If your child seems to catch a cold every few weeks, there's a reason: respiratory infections are among the most common reasons kids visit the doctor. A new large-scale study from West China Second University Hospital analysed data from over 32,000 children tested for 13 different respiratory viruses over three years. The results show which viruses are circulating, when they peak, and which ages are most vulnerable—patterns that can help you prepare.
Researchers tested children across all age groups and identified the viruses causing illness, tracking which ones appeared together and when they were most common.
Rhinovirus leads, but RSV is the worry for babies
Human rhinovirus (the common cold) affected nearly 23% of infected children, making it the most common culprit. Respiratory syncytial virus (RSV) came second at 15%. The important detail: most children caught just one virus at a time, but roughly 1 in 7 children caught two viruses simultaneously—a co-infection that made symptoms worse and slowed recovery.
Age matters significantly. Babies are especially vulnerable to RSV, which can become serious in infants under one year old. Toddlers and preschoolers commonly catch rhinoviruses and parainfluenza. By school age, children increasingly encounter Mycoplasma pneumoniae, which causes stubborn coughs that linger longer.
Each season brings predictable viruses
Rhinoviruses surge in spring and autumn. Summer brings parainfluenza, adenoviruses, and coronaviruses. Winter is peak season for RSV and influenza. This seasonal pattern means you can anticipate which bugs are most likely circulating at any given time.
For Singapore families, our tropical climate doesn't follow the same seasonal rhythm as mainland China, where this study was conducted, so the exact timing won't match. However, the core insight applies: viruses circulate in predictable waves. During monsoon transitions when immune systems are stressed and children are crowded together in schools and public transport, co-infections are a real concern. Viral circulation patterns in our densely packed environment make hand hygiene and keeping sick children home especially important.
A positive test doesn't always mean illness
One critical finding: rhinovirus can be detected in children's noses without actually causing illness. A child can be a carrier—spreading the virus without being sick themselves. This matters because a positive test result doesn't automatically mean your child needs treatment, reducing unnecessary worry and antibiotic overuse.
- During December–February, protect babies and young toddlers from RSV by avoiding crowds and keeping visitors with cold symptoms away.
- If your child tests positive for rhinovirus but has no symptoms, they may be a carrier—ask your doctor before starting treatment.
- During spring and autumn when rhinovirus peaks, expect more runny noses but prepare for milder illness than RSV or winter flu.