Changes in the Epidemiology and Surveillance of Viral Respiratory Diseases in the Madrid Region: Beyond Covid-19

Respiratory infections are the second cause of morbidity and mortality in the world and the first cause of infectious disease in Spain and Europe. After the arrival of COVID-2019, with great impact on all health and social indicators, the non-pharmacological measures taken limited the incidence of other respiratory viruses by making their transmission difficult. Derived from this pandemic situation, the population has had a greater susceptibility to other respiratory viruses, since it could not acquire natural immunity as the circulation of these viruses was hampered. The pandemic situation and the control measures implemented initially had a favorable impact on the control of other respiratory diseases, but these increased in 2022. Co-circulation of respiratory viruses may occur and produce almost simultaneous epidemic peaks in the winter season. This simultaneous transmission poses important challenges in the clinical management of patients and in the planning of a possible care overload, both at the outpatient and hospital levels. Aging and chronicity associated with increased life expectancy suggest that acute respiratory infections will continue to be highly prevalent in the coming years. Added to this are respiratory syncytial virus (RSV) infections or other viruses that mainly affect the younger paediatric population population (0 to 4 years old) and are currently the leading cause of lower respiratory tract infection and hospitalization in infants. After the pandemic, it has been necessary to readapt the epidemiological surveillance systems against viral infections of the respiratory system, maintaining an adequate balance between sentinel and classic systems.

Keywords:COVID-19; virus diseases; respiratory syncytial virus; human; influenza; public health surveillance; sentinel surveillance; epidemiology

Abbreviations:ARI: Acute Respiratory Infections; RSV: Respiratory Syncytial Virus; NPIs: Non-Pharmacological Interventions; SARS-CoV-2: Severe acute respiratory syndrome coronavirus 2