Respiratory syncytial virus (RSV) is already one of the most common causes of babies being admitted to hospital in WA, but new research suggests the number of known cases is only the tip of the iceberg.
New research from the Telethon Kids Institute shows the true number of cases of the virus, known as RSV, is likely 30 to 50 per cent higher than the current data suggests.
"It is a big concern because [RSV] causes so many hospital admissions," said Hannah Moore, co-author of the research paper published in Nature journal last month.
"Some children who have severe RSV infections can then go on to have wheezing and asthma later on in childhood."
Dr Moore, who is also the co-head of the infectious disease epidemiology team at Telethon Kids Institute, said there was no systematic approach to testing for the virus in WA.
The result is that not all cases are recorded, and the true number of cases is unknown.
The goal of the new research was to develop a model that can estimate how many cases are actually occurring in WA and, in turn, assess the burden it has on the state's healthcare system.
Virus not vaccine-preventable
"RSV is currently not vaccine-preventable, but it's been prioritised by the World Health Organization for prevention through vaccination," said Dr Moore, adding that treatments and vaccines are currently under development.
"So, there are all these prevention products that are in clinical trials around the world at the moment, and for us to be able to understand what impact these prevention products and vaccines might have, we first need to understand more, what's the actual burden of the disease?"
RSV affects the airways and the lungs, including inflammation in the lungs, and it can develop into pneumonia in babies and young children.
Dr Moore is now planning to do a community awareness study to assess how much parents know about the virus.
"A lot of parents will be concerned about lung infections in babies and pneumonia, but they probably don't realise that that's the most likely cause of pneumonia in young children," she said.
To develop their model, the scientists used records of 34,000 cases of RSV in WA children who were hospitalised and tested for RSV between 2000 to 2012.
They then considered factors such as age, smoking during pregnancy, socio-economic status and the reason the child was in hospital, such as pneumonia or asthma.
With this in mind, they developed a model to predict the probability of a child testing positive.
Predictions inform prevention
Dr Moore said estimating the true number of cases provided better data to inform resourcing in terms of hospital staff and beds and helped to develop effective prevention strategies.
She said that predicting RSV spikes had become even more difficult since the arrival of COVID-19.
RSV cases fell drastically at the onset of the pandemic due to lockdowns and isolation before a big resurgence of cases at the beginning of summer in late 2020.
"And we're still trying to get a handle on now when seasonality of RSV will fall back into that general pattern of having infections in winter."
Telethon Kids Institute has just started recruitment for an RSV study, the GRACE study, involving pregnant women.
Its goal is for women to have an RSV vaccine in pregnancy to provide protection for newborns, just like influenza and whooping cough.
