Group B streptococcal bacteraemia: changing trends in a tropical region of Australia.

BACKGROUND: Group B streptococcus (GBS) is a recognised perinatal and neonatal pathogen. There are reports of increasing GBS sepsis globally outside this demographic. North Queensland is part of tropical Australia, with a relatively high proportion of Indigenous Australians. AIMS: To analyse the epidemiology of GBS bacteraemia and explore associated risk factors. METHODS: This was a 10-year retrospective review of GBS bacteraemia in a tertiary facility in North Queensland, between 2010 and February 2020. Data variables collected included: demographics, risk factors, clinical source and outcomes. Multivariable logistic regression was performed to examine the association of indigenous status and other relevant clinical factors with mortality from GBS bacteraemia at 3 months. RESULTS: Of the 164 total cases, 123 were not pregnancy related. The annual rate of GBS bacteraemia for the indigenous population was 12.48 per 100 000 and 4.84 per 100 000 for the non-indigenous population. Indigenous patients were more likely to have diabetes and chronic kidney disease compared with the non-indigenous patients. Males (adjusted odds ratio (AOR) = 4.34; 95% CI 1.14-16.56; P = 0.031) and immunosuppressed patients (AOR = 11.49; 95% CI 2.73-48.42; P < 0.001) were more likely to experience mortality at 3 months from GBS bacteraemia even after adjusting for other risk factors respectively. CONCLUSION: GBS bacteraemia is deviating from being primarily a neonatal disease. While the indigenous population of North Queensland are disproportionately affected, the demographics affected differ. GBS appears to target the older non-indigenous patients with greater comorbidities. In the non-indigenous population, invasive GBS disease is an emerging issue. Three-month mortality appears to be increased in males and the immunosuppressed.

The Laboratory Diagnosis of Syphilis.

Syphilis is a multisystem infection caused by the spirochete Treponema pallidum. Currently, cases of possible syphilis are commonly investigated using the treponemal serological tests T. pallidum IgG chemiluminescence immunoassay (CLIA) and the T. pallidum particle agglutination (TPPA). The nontreponemal rapid plasma reagin (RPR) flocculation test is used to assess disease activity. There has been a resurgence of syphilis diagnoses in Australia. Large foci of infection have been identified in isolated communities. The remoteness of these locations, in conjunction with the particular sociocultural characteristics of the population, pose unique challenges to the traditional diagnostic and treatment paradigms for syphilis. As a consequence of this increased incidence of syphilis, there has been interest in the utility of point-of-care tests (POCTs), nucleic acid amplification tests (NAATs), the role of IgM testing in suspected congenital syphilis, and the laboratory investigation of possible neurosyphilis. This review looks at the current status of traditional serological assays and provides an update on more recent methods. It assesses the published literature in this area and makes recommendations for the rational use of pathology testing to aid in the diagnosis of the many facets of syphilis.

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.

Hearing impairment as an unusual presenting sign of Cryptococcus gattii meningoencephalitis.

Hearing loss is an unusual presenting feature of Cryptococcus gattii meningoencephalitis. Two cases of HIV-negative patients who presented with hearing loss are discussed and a literature review of published cases was conducted. Possible mechanisms for hearing loss with C. gattii infection are explored. This case series aims to raise awareness among clinicians that hearing loss can be a concerning feature in patients with persistent headache necessitating further investigation.

Utility of positron emission tomography imaging in the diagnosis of chronic Q fever: A Systematic Review.

Chronic Q fever is a diagnostic challenge. Diagnosis relies on serology and/or the detection of DNA from blood or tissue samples. PET-CT identifies tissues with increased glucose metabolism, thus identifying foci of inflammation. Our aim was to review the existing literature on the use of PET-CT to help diagnose chronic Q fever. A literature search was conducted in PubMed and Google Scholar to ascertain publications that included the terms 'Positron Emission Tomography' and 'PET CT' in combination with subheadings 'chronic Q fever' and 'Coxiella burnetii' within the search. To broaden our search retrieval, we used the terms 'chronic Q fever' and 'PET-CT'. Published literature up to 16th April 2020 was included. 274 articles were initially identified. Post-exclusion criteria, 46 articles were included. Amongst case reports and series, the most frequent focus of infection was vascular, followed by musculoskeletal then cardiac. 79.5% of patients had a focus detected with 55.3% of these having proven infected prosthetic devices. Amongst the retrospective and prospective studies, a total of 394 positive sites of foci were identified with 186 negative cases. Some had follow-up scans (53), with 75.5% showing improvement or resolution. Average timeframe for documented radiological resolution post-initiating treatment was 8.86 months. PET-CT is a useful tool in the management of chronic Q fever. Knowledge of a precise focus enables for directed surgical management helping reduce microbial burden, preventing future complications. Radiological resolution of infection can give clinicians reassurance on whether antimicrobial therapy can be ceased earlier, potentially limiting side effects.

Hepatic tuberculosis masquerading as cholangiocarcinoma: an unusual differential for a liver mass.

A 54-year-old woman presented with an incidentally identified asymptomatic liver lesion with imaging characteristics suspicious for malignancy. She underwent a left hemihepatectomy for presumed cholangiocarcinoma. Histopathology revealed granulomas with microbiological investigations later revealing a diagnosis of isolated hepatic tuberculosis. There were no pulmonary or other disease sites identified. The patient has been medically managed for primary hepatic tuberculosis and remains well postoperatively. This case identifies a rare differential for a liver mass that needs to be considered in the clinicians' workup.

Q fever in an endemic region of North Queensland, Australia: A 10 year review.

BACKGROUND: Q fever is a zoonotic infection caused by Coxiella burnetii. Endemic Q fever has long been recognised in north Queensland, with north Queensland previously acknowledged to have the highest rate of notification in Australia. In this retrospective study, we reviewed the demographics and exposure of patients diagnosed with Q fever in an endemic region of north Queensland, to identify trends and exposure factors for the acquisition of Q fever. METHODS: A retrospective study looking at patients in the region that had tested positive for Q fever by case ascertainment between 2004 and 2014. This involved both a chart review and the completion of a patient questionnaire targeting demographics, clinical presentation, risk factors and outcomes. RESULTS: There were 101 patients with a positive Q fever serology and/or PCR that were identified in the region of north Queensland that was studied, between 2004 and 2014. The cohort was residents of Mackay Hospital and Health Service. Of these, 4 patients were excluded and 63 patients successfully completed a questionnaire on demographic and risk factors. Out of the 63 patients, the highest prevalence was in the patients residing in the coastal region of Proserpine (42/100,000 people per year) followed by the Whitsundays region (14.8/100,000 people per year). A significantly higher proportion of patients were reportedly exposed to macropods (69.8%) and possums (66.7%) as compared to cattle (23.8%). A trend between increased cases of Q fever infection and high seasonal rainfall was noted. CONCLUSIONS: In this endemic region of north Queensland, exposure to wildlife and seasonal rainfall may be substantial exposure factors for the development of Q fever. The region studied is a popular tourist destination. An understanding of risk factors involved can help practitioners who see residents or returned travelers from the region, with an undifferentiated fever.