Determining the viral load and infectivity of SARS-CoV-2 in macroscopic respiratory droplets, bioaerosols, and other bodily fluids and secretions is important for identifying transmission modes, assessing risks and informing public health guidelines. Here we show that viral load of SARS-CoV-2 Ribonucleic Acid (RNA) in participants’ naso-pharyngeal (NP) swabs positively correlated with RNA viral load they emitted in both droplets >10 $$\upmu \hbox {m}$$ μ m and bioaerosols <10 $$\upmu \hbox {m}$$ μ m directly captured during the combined expiratory activities of breathing, speaking and coughing using a standardized protocol, although the NP swabs had $$\approx$$ ≈ 10$$^3\times$$ 3 × more RNA on average. By identifying highly-infectious individuals (maximum of 18,000 PFU/mL in NP), we retrieved higher numbers of SARS-CoV-2 RNA gene copies in bioaerosol samples (maximum of 4.8$${\times }10^{5}$$ × 10 5 gene copies/mL and minimum cycle threshold of 26.2) relative to other studies. However, all attempts to identify infectious virus in size-segregated droplets and bioaerosols were negative by plaque assay (0 of 58). This outcome is partly attributed to the insufficient amount of viral material in each sample (as indicated by SARS-CoV-2 gene copies) or may indicate no infectious virus was present in such samples, although other possible factors are identified.

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BackgroundHistoplasmosis is a serious fungal infection caused by the geographically restricted, dimorphic fungus Histoplasma capsulatum. In Canada, the geographic range of H. capsulatum is classically thought to be restricted to southern parts of Ontario and Quebec. Over the past decade, histoplasmosis has occasionally been diagnosed in patients in Alberta without travel to areas of known geographic risk (Figure 1). We studied the epidemiology and geographic distribution of histoplasmosis in Alberta to assess evidence for locally-acquired infections.MethodsWe retrospectively reviewed all laboratory-confirmed (culture, antigen and/or immunodiffusion positive) cases of histoplasmosis diagnosed from January 1, 2011 to June 30, 2018. Data collected by public health and clinical charts were reviewed for clinical presentation, exposure and travel histories, and geographic distribution of cases. Cases of histoplasmosis in patients who had not left Alberta or associated with a local point source were classified as definite local acquisition; cases in patients with remote travel but with local exposures and appropriate timing of disease onset were deemed “probable” cases of local infection. University of Alberta’s Research Ethics Board approved this study.ResultsWe identified 45 laboratory-confirmed cases of histoplasmosis, including 17 cases that were locally acquired. Among these, there were 12 cases of definite local acquisition, including 8 patients from 3 point-source outbreaks—all involving exposure to bats and/or their droppings in chimneys or attics of private dwellings or churches—and 4 sporadic cases in patients who had never traveled. Of the other 5 cases probably acquired in Alberta, patients had previously traveled (n = 4) or travel history was incomplete (n = 1) but local exposures preceding infection were considered compelling. The mean incidence rate of locally acquired infection was 0.062/100,000 population with incidence increasing since 2014. Table 1 shows features of locally acquired cases.ConclusionThis study, for the first time, establishes Alberta as a region of geographic risk for histoplasmosis. The diagnosis should be considered in patients with compatible symptoms and exposure history, even in the absence of travel. Disclosures All authors: No reported disclosures.

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BackgroundThroughout the pandemic, there has been ongoing concern that people with autoimmune diseases such as rheumatoid arthritis (RA) and axial spondyloarthritis (axSpA) will have more severe COVID-19 disease due to immune dysfunction associated with autoimmune diseases and their treatment.ObjectivesWe aimed to compare the severity of COVID-19 in patients with RA versus axSpA and characterize the predictors of COVID-19 severity during the pre-Omicron pandemic phases.MethodsThe IMPACT (IMPact of inflammatory Arthritis on COVID Outcomes STudy) study is a monthly survey of two established northern Alberta, Canada prospective cohorts of RA and axSpA patients from November 2020-2021 who answered Redcap surveys through de-identified email link surveying patient demographics, disease characteristics, COVID-19 symptoms, treatment of RA and axSpA, health care utilization, vaccination status and vaccine adverse events. Descriptive and univariate analyses (dependent variable = severe COVID-19) were performed followed by multivariate analyses of all significant and clinically relevant independent variables from the univariate analysis. Infection severity was defined as any patient with COVID-19 symptoms who visited a doctor, ER or required hospital admission.Results773 of 2167 (36%) patients (RA n=574, axSpA n=197) registered in both cohorts answered at least one baseline survey, 28 (4%) reporting positive COVID-19 tests (24 positive once). Of 442 reporting COVID-19 symptoms during the survey, 11 (3%) were admitted for a mean of 4 days, 2 requiring ICU or blood clot treatment and 1 requiring advanced therapy. 116 (26%) visited a physician for Covid symptoms. Univariate analysis showed that the use of steroids, NSAIDs and increased disease activity were associated with having less severe infection but these associations were not significant in the multivariate analysis (Table 1). There were no significant impacts of RA vs axSpA, age, gender, treatment, disease activity, or smoking.Table 1.Multivariate Level Mixed-Effect Logistic Regression Model: IMPACT of RA and axSpA Disease Characteristics on COVID Infection Severity Defined as Patients with COVID Symptoms Requiring Visit to Doctor, Emergency Room and/or Hospital Admission.VariableCoefficient (S.E)Odds Ratio (95 % Confidence Interval)P-valueGenderMale0.17 (0.34)1.18 (0.61 – 2.31)0.6193FemaleReferenceAge-0.01 (0.01)0.99 (0.97 – 1.01)0.2543Rheumatic Disease TypeRA0.18 (0.40)1.20 (0.58 – 2.48)0.6213SpAReferenceSteroidsYes-0.40 (0.56)0.67 (0.23 – 2.01)0.4757NoReferenceNSAIDSYes-0.20 (0.26)0.82 (0.49 – 1.37)0.4508NoReferenceCurrent Disease Activity-0.04 (0.06)0.96 (0.85 – 1.09)0.5275HAQ-0.03 (0.29)0.97 (0.55 – 1.70)0.9041Nicotine productsYes-0.67 (0.37)0.51 (0.25 – 1.06)0.0714NoReferenceCannabis productsYes-0.45 (0.31)0.64 (0.35 – 1.18)0.1510NoReferenceDMARDsYes0.26 (0.30)1.30 (0.72 – 2.35)0.3860NoReferenceBiologic DMARDYes-0.46 (0.43)0.63 (0.27 – 1.46)0.2813NoReferenceConclusionPossible disease related risk factors for increased COVID-19 severity in RA and axSpA patients preceding the onset of the Omicron variant including use of steroids or DMARDs were not associated with severe infection. These findings are consistent with other international studies whereby other non-rheumatic disease comorbidities played a greater role in infection severity.AcknowledgementsEpidemiology Coordinating and Research (EPICORE) Centre provided support for the REDCAP survey and biostatistical anayses.Disclosure of InterestsStephanie Keeling Speakers bureau: Abbvie, GSK, Pfizer, UCB, Consultant of: Abbvie, GSK, Pfizer, Sandoz, UCB, Eli-Lilly, Galapagos, Novartis, Grant/research support from: Abbvie, UCB, Sandoz, Pfizer, Merck, Bo Pan: None declared, Edna Hutchings Shareholder of: BMS, Stephanie Wichuk: None declared, Mohammed Osman Speakers bureau: Boehringer Ingelheim, Takeda Pharmaceuticals, Grant/research support from: Yes, Boehringer Ingelheim and CSL-Behring, Ameeta Singh: None declared, Ashlesha Sonpar Speakers bureau: Novartis, Ilan Swartz: None declared, Walter P Maksymowych Speakers bureau: Abbvie, Janssen, Novartis, Pfizer, UCB, Consultant of: Abbvie, Boehringer Ingelheim, Celegene, Eli-Lilly, Galapagos, Novartis, Pfizer, UCB, Grant/research support from: Abbvie, Novartis, Pfizer, UCB

Mycoplasma hominis is part of the genitourinary flora in sexually active people and can cause disseminated infection in immunocompromised patients. We describe a rare case of an immunocompetent pregnant woman with simultaneous necrotizing HSV hepatitis and disseminated M. hominis infection. Detection of M. hominis and antimicrobial susceptibility testing of this fastidious organism in the clinical laboratory is discussed.

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