Practical challenges to the clinical implementation of saliva for SARS-CoV-2 detection.

Due to global shortages of flocked nasopharyngeal swabs and appropriate viral transport media during the COVID-19 pandemic, alternate diagnostic specimens for SARS-CoV-2 detection are sought. The accuracy and feasibility of saliva samples collected and transported without specialized collection devices or media were evaluated. Saliva demonstrated good concordance with paired nasopharyngeal swabs for SARS-CoV-2 detection in 67/74 cases (90.5%), though barriers to saliva collection were observed in long-term care residents and outbreak settings. SARS-CoV-2 RNA was stable in human saliva at room temperature for up to 48 h after initial specimen collection, informing appropriate transport time and conditions.

Performance of basophil activation test and specific IgG4 as diagnostic tools in nonspecific lipid transfer protein allergy: Antwerp-Barcelona comparison.

BACKGROUND: Recent studies show that nsLTP sensitization is not limited to the Mediterranean basin and can present diverse clinical phenotypes. It remains challenging to predict clinical outcome when specific IgE antibodies (sIgE) to nsLTPs are present. This study compares both clinical and in vitro allergy characteristics but also diagnostic performance of a basophil activation test (BAT) and sIgG4 in nsLTP-sensitized patients from Antwerp (ANT, Belgium) and Barcelona (BCN, Spain). METHODS: Adult subjects with positive sIgE rPru p 3 and/or rMal d 3 ≥ 0.10 kUA /L (n = 182) and healthy controls (n = 37) were included. NsLTP-sensitized individuals were stratified according to clinical symptoms with peach/apple, respectively. BAT rPru p 3 and rMal d 3 were performed and sIgG4 antibodies to both components quantified. RESULTS: In BCN, only ratios of sIgG4/sIgE rMal d 3 and BAT rMal d 3 (0.001 µg/mL) can identify clinically relevant Mal d 3 sensitization (sensitivity of 60%-63% and a specificity of 75%-67%, respectively). In ANT, only the sIgE/total IgE rPru p 3 ratio shows added value (sensitivity 60% and specificity 83%). Finally, it appears that symptomatic patients in BCN are more sensitive to lower allergen concentrations compared to ANT. In addition, it was shown that ANT patients were more often sensitized to pollen and that specific pollen sources differed between regions. CONCLUSIONS: NsLTP-related allergy profiles and diagnostic performance differ significantly between regions and are component-specific, which makes extrapolation of data difficult to do. In addition, it seems that basophil sensitivity might show geographical differences. Additional research is needed to confirm these findings.

Epidemiology of cytomegalovirus antiviral resistance testing for solid organ and bone marrow transplant patients from 2011 - 2019.

BACKGROUND: CMV reactivation post-transplantation is common, with need for prompt identification of patients most at-risk for CMV antiviral drug resistance (AVDR). OBJECTIVES: This study describes CMV AVDR frequencies, antiviral prescribing practices, and AVDR risk factors in patients from 2011 to 2019 in British Columbia, Canada. STUDY DESIGN: Retrospective review of demographics, transplant type, viral loads, antiviral exposure duration, and 12-month mortality was conducted for all patients with samples submitted for CMV AVDR testing from 2011 to 2019. Genotyping of AVDR mutations occurred at the national reference laboratory. Mann-Whitney U, T-test or Fisher's exact tests examined differences between patients with and without AVDR. RESULTS: Fifty-three plasma and three tissue/fluid specimens successfully underwent CMV AVDR testing; of these samples, 27/56 (48%) had AVDR mutations detected. The commonest AVDR mutations were at UL97 loci A594 (20%), H596 (12%) and L595 (12%). Mutations occurred more frequently in requests from solid organ than hematopoietic stem cell transplant patients (58% vs. 27%, p = 0.05). Previous resistance testing was a significant risk factor for AVDR (p < 0.001). Patients with AVDR had approximately 51 more days of antiviral therapy (p = 0.007) and took 9 days longer to clear viremia (p = 0.23). The median turnaround time from sample send-out to reporting was nine days. However, empiric use of second-line antivirals occurred in most cases (39/53, 74%) before results were available. DISCUSSION: Laboratories should strive to provide timely CMV AVDR testing for transplant patients, to minimize unnecessary exposure to second-line antiviral agents. The findings of this study may help guide clinicians when selecting empiric antiviral therapy.

Risk of infection following a visit to the emergency department: a cohort study.

BACKGROUND: The risk of infection following a visit to the emergency department is unknown. We explored this risk among elderly residents of long-term care facilities. METHODS: We compared the rates of new respiratory and gastrointestinal infections among elderly residents aged 65 years and older of 22 long-term care facilities. We used standardized surveillance definitions. For each resident who visited the emergency department during the study period, we randomly selected two residents who did not visit the emergency department and matched them by facility unit, age and sex. We calculated the rates and proportions of new infections, and we used conditional logistic regression to adjust for potential confounding variables. RESULTS: In total, we included 1269 residents of long-term care facilities, including 424 who visited the emergency department during the study. The baseline characteristics of residents who did or did not visit the emergency department were similar, except for underlying health status (visited the emergency department: mean Charlson Comorbidity Index 6.1, standard deviation [SD] 2.5; did not visit the emergency department: mean Charlson Comorbidity index 5.5, SD 2.7; p < 0.001) and the proportion who had visitors (visited the emergency department: 46.9%; did not visit the emergency department: 39.2%; p = 0.01). Overall, 21 (5.0%) residents who visited the emergency department and 17 (2.0%) who did not visit the emergency department acquired new infections. The incidence of new infections was 8.3/1000 patient-days among those who visited the emergency department and 3.4/1000 patient-days among those who did not visit the emergency department. The adjusted odds ratio for the risk of infection following a visit to the emergency department was 3.9 (95% confidence interval 1.4-10.8). INTERPRETATION: A visit to the emergency department was associated with more than a threefold increased risk of acute infection among elderly people. Additional precautions should be considered for residents following a visit to the emergency department.

Hospital-Acquired Methicillin-Resistant Staphylococcus aureus Bloodstream Infections in Québec: Impact of Guidelines.

OBJECTIVE We examined the impact of methicillin-resistant Staphylococcus aureus (MRSA) guidelines in Québec adult hospitals from January 1, 2006, to March 31, 2015, by examining the incidence rate reduction (IRR) in healthcare-associated MRSA bloodstream infections (HA-MRSA), using central-line associated bloodstream infections (CLABSIs) as a comparator. METHODS In this study, we utilized a quasi-experimental design with Poisson segmented regression to model HA-MRSA and CLABSI incidence for successive 4-week surveillance segments, stratified by teaching status. We used 3 distinct periods with 2 break points (April 1, 2007, and January 3, 2010) corresponding to major MRSA guideline publications and updates. RESULTS Over the study period, HA-MRSA incidence decreased significantly in adult teaching facilities but not in nonteaching facilities. Prior to MRSA guideline publication (2006-2007), HA-MRSA incidence decrease was not significant (P=.89), while CLABSI incidence decreased by 4% per 4-week period (P=.05). After the publication of guidelines (2007-2009), HA-MRSA incidence decreased significantly by 1% (P=.04), while no significant decrease in CLABSI incidence was observed (P=.75). HA-MRSA and CLABSI decreases were both significant at 1% for 2010-2015 (P<.001 and P=.01, respectively). These decreases were gradual rather than sudden; break points were not significant. Teaching facilities drove these decreases. CONCLUSION During the study period, HA-MRSA and CLABSI rates decreased significantly. In 2007-2009, the significant decrease in HA-MRSA rates with stable CLABSI rates suggests an impact from MRSA-specific guidelines. In 2010-2015, significant and equal IRRs for HA-MRSA and CLABSI may be due to the continuing impact of MRSA guidelines, to the impact of new interventions targeting device-associated infections in general by the 2010-2015 Action Plan, or to a combination of factors. Infect Control Hosp Epidemiol 2017;38:840-847.

Central-Line-Associated Bloodstream Infections in Québec Intensive Care Units: Results from the Provincial Healthcare-Associated Infections Surveillance Program (SPIN).

BACKGROUND Following implementation of bundled practices in 2009 in Quebec and Canadian intensive care units (ICUs), we describe CLABSI epidemiology during the last 8 years in the province of Québec (Canada) and compare rates with Canadian and American benchmarks. METHODS CLABSI incidence rates (IRs) and central venous catheter utilization ratios (CVCURs) by year and ICU type were calculated using 2007-2014 data from the Surveillance Provinciale des Infections Nosocomiales (SPIN) program. Using American and Canadian surveillance data, we compared SPIN IRs to rates in other jurisdictions using standardized incidence ratios (SIRs). RESULTS In total, 1,355 lab-confirmed CLABSIs over 911,205 central venous catheter days (CVC days) were recorded. The overall pooled incidence rate (IR) was 1.49 cases per 1,000 CVC days. IRs for adult teaching ICUs, nonteaching ICUs, neonatal ICUs (NICUs), and pediatric ICUs (PICUs) were 1.04, 0.91, 4.20, and 2.15 cases per 1,000 CVC days, respectively. Using fixed SPIN 2007-2009 benchmarks, CLABSI rates had decreased significantly in all ICUs except for PICUs by 2014. Rates declined by 55% in adult teaching ICUs, 52% in adult nonteaching ICUs, and 38% in NICUs. Using dynamic American and Canadian CLABSI rates as benchmarks, SPIN adult teaching ICU rates were significantly lower and adult nonteaching ICUs had lower or comparable rates, whereas NICU and PICU rates were higher. CONCLUSION Québec ICU CLABSI surveillance shows declining CLABSI rates in adult ICUs. The absence of a decrease in CLABSI rate in NICUs and PICUs highlights the need for continued surveillance and analysis of factors contributing to higher rates in these populations. Infect Control Hosp Epidemiol 2016;1-9.

Osmotic stress regulates the anticoagulant efficiency of dermatan sulfate.

Glycosaminoglycans (GAGs) in pericellular and interstitial spaces help to maintain local water homeostasis and blood coagulation balance. This study explored whether dehydrating microenvironment conditions influence dermatan sulfate's (DS) anticoagulant activity. Water transfer during antithrombin activation by dermatan sulfate was measured using osmotic stress techniques. Anticoagulant activity was determined from the change in the rate of coagulation factor Xa (fXa) inhibition. Osmotic stress accelerated reaction rates, indicating water transfer from reactants to bulk. The net volume transferred, measured using osmotic probes similar in size to the reacting proteins, was approximately 2500 mol of water per mole of fXa inhibited. The reaction efficiency, V(sat)/K 1/2 (rate at saturation/concentration resulting in half-maximal rates), determined in titrations with monosulfated dermatan sulfate and disulfated dermatan sulfate (DDS), were 4x10(4) and 2x10(5) M-1 s-1 under osmotic stress and in the presence of calcium, corresponding to 34- and 81-fold increases over efficiency measured under standard conditions. These results indicate that dermatan sulfate can contribute significantly to antithrombin activation, and that in dehydrating environments and depending of ionic conditions, its anticoagulant efficiency can exceed that of heparan sulfate (HS).