Persistence of infectivity in elderly individuals diagnosed with severe acute respiratory coronavirus virus 2 (SARS-CoV-2) infection 10 days after onset of symptoms: A cross-sectional study.

We performed viral culture of nasopharyngeal specimens in individuals aged 79 and older, infected with severe acute respiratory coronavirus virus 2 (SARS-CoV-2), 10 days after symptom onset. A positive viral culture was obtained in 10 (45%) of 22 participants, including 4 (33%) of 12 individuals with improving symptoms. The results of this small study suggest that infectivity may be prolonged among older individuals.

Trends in Severe Outcomes Among Adult and Pediatric Patients Hospitalized With COVID-19 in the Canadian Nosocomial Infection Surveillance Program, March 2020 to May 2022.

Importance: Trends in COVID-19 severe outcomes have significant implications for the health care system and are key to informing public health measures. However, data summarizing trends in severe outcomes among patients hospitalized with COVID-19 in Canada are not well described. Objective: To describe trends in severe outcomes among patients hospitalized with COVID-19 during the first 2 years of the COVID-19 pandemic. Design, Setting, and Participants: Active prospective surveillance in this cohort study was conducted from March 15, 2020, to May 28, 2022, at a sentinel network of 155 acute care hospitals across Canada. Participants included adult (aged ≥18 years) and pediatric (aged 0-17 years) patients hospitalized with laboratory-confirmed COVID-19 at a Canadian Nosocomial Infection Surveillance Program (CNISP)-participating hospital. Exposures: COVID-19 waves, COVID-19 vaccination status, and age group. Main Outcomes and Measures: The CNISP collected weekly aggregate data on the following severe outcomes: hospitalization, admission to an intensive care unit (ICU), receipt of mechanical ventilation, receipt of extracorporeal membrane oxygenation, and all-cause in-hospital death. Results: Among 1 513 065 admissions, the proportion of adult (n = 51 679) and pediatric (n = 4035) patients hospitalized with laboratory-confirmed COVID-19 was highest in waves 5 and 6 of the pandemic compared with waves 1 to 4 (77.3 vs 24.7 per 1000 patient admissions). Despite this, the proportion of patients with positive test results for COVID-19 who were admitted to an ICU, received mechanical ventilation, received extracorporeal membrane oxygenation, and died were each significantly lower in waves 5 and 6 when compared with waves 1 through 4. Admission to the ICU and in-hospital all-cause death rates were significantly higher among those who were unvaccinated against COVID-19 when compared with those who were fully vaccinated (incidence rate ratio, 4.3 and 3.9, respectively) or fully vaccinated with an additional dose (incidence rate ratio, 12.2 and 15.1, respectively). Conclusions and Relevance: The findings of this cohort study of patients hospitalized with laboratory-confirmed COVID-19 suggest that COVID-19 vaccination is important to reduce the burden on the Canadian health care system as well as severe outcomes associated with COVID-19.

COVID-19 Vaccination Acceptance in Iran, a Nationwide Survey on Factors Associated with the Willingness toward Getting Vaccinated.

Background: In the name of extensive vaccine uptake, understanding the public's attitude, perception, and intent toward COVID-19 vaccination is a significant challenge for public health officials. Methods: A cross-sectional survey via an online questionnaire rooted in the Health Belief Model and Integrated Behavioral Model was conducted to evaluate COVID-19 vaccination intent and its associated factors. Factor analysis and multivariate logistic regression were operated to be satisfactory. Results: Among the 4,933 respondents, 24.7% were health care workers, and 64.2% intended to accept COVID-19 vaccination. The adjusted odds (aOR) of COVID-19 vaccination intent was higher for individuals with greater exposure to social norms supportive of COVID-19 vaccination (aOR = 3.07, 95% Confidence Interval (CI) = 2.71, 3.47) and higher perceived benefits of COVID-19 vaccination (aOR = 2.9, 95% CI = 2.49, 3.38). The adjusted odds of vaccination intent were lower for individuals with greater COVID-19 vaccine safety concerns (aOR = 0.28, 95%CI = 0.25, 0.31). Lower vaccination intent was also associated with increasing age ((aOR = 0.99, 95% CI = 0.98, 0.999), female sex (aOR = 0.76, 95% CI = 0.65, 0.88), and working in the health care field (aOR = 0.75, 95% CI = 0.63, 0.9). Conclusions: The odds of COVID-19 vaccination intent were higher three or more times among those with a greater belief in vaccine effectiveness, lower concerns about vaccine safety, and greater exposure to cues to vaccinate, including from doctors. This last finding is concerning as vaccine acceptance was surprisingly lower among health care workers compared to others. The remarkable results of factor analysis and reliability of the questionnaire may encourage local health authorities to apply it to their regional population.

Symptomatology during previous SARS-CoV-2 infection and serostatus before vaccination influence the immunogenicity of BNT162b2 COVID-19 mRNA vaccine.

Public health vaccination recommendations for COVID-19 primary series and boosters in previously infected individuals differ worldwide. As infection with SARS-CoV-2 is often asymptomatic, it remains to be determined if vaccine immunogenicity is comparable in all previously infected subjects. This study presents detailed immunological evidence to clarify the requirements for one- or two-dose primary vaccination series for naturally primed individuals. The main objective was to evaluate the immune response to COVID-19 mRNA vaccination to establish the most appropriate vaccination regimen to induce robust immune responses in individuals with prior SARS-CoV-2 infection. The main outcome measure was a functional immunity score (zero to three) before and after vaccination, based on anti-RBD IgG levels, serum capacity to neutralize live virus and IFN-γ secretion capacity in response to SARS-CoV-2 peptide pools. One point was attributed for each of these three functional assays with response above the positivity threshold. The immunity score was compared based on subjects' symptoms at diagnosis and/or serostatus prior to vaccination. None of the naïve participants (n=14) showed a maximal immunity score of three following one dose of vaccine compared to 84% of the previously infected participants (n=55). All recovered individuals who did not have an immunity score of three were seronegative prior to vaccination, and 67% had not reported symptoms resulting from their initial infection. Following one dose of vaccine, their immune responses were comparable to naïve individuals, with significantly weaker responses than individuals who were symptomatic during infection. These results indicate that the absence of symptoms during initial infection and negative serostatus prior to vaccination predict the strength of immune responses to COVID-19 mRNA vaccine. Altogether, these findings highlight the importance of administering the complete two-dose primary regimen and following boosters of mRNA vaccines to individuals who experienced asymptomatic SARS-CoV-2 infection.

Risk and protective factors for severe acute respiratory coronavirus virus 2 (SARS-CoV-2) infection among healthcare workers: A test-negative case-control study in Québec, Canada.

OBJECTIVES: In Québec, Canada, we evaluated the risk of severe acute respiratory coronavirus virus 2 (SARS-CoV-2) infection associated with (1) the demographic and employment characteristics among healthcare workers (HCWs) and (2) the workplace and household exposures and the infection prevention and control (IPC) measures among patient-facing HCWs. DESIGN: Test-negative case-control study. SETTING: Provincial health system. PARTICIPANTS: HCWs with PCR-confirmed coronavirus disease 2019 (COVID-19) diagnosed between November 15, 2020, and May 29, 2021 (ie, cases), were compared to HCWs with compatible symptoms who tested negative during the same period (ie, controls). METHODS: Adjusted odds ratios (aORs) of infection were estimated using regression logistic models evaluating demographic and employment characteristics (all 4,919 cases and 4,803 controls) or household and workplace exposures and IPC measures (2,046 patient-facing cases and 1,362 controls). RESULTS: COVID-19 risk was associated with working as housekeeping staff (aOR, 3.6), as a patient-support assistant (aOR, 1.9), and as nursing staff (aOR, 1.4), compared to administrative staff. Other risk factors included being unexperienced (aOR, 1.5) and working in private seniors' homes (aOR, 2.1) or long-term care facilities (aOR, 1.5), compared to acute-care hospitals. Among patient-facing HCWs, exposure to a household contact was reported by 9% of cases and was associated with the highest risk of infection (aOR, 7.8). Most infections were likely attributable to more frequent exposure to infected patients (aOR, 2.7) and coworkers (aOR, 2.2). Wearing an N95 respirator during contacts with COVID-19 patients (aOR, 0.7) and vaccination (aOR, 0.2) were the measures associated with risk reduction. CONCLUSION: In the context of the everchanging SARS-CoV-2 virus with increasing transmissibility, measures to ensure HCW protection, including vaccination and respiratory protection, and patient safety will require ongoing evaluation.

Trends in Clostridioides difficile infection rates in Canadian hospitals during the coronavirus disease 2019 (COVID-19) pandemic.

The coronavirus disease 2019 (COVID-19) pandemic has placed significant burden on healthcare systems. We compared Clostridioides difficile infection (CDI) epidemiology before and during the pandemic across 71 hospitals participating in the Canadian Nosocomial Infection Surveillance Program. Using an interrupted time series analysis, we showed that CDI rates significantly increased during the COVID-19 pandemic.

The REinfection in COVID-19 Estimation of Risk (RECOVER) study: Reinfection and serology dynamics in a cohort of Canadian healthcare workers.

BACKGROUND: Understanding the immune response to natural infection by SARS-CoV-2 is key to pandemic management, especially in the current context of emerging variants. Uncertainty remains regarding the efficacy and duration of natural immunity against reinfection. METHODS: We conducted an observational prospective cohort study in Canadian healthcare workers (HCWs) with a history of PCR-confirmed SARS-CoV-2 infection to (i) measure the average incidence rate of reinfection and (ii) describe the serological immune response to the primary infection. RESULTS: Our cohort comprised 569 HCWs; median duration of individual follow-up was 371 days. We detected six cases of reinfection in absence of vaccination between August 21, 2020, and March 1, 2022, for a reinfection incidence rate of 4.0 per 100 person-years. Median duration of seropositivity was 415 days in symptomatics at primary infection compared with 213 days in asymptomatics (p < 0.0001). Other characteristics associated with prolonged seropositivity for IgG against the spike protein included age over 55 years, obesity, and non-Caucasian ethnicity. CONCLUSIONS: Among unvaccinated healthcare workers, reinfection with SARS-CoV-2 following a primary infection remained rare.

Séroprévalence du SRAS-CoV-2 chez les travailleurs de la santé de 10 hôpitaux du Québec, au Canada: étude transversale.

CONTEXTE: La pandémie de COVID-19 a affecté de manière disproportionnée les travailleurs de la santé. Nous avons voulu mesurer la séroprévalence du SRAS-CoV-2 chez les travailleurs de la santé dans les hôpitaux du Québec, au Canada, après la première vague de la pandémie, afin d'explorer les facteurs associés à la SRAS-CoV-2-séropositivité. MÉTHODES: Entre le 6 juillet et le 24 septembre 2020, nous avons recruté des travailleurs de la santé de 10 hôpitaux, dont 8 d'une région où l'incidence de la COVID-19 était élevée (région de Montréal) et 2 de régions du Québec où l'incidence était faible. Les travailleurs de la santé admissibles étaient des médecins, des infirmières, des préposées aux bénéficiaires et des préposés à l'entretien ménager travaillant dans 4 types d'unité de soins (urgences, soins intensifs, unité hospitalière COVID-19 et unité hospitalière non-COVID-19). Les participants ont répondu à un questionnaire et subi un dépistage sérologique du SRAS-CoV-2. Nous avons identifié les facteurs ayant un lien indépendant avec une séroprévalence plus élevée. RÉSULTATS: Parmi les 2056 travailleurs de la santé recrutés, 241 (11,7 %) se sont révélés SRAS-CoV-2-positifs. Parmi eux, 171 (71,0 %) avaient déjà reçu un diagnostic de COVID-19. La séroprévalence a varié d'un hôpital à l'autre, de 2,4 %­3,7 % dans les régions où l'incidence était faible, à 17,9 %­32,0 % dans les hôpitaux ayant connu des éclosions touchant 5 travailleurs de la santé ou plus. La séroprévalence plus élevée a été associée au fait de travailler dans un hôpital où des éclosions sont survenues (rapport de prévalence ajusté 4,16, intervalle de confiance [IC] à 95 % 2,63­6,57), au fait d'être infirmière ou auxiliaire (rapport de prévalence ajusté 1,34, IC à 95 % 1,03­1,74), préposée aux bénéficiaires (rapport de prévalence ajusté 1,49, IC à 95 % 1,12­1,97) et d'ethnicité noire ou hispanique (rapport de prévalence ajusté 1,41, IC à 95 % 1,13­1,76). La séroprévalence moindre a été associée au fait de travailler dans une unité de soins intensifs (rapport de prévalence ajusté 0,47, IC à 95 % 0,30­0,71) ou aux urgences (rapport de prévalence ajusté 0,61, IC à 95 % 0,39­0,98). INTERPRÉTATION: Les travailleurs de la santé des hôpitaux du Québec ont été exposés à un risque élevé d'infection par le SRAS-CoV-2, particulièrement lors des éclosions. Il faudra travailler à mieux comprendre la dynamique de la transmission du SRAS-CoV-2 dans les milieux de soins.

Infectivity of healthcare workers diagnosed with coronavirus disease 2019 (COVID-19) approximately 2 weeks after onset of symptoms: A cross-sectional study.

We performed viral culture of respiratory specimens in 118 severe acute respiratory coronavirus virus 2 (SARS-CoV-2)-infected healthcare workers (HCWs), ∼2 weeks after symptom onset. Only 1 HCW (0.8%) had a positive culture. No factors for prolonged viral shedding were identified. Infectivity is resolved in nearly all HCWs ∼2 weeks after symptom onset.

SARS-CoV-2 seroprevalence in health care workers from 10 hospitals in Quebec, Canada: a cross-sectional study.

BACKGROUND: The COVID-19 pandemic has disproportionately affected health care workers. We sought to estimate SARS-CoV-2 seroprevalence among hospital health care workers in Quebec, Canada, after the first wave of the pandemic and to explore factors associated with SARS-CoV-2 seropositivity. METHODS: Between July 6 and Sept. 24, 2020, we enrolled health care workers from 10 hospitals, including 8 from a region with a high incidence of COVID-19 (the Montréal area) and 2 from low-incidence regions of Quebec. Eligible health care workers were physicians, nurses, orderlies and cleaning staff working in 4 types of care units (emergency department, intensive care unit, COVID-19 inpatient unit and non-COVID-19 inpatient unit). Participants completed a questionnaire and underwent SARS-CoV-2 serology testing. We identified factors independently associated with higher seroprevalence. RESULTS: Among 2056 enrolled health care workers, 241 (11.7%) had positive SARS-CoV-2 serology. Of these, 171 (71.0%) had been previously diagnosed with COVID-19. Seroprevalence varied among hospitals, from 2.4% to 3.7% in low-incidence regions to 17.9% to 32.0% in hospitals with outbreaks involving 5 or more health care workers. Higher seroprevalence was associated with working in a hospital where outbreaks occurred (adjusted prevalence ratio 4.16, 95% confidence interval [CI] 2.63-6.57), being a nurse or nursing assistant (adjusted prevalence ratio 1.34, 95% CI 1.03-1.74) or an orderly (adjusted prevalence ratio 1.49, 95% CI 1.12-1.97), and Black or Hispanic ethnicity (adjusted prevalence ratio 1.41, 95% CI 1.13-1.76). Lower seroprevalence was associated with working in the intensive care unit (adjusted prevalence ratio 0.47, 95% CI 0.30-0.71) or the emergency department (adjusted prevalence ratio 0.61, 95% CI 0.39-0.98). INTERPRETATION: Health care workers in Quebec hospitals were at high risk of SARS-CoV-2 infection, particularly in outbreak settings. More work is needed to better understand SARS-CoV-2 transmission dynamics in health care settings.

Covid-19 vaccine acceptance, hesitancy, and refusal among Canadian healthcare workers: A multicenter survey.

BACKGROUND: Determinants of COVID-19 vaccine acceptance among healthcare workers (HCW) remains poorly understood. We assessed HCWs' willingness to be vaccinated and reasons underlying hesitancy. METHODS: Cross-sectional survey across 17 healthcare institutions. HCWs eligible for vaccination (Pfizer-BioNTech mRNA) in December 2020 were invited to receive immunization. Multivariate logistic regression was performed to identify predictors of acceptance. Reasons for refusal among those who never intended to be vaccinated (ie, firm refusers) and those who preferred delaying vaccination (ie, vaccine hesitants) were assessed. RESULTS: Among 2,761 respondents (72% female, average age, 44), 2,233 (80.9%) accepted the vaccine. Physicians, environmental services workers and healthcare managers were more likely to accept vaccination compared to nurses. Male sex, age over 50, rehabilitation center workers, and occupational COVID-19 exposure were independently associated with vaccine acceptance by multivariate analysis. Factors for refusal included vaccine novelty, wanting others to receive it first, and insufficient time for decision-making. Among those who declined, 74% reported they may accept future vaccination. Vaccine firm refusers were more likely than vaccine hesitants to distrust pharmaceutical companies and to prefer developing a natural immunity by getting COVID-19. CONCLUSIONS: Vaccine hesitancy exists among HCWs. Our findings provide useful information to plan future interventions and improve acceptance.

Appropriateness for SARS-CoV-2 vaccination for otolaryngologist and head and neck surgeons in case of pregnancy, breastfeeding, or childbearing potential: Yo-IFOS and CEORL-HNS joint clinical consensus statement.

PURPOSE: SARS-CoV-2 vaccines are a key step in fighting the pandemic. Nevertheless, their rapid development did not allow for testing among specific population subgroups such as pregnant and breastfeeding women, or elaborating specific guidelines for healthcare personnel working in high infection risk specialties, such as otolaryngology (ORL). This clinical consensus statement (CCS) aims to offer guidance for SARS-CoV-2 vaccination to this high-risk population based on the best evidence available. METHODS: A multidisciplinary international panel of 33 specialists judged statements through a two-round modified Delphi method survey. Statements were designed to encompass the following topics: risk of SARS-Cov-2 infection and use of protective equipment in ORL; SARS-Cov-2 infection and vaccines and respective risks for the mother/child dyad; and counseling for SARS-CoV-2 vaccination in pregnant, breastfeeding, or fertile healthcare workers (PBFHW). All ORL PBFHW were considered as the target audience. RESULTS: Of the 13 statements, 7 reached consensus or strong consensus, 2 reached no consensus, and 2 reached near-consensus. According to the statements with strong consensus otorhinolaryngologists-head and neck surgeons who are pregnant, breastfeeding, or with childbearing potential should have the opportunity to receive SARS-Cov-2 vaccination. Moreover, personal protective equipment (PPE) should still be used even after the vaccination. CONCLUSION: Until prospective evaluations on these topics are available, ORL-HNS must be considered a high infection risk specialty. While the use of PPE remains pivotal, ORL PBFHW should be allowed access to SARS-CoV-2 vaccination provided they receive up-to-date information.

Positive no-touch surfaces and undetectable SARS-CoV-2 aerosols in long-term care facilities: An attempt to understand the contributing factors and the importance of timing in air sampling campaigns.

BACKGROUND: Long-term care facilities (LTCF) are environments particularly favorable to coronavirus disease (SARS-CoV-2) pandemic outbreaks, due to the at-risk population they welcome and the close proximity of residents. Yet, the transmission dynamics of the disease in these establishments remain unclear. METHODS: Air and no-touch surfaces of 31 rooms from 7 LTCFs were sampled and SARS-CoV-2 was quantified by real-time reverse transcription polymerase chain reaction (RT-qPCR). RESULTS: Air samples were negative but viral genomes were recovered from 20 of 62 surface samples at concentrations ranging from 13 to 36,612 genomes/surface. Virus isolation (culture) from surface samples (n = 7) was negative. CONCLUSIONS: The presence of viral RNA on no-touch surfaces is evidence of viral dissemination through air, but the lack of airborne viral particles in air samples suggests that they were not aerosolized in a significant manner during air sampling sessions. The air samples were collected 8 to 30 days after the residents' symptom onset, which could indicate that viruses are aerosolized early in the infection process. Additional research is needed to evaluate viral viability conservation and the potential role of direct contact and aerosols in SARS-CoV-2 transmission in these institutions.

Low incidence of airborne SARS-CoV-2 in acute care hospital rooms with optimized ventilation.

The worldwide repercussions of COVID-19 sparked important research efforts, yet the detailed contribution of aerosols in the transmission of SARS-CoV-2 has not been elucidated. In an attempt to quantify viral aerosols in the environment of infected patients, we collected 100 air samples in acute care hospital rooms hosting 22 patients over the course of nearly two months using three different air sampling protocols. Quantification by RT-qPCR (ORF1b) led to 11 positive samples from 6 patient rooms (Ct < 40). Viral cultures were negative. No correlation was observed between particular symptoms, length of hospital stay, clinical parameters, and time since symptom onset and the detection of airborne viral RNA. Low detection rates in the hospital rooms may be attributable to the appropriate application of mitigation methods according to the risk control hierarchy, such as increased ventilation to 4.85 air changes per hour to create negative pressure rooms. Our work estimates the mean emission rate of patients and potential airborne concentration in the absence of ventilation. Additional research is needed understand aerosolization events occur, contributing factors, and how best to prevent them.

Impact of extended use and decontamination with vaporized hydrogen peroxide on N95 respirator fit.

BACKGROUND: To address the shortage of N95 respirators in the wake of the COVID-19 pandemic, some organizations have recommended the decontamination of respirators using vaporized hydrogen peroxide (VHP) sterilizer for up to 10 times. However, these recommendations are based on studies that did not take into account the extended use of respirators, which can degrade respirator fit. METHODS: We investigated the impact of extended use and decontamination with VHP on N95 Respirator Fit. We performed a prospective cohort study to determine the number of times respirators can be decontaminated before respirator fit test failure. The primary outcome was the overall number of cycles required for half of the respirators to fail (either mechanical failure or fit test failure). RESULTS: Thirty-six participants completed 360 hours of respirator usage across 90 cycles. The median number of cycles completed by participants before respirator failure was 2. The overall number of cycles required for half of respirators to fail was 1, 3, 5, and 4 for the 3M 1860(S), 3M 1870+, Moldex 151X and ProGear 88020 respirators, respectively. CONCLUSIONS: The combination of prolonged usage and VHP decontamination was associated with early failure. Decontamination and prolonged usage of respirators must be done cautiously.