Shift in influenza activity during COVID-19 at a tertiary care center in Lebanon

Introduction: Lebanon suffers from a seasonal increase in severe acute respiratory infections caused by Influenza viruses each year. Patients present with mild to severe symptoms which may require hospitalization. The increase in morbidity and mortality is usually noted in elderly and in patients with comorbidities. Objectives: We studied the Influenza activity at the American University of Beirut Medical Center (AUBMC) before and during the COVID-19 pandemic. Methods: In Lebanon, the Influenza season extends from September to May with a noted peak during winter. Close monitoring of the Influenza activity is performed at our center by the Infection Control team. Patients with suspected or confirmed Influenza are placed in a single room under droplet precautions. Influenza infections are confirmed by either Rapid Influenza Diagnostic test or Reverse Transcription Polymerase Chain Reaction (RT-PCR) test. During COVID-19 pandemic, public health measures such as lockdown, mandatory masking and physical distancing were implemented in the country with discrepancy in compliance between geographical regions. Results: Since September 2020, all the respiratory specimens that were tested for Influenza at AUBMC came back negative. While positive results reached 27% in 2019-2020 season and 20% in 2018-2019 Influenza season. The number of specimens tested during season 20-21 was 150 compared to 4592 and 4457 samples tested during the last 2 seasons, respectively. Conclusion: The exceptional zero Influenza cases encountered during the 2020-2021 Influenza season at our center in comparison to the previous 2 seasons is reasonably explained. The dramatic decrease in Influenza cases, hospitalization, morbidities, and mortalities is the result of the public health measures that were imposed by the authorities to control the spread of COVID- 19 in the country. A similar decline in Influenza cases is similarly observed in the United States where the positivity rate is reported at 0.1% during the same season. (Figure Presented).