Case report: a missed case of chronic Q fever infective endocarditis demonstrating the ongoing diagnostic challenges.

Diagnosis of chronic Q fever is often difficult for clinicians, particularly in the presence of a second pathology. In addition to the chronic constitutional symptoms, the most common manifestations of chronic Q fever include infective endocarditis and endovascular infection. We describe a case of prosthetic valve infective endocarditis caused by both Streptococcus sanguinis and Coxiella burnetti on a background of a previous aortic graft and bioprosthetic aortic valve replacement 2 years earlier. The diagnosis of chronic Q fever infective endocarditis was delayed because the significance of the abnormal valve histology from the patient's previous surgery was initially overlooked. It was only after the patient had relapsed on appropriate therapy for the S. sanguinis prosthetic valve endocarditis that a subsequent review of the operative valve histology, along with the patient's epidemiological risk factors, led to consideration of an additional culture-negative cause for infective endocarditis. Histological examination of the valve tissue had shown exophytic fibrin vegetations and acute inflammation. Further clinical assessment revealed previous exposure to Q fever and C. burnetti DNA was detected via polymerase chain reaction on the valve tissue. Q fever infective endocarditis must be considered if valves are inflamed or have vegetations with a subsequent negative culture. It should also still be considered in the presence of an alternative bacteraemia if the patient has risk factors for exposure.

Fatal granulomatous amebic encephalitis initially presenting with a cutaneous lesion.

We present a case of a 66-year-old man with a cutaneous Balamuthia mandrillaris lesion that progressed to fatal granulomatous amoebic encephalitis. We provide a summary of Australian cases and describe the clinical features and approach to diagnosing this rare but devastating condition, including the importance of PCR for diagnosis.

Infective Endocarditis: A Contemporary Study of Microbiology, Echocardiography and Associated Clinical Outcomes at a Major Tertiary Referral Centre.

BACKGROUND: The epidemiology of infective endocarditis (IE) continues to evolve, with antimicrobial resistance and clinical outcomes largely dependent on the environment of acquisition. This study aimed to provide a contemporary review of the microbiology and antimicrobial management of IE and report echocardiographic findings and predictors of adverse outcomes in community-acquired and health care-associated IE. METHODS: Consecutive presentations of IE to a major Australian tertiary referral centre between January 2011 and April 2016 were examined. Culprit organisms and resistance patterns were recorded, as was transthoracic and transoesophageal echocardiography. Real-world antimicrobial prescription and use of an outpatient parenteral antimicrobial therapy (OPAT) service were also assessed, and clinical outcomes analysed. RESULTS: Of 204 consecutive cases, 30% were associated with health care, a group with a higher burden of comorbidities and more prone to complications. Health care-associated cases had lower rates of surgical intervention but higher mortality. A history of intravenous drug use (IVDU) conferred risk for recurrent IE whereas multivalvular involvement predicted heart failure hospitalisation. Staphylococcus aureus was isolated in 45%. Whilst methicillin resistance remains low, the prevalence of S. aureus IE is increasing. Single antimicrobial agents were commonly used (83%) and therapy via OPAT was safe and significantly reduced length of hospital stay. Not undergoing transoesophageal echocardiography (TOE) or definitive surgical management conferred poorer prognosis. CONCLUSIONS: The epidemiology of IE is evolving and there is need for updated epidemiological data and associated clinical outcomes. Environment of acquisition remains important in the face of increasing health care provision and the changing predominance of culprit microorganisms.