Syphilis is a multisystem infection caused by the spirochaete 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 non-treponemal 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 socio-cultural 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 (POCT), nucleic acid amplification tests (NAAT), 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.

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BackgroundQ 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.MethodsA 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.ResultsThere 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.ConclusionsIn 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.

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 16 th 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 postinitiating 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.