Modeling the effect of temperature and relative humidity on exposure to SARS-CoV-2 in a mechanically ventilated room.

Computational fluid dynamics models have been developed to predict airborne exposure to the SARS-CoV-2 virus from a coughing person in a mechanically ventilated room. The models were run with three typical indoor air temperatures and relative humidities (RH). Quantile regression was used to indicate whether these have a statistically significant effect on the airborne exposure. Results suggest that evaporation is an important effect. Evaporation leads to respiratory particles, particularly those with initial diameters between 20 and 100 µm, remaining airborne for longer, traveling extended distances and carrying more viruses than expected from their final diameter. In a mechanically ventilated room, with all of the associated complex air movement and turbulence, increasing the RH may result in reduced airborne exposure. However, this effect may be so small that other factors, such as a small change in proximity to the infected person, could rapidly counter the effect. The effect of temperature on the exposure was more complex, with both positive and negative correlations. Therefore, within the range of conditions studied here, there is no clear guidance on how the temperature should be controlled to reduce exposure. The results highlight the importance of ventilation, face coverings and maintaining social distancing for reducing exposure.

The impact of COVID-19 pandemic on health-related quality of life of adults visiting emergency departments and primary care settings in Alberta.

OBJECTIVES: To examine the impact of COVID-19 pandemic on health-related quality of life (HRQL) of adults visiting emergency departments (ED) and primary care (PC) settings in Alberta, Canada, and explore whether this impact varies across demographic subgroups. METHODS: Data from two repeated cross-sectional surveys that measured HRQL using EQ-5D-5L were used; "pre-COVID" Sept 2019-Feb 2020 (ED, N=5927; PC, N=317), "Wave-1" Mar 2020-Aug 2020 (ED, N=4781; PC, N=375), and "Wave-2" Sept 2020-Jan 2021 (ED, N=4443; PC, N=327). RESULTS: In the ED sample, there were decrements in mild-extreme problems of 3.7% in mobility and 4.1% in usual activities from pre-COVID to wave 2. There were very minor changes in mild-extreme problems in self-care (decrement=1.3%), pain/discomfort (decrement=2.6%), and anxiety/depression (decrement=0.9%). In the PC sample, there were increases of 4.8% in mild-extreme pain/discomfort and 10.7% in anxiety/depression from pre-COVID to wave 2. Despite these changes, HRQL of both samples pre-COVID and during waves 1 and 2 was worse than that of the general Alberta population. There were no significant variations in the impact of COVID-19 pandemic on HRQL across age, sex, and income subgroups in the ED survey; however, such variations were observed in the PC survey whereby younger adults, females, and those with high income had the largest HRQL deteriorations. CONCLUSION: The impact of COVID-19 pandemic on HRQL was minimal in adults seeking ED care, but more pronounced in those seen in PC, especially in terms of mental health. Policies around COVID-19 should take into account the needs of certain groups of the population, especially women and young people.

RéSUMé: OBJECTIFS: Examiner l'impact de la pandémie de COVID-19 sur la qualité de vie liée à la santé (QVLS) des adultes visitant les services d'urgence (SU) et les établissements de soins primaires (SP) en Alberta, au Canada, et déterminer si cet impact varie selon les sous-groupes démographiques. MéTHODES: Les données de deux enquêtes transversales répétées qui ont mesuré la QVL à l'aide de l'EQ-5D-5L ont été utilisées; « pré-COVID ¼ septembre 2019-février 2020 (SU, N=5 927; SP, N=317), « Vague-1 ¼ mars 2020-août 2020 (SU, N=4 781; SP, N=375) et « Vague-2 ¼ septembre 2020-janvier 2021 (SU, N=4 443; SP, N=327). RéSULTATS: Dans l'échantillon du SU, il y a eu des diminutions des problèmes légers à extrêmes de 3,7 % dans la mobilité et de 4,1 % dans les activités habituelles de la période pré-COVID à la vague 2. Il y a eu des changements très mineurs dans les problèmes légers à extrêmes dans les soins personnels (diminution = 1,3 %), douleur/gêne (diminution=2,6 %) et anxiété/dépression (diminution=0,9 %). Dans l'échantillon SP, il y a eu des augmentations de 4,8 % de la douleur/gêne légère à extrême et de 10,7 % de l'anxiété/de la dépression de la période pré-COVID à la vague 2. Malgré ces changements, la QVLS des deux échantillons avant la COVID et pendant les vagues 1 et 2 était pire que celle de la population générale de l'Alberta. Il n'y avait pas de variations significatives de l'impact de la pandémie de COVID-19 sur la QVLS selon l'âge, le sexe et les sous-groupes de revenu dans l'enquête SU; cependant, de telles variations ont été observées dans l'enquête SP, où les jeunes adultes, les femmes et les personnes à revenu élevé présentaient les plus fortes détériorations de la QVLS. CONCLUSION: L'impact de la pandémie de COVID-19 sur la QVLS était minime chez les adultes cherchant des SU, mais plus prononcé chez ceux observés dans le SP, en particulier en termes de santé mentale. Les politiques autour de COVID-19 devraient prendre en compte les besoins de certains groupes de la population, en particulier les femmes et les jeunes.