ORCID Profile
0000-0002-3266-3250
Current Organisation
Royal Brisbane and Women's Hospital
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Publisher: Springer Science and Business Media LLC
Date: 24-07-2019
Publisher: Public Library of Science (PLoS)
Date: 18-07-2019
Publisher: MDPI AG
Date: 13-10-2021
DOI: 10.3390/PATHOGENS10101319
Abstract: Rickettsia species causing human illness are present globally and can cause significant disease. Diagnosis and identification of this intracellular bacteria are challenging with many available diagnostic modalities suffering from several shortcomings. Detection of antibodies directed against Rickettsia spp. via serological methods remains widely used with a broad range of sensitivity and specificity values reported depending on the assay. Molecular methods, including polymerase chain reaction (PCR) testing, enables species-specific identification with a fast turnaround time however, due to resource requirements, use in some endemic settings is limited. Reports on the use of next-generation sequencing (NGS) and metagenomics to diagnose Rickettsia spp. infection have been increasing. Despite offering several potential advantages in the diagnosis and surveillance of disease, genomic approaches are currently only limited to reference and research laboratories. Continued development of Rickettsia spp. diagnostics is required to improve disease detection and epidemiological surveillance, and to better understand transmission dynamics.
Publisher: Public Library of Science (PLoS)
Date: 25-05-2022
DOI: 10.1371/JOURNAL.PGPH.0000506
Abstract: An understanding of the seasonality of infections informs public health strategies and assists clinicians in their management of patients with undifferentiated illness. The seasonality of infections is driven by a variety of environmental and human factors however, the role of in idual climatic factors has garnered much attention. This study utilises Poisson regression models to assess the seasonality of six important infections in tropical Australia and their association with climatic factors and severe weather events over a 21-year period. Melioidosis and leptospirosis showed marked wet season predominance, while more cases of rickettsial disease and cryptococcosis were seen in cooler, drier months. Staphylococcus aureus infections were not seasonal, while influenza demonstrated inter-seasonality. The climate did not significantly change during the 21 years of the study period, but the incidence of melioidosis and rickettsial disease increased considerably, highlighting the primacy of other factors—including societal inequality, and the impact of urban expansion—in the incidence of these infections. While anthropogenic climate change poses a threat to the region—and may influence the burden of these infections in the future—this study highlights the fact that, even for seasonal diseases, other factors presently have a greater effect on disease incidence. Public health strategies must also target these broader drivers of infection if they are to be effective.
Publisher: Wiley
Date: 15-03-2021
DOI: 10.1002/RCR2.740
Publisher: BMJ
Date: 07-2022
Abstract: A man in his 50s was admitted with 4 months of myalgia, headaches, hypercalcaemia and declining renal function on a background of lung transplantation for cystic fibrosis 5 years prior. MRI confirmed myositis and a muscle biopsy revealed invasive muscular microsporidial infection. Positron emission tomography(PET)/CT revealed widespread dissemination of the infection. Albendazole was commenced and after a 1 week systemic inflammatory response syndrome, the patient made a significant recovery and was discharged home. PCR testing confirmed the species as Anncaliia algerae , which is known to infect mosquitoes, larvae and contaminate water supplies. This case highlights the need to relentlessly pursue a diagnosis and to consider atypical pathology in immune compromised patients. A tissue s le yielded highly beneficial and unexpected results. A multispecialty approach was essential given the varied infection manifestations, which included myositis, keratitis and possible central nervous system, vocal cord, parapharyngeal and renal involvement.
Publisher: Frontiers Media SA
Date: 26-11-2021
DOI: 10.3389/FPHAR.2021.784909
Abstract: Primaquine, an 8-aminoquinoline, is the only medication approved by the World Health Organization to treat the hypnozoite stage of Plasmodium vivax and P. ovale malaria. Relapse, triggered by activation of dormant hypnozoites in the liver, can occur weeks to years after primary infection, and provides the predominant source of transmission in endemic settings. Hence, primaquine is essential for in idual treatment and P. vivax elimination efforts. However, primaquine use is limited by the risk of life-threatening acute hemolytic anemia in glucose-6-phosphate dehydrogenase (G6PD) deficient in iduals. More recently, studies have demonstrated decreased efficacy of primaquine due to cytochrome P450 2D6 ( CYP2D6 ) polymorphisms conferring an impaired metabolizer phenotype. Failure of standard primaquine therapy has occurred in in iduals with decreased or absent CYP2D6 activity. Both G6PD and CYP2D6 are highly polymorphic genes, with considerable geographic and interethnic variability, adding complexity to primaquine use. Innovative strategies are required to overcome the dual challenge of G6PD deficiency and impaired primaquine metabolism. Further understanding of the pharmacogenetics of primaquine is key to utilizing its full potential. Accurate CYP2D6 genotype-phenotype translation may optimize primaquine dosing strategies for impaired metabolizers and expand its use in a safe, efficacious manner. At an in idual level the current challenges with G6PD diagnostics and CYP2D6 testing limit clinical implementation of pharmacogenetics. However, further characterisation of the overlap and spectrum of G6PD and CYP2D6 activity may optimize primaquine use at a population level and facilitate region-specific dosing strategies for mass drug administration. This precision public health approach merits further investigation for P. vivax elimination.
Publisher: American Society of Tropical Medicine and Hygiene
Date: 02-12-2020
Publisher: Elsevier BV
Date: 2021
Publisher: American Society of Tropical Medicine and Hygiene
Date: 05-01-2022
Abstract: Many patients with leptospirosis, melioidosis, and rickettsial infection require intensive care unit (ICU) admission in tropical Australia every year. The multi-organ dysfunction associated with these infections results in significantly elevated severity of illness (SOI) scores. However, the accuracy of these SOI scores in predicting death from these tropical infections is incompletely defined. This retrospective study was performed at Cairns Hospital, a tertiary-referral hospital in tropical Australia. All patients admitted to ICU with laboratory-confirmed leptospirosis, melioidosis, and rickettsial disease between January 1, 1999 and June 30, 2020, were eligible for the study. The ability of Acute Physiology and Chronic Health Evaluation (APACHE) II, APACHE III, Simplified Acute Physiology Scores (SAPS) II, and Sequential Organ Failure Assessment (SOFA) scores to predict death before ICU discharge was evaluated. Overall, 18 (12.1%) of the 149 included patients died: 15/74 (20.3%) with melioidosis, 2/54 (3.7%) with leptospirosis and 1/21 (4.8%) with rickettsial disease. However, the APACHE II, APACHE III, SAPS II, and SOFA scores significantly overestimated the case-fatality rate of all the infections the disparity between the predicted and observed mortality was most marked in the cases of leptospirosis and rickettsial disease. Commonly used SOI scores significantly overestimate the case-fatality rate of melioidosis, leptospirosis, and rickettsial infections in Australian ICU patients. This may be at least partly explained by the unique pathophysiology of these infections, particularly leptospirosis and rickettsial disease. However, SOI scores may still be useful in facilitating the comparison of disease severity in clinical trials that examine patients with these pathogens.
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
No related grants have been discovered for Alexandra Stewart.