Browsing by Author "Vaughan, Stephen"

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    Chronic Q Fever in Alberta: A Case of Coxiella burnetii Mycotic Aneurysm and Concomitant Vertebral Osteomyelitis
    (2016-05-11) Stokes, William; Janvier, Jack; Vaughan, Stephen
    Chronic Q fever is a potentially life-threatening infection from the intracellular, Gram-negative Coxiella burnetii. It presents most commonly as endocarditis or vascular infection in people with underlying cardiac or vascular disease. We discuss a case of a 67-year-old male with Coxiella burnetii vascular infection of a perirenal abdominal aortic graft. The patient had a history of an abdominal aortic aneurysm (AAA) repair 5 years earlier. He presented with a 12 × 6 × 8 cm perirenal pseudoaneurysm and concomitant L1, L2, and L3 vertebral body discitis. He underwent an open repair which revealed a grossly infected graft perioperatively. Q fever serology revealed phase I serological IgG titer of 1 : 2048 and phase II 1 : 1024 consistent with chronic Q fever. Polymerase chain reaction (PCR) on infected vascular tissue was positive for C. burnetii. The patient was started on doxycycline and hydroxychloroquine with good clinical response and decreasing serological titers. Recognizing chronic Q fever is a difficult task as symptoms are nonspecific, exposure risk is difficult to ascertain, and diagnosis is hidden from conventional microbiological investigations. Its recognition, however, is critical as C. burnetii is inherently resistant to standard empiric therapies used in cardiovascular infections.
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    Clinical Implications for the Timely Diagnosis of Mycobacterium marinum in the Age of Biologic Therapy: A Case Report and Review of the Literature
    (2017-03-14) Lata, Chris J.; Edgar, Kelle; Vaughan, Stephen
    Mycobacterium marinum infections typically present as cutaneous nodular lesions with a sporotrichoid lymphatic spread on extensor surfaces of extremities. The natural history of this infection can be altered if the host is immunosuppressed, leading to disseminated presentations. A detailed exposure history and high degree of suspicion for this indolent pathogen are often required for the correct diagnosis of this disease. We present a case of a 67-year-old male misdiagnosed with seronegative rheumatoid arthritis presenting with rheumatic nodules. Initiation of chronic immunosuppressant therapy including biologic monoclonal antibodies resulted in the exacerbation of initially localized disease to broadly disseminated lymphatic, joint, and myotendinous granulomatous disease and led to delay in the correct diagnosis. Cessation of immunosuppressants, with a prolonged course of antimicrobial therapy and multiple surgical debridements were required for cure.
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    Cost-effectiveness of screening and treatment for schistosomiasis among refugees coming to Canada
    (2019-01-14) Webb, John Angus; McBrien, Kerry Alison; Spackman, David Eldon; Vaughan, Stephen; Heitman, Steven James; Fabreau, Gabriel E.
    Background: Depending on their countries of origin, between 12% and 73% of resettled refugees and asylum seekers from endemic countries are infected with schistosomiasis when they arrive in Canada. Many are asymptomatic, but they are at risk for complications that may develop decades later. In Canada, clinicians previously practiced watchful waiting, treating patients if they developed symptoms; but in 2011 new guidelines recommended screening and treatment instead. In the United States, refugees from Africa are presumptively treated for schistosomiasis before they leave their country of origin. The cost-effectiveness of screening or presumptive treatment for schistosomiasis has never been studied. Methods: We constructed a decision-tree model to examine the cost-effectiveness of three management strategies: watchful waiting; screening and treatment; and presumptive treatment. We obtained model data from the literature and other sources, predicting deaths and chronic complications caused by schistosomiasis; as well as costs, and net monetary benefit. Results: Presumptive treatment was cost-saving if the prevalence of schistosomiasis in the target population was greater than 2.4%. In our base case analysis, presumptive treatment was associated with an increase of 0.15 quality-adjusted life years and a cost savings of $383 per person, compared to watchful waiting. It was also more effective and less costly than screening and treatment. Interpretation: Presumptive treatment for schistosomiasis among recently resettled refugees and asylum claimants to Canada is less costly and more effective than watchful waiting or screening and treatment, in groups with prevalence greater than 2.4%. Our results support a revision of the current Canadian guidelines.
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    Glomerulonephritis during Mycobacterium tuberculosis infection: scoping review
    (2024-08-31) Forster, Adam; Sabur, Natasha; Iqbal, Ali; Vaughan, Stephen; Thomson, Benjamin
    Abstract Introduction People with Tuberculosis (TB) infection may present with glomerulonephritis (GN). The range of presentations, renal pathologies, and clinical outcomes are uncertain. Whether clinical features that establish if GN etiology is medication or TB related, and possible benefits of immunosuppression remain uncertain. Methods A scoping review was completed, searching MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, Web of Science and Conference Abstracts from Inception to December, 2023. The study population included patients with TB infection who developed GN and underwent renal biopsy. All data regarding presentation, patient characteristics, renal pathology, management of TB and GN, and outcomes were summarized. Results There were 62 studies identified, with 130 patients. These cases included a spectrum of presentations including acute kidney injury, nephrotic syndrome and hypertension, and a range of 10 different renal pathology diagnoses. Cases that included immunosuppression and outcomes ranged from complete remission to long-term dialysis dependence. The presence of granulomas (4/4, 100%), anti-glomerular basement membrane disease (3/3, 100%), amyloidosis (75/76, 98.7%), and focal segmental glomerulosclerosis (2/2, 100%) were specific for GN being TB-infection related. On the other hand, minimal change disease was specific for anti-TB therapy related (7/7, 100%). While patients with more aggressive forms of GN commonly were prescribed immunosuppression, this study was unable to confirm efficacy. Only rifampin or isoniazid were implicated in drug-associated GN. Discussion This study provides a clear rationale for renal biopsy in patients with TB and GN, and outlines predictors for the GN etiology. Thus, this study establishes key criteria to optimize diagnosis and management of patients with TB and GN.
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    Schistosoma and Strongyloides screening in migrants initiating HIV Care in Canada: a cross sectional study
    (2020-01-28) McLellan, Jessica; Gill, M. J; Vaughan, Stephen; Meatherall, Bonnie
    Abstract Background Following migration from Schistosoma and Strongyloides endemic to non-endemic regions, people remain at high risk for adverse sequelae from these chronic infections. HIV co-infected persons are particularly vulnerable to the serious and potentially fatal consequences of untreated helminth infection. While general screening guidelines exist for parasitic infection screening in immigrant populations, they remain silent on HIV positive populations. This study assessed the seroprevalence, epidemiology and laboratory characteristics of these two parasitic infections in a non-endemic setting in an immigrant/refugee HIV positive community. Methods Between February 2015 and 2018 individuals born outside of Canada receiving care at the centralized HIV clinic serving southern Alberta, Canada were screened by serology and direct stool analysis for schistosomiasis and strongyloidiasis. Canadian born persons with travel-based exposure risk factors were also screened. Epidemiologic and laboratory values were analyzed using bivariate logistic regression. We assessed the screening utility of serology, direct stool analysis, eosinophilia and hematuria. Results 253 HIV positive participants were screened. The prevalence of positive serology for Schistosoma and Strongyloides was 19.9 and 4.4%, respectively. Age between 40 and 50 years (OR 2.50, 95% CI 1.13–5.50), refugee status (3.55, 1.72–7.33), country of origin within Africa (6.15, 2.44–18.60), eosinophilia (3.56, 1.25–10.16) and CD4 count < 200 cells/mm3 (2.46, 1.02–5.92) were associated with positive Schistosoma serology. Eosinophilia (11.31, 2.03–58.94) was associated with positive Strongyloides serology. No Schistosoma or Strongyloides parasites were identified by direct stool microscopy. Eosinophilia had poor sensitivity for identification of positive serology. Hematuria was not associated with positive Schistosoma serology. Conclusion Positive Schistosoma and Strongyloides serology was common in this migrant HIV positive population receiving HIV care in Southern Alberta. This supports the value of routine parasitic screening as part of standard HIV care in non-endemic areas. Given the high morbidity and mortality in this relatively immunosuppressed population, especially for Strongyloides infection, screening should include both serologic and direct parasitological tests. Eosinophilia and hematuria should not be used for Schistosoma and Strongyloides serologic screening in HIV positive migrants in non-endemic settings.
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    Ureaplasma urealyticum disseminated multifocal abscesses in an immunocompromised adult patient: a case report
    (2020-01-15) Diaz Pallares, Carolina; Griener, Thomas; Vaughan, Stephen
    Abstract Background Ureaplasma urealyticum is a fastidious bacteria which lacks a cell wall. Extragenital infections are rare in immunocompetent adults. There are few literature reports of perinephric abscess. We present a case of non-resolving multifocal “culture-negative” abscesses in a hypogammaglobulinemic adult female due to U. urealyticum. Case presentation 66-year-old female with a one-week history of fever, malaise and new right hip and leg pain. Past medical history was notable for chronic pancytopenia secondary to in remission B cell follicular lymphoma, ESRD on intermittent hemodialysis with bilateral nephrostomy tubes and Crohn’s. CT abdomen/pelvis revealed a small left perinephric hematoma and proximal right femur fluid collection. Persistent right thigh pain led to additional ultrasound with anterior thigh collection and CT revealed an irregular rim-enhancing fluid collection in the left posterior pararenal space. Antimicrobial therapy included ertapenem and vancomycin followed by meropenem, trimethoprim-sulfamethoxazole, daptomycin and metronidazole in setting of persistent culture-negative results and clinical deterioration. Following detection of U. urealyticum by 16S rDNA PCR in both left pararenal and right trochanteric bursa abscesses doxycycline was started. Despite this, the patient died four days later. Conclusions Disseminated infection by U. urealyticum has been documented in immunocompromised adult patients with few reports of perinephric abscess. We propose that ascending genitourinary route led to perinephric abscess. The multiple disseminated fluid collections make it highly suspicious for hematogenous spread given the lack of radiographic enhancement to suggest contiguous spread. Diagnosis and treatment of U. urealyticum-disseminated infection is extremely challenging as culture is laborious and not routinely performed. Furthermore, the lack of cell wall renders beta-lactams and vancomycin ineffective and therefore requirement for “atypical” coverage. Early diagnosis and treatment are key to prevent further complications and death.