The National Institute for Communicable Diseases (NICD) has noted the rise in respiratory syncytial virus (RSV) cases, detailing its infection patterns since the outbreak of the Covid-19 pandemic.

“RSV is the most common cause of bronchiolitis and lower respiratory tract illness (LRTI) among young children,” it explained.

The virus is highly contagious and infection does not result in permanent or long-term immunity, so reinfection can occur.

Infections usually spiked around the end of February to the middle of March, just before the flu season,

However this infection pattern has been disrupted by the Covid-19 pandemic and government’s response to it.

“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,” it said.

To date this year, the virus has been detected in 19% of children aged under five  years and hospitalised with LRTI at sentinel pneumonia surveillance sites.

The institute said the number of positive cases among children aged younger than five years started to increase in the week ending February 13. It continues to increase, with 35% and 32% of children hospitalised with LRTI testing RSV positive in the weeks ending March 6 and 13 respectively.