Co-infection of SARS-CoV-2 with human coronavirus OC43 in a patient with underlying lung disease: A case report

Co-infections with SARS-CoV-2 remain relatively rare and there is limited published data on the consequences of these events. We present the case of a 26-year-old man with SARS-CoV-2 and human coronavirus OC43 who had a severe infection resulting in prolonged hospitalization. Consideration of co-infections should be considered in high-risk patients.

Fixed versus individualized treatment for five common bacterial infectious syndromes: a survey of the perspectives and practices of clinicians

Background

Traditionally, bacterial infections have been treated with fixed-duration antibiotic courses; however, some have advocated for individualized durations. It is not known which approach currently predominates.

Methods

We conducted a multinational clinical practice survey asking prescribers their approach to treating skin and soft tissue infection (SSTI), community-acquired pneumonia (CAP), pyelonephritis, cholangitis and bloodstream infection (BSI) of an unknown source. The primary outcome was self-reported treatment approach as being fully fixed duration, fixed minimum, fixed maximum, fixed minimum and maximum, or fully individualized durations. Secondary questions explored factors influencing duration of therapy. Multivariable logistic regression with generalized estimating equations was used to examine predictors of use of fully fixed durations.

Results

Among 221 respondents, 170 (76.9%) completed the full survey; infectious diseases physicians accounted for 60.6%. Use of a fully fixed duration was least common for SSTI (8.5%) and more common for CAP (28.3%), BSI (29.9%), cholangitis (35.7%) and pyelonephritis (36.3%). Fully individualized therapy, with no fixed minimum or maximum, was used by only a minority: CAP (4.9%), pyelonephritis (5.0%), cholangitis (9.9%), BSI (13.6%) and SSTI (19.5%). In multivariable analyses, a fully fixed duration approach was more common among Canadian respondents [adjusted OR (aOR) 1.76 (95% CI 1.12-2.76)] and for CAP (aOR 4.25, 95% CI 2.53-7.13), cholangitis (aOR 6.01, 95% CI 3.49-10.36), pyelonephritis (aOR 6.08, 95% CI 3.56-10.39) and BSI (aOR 4.49, 95% CI 2.50-8.09) compared with SSTI.

Conclusions

There is extensive practice heterogeneity in fixed versus individualized treatment; clinical trials would be helpful to compare these approaches.

Antibiotic Selection and Duration for Catheter-Associated Urinary Tract Infection in Non-Hospitalized Older Adults: A Population-Based Cohort Study

Background

We sought to evaluate the impact of antibiotic selection and duration of therapy on treatment failure in older adults with catheter-associated urinary tract infection (CA-UTI).

Methods

We conducted a population-based cohort study comparing antibiotic treatment options and duration of therapy for non-hospitalized adults aged 66 and older with presumed CA-UTI (defined as an antibiotic prescription and an organism identified in urine culture in a patient with urinary catheterization documented within the prior 90 d). The primary outcome was treatment failure, a composite of repeat urinary antibiotic prescribing, positive blood culture with the same organism, all-cause hospitalization or mortality, within 60 days. We determined the risk of treatment failure accounting for age, sex, comorbidities, and healthcare exposure using log-binomial regression.

Results

Of 4,436 CA-UTI patients, 2,709 (61.1%) experienced treatment failure. Compared to a reference of TMP-SMX (61.9% failure), of those treated with fluoroquinolones, 56.3% experienced failure (RR 0.91, 95% CI: 0.85-0.98) and 60.9% of patients treated with nitrofurantoin experienced failure (RR 1.02, 95% CI: 0.94-1.10). Compared to 5-7 days of therapy (treatment failure: 59.4%), 1-4 days was associated with 69.5% failure (RR 1.15, 95% CI: 1.05-1.27), and 8-14 days was associated with a 62.0% failure (RR 1.05, 95% CI: 0.99-1.11).

Conclusions

Although most treatment options for CA-UTI have a similar risk of treatment failure, fluoroquinolones, and treatment durations ≥ 5 days in duration appear to be associated with modestly improved clinical outcomes. From a duration of therapy perspective, this study provides reassurance that relatively short courses of 5-7 days may be reasonable for CA-UTI.

Highly versus less bioavailable oral antibiotics in the treatment of gram-negative bloodstream infections: a propensity-matched cohort analysis

OBJECTIVES

In this study, we evaluated the clinical outcomes associated with the use of highly bioavailable oral antibiotics (fluoroquinolones and trimethoprim-sulfamethoxazole) compared with the less-bioavailable oral antibiotics (β-lactams) in gram-negative bloodstream infections (BSIs).

METHODS

Among hospitalized older adult patients in Ontario, Canada, discharged home on oral treatment for gram-negative BSI between 1 January 2017 and 31 December 2019, we used a matched cohort design to compare outcomes among those receiving highly versus less-bioavailable agents; hard-matching 1:1 on sex, BSI pathogen (Escherichia coli vs. non-E. coli), and infection source (urinary vs. non-urinary/unknown source) along with a propensity score, incorporating specific pathogen, patient, and infection characteristics. The primary outcome was the composite of 90-day all-cause mortality, recurrent BSI with the same pathogen (genus and species), and re-admission to any Ontario hospital.

RESULTS

A total of 2012 patients were included in the study (1006 in each bioavailability category). Those who received highly (compared with less) bioavailable antibiotics at discharge had lower rates of the composite outcome (171/1006 [17.0%] vs. 216/1006 [21.5%]), adjusted odds ratio being 0.74 (95% CI, 0.60-0.92). Recurrent BSI at 90 days was the main driver for the composite outcome occurring in 64 (5.4%) and 107 (9.4%) patients of the highly and less-bioavailable groups, respectively (p < 0.001) (adjusted odds ratio, 0.56; 95% CI, 0.40-0.78).

DISCUSSION

Use of highly (compared with less) bioavailable antibiotics at discharge was associated with significantly better clinical outcomes among patients with gram-negative BSIs.

Antimicrobial resistance in patients with COVID-19: a systematic review and meta-analysis

BACKGROUND

Frequent use of antibiotics in patients with COVID-19 threatens to exacerbate antimicrobial resistance. We aimed to establish the prevalence and predictors of bacterial infections and antimicrobial resistance in patients with COVID-19.

METHODS

We did a systematic review and meta-analysis of studies of bacterial co-infections (identified within ≤48 h of presentation) and secondary infections (>48 h after presentation) in outpatients or hospitalised patients with COVID-19. We searched the WHO COVID-19 Research Database to identify cohort studies, case series, case-control trials, and randomised controlled trials with populations of at least 50 patients published in any language between Jan 1, 2019, and Dec 1, 2021. Reviews, editorials, letters, pre-prints, and conference proceedings were excluded, as were studies in which bacterial infection was not microbiologically confirmed (or confirmed via nasopharyngeal swab only). We screened titles and abstracts of papers identified by our search, and then assessed the full text of potentially relevant articles. We reported the pooled prevalence of bacterial infections and antimicrobial resistance by doing a random-effects meta-analysis and meta-regression. Our primary outcomes were the prevalence of bacterial co-infection and secondary infection, and the prevalence of antibiotic-resistant pathogens among patients with laboratory-confirmed COVID-19 and bacterial infections. The study protocol was registered with PROSPERO (CRD42021297344).

FINDINGS

We included 148 studies of 362  976 patients, which were done between December, 2019, and May, 2021. The prevalence of bacterial co-infection was 5·3% (95% CI 3·8-7·4), whereas the prevalence of secondary bacterial infection was 18·4% (14·0-23·7). 42 (28%) studies included comprehensive data for the prevalence of antimicrobial resistance among bacterial infections. Among people with bacterial infections, the proportion of infections that were resistant to antimicrobials was 60·8% (95% CI 38·6-79·3), and the proportion of isolates that were resistant was 37·5% (26·9-49·5). Heterogeneity in the reported prevalence of antimicrobial resistance in organisms was substantial (I2=95%).

INTERPRETATION

Although infrequently assessed, antimicrobial resistance is highly prevalent in patients with COVID-19 and bacterial infections. Future research and surveillance assessing the effect of COVID-19 on antimicrobial resistance at the patient and population level are urgently needed.

FUNDING

WHO.

Antimicrobial resistance and mortality following E. coli bacteremia

BACKGROUND

Global estimates suggest millions of deaths annually are associated with antimicrobial resistance (AMR) but these are generated from scarce data on the relative risk of death attributable to drug-resistant versus drug-sensitive infections.

METHODS

We examined all episodes of E. coli bloodstream infection in Ontario, Canada between 2017 and 2020, and measured 90 day mortality among those with resistant versus sensitive isolates for each of 8 commonly used antibiotic classes and a category of difficult to treat resistance (DTTR). We used multivariable logistic regression to calculate an adjusted odds of mortality associated with AMR, after accounting for patient demographics, comorbidities, and prior healthcare exposure.

FINDINGS

Among 14,548 eligible episodes of E. coli bloodstream infection, resistance was most common to aminopenicillins (46.8%), followed by first generation cephalosporins (38.8%), fluoroquinolones (26.5%), sulfonamides (24.1%), third generation cephalosporins (13.8%), aminoglycosides (11.7%), beta-lactam-beta-lactamase-inhibitors (9.1%) and carbapenems (0.2%). Only 18 (0.1%) episodes exhibited DTTR. For each antibiotic class, the unadjusted odds of mortality (OR) were higher among resistant isolates, but after accounting for patient characteristics the adjusted odds (aOR) of mortality were attenuated: aminopenicillins (OR 1.22, 95% CI 1.12-1.33; aOR 1.09, 95% CI 0.99-1.20), first generation cephalosporins (OR 1.24, 95% CI 1.14-1.35; aOR 1.07, 95% CI 0.97-1.18), third generation cephalosporins (OR 1.64, 95% CI 1.47-1.82; aOR 1.29, 95% CI 1.15-1.46), beta-lactam-beta-lactamase-inhibitors (OR 1.69, 95% CI 1.52-1.89, aOR 1.28, 95% CI 1.13-1.45), carbapenems (OR 3.11, 95% CI 1.52-6.34; aOR 2.06, 95% CI 0.91-4.66), sulfonamides (OR 1.19, 95% CI 1.07-1.31, aOR 1.06, 95% CI 0.95-1.18), fluoroquinolones (OR 1.49, 95% CI 1.36-1.64, aOR 1.16, 95% CI 1.05-1.29), aminoglycosides (OR 1.43, 95% CI 1.27-1.62; aOR 1.27, 95% CI 1.11-1.46), and DTTR (OR 3.71, 95% CI 1.46-9.41; aOR 2.58, 95% CI 0.87-7.66).

INTERPRETATION

AMR is associated with substantial increased mortality among patients with E. coli bloodstream infection, particularly for resistance to classes commonly used as empiric treatment. Surveillance for AMR-associated mortality should incorporate adjustment for patient characteristics and prior healthcare utilization.

FUNDING

This work was supported by a project grant from CIHR (grant number 159503). This study was also supported by ICES, which is funded by an annual grant from Ontario Ministry of Health and Long-Term Care (MOHLTC).

Retrospective analysis of the management strategies for surgical site infections post total hip and knee arthroplasty from tertiary care centres in Edmonton, Alberta

BACKGROUND

Surgical site infection (SSI) following hip and knee arthroplasty poses serious health and economic burden.

AIM

To evaluate SSI management strategies and outcomes to help address this problem.

METHODS

We performed a retrospective cohort study of adults undergoing primary total hip or knee arthroplasty who were identified to have a complex SSI by infection prevention and control surveillance audit. Audits identified SSI within 90 days of arthroplasty. Patients at two tertiary referral centres in Edmonton, Alberta, Canada from 2012 to 2019 were included and SSI cases were followed for two years.

FINDINGS

We identified 240 SSIs and found that 202 (84%) were managed with debridement with antibiotics and implant retention (DAIR), of which 71% achieved cure. The use of any topical intra-operative antibiotic in DAIR was not associated with improved outcome (OR = 1.68, 95% CI 0.91 - 3.10, p-value = 0.097). DAIR performed at 31-90 days from arthroplasty had lower chance of cure compared to DAIR performed within 30 days, however this was not statistically significant (60 vs 73%, p-value = 0.123). Initial treatment failures requiring additional surgery had 51% cure. The majority (78%) of treatment failures initially managed with DAIR ultimately required two-stage revision.

CONCLUSIONS

We provide insight from a population-based perspective on the surgical management of SSIs after primary total hip and knee arthroplasty in a large cohort. Additionally, we follow SSIs that had initial management failure. This data can inform future studies such as the economic burden associated with these infections, and plan interventions to optimize SSI management.

Economic Burden of Surgical Management of Prosthetic Joint Infections Following Hip and Knee Replacements in Alberta, Canada: An analysis and comparison of two major urban centers

BACKGROUND

Complex surgical site infections (SSIs) and revisions for these infectious complications following total knee and hip arthroplasties are associated with significant economic costs.

AIM

To evaluate the cost of one-stage and two-stage revisions; debridement, antibiotic, and implant retention (DAIR) and DAIR with liner exchange for complex hip or knee SSIs in Alberta, Canada.

METHODS

We used the Alberta Health Services Infection Prevention and Control database to identify individuals >18 years old from the two major urban centers in Alberta, Calgary, and Edmonton zone, with complex hip or knee SSIs who underwent surgical intervention between April 1, 2012, and March 31, 2019. Micro-costing and gross-costing methods were used to estimate 12 and 24-month costs following the initial hospital admission for arthroplasty. Subgroup, inverse gaussian and gamma regression analysis were used to evaluate the associations of the revision procedure, age, sex, and comorbidities on cost.

FINDINGS

A total of 382 patients with complex SSIs were identified with a mean age of 66.1 years. DAIR and DAIR with liner exchange resulted in the lowest 12- and 24-month costs at $53,197 (95% CI, $38,006 - $68,388) and $57,340 (95% CI, $48,576 - $66,105), respectively; two-stage revision was the costliest procedure. Most of the incurred costs (>98%) were accrued within the first 12 months following the initial procedure.

CONCLUSIONS

Medical costs are highest 12 months following initial arthroplasty and for two-stage revisions in hip and knee complex SSI.

224. Evaluating the Epidemiology of Bloodstream Infections: A Population-Based Study

Background

Bloodstream infections (BSI) are a major cause of morbidity, mortality, and health care costs worldwide. Population-based studies are key to assess BSI epidemiology over time while minimizing selection bias but remain limited. Therefore, we aimed to assess the incidence of BSI in a large Canadian health region in a contemporary period. We hypothesized that there would be significant age and sex-based differences including over time.

Methods

We conducted a retrospective cohort study from 2011 through 2018 using a population-based microbiology database to determine the annual age- and sex-specific BSI testing and case rates with the census as the population reference. BSI was defined as a positive blood culture for a pathogen. Episodes > 30 days apart were included for analysis. Incidence rate ratios (IRR) for testing and case rates including by sex were calculated to assess changes over time. All analyses were run at a two-sided α of 0.05 and were conducted with R 4.0.4.

Results

A total of 154,147 distinct individuals (49.9% male) were analyzed and 22,869 (14.8%) had a BSI at the first encounter in the study period. Overall BSI testing incidence ranged from 1529 to 1707 per 100,000 person-years and case incidence ranged from 180 to 292 per 100,000 person-years. Testing and case incidence for BSI was greatest in the 0-4 and 75+ years age groups (p < 0.01). Males compared to females had greater testing and case incidence rates in young and old age groups, but females had greater rates in the 15-44 years groups (p < 0.01). Overall IRR for cases comparing 2018 to 2011 was 0.62 (95% CI 0.59-0.65) reflecting a significant decrease over time. Testing also decreased over the study period with an IRR of 0.90 (95% CI 0.88-0.91). Testing and case IRRs were not significantly different stratified by sex.

Incidence rates (per 100,000 person-years) of BSI testing and cases by sex from 2011 through 2018 in a Canadian health region

Conclusion

In our large population-based study of BSI, we identified that BSI remain frequent and the youngest and oldest age groups as well as males in these age groups have the greatest BSI incidence rates which may reflect both biological sex and gender-based differences. Encouragingly, BSI incidence rates have decreased over time at a greater increment relative to testing rates. Future studies of BSI should focus on pathogen and outcome-based evaluations.

Disclosures

All Authors: No reported disclosures

Mathematical model of the cost-effectiveness of the BioFire FilmArray Blood Culture Identification (BCID) Panel molecular rapid diagnostic test compared with conventional methods for identification of Escherichia coli bloodstream infections

BACKGROUND

Gram-negative pathogens, such as Escherichia coli, are common causes of bloodstream infections (BSIs) and increasingly demonstrate antimicrobial resistance. Molecular rapid diagnostic tests (mRDTs) offer faster pathogen identification and susceptibility results, but higher costs compared with conventional methods. We determined the cost-effectiveness of the BioFire FilmArray Blood Culture Identification (BCID) Panel, as a type of mRDT, compared with conventional methods in the identification of E. coli BSIs.

METHODS

We constructed a decision analytic model comparing BCID with conventional methods in the identification and susceptibility testing of hospitalized patients with E. coli BSIs from the perspective of the public healthcare payer. Model inputs were obtained from published literature. Cost-effectiveness was calculated by determining the per-patient admission cost, the QALYs garnered and the incremental cost-effectiveness ratios (ICERs) where applicable. Monte Carlo probabilistic sensitivity analyses and one-way sensitivity analyses were conducted to assess the robustness of the model. All costs reflect 2019 Canadian dollars.

RESULTS

The Monte Carlo probabilistic analyses resulted in cost savings ($27 070.83 versus $35 649.81) and improved QALYs (8.65 versus 7.10) in favour of BCID. At a willingness to pay up to $100 000, BCID had a 72.6%-83.8% chance of being cost-effective. One-way sensitivity analyses revealed length of stay and cost per day of hospitalization to have the most substantial impact on costs and QALYs.

CONCLUSIONS

BCID was found to be cost-saving when used to diagnose E. coli BSI compared with conventional testing. Cost savings were most influenced by length of stay and cost per day of hospitalization.

Age and sex-specific incidence rates of group A streptococcal pharyngitis between 2010 and 2018: a population-based study

Aim: Group A streptococcus (GAS) pharyngitis is a common clinical infection with significant morbidity but remains understudied. Materials & methods: We sought to assess the rates of testing and incidence of GAS pharyngitis in Calgary, Alberta based on age and sex. Results: A total of 1,074,154 tests were analyzed (58.8% female, mean age 24.8 years) of which 16.6% were positive. Age-standardized testing and positivity was greatest in the 5-14 years age group and lowest in persons over 75 years. Females had greater rates of testing and positivity throughout. Testing rates (incidence rate ratios: 1.40, 95% CI: 1.39-1.41) and case rates (incidence rate ratios: 1.36, 95% CI: 1.33-1.39) increased over time. Conclusion: Future studies should focus on evaluating disparities in testing and treatment outcomes to optimize the approach to this infection.

Assessing the efficacy and safety of hydroxychloroquine as outpatient treatment of COVID-19: a randomized controlled trial

BACKGROUND

Identification of therapies to prevent severe COVID-19 remains a priority. We sought to determine whether hydroxychloroquine treatment for outpatients with SARS-CoV-2 infection could prevent hospitalization, mechanical ventilation or death.

METHODS

This randomized controlled trial was conducted in Alberta during the first wave of the COVID-19 pandemic without direct contact with participants. Community-dwelling individuals with confirmed SARS-CoV-2 infection (by reverse transcription polymerase chain reaction [RT-PCR] viral ribonucleic acid test) within the previous 4 days, and symptom onset within the previous 12 days, were randomly assigned to oral hydroxychloroquine or matching placebo for 5 days. Enrolment began Apr. 15, 2020. The primary outcome was the composite of hospitalization, invasive mechanical ventilation or death within 30 days. Secondary outcomes included symptom duration and disposition at 30 days. Safety outcomes, such as serious adverse events and mortality, were also ascertained. Outcomes were determined by telephone follow-up and administrative data.

RESULTS

Among 4919 individuals with a positive RT-PCR test, 148 (10.2% of a planned 1446 patients) were randomly assigned, 111 to hydroxychloroquine and 37 to placebo. Of the 148 participants, 24 (16.2%) did not start the study drug. Four participants in the hydroxychloroquine group met the primary outcome (4 hospitalizations, 0 mechanical ventilation, 4 survived to 30 days) and none in the placebo group. Hydroxychloroquine did not reduce symptom duration (hazard ratio 0.77, 95% confidence interval 0.49-1.21). Recruitment was paused on May 22, 2020, when a since-retracted publication raised concerns about the safety of hydroxychloroquine for hospitalized patients with COVID-19. Although we had not identified concerns in a safety review, enrolment was slower than expected among those eligible for the study, and cases within the community were decreasing. Recruitment goals were deemed to be unattainable and the trial was not resumed, resulting in a study underpowered to assess the effect of treatment with hydroxychloroquine and safety.

INTERPRETATION

There was no evidence that hydroxychloroquine reduced symptom duration or prevented severe outcomes among outpatients with proven COVID-19, but the early termination of our study meant that it was underpowered.

TRIAL REGISTRATION

ClinicalTrials.gov, no. NCT04329611.

Differences in outcomes for hospitalizations of systemic and non-systemic infections associated with vascular and cardiac grafts and devices: a population-based study

BACKGROUND

Use of vascular and cardiac devices has expanded and is associated with a relative, though disproportionate, increase in device-associated infections.

AIM

To describe the association between cardiac/vascular device infections and outcomes in those with, and without systemic infections.

METHODS

We used the 2016 National Inpatient Sample and the International Classification of Diseases - 10^th revision codes to identify hospitalized individuals with vascular and cardiac device infections. Linear and logistic regression models were utilized to compare outcomes of death, length of stay (LOS) and hospitalization costs between individuals with and without systemic infection.

FINDINGS

There were a total of 65,110 hospitalizations associated with device infections with a mean age of 61.3 ± 15.9 years (standard deviation); 28,650 (44%) had systemic infections. Elixhauser comorbidity scores of three or greater were observed in 91.2% of individuals with systemic infections along with a higher prevalence of diabetes, renal disease and heart failure. The primary outcome of mortality was observed in 3965 individuals with an odds ratio of 3.97 (95% confidence interval (CI), 2.92-3.95) in those with systemic infections compared with those without. Mean LOS was 3.44 days longer (95% CI, 2.92-3.95) and mean cost was US$11,776 greater (95% CI, US$9826-12,727) in the systemic infection cohort.

CONCLUSION

Systemic cardiac and vascular device infections were associated with increased mortality, LOS and costs. Considering the increasing use of these life-saving devices, further work is needed to identify those at risk for infectious complications, particularly systemic infection, in order to enhance preventative strategies and improve health outcomes.

755. Clinical Adherence to Latent Tuberculosis Screening Recommendations in Adults with Inflammatory Bowel Disease (IBD) Prior to Biologic Therapy

Background

Biological agents have become increasingly common in the treatment of immune-mediated illnesses. Their use, however, is associated with an increased risk of progression from latent to active tuberculosis (TB) infection. The American Thoracic Society (ATS) recommends both a tuberculin skin test (TST) and an interferon gamma release assay (IGRA) be conducted to screen for latent TB prior to initiation of biologic therapy. We examined the adherence to these recommendations for adults with inflammatory bowel disease (IBD) in the Calgary region of Alberta.

Methods

In this retrospective cross-sectional study, we used the Alberta Health Services’ Sunrise Clinical Manager and Netcare databases to identify IBD patients initiated on biologic therapy (age &gt;18 years) in Calgary, Alberta between 2008 and 2018. Socio-demographic and clinical characteristics of patients were described. Linear and logistic regression models were constructed to identify factors associated with screening. All analyses were conducted using Stata 15.0 (University of London, UK).

Results

There was a total of 247 identified cases (48.18% female). Of these 96 were Ulcerative Colitis and 151 Crohn’s Disease. The mean age was 39.5 (14.8 SD). There was a total of 210 (85%) who had documented screening with the TST and nine (3.4%) with the IGRA. In a multivariable analysis, factors associated with latent TB screening were age and outpatient setting at the time of screen. Six patients (2.43%) had positive screens and four of those six were treated for latent TB infection.

Conclusion

TST remains the predominant screening method for latent TB infection although the ATS recommends both IGRA and TST prior to biologic therapy. Screening varied with age and higher rates were noted in those evaluated as outpatients compared with inpatients. Further work is needed to evaluate the barriers to screening and to improve access to latent TB screening particularly in the inpatient setting.

Disclosures

All authors: No reported disclosures.