RESUMEN
BackgroundA comprehensive description of the combined effect of SARS-CoV-2 and respiratory viruses (RV) other than SARS-CoV-2 (ORV) on hospitalisations is lacking. AimTo compare viral etiology of acute respiratory infections (ARI) hospitalisations before and during two pandemic years from a surveillance network in Quebec, Canada. MethodWe compared detection of ORV and SARS-CoV-2 during 2020-21 and 2021-22 to 8 pre-pandemic influenza seasons in patients hospitalised with ARI who were tested systematically by a multiplex PCR. ResultsDuring pre-pandemic influenza seasons, overall RV detection was 92.7% (1,493) (48.3% respiratory syncytial virus (RSV)) in children and 62.8% (4,339) (40.1% influenza) in adults. Overall RV detection in 2020-21 was 58.6% (29) in children (all ORV) and 43.7% (333) in adults (3.4% ORV, 40.3% SARS-CoV2, both including coinfections). In 2021-22 overall RV detection was 91.0% (201) in children (82.8% ORV, 8.1% SARS-CoV-2, both including coinfections) and 55.5% (527) in adults (14.1% ORV, 41.4% SARS-CoV-2, both including coinfections). Virtually no influenza was detected in 2020-21 and in 2021-22 up to epi-week 2022-9 presented here; no RSV was detected in 2020-21. In 2021-22, detection of RSV was comparable to pre-pandemic years but with an unusually early season. There were significant differences in ORV and SARS-CoV-2 detection between time periods and age groups. ConclusionSignificant continuous shifts in age distribution and viral etiology of ARI hospitalisations occurred during two pandemic years. This reflects evolving RV epidemiology and underscores the need for increased scrutiny of ARI hospitalisation etiology to inform tailored public health recommendations.
RESUMEN
BackgroundWe estimated the protection against the Omicron BA.2 variant associated with prior primary infection (PI) due to pre-Omicron or Omicron BA.1 virus, with and without mRNA vaccination. MethodsA test-negative case-control study was conducted among healthcare workers (HCWs) tested for SARS-CoV-2 in Quebec, Canada, between March 27 and June 4, 2022, when BA.2 predominated and was presumptively diagnosed. Logistic regression models compared the likelihood of BA.2 reinfection (second positive test [≥]30 days after PI) among HCWs with history of PI and none to three doses of mRNA vaccine versus infection-naive, unvaccinated HCWs. FindingsAmong 37,732 presumed BA.2 cases, 2,521 (6.7%) and 659 (1.7%) were reinfections following pre-Omicron or BA.1 PI, respectively. Among 73,507 controls, 7,360 (10.0%) and 12,315 (16.8%) had a pre-Omicron or BA.1 PI, respectively. Pre-Omicron PI was associated with 38% (95%CI:19-53) reduction in BA.2 infection risk, with higher BA.2 protection among those also vaccinated with one (56%), two (69%) or three (70%) vaccine doses. Omicron BA.1 PI was associated with greater protection against BA.2 (72%; 95%CI:65-78), higher among two-dose vaccinated at 96% (95%CI:95-96) but not improved with a third dose (96%; 95%CI:95-97). Hybrid Omicron BA.1 PI plus two or three dose vaccine-induced protection persisted for five months post-infection. InterpretationTwice-vaccinated individuals who experienced BA.1 infection were subsequently well-protected for a prolonged period against BA.2 reinfection and derived no meaningful added benefit against BA.2 from a third dose of mRNA vaccine.
RESUMEN
ImportanceOmicron is phylogenetically- and antigenically-distinct from earlier SARS-CoV-2 variants and the original vaccine strain. Protection conferred by prior SARS-CoV-2 infection against Omicron re-infection, and the added value of vaccination, require quantification. ObjectiveTo estimate protection against Omicron re-infection and hospitalization conferred by prior heterologous SARS-CoV-2 (non-Omicron) infection and/or up to three doses of (ancestral, Wuhan-like) mRNA vaccine. DesignTest-negative study between December 26 (epi-week 52), 2021 and March 12 (epi-week 10), 2022. SettingPopulation-based, province of Quebec, Canada ParticipantsCommunity-dwelling [≥]12-year-olds tested for SARS-CoV-2. ExposuresPrior laboratory-confirmed infection with/without mRNA vaccination. OutcomesLaboratory-confirmed SARS-CoV-2 re-infection and hospitalization, presumed Omicron by genomic surveillance. The odds of prior non-Omicron infection with/without vaccination were compared among Omicron cases/hospitalizations versus test-negative controls (single randomly-selected per individual). Adjusted odds ratios controlled for age, sex, testing-indication and epi-week. Analyses were stratified by severity and time since last non-Omicron infection or vaccine dose. ResultsWithout vaccination, prior non-Omicron infection reduced the Omicron re-infection risk by 44% (95%CI:38-48), decreasing from 66% (95%CI:57-73) at 3-5 months to 35% (95%CI:21-47) at 9-11 months post-infection and <30% thereafter. The more severe the prior infection, the greater the risk reduction: 8% (95%CI:17-28), 43% (95%CI:37-49) and 68% (95%CI:51-80) for prior asymptomatic, symptomatic ambulatory or hospitalized infections. mRNA vaccine effectiveness against Omicron infection was consistently significantly higher among previously-infected vs. non-infected individuals at 65% (95%CI:63-67) vs. 20% (95%CI:16-24) for one-dose; 68% (95%CI:67-70) vs. 42% (95%CI:41-44) for two doses; and 83% (95%CI:81-84) vs. 73% (95%CI:72-73) for three doses. Infection-induced protection against Omicron hospitalization was 81% (95%CI: 66-89) increasing to 86% (95%CI:77-99) with one, 94% (95%CI:91-96) with two and 97%(95%CI:94-99) with three mRNA vaccine doses. Two-dose effectiveness against hospitalization among previously-infected individuals did not wane across 11 months and did not significantly differ from three-dose effectiveness despite longer follow-up (median 158 and 27 days, respectively). Conclusions and relevancePrior heterologous SARS-CoV-2 infection provided substantial and sustained protection against Omicron hospitalization, greatest among those also vaccinated. In the context of program goals to prevent severe outcomes and preserve healthcare system capacity, >2 doses of ancestral Wuhan-like vaccine may be of marginal incremental value to previously-infected individuals.
RESUMEN
ImportanceMost adults with COVID-19 do not require hospitalization, but the subsequent risk of post-COVID condition, including associated psychological and cognitive dysfunction, remains poorly understood among non-hospitalized versus hospitalized cases. ObjectiveTo assess the prevalence and duration of post-COVID condition, including physical, psychological and cognitive symptoms. DesignCase series and case-control study between December 2020 and May 2021 SettingHealthcare workers in Quebec, Canada ParticipantsEligible cases were symptomatic healthcare workers with PCR-confirmed COVID-19 between July 2020 and May 2021. Among 17,717 contacted cases, 6061 (34%) participated. A random sample of symptomatic healthcare workers with negative PCR result between November 2020 and May 2021 served as controls. Among 11,498 contacted controls, 4390 (38%) participated. ExposuresIn multivariable models, sociodemographic and clinical characteristics, as well as vaccine history, were evaluated as potential risk factors. Prevalence ratios compared self-reported cognitive dysfunctions (difficulty concentrating; difficulty organizing oneself; forgetfulness; loss of necessary items) among cases with post-COVID condition to controls, adjusting for psychological distress and fatigue. OutcomesPost-COVID condition was defined by symptoms persisting [≥]4 weeks or [≥]12 weeks after COVID-19 onset. ResultsFour-week and 12-week post-COVID condition prevalences of 46% (2,746/5,943) and 40% (653/1,746), respectively, were observed among non-hospitalized cases and 76% (90/118) and 68% (27/37), respectively, among hospitalized cases. Hospitalization, female sex and age were associated with higher risk. A substantial proportion of non-hospitalized cases with 4-week post-COVID condition often or very often reported cognitive dysfunction, including concentration (33%) or organizing (23%) difficulties, forgetfulness (20%) and loss of necessary items (10%), with no decline at 12 weeks. All four aspects of cognitive dysfunction were 2.2 to 3.0 times more prevalent among cases with post-COVID condition than in controls, but also independently associated with psychological distress and fatigue. Conclusions and relevancePost-COVID condition may be a frequent sequela of ambulatory COVID-19 in working-age adults, with important effects on cognition. With so many healthcare workers infected since the beginning of the COVID-19 pandemic, the ongoing implications for quality healthcare delivery could be profound should cognitive dysfunction and other severe post-COVID symptoms persist in a professionally-disabling way over the longer term. Key pointsO_ST_ABSQuestionC_ST_ABSHow common and long-lasting are the physical, psychological and cognitive effects of post-COVID condition in healthcare workers, both hospitalized and non-hospitalized? FindingsThe prevalence of post-COVID condition was 46% at 4 weeks and 40% at 12 weeks among non-hospitalized cases and 76% and 68% among hospitalized cases. One third of non-hospitalized healthcare workers with post-COVID condition reported cognitive impairment, which was independently associated with persistent physical symptoms, but also psychological distress and fatigue. MeaningPersistent cognitive and other professionally-disabling sequelae of COVID-19 in essential workers could have critical implications for quality healthcare delivery during and after the pandemic.
RESUMEN
Background and ObjectivesOlfactory and gustatory dysfunctions (OD, GD) are prevalent symptoms following COVID-19 and persist in 6%-44% of individuals in the first months after the infection. As only few reports have described their prognosis more than 6 months later, the main objective of this study was to assess the prevalence of OD and GD 11 months after COVID-19. We also aimed to determine test-retest reliability of subjective chemosensory ratings for the follow-up of chemosensory sensitivity, as this measure is often used for remote follow-up. MethodsInclusion criteria included a PCR-confirmed SARS-CoV-2 infection; exclusion criteria were the presence of other respiratory infections and chronic sinusitis. To assess whether OD and GD had changed compared to pre-pandemic levels, we designed an observational study and distributed an online questionnaire assessing quantitative chemosensory function to healthcare workers 5 and 11 months after COVID-19. Specifically, we assessed olfaction, gustation, and trigeminal sensitivity (10-point visual analog scale) and function (4-point Likert scale) separately. We further assessed clinically relevant OD using the Chemosensory Perception Test, a psychophysical test designed to provide a reliable remote olfactory evaluation. Qualitative chemosensory dysfunction was also assessed. ResultsWe included a total of 366 participants (mean age of 44.8 years old (SD: 11.7)). They completed the last online questionnaire 10.6 months (SD: 0.7) after the onset of COVID-19 symptoms. Of all participants, 307 (83.9%) and 301 (82.2%) individuals retrospectively reported lower olfactory or gustatory sensitivity during the acute phase of COVID-19. Eleven months later, 184 (50.3%) and 163 (44.5%) indicated reduced chemosensory sensitivity, 32.2% reported impairment of olfactory function while 24.9% exhibited clinically relevant OD. Three variables predicted OD at follow-up, namely chest pain and GD during COVID-19 and presence of phantosmia at 5 months. Olfactory sensitivity ratings had a high test-retest reliability (intraclass correlation coefficient: 0.818 (95% CI: 0.760 - 0.860)) DiscussionThis study suggests that chemosensory dysfunctions persist in a third of COVID-19 patients 11 months after COVID-19. Subjective measures have a high test-retest reliability and thus can be used to monitor post-COVID-19 OD. OD appears to be a common long-term symptom of COVID-19 important to consider when treating patients.
RESUMEN
ObjectiveWe aimed to measure the prevalence of psychological distress among Quebec healthcare workers (HCWs) during the second and third pandemic waves and to assess the effect of psychosocial risk factors (PSRs) on work-related psychological distress among SARS-CoV-2 infected (cases) and non-infected (controls) HCWs. MethodsA self-administered survey was used to measure validated indicators of psychological distress (K6 scale) and PSR (questions based on Karasek and Siegrist models, value conflicts and work-life balance). Adjusted robust Poisson models were used to estimate prevalence ratios. Results4068 cases and 4152 controls completed the survey. Prevalence of high work-related psychological distress was 42%; it was associated with PSRs (mainly work-life balance, value conflicts and high psychological demands) but not with SARS-CoV-2 infection. ConclusionPrimary prevention measures targeting PSRs are needed to reduce mental health risks of HCWs.
RESUMEN
IntroductionIn Canada, first and second doses of mRNA vaccines against SARS-CoV-2 were uniquely spaced 16 weeks apart, but the duration of single-dose protection remains uncertain. We estimated one- and two-dose mRNA vaccine effectiveness (VE) among healthcare workers (HCWs) in Quebec, Canada including protection against varying outcome severity, variants of concern (VOC), and the stability of single-dose protection out to 16 weeks post-vaccination. MethodsA test-negative design compared vaccination among SARS-CoV-2 test-positive and weekly-matched (10:1), randomly-sampled, test-negative HCWs using linked surveillance and immunization databases. Vaccine status was defined by one dose [≥]14 days or two doses [≥]7 days before illness onset or specimen collection. Adjusted VE was estimated by conditional logistic regression. ResultsPrimary analysis included 5,316 cases and 53,160 controls. Single-dose VE was 70% (95%CI: 68-73) against SARS-CoV-2 infection, 73% (95%CI: 71-75) against COVID-19 illness and 97% (95%CI: 92-99) against associated hospitalization. Two-dose VE was 86% (95%CI: 81-90) and 93% (95%CI: 89-95), respectively, with no associated hospitalizations. VE was higher for non-VOC than VOC (73% Alpha) among single-dose (77%, 95%CI: 73-81 versus 63%, 95%CI: 57-67) but not two-dose recipients (87%, 95%CI: 57-96 versus 94%, 95%CI: 89-96). Across 16 weeks, no decline in single-dose VE was observed with appropriate stratification based upon prioritized vaccination determined by higher versus lower likelihood of direct patient contact. ConclusionOne mRNA vaccine dose provided substantial and sustained protection to HCWs extending at least four months post-vaccination. In circumstances of vaccine shortage, delaying the second dose may be a pertinent public health strategy to consider.
RESUMEN
Several studies have revealed either self-reported chemosensory alterations in large groups or objective quantified chemosensory impairments in smaller populations of patients diagnosed with COVID-19. However, due to the great variability in published results regarding COVID-19-induced chemosensory impairments and their follow-up, prognosis for chemosensory functions in patients with such complaints remains unclear. Our objective is to describe the various chemosensory alterations associated with COVID-19 and their prevalence and evolution after infection. A cross-sectional study of 704 healthcare workers with a RT-PCR confirmed SARS-CoV-2 infection between 28/2/2020 and 14/6/2020 was conducted 3 to 7 months after onset of symptoms. Data were collected with an online questionnaire. Outcomes included differences in reported chemosensory self-assessment of olfactory, gustatory, and trigeminal functions across time points and Chemosensory Perception Test scores from an easy-to-use at-home self-administered chemosensory test. Among the 704 participants, 593 (84.2%) were women, the mean (SD) age was 42 (12) years, and the questionnaire was answered on average 4.8 (0.8) months after COVID-19. During COVID-19, a decrease in olfactory, gustatory, and trigeminal sensitivities were reported by 81.3%, 81.5% and 48.0% respectively. Three to seven months later, reduced sensitivity was still reported by 52.0%, 41.9% and 23.3% respectively. Chemosensory Perception Test scores indicate that 19.5% of participants had objective olfactory impairment. These data suggest a significant proportion of COVID-19 cases have persistent chemosensory impairments at 3 to 7 months after their infection but the majority of those who had completely lost their olfactory, gustatory, and trigeminal sensitivity have improved.
