Respiratory syncytial virus cases are rising in Australia — how is testing done?
By Daniel KeaneThe words "respiratory syncytial virus" don't exactly roll off the tongue, but the initials "RSV" have been on a lot of lips of late.
Reported cases of the virus, which causes respiratory infections, have been on the rise, with numbers in some states close to 10 times what they were at the same time last year.
"I can't tell you when the peak will happen, but the cases are still going up," Louise Flood, the director of Disease Prevention and Control at SA Health, said this week.
"Respiratory syncytial virus is spread through coughing and sneezing, and there's quite a bit around at the moment, so we do encourage people to do what they can to minimise the risk."
With almost 70,000 cases recorded in Australia so far this year, there has been a rise in interest not only in the virus, but in how to get tested for it.
How is testing done?
RSV is diagnosed in several different ways by GPs and emergency department doctors.
University of South Australia epidemiologist Adrian Esterman said doctors had become proficient at "working out the difference between COVID-19, RSV and flu" from symptoms alone.
"Especially GPs, because they see so many young kids, are very, very good at diagnosing it just by signs and symptoms — they look for fever, lethargy, a wheeze," he said.
But diagnosis can be confirmed by PCR or blood testing.
"The virus can be identified by a PCR test (nose or throat swab)," a NSW Health fact sheet states.
"Some pathology providers test for multiple viruses and may send you test results for RSV, influenza and COVID-19 at the same time."
Professor Esterman said a GP who suspected a patient had RSV would typically take a sample and send it off to a laboratory.
"There are two ways of testing [for] it — one is by taking either a nasal swab or a nasal wash and sending it off for a PCR test, just like COVID, and that is very accurate," Professor Esterman said.
"The other way, which I don't think is used anywhere near as much, is to take a blood sample and look for tiny little bits of the virus in it."
How are case numbers recorded?
According to the nation's Immunisation Coalition, there were 69,997 reported RSV cases in the year to July 3.
But that number only reflects notifications of "laboratory-confirmed" RSV — and the total number could be much higher.
"It's very, very common … [and] just about every child's been exposed to it," Professor Esterman said.
The virus has only been notifiable in Australia since 2021, and that fact at least partly accounts for the current surge in cases — as more tests are carried out, more virus is detected.
"If you are unwell with RSV, or you think your child has RSV, we do encourage you — if your child is getting more unwell — to go and get seen by a doctor because they might need some treatment," Dr Flood said.
Adelaide GP Daniel Byrne agreed that, depending on the strength of the symptoms, testing could be an important step.
"I see mostly elderly patients and … RSV can knock them for six because if they've got asthma, emphysema, heart failure, diabetes [then] this little virus on top can turn into a real complication for them and they end up in hospital," he said.
But he cautioned that testing should not be done for the sake of it.
"If you're otherwise fit and healthy and just got a cold virus, and you've ruled out COVID, then I don't think we need to bother doing another PCR swab to find out the name of the virus," he said.
"I'm not going to do a swab on every single kid with just a runny nose — they have to be sick. You've got to earn your swab."
Dr Flood said the public health advice around RSV was in line with the advice for other illnesses.
"We just do encourage everyone to do what they can to minimise the spread to others," she said.
"Stay home if you're unwell, cough into your arm or use a tissue, then wash your hands — so the same general respiratory hygiene we recommend for other illnesses such as flu."
Are there RSV RAT kits?
In May, the Therapeutic Goods Administration (TGA) approved a RAT for self-testing that can detect RSV, influenza A, B and COVID-19, although it is not yet as widely available as COVID-only tests.
There are also several approved RAT kits that test for flu and COVID-19 that have become more readily available in recent months.