analysis, the only predictors of embolism were vegetation length (p 5 0.03) and mobility (p 5 0.01). CONCLUSIONS Our study shows that the presence of vegetations on TEE is predictive of embolism and that the morphologic characteristics of vegetations are helpful in predicting EEs in both mitral and aortic valve IE. It also suggests that early operation may be recommended in patients with vegetations .15 mm and high mobility, irrespective of the degree of valve destruction, heart failure and response to antibiotic therapy. (J Am Coll Cardiol 2001;37:1069 –76) © 2001 by the American College of Cardiolog