Respiratory syncytial virus or 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.

In 2022 to date, RSV has been detected in 19% (105/529) of children aged younger than five hospitalised with LRTI at sentinel pneumonia surveillance sites.

The National Institute for Communicable Diseases said the number testing positive for RSV among children aged 5 and under started to increase in early February.

The NICD said cases have been steadily increasing with more children testing positive.

The NICD said before Covid-19, the RSVV season in the country is usually preceded the influenza season with the usual average onset between February and March over the last decade.

"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," the NICD said.

The NICD said Bronchiolitis is mostly self –limiting with patients presenting with upper respiratory tract illness signs, low grade fever and wheezing.

The majority of infants with RSV-associated bronchiolitis do not require hospitalisation, but certain children are at risk of severe disease or require supplemental oxygen. Infants under 6-months may develop severe disease like hypoxia, severe respiratory distress (tachypnoea, nasal flaring or lower chest retractions), inability to feed or apnoea requiring hospitalisation.

"In very young infants, irritability, decreased activity, and breathing difficulties may be the only presenting symptoms. Risk factors for severe RSV-associated disease include prematurity, congenital heart disease, chronic lung disease of prematurity, neurological disease, infants aged below 6-months, immunodeficiency and lack of breast feeding.

"Environmental factors that are risk factors for severe RSV-associated disease include overcrowding, poverty and day care centre attendance," the NICD said.

Prevention

Prevention, including isolation of children with influenza-like symptoms (sick children should not go to crèches or schools for a few days), and teaching children (and adults looking after infants) to practice sneeze and cough hygiene, is important.

Use of prophylactic antibiotics for children with upper respiratory tract infections is not recommended. The monoclonal antibody, palivizumab, administered monthly throughout the RSV season to infants and children at high risk of severe RSV disease, has been shown to be effective for prevention.

However, high costs and the need for monthly intramuscular injections throughout the RSV season, limit its use. Clinicians and paediatric hospitals/ intensive care units are reminded to anticipate an increase in paediatric admissions during the 2022 RSV season. The results from the models, suggested an intensive RSV season in 2022 with a higher and earlier than usual peak number of RSV-related hospitalizations in early April.

Healthcare providers are encouraged to prepare and allocate adequate resources to respond to the surge in RSV cases.

IOL