Global analysis of respiratory virus patterns and epidemic timing before and during the COVID-19 pandemic

Below is a summary of the “Global analysis of respiratory viral circulation and timing of epidemics in the pre-COVID-19 and COVID-19 pandemic periods based on data from the Global Influenza Surveillance and Response System (GISRS),” published in the April 2024 issue of Infectious diseases by Riccio et al.

The COVID-19 pandemic has changed interventions against respiratory viruses, such as wearing masks to avoid possible virus interactions.

The researchers conducted a retrospective study to determine whether respiratory virus circulation patterns have returned to pre-pandemic levels by comparing the timing and duration of peak loads during the first three SARS-CoV-2 seasons with the pre-pandemic period.

They used data from the Global Influenza Surveillance and Response System (GISRS) from 194 countries (2014 to 2023) to examine the timing and duration of epidemic peaks. The focus was on the periods before and during the pandemic in both hemispheres and the intertropical belts, with strict criteria for data inclusion ensuring robustness.

The results showed that from 2022 to 2023, influenza and RSV peaked 1.9 months earlier in the Northern Hemisphere (P<0.001). Flu epidemics lasted 2.2 weeks longer (P<0.001), with RSV showing a similar trend. The shift in the flu peak in the southern hemisphere was not significant (P=0.437). In the tropical regions, the hMPV and adenovirus epidemics were 7.2 and 6.5 weeks shorter, respectively (P<0.001).

The researchers concluded that the pandemic has altered the typical patterns of influenza and RSV, with incidence peaking in temperate regions in 2022. The need for robust surveillance data to guide future public health plans regarding viral patterns continues to grow.

Source: ijidonline.com/article/S1201-9712(24)00122-X/fulltext#%20