Background: Epidemiological studies and control actions have historically prioritized Seasonal influenza, RSV, and recently, SARS-CoV-2 over other respiratory viruses (ORV). The COVID-19 pandemic has reinvigorated interest in understanding the impact of non-pharmaceutical interventions in respiratory virus control beyond SARS-CoV-2. This study aimed to detect and determine the circulation of ORVs in Maputo in 2022.

Methodology: A total of 4280 specimens were available, but only 430 negative specimens for SARS-CoV-2 and influenza were selected for analysis. These specimens were collected from children aged 0-14 years and older adults ≥60 years old from the sentinel surveillance for acute respiratory infections were retrospectively and randomly selected and screened for Parainfluenza (1-3), Metapneumovirus, Adenovirus, and Seasonal Coronaviruses (OC43, 229E and NL63) using real-time RT-PCR. Frequencies were calculated and associations of variables including non-pharmaceutical interventions to control SARS-CoV-2 and massive vaccination periods, were examined.

Results: Preliminary results found that in 2022, Adenovirus (7.21%, 31/430), Metapneumovirus (3,02%, 13/430), Parainfluenza 1 (1.63%, 7/430), Parainfluenza 2 (0.47%, 2/430), Parainfluenza 3 (2.33%, 10/430) and Coronavirus NL63 (0.7%, 3/430) were detected among the study sample. Of the positive samples, 87.9% (58/66) were from children ≤3 years old and 12.1% (8/66) were from children older than 3 years and older adults. All viruses were detected throughout the year without apparent epidemic period, except for Adenovirus which showed high activity (61.29%, 17/31) between July and September. The lowest detections of the tested viruses were observed between January and April, coinciding with the 4th wave of SARS-CoV-2 and after massive vaccination for SARS-CoV-2 in the country.

Conclusion: Other respiratory viruses were present throughout the year without clear epidemic periods and appeared to be more common in children ≤3 years old than older adults. The data suggests that waves of SARS-CoV-2, non-pharmaceutical interventions and vaccination campaigns might have significantly impacted the circulation of ORV.