Different patterns of hospitalization for acute respiratory infections before and during two pandemics years

In a recent article published in medRxiv* Preprint server, researchers analyzed various patterns of respiratory viruses that resulted in hospitalization in Canada from 2012 to 2013 to 2021 to 2022.

Background

Strict mitigation measures such as border closure, travel restrictions, social exclusion, business / school closure, lockdown, remote work, and the use of masks in public spaces are the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). ) Is being implemented worldwide to reduce the spread. And its impact on hospital bed availability.

Respiratory viruses other than SARS-CoV-2 (ORV) dominated the Northern Hemisphere in the first few weeks of 2020. However, SARS-CoV-2 quickly replaced seasonal ORV as the major respiratory virus, altering the traditional seasonality of some RVs and effectively eradicating it. Others over a long period of time in different parts of the world.

Nevertheless, there is no complete explanation for the combined effects of SARS-CoV-2 and ORV on hospitalization. By understanding the combined effect of ORV and SARS-CoV-2 on the pandemic year-long hospital capacity of two coronavirus diseases 2019 (COVID-19) and comparing it with the pre-pandemic season, ORV and SARS pandemic. You can shed light on later time frames-CoV-2 co-circulates.

About research

In this study, researchers aim to analyze the viral etiology of acute respiratory infection (ARI) admissions from a surveillance network in Quebec, Canada, during and before the two COVID-19 pandemic years. And said. During the influenza pandemic 2012-2013, Quebec introduced a hospital-based monitoring system that systematically screens a panel of 17 respiratory viruses in ARI-hospitalized adult and pediatric patients. .. The SARS-CoV-2 pandemic was monitored using the same system and expanded to include SARS-CoV-2 in the panel.

The team has systematically tested the detection of SARS-CoV-2 and ORV from 2020 to 2021 and 2021 to 2022 by multiplex polymerase chain reaction (PCR) for pre-pandemic influenza in inpatient ARI patients. Compared to 8 seasons. Four regional hospitals with a body of water of approximately 10% of Quebec’s population were included in the eight-season surveillance of influenza from 2012 to 2013.

Due to hospital resource issues during the COVID-19 pandemic, one of the four hospitals did not participate between 2020 and 2021. The agency rejoined the network from 2021 to 2022. From 2021 to 2022, two more tertiary hospitals (children and adults) were added to the network.

result

The results of the study showed that there were significant continuous changes in viral etiology and age distribution of ARI admissions not only between the two COVID-19 pandemic years and the pre-pandemic period, but also between the first and second pandemic years. I showed that. SARS-CoV-2 was generally the most common viral cause of ARI hospitalization in both pandemic years. However, it was not prevalent in children in the first year, but was seen in children in the second year.

The changes observed in the etiology and age distribution of respiratory hospitalization were sequelae of changes in SARS-CoV-2 and ORV circulation based on the scale of the COVID-19 palliative intervention. The emergence of SARS-CoV-2 mutants was another possible factor. For example, the SARS-CoV-2 ancestors and alpha variants were prevalent in the winter and fall of 2021-2022 and affected primarily adults, while the Delta and Omicron variants were both. It mainly afflicted children and was predominant in the winter and fall of 2021-2022.

In addition, children hospitalized for ORV, primarily RSV, and SARS-CoV-2 due to out-of-season respiratory syncytial virus (RSV) outbreaks in August and September 2021 compared to the first pandemic season. The ratio of is high. In addition, the availability and use of COVID-19 outpatient antivirals and vaccinations to help avoid hospitalization varied by age group. In the second year of the pandemic, the SARS-CoV-2 vaccination program prioritized older patients and made outpatient antiviral therapy available to many patients with comorbidities. In addition, COVID-19 vaccination was not readily available to children until much later, and vaccination rates for young adults were lower than for older adults.

RSV and influenza were the two most frequently found viruses among ARI patients hospitalized during the pre-pandemic influenza season. During the first year of the COVID-19 pandemic, SARS-CoV-2 was the most important respiratory virus. However, from 2021 to 2022, while the impact of ORV increased, its contribution declined. Nevertheless, there was variability between the child and adult populations.

RVs, primarily RSVs, affected more children than adults during the pre-pandemic winter. The overall impact of RV during the pandemic was small, but ORV rather than SARS-CoV-2 had a dramatic impact on the pediatric population in both pandemics. Influenza was the most important virus in the years before the adult pandemic. However, during the two years of the pandemic, SARS-CoV-2 was more prevalent than adult ORV.

Conclusion

Current reports based on comprehensive RV detection show 17 RVs and SARS-CoV-2 in ARI hospitalization for 2 years of COVID-19 pandemic compared to 8 years prior to the pandemic of the same cohort. It shows a change in etiology. According to the authors, this study covers the widest follow-up period for inpatients in adults and children during the pandemic and pre-pandemic stages of SARS-CoV-2.

In summary, the findings showed that during the first two years of the COVID-19 pandemic, there were significant changes in the age distribution and viral cause of ARI hospitalization in adults and children. The second pandemic year was the same as the pre-pandemic winter in terms of RV contribution and age distribution, but the first pandemic year was dramatically different.

Fluctuations in SARS-CoV-2 and ORV contributions across hospital morbidity include mitigation strategies, long-term trends, and ORV-specific seasonality, COVID-19 vaccine intake, and EffectivenessChanges in circulating SARS-CoV-2 mutants, and their severity, outpatient antiviral therapy, and potential viral interference.

Current analysis emphasizes the importance of monitoring in understanding the modified seasonal trends in RV, and even if researchers do not document data for the entire 2021-2022 season, for ORV. It shows that the effects of SARS-CoV-2 are continuously changing. These findings indicate that changes in RV epidemiology and the cause of ARI admissions need to be investigated in detail to develop targeted public health recommendations.

*Important Notices

medRxiv publishes unpeer-reviewed preliminary scientific reports and should not be considered definitive, guide clinical / health-related behaviors, or be treated as established information.