Australian experts play down fears of a new epidemic out of China

Experts have played down fears of a new epidemic potentially arising in China after a surge in childhood respiratory illnesses.

Chinese officials said they did not detect any "unusual or novel diseases" in the country, the World Health Organisation said last week, following an official request by the UN health agency for information about a potentially worrying spike in respiratory illnesses and clusters of pneumonia in children.

WHO cited unspecified media reports and a global infectious disease monitoring service as reporting clusters of undiagnosed pneumonia in children in northern China and formally requested more details from China last week.

READ MORE: 'Totally preventable occurrences' blamed for baby's death in hospital

Outside scientists said the situation warranted close monitoring, but were not convinced that the recent spike in respiratory illnesses in China signalled the start of a new global outbreak.

Vaccine consultant Professor Booy from the University of Sydney said there had been a surge in "well-recognised" infections such as the flu, respiratory syncytial virus (RSV) and mycoplasma pneumoniae.

"As this does not appear to be occurring in adults, that suggests that adults have prior immunity, which points to an existing pathogen as the likely cause, rather than anything new," he said.

READ MORE: Aussie scaffolder needs stitches after 'cowardly' attack in Bali

Sydney Infectious Diseases Institute director Professor Ben Marais said the increase in "common" respiratory infections was likely due to the beginning of the northern hemisphere winter.

"This is not unexpected and probably reflects the 'immune deficit' effect of strict COVID lock down policies that prevented exposure to common viruses (and the acquisition of protective immunity) in young children," he said.

Professor Raina MacIntyre, the head of the biosecurity program at the University of NSW's Kirby Institute, said COVID-19 could have contributed to the outbreak of other diseases.

READ MORE: Child spotted on windscreen of moving car

"Beijing has very good surveillance, so would be in a better position to identify a novel pathogen than perhaps Wuhan," she said.

"The widespread transmission of SARS-CoV-2 in China and globally may also be contributing to high rates of other infections, as there is now a large body of research showing SARS-CoV-2 can cause immune dysregulation that may persist after the acute infection."

- Reported with Associated Press