Pneumonia: Everything we know about respiratory virus in China - and what has the WHO said?

Chinese officials say they have not detected any “unusual or novel diseases”, the World Health Organisation (WHO) said, after an official request by the UN health agency for information about a spike in respiratory illnesses and clusters of pneumonia in children.

Since October, there has been a sharp rise in the number of respiratory illnesses in China, after an outbreak in the north of the country. Since then, reports have emerged of hospitals "overwhelmed with children" suffering from pneumonia.

Now, as the WHO urges China to reinforce wearing masks and social distancing, here's everything we know about the illness so far.

How serious is it?

When we think of illnesses coming out of China - particularly respiratory ones - it's natural for many people's minds to immediately drift towards Covid-19. Indeed, it was a global infectious disease monitoring service as reporting clusters of undiagnosed pneumonia in children in northern China.

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

The emergence of new flu strains or other viruses capable of triggering pandemics typically starts with undiagnosed clusters of respiratory illness. Sars and Covid-19 were first reported as unusual types of pneumonia.

Who is being affected?

The average number of patients in the internal medicine department at Beijing Children’s Hospital topped 7,000 per day, exceeding the hospital’s capacity, state-owned China National Radio said in an online article earlier this week.

Although the disease can affect anyone, statistics show that it is largely children who are being infected, and who subsequently end up hospitalised. Francois Balloux of University College London said China was probably experiencing a significant wave of childhood infections because this was the first winter since lockdown restrictions were lifted, which is likely to have reduced children’s immunity to common bugs.

What happens next?

The WHO has made an official request for more information from Chinese authorities. This means the government will have to send the organisation details of infection rates, location and so on.

It is rare for the UN health agency to publicly ask for more detailed information from countries, as such requests are typically made internally. WHO said it requested further data from China through an international legal mechanism. According to internal accounts in China, the outbreaks have swamped some hospitals in northern China, including in Beijing, and health authorities have asked the public to take children with less severe symptoms to clinics and other facilities.