Prevalence of childhood virus on the rise across parts of England

Cases of a viral infection that can cause severe breathing difficulties in young children have risen sharply in the North West and southern parts of England, government data show.

Respiratory syncytial virus (RSV) is very common in the UK and will infect most children before the age of two, often leading to a mild cough and cold. But in some rare cases, bronchiolitis can develop, which requires hospitalisation and possibly ventilation.

RSV had largely vanished during the Covid lockdowns but, after restrictions were eased, the prevalence of the virus jumped across the north and south of the country, according to positivity rates published by Public Health England.

Internal PHE data seen by The Independent shows that the North West was the first to see a significant rise in cases. By the middle of July, more than 200 weekly infections were being reported in under-3s across the region – the highest in the country. However, it has since passed the peak of its RSV wave, with cases now in decline.

Dr Liz Whittaker, a lecturer in paediatric infectious diseases and immunology at Imperial College London, said the North West was always the first to record an increase in infections during a normal RSV season in Britain – though experts are unsure why.

PHE said that it is difficult to make comparisons between different regions and draw firm conclusions on why rates have risen faster in some areas than others.

Although cases have fallen more generally across the north of England, the prevalence of RSV remains at its highest across the south of the country, according to PHE data available up to 15 August. Positivity rates have meanwhile plateaued in the Midlands and East of England, and are on a downward trajectory in London.

Most infants are normally infected during October through to February, with the peak of the annual RSV season coming in December. But because of the coronavirus lockdowns and social distancing, a greater proportion of children have yet to be infected over the past year.

Health experts are concerned that reduced circulation of RSV might mean that infants and toddlers could have an elevated risk of severe disease since they did not experience normal levels of exposure to the virus compared to past seasons – referring to it as an “immunity debt”.

In an RSV document recently circulated among health officials, PHE said the peak in cases currently being recorded is “out of the usual season”. The document also suggests that, by mid-July, roughly 17 out of 100,000 infections in under-5s required hospital care.

“There is definitely more about than there should be for this time of year, and other viruses too, but we holding our position as it stands,” said Dr Ashley Reece, a general paediatrician from the Royal College of Paediatrics and Child Health.

Typically, RSV accounts for approximately 450,000 GP appointments, 29,000 hospitalisations and 83 deaths per year in UK children and adolescents, the majority among infants, according to modelling.

It typically causes 85 per cent of respiratory presentations seen in hospitalised children between November and March each year.

Despite the recent rise in cases following the lifting of Covid restrictions, “the numbers are very manageable at the moment,” said Dr Whittaker. However, she warned that it is “not clear what will happen when schools go back” at the start of next month.

The respiratory infection, like Sars-CoV-2, the virus that causes Covid-19, can spread through droplets in the air when someone coughs or sneezes.

Dr Reece said that the current RSV levels will likely “continue at this rate and gradually increase into autumn and through winter as would happen normally.”

In June, The Independent reported that an alert had been issued to the NHS to expand the use of Palivizumab, a monoclonal antibody treatment for RSV that can give what is called ‘passive immunity’ to children by providing infants with the antibodies they need against the virus.

Unlike with a vaccine, the body is not induced to generate antibodies itself so the treatment is not a permanent defence but can help with infections.