[ad_1]
Hospitals across the UK are seeing an increase in the number of children with serious respiratory infections. This includes a nonseasonal flare-up of an infection called respiratory syncytial virus (RSV), in children as young as two months old.
This has resulted in an increasing number of hospital admissions for bronchiolitis, an inflammation of the lungs similar to bronchitis.
So why does RSV, considered a winter disease, peak in the summer of 2021?
Simply put, the restrictions put in place to prevent the spread of COVID-19 have also put the brakes on other respiratory viruses. As many countries lift these restrictions, many respiratory diseases are spreading again.
RSV is a common respiratory pathogen – so common in fact that almost all of us are infected with this virus by the age of two. For the vast majority of people, this virus causes a mild illness resembling a bad cold, with runny nose and cough. These symptoms normally go away without treatment within a week or two.
However, in about one in three children, RSV can cause bronchiolitis, an inflammation of the bronchioles, the smallest tubes in our lungs. This restricts the airways and patients experience high temperatures and difficulty breathing, often making a wheezing sound when inhaling air.
While bronchiolitis can often be treated without much more than fluids and paracetamol, it can sometimes progress to serious illness. If a youngster’s breathing becomes severely restricted, symptoms can worsen, causing temperatures above 38 degrees Celsius, blue lips, and increased difficulty in breathing.
In young children, this can lead to refusal of feedings and dry diapers for long periods of time. This is when many parents rightly make the decision to take their child to the hospital.
Very young children – those in their first months of life – are most likely to be hospitalized because of their smaller airways.
While most cases can be controlled, bronchiolitis is sometimes fatal. About 3.5 million children worldwide are hospitalized each year, with about 5 percent of these cases sadly resulting in death.
Delayed overvoltage
It would appear that COVID responses like increased hand washing, mask wear and reduced close contact between people led to a drastically reduced influenza season in winter 2020-21.
The same was true for RSV, with studies reporting 84% fewer hospitalizations due to bronchiolitis in northern hemisphere countries compared to previous years. Dramatic reductions have also been noted in Australia.
Now the opposite is happening, affecting an entire year of newborns who will not have encountered many respiratory viruses while the restrictions were in place.
We do not know why some children with RSV have mild symptoms and others become seriously ill. Many risk factors associated with severe RSV disease have been identified, including age (one month old children are most at risk), sex (men are statistically more at risk than women), environmental factors such as exposure to smoke, underlying lung disease and some genetic factors.
Despite this knowledge, it is still not possible to identify with certainty which children will develop bronchiolitis. However, in some countries, individuals are identified as high risk based on these known risk factors and receive prophylactic treatment.
As with all infectious agents, a robust immune response is essential to clear infection. We know that large amounts of neutralizing antibodies (including maternal antibodies and antibody treatments such as palivizumab) protect against serious illness.
Yet immunity to RSV is not complete or particularly long-lasting, as most of us are re-infected throughout our lives. This is part of the reason why, despite the monumental efforts of many research groups, no vaccine is currently available.
In addition, our immune system can sometimes damage our body when it tries to clear an infection. With RSV, certain immune responses have been shown to increase disease severity and have been linked to the development of asthma.
Due to the prevalent nature of RSV and asthma in the UK, the link between the two is being studied extensively, including in the Wellcome Trust funded Breathing Together project that I am currently working on.
Any treatment or vaccine against RSV must be beneficial in terms of eliminating the infection but without producing negative effects. Mistakes have been made in the past, with previous RSV vaccine attempts in the 1960s resulting in seriously ill children.
But with immunity to RSV being much better studied and understood now, vaccines are at least under development. Several are currently in clinical trials in the hope that we can finally protect all children from RSV-induced bronchiolitis.
Grace C Roberts, Virology Researcher, Queen’s University Belfast.
This article is republished from The Conversation under a Creative Commons license. Read the original article.
[ad_2]
Source link