Outcomes of laboratory-confirmed SARS-CoV-2 infection during resurgence driven by Omicron lineages BA.4 and BA.5 compared with previous waves in the Western Cape Province, South Africa (preprint)

ObjectiveWe aimed to compare clinical severity of Omicron BA.4/BA.5 infection with BA.1 and earlier variant infections among laboratory-confirmed SARS-CoV-2 cases in the Western Cape, South Africa, using timing of infection to infer the lineage/variant causing infection. MethodsWe included public sector patients aged [≥]20 years with laboratory-confirmed COVID-19 between 1-21 May 2022 (BA.4/BA.5 wave) and equivalent prior wave periods. We compared the risk between waves of (i) death and (ii) severe hospitalization/death (all within 21 days of diagnosis) using Cox regression adjusted for demographics, comorbidities, admission pressure, vaccination and prior infection. ResultsAmong 3,793 patients from the BA.4/BA.5 wave and 190,836 patients from previous waves the risk of severe hospitalization/death was similar in the BA.4/BA.5 and BA.1 waves (adjusted hazard ratio [aHR] 1.12; 95% confidence interval [CI] 0.93; 1.34). Both Omicron waves had lower risk of severe outcomes than previous waves. Prior infection (aHR 0.29, 95% CI 0.24; 0.36) and vaccination (aHR 0.17; 95% CI 0.07; 0.40 for boosted vs. no vaccine) were protective. ConclusionDisease severity was similar amongst diagnosed COVID-19 cases in the BA.4/BA.5 and BA.1 periods in the context of growing immunity against SARS-CoV-2 due to prior infection and vaccination, both of which were strongly protective.

Outcomes of laboratory-confirmed SARS-CoV-2 infection in the Omicron-driven fourth wave compared with previous waves in the Western Cape Province, South Africa (preprint)

Objectives: We aimed to compare COVID-19 outcomes in the Omicron-driven fourth wave with prior waves in the Western Cape, the contribution of undiagnosed prior infection to differences in outcomes in a context of high seroprevalence due to prior infection, and whether protection against severe disease conferred by prior infection and/or vaccination was maintained. Methods: In this cohort study, we included public sector patients aged [≥]20 years with a laboratory confirmed COVID-19 diagnosis between 14 November-11 December 2021 (wave four) and equivalent prior wave periods. We compared the risk between waves of the following outcomes using Cox regression: death, severe hospitalization or death and any hospitalization or death (all [≤]14 days after diagnosis) adjusted for age, sex, comorbidities, geography, vaccination and prior infection. Results: We included 5,144 patients from wave four and 11,609 from prior waves. Risk of all outcomes was lower in wave four compared to the Delta-driven wave three (adjusted Hazard Ratio (aHR) [95% confidence interval (CI)] for death 0.27 [0.19; 0.38]. Risk reduction was lower when adjusting for vaccination and prior diagnosed infection (aHR:0.41, 95% CI: 0.29; 0.59) and reduced further when accounting for unascertained prior infections (aHR: 0.72). Vaccine protection was maintained in wave four (aHR for outcome of death: 0.24; 95% CI: 0.10; 0.58). Conclusions: In the Omicron-driven wave, severe COVID-19 outcomes were reduced mostly due to protection conferred by prior infection and/or vaccination, but intrinsically reduced virulence may account for an approximately 25% reduced risk of severe hospitalization or death compared to Delta.

An analysis of patients’ perspectives on qualitative olfactory dysfunction using social media (preprint)

SUMMARY Background The impact of qualitative olfactory disorders is underestimated. Parosmia is the triggered perception of distorted odours whereas phantosmia is the perception of odours in the absence of a trigger. Both can arise from post-infectious anosmia and have increased substantially since the outbreak of COVID-19. Methodology/Principal Thematic analysis of a social media support group for parosmia and phantosmia was used to articulate the perspectives and concerns of those affected by these debilitating olfactory disorders. Results A novel symptom (olfactory perseveration) was identified where a triggered, identifiable, and usually unpleasant olfactory percept persisted in the absence of an ongoing stimulus. Fluctuations in intensity and duration of perseveration, parosmia and phantosmia were observed. Coffee, meat, onion, and toothpaste were identified as common triggers of these disorders, but people struggled to describe the distortions, using words associated with disgust and revulsion. Common strategies to avoid triggers may result in a diet lacking in both nutrition and reward. The emotional aspect of living with qualitative olfactory dysfunction was evident and highlighted the detrimental impact on mental health. Conclusions The data acquired can inform rehabilitation strategies and drive our ongoing research into understanding the molecular triggers associated with parosmia, and research into patient benefit.

Altered Smell and Taste: anosmia, parosmia and the long impact of Covid-19 (preprint)

Abstract Background: Qualitative olfactory (smell) dysfunctions are a common side effect of post-viral illness and known to impact on quality of life and health status. Evidence is emerging that taste and smell loss are common symptoms of Covid-19 that may emerge and persist long after initial infection. The aim of the present study was to document the impact of post Covid-19 alterations to taste and smell. Methods: We conducted passive and active thematic analysis of user-generated text from 9000 users of the AbScent Covid-19 Smell and Taste Loss moderated Facebook support group from March 24 to 30th September 2020. Results: Participants reported difficulty understanding, explaining and managing altered taste and smell; a lack of interpersonal and professional explanation or support; altered eating; appetite loss, weight change; loss of pleasure in food, eating and social engagement; altered intimacy and an altered relationship to self and others. Conclusions: Our findings suggest altered taste and smell with Covid-19 lead to a severe disruption to daily living that impacts on psychological well-being and health. Moreover, this impact is broad, spanning flavour perception; desire and ability to eat and prepare food; weight gain, loss and nutritional sufficiency; emotional wellbeing; professional practice; intimacy; social bonding and erosion of peoples very sense of reality. Our findings should inform the training, assessment and treatment practices of health care professionals working with long Covid.