Respiratory syncytial virus (RSV) is the most common cause of bronchiolitis and lower respiratory tract illness (LRTI) among young children. It is highly contagious and infection with RSV does not result in permanent or long-term immunity and re-infections can occur.
Before the COVID-19 pandemic, the RSV season in South Africa usually preceded the influenza season with the usual average onset at the end of February (range early February – mid-March) over the last 10 years. However, since the start of COVID-19 pandemic, with non-pharmaceutical interventions to prevent SARS-CoV-2 transmission in place, RSV circulation has been disrupted, with fewer cases and out of season outbreaks reported.
In 2022 to date, RSV has been detected in 19% (105/529) of children aged <5 years, hospitalised with LRTI at sentinel pneumonia surveillance sites, site details summarised in weekly respiratory pathogens surveillance report. The number testing positive for RSV among children aged <5 years started to increase in week 5 (week ending 13 February) and continues to increase, with 35% (28/81) and 32% (24/74) of children hospitalised with LRTI at sentinel sites in week 9 (week ending 6 March) and 10 (week ending 13 March) testing RSV positive, respectively. Read full alert here