Epidemiology and seasonality of respiratory syncytial virus in the UAE. A five-year (2018-2022) study at Tawam Hospital

Respiratory Syncytial Virus (RSV) remains a chief cause of severe lower respiratory tract infections and subsequent hospital admissions among infants and young children worldwide. Understanding its local transmission patterns is vital for implementing timely and effective preventative measures, such as monoclonal antibody prophylaxis.

Historically, RSV exhibits a predictable seasonal pattern, but the COVID-19 pandemic and associated non-pharmaceutical interventions (NPIs)—like physical distancing and school closures—significantly disrupted this global viral circulation.

The retrospective review analyzed 39,760 RSV tests conducted on 15,326 unique children aged five years and younger. The overall RSV positivity rate fluctuated substantially during the study period, dropping to a low of 2.9% in 2020 (a year with strict NPIs) but soaring to a peak of 16.3% in 2021 following the relaxation of public health measures. Pre-pandemic, the mean age of RSV-positive children was around 15 months; however, it rose to 20.7 months in 2021. This shift suggests a larger cohort of older, immunologically naïve children may have become susceptible after a period of reduced viral exposure. The mean age declined slightly to 16.0 months in 2022.

The typical seasonal pattern was fundamentally altered. Prior to the pandemic, RSV activity had typical winter peaks; however, the 2020-2021 season onset was delayed, leading to an atypical, prolonged season. In 2022, seasonality began to return to pre-pandemic timing. Viral type dominance also shifted: RSV type B was dominant in 2018, but RSV type A predominated during the pandemic years of 2020 and 2021. By 2022, RSV-B re-emerged as the most common strain.

Of the children infected, 2,189 required hospitalization, with over 60% of those occurring in the two years post-disruption (2021-2022). Infants under six months had the longest hospital stays, averaging 5.8 days. Notably, infection with RSV-B was associated with a significantly higher likelihood of hospitalization—a 6.7-times greater odds—compared to RSV-A.

In conclusion, the study highlights the profound impact of the COVID-19 pandemic on RSV epidemiology in the UAE. The dynamic changes in seasonality, age distribution, and viral type dominance emphasize the critical need for sustained, high-resolution surveillance. Such data is essential to accurately define the local RSV season onset and offset, allowing policymakers to optimize the timing and efficacy of novel preventative strategies for vulnerable paediatric populations.

Reference Source
Alamiri, H. A., Hamwi, S., Alsamri, M. T., et al. (2025). Epidemiological characterization and seasonality of respiratory syncytial virus in the United Arab Emirates: A five-year study at a tertiary care hospital, 2018-2022. Journal of Infection and Public Health, 18(2025), DOI https://doi.org/10.1016/j.jiph.2025.103007