SHENZHEN, China (Reuters) -China’s surge in respiratory illness is caused by known pathogens and there is no sign of new infectious diseases, a health official said on Saturday as the country faces its first full winter since lifting strict COVID-19 restrictions.

The spike in illness in the country where COVID emerged in late 2019 attracted the spotlight when the World Health Organization sought information last week, citing a report on clusters of undiagnosed pneumonia in children.

Chinese authorities will open more paediatric outpatient clinics, seek to ensure more elderly people and children receive flu vaccines and encourage people to wear masks and wash their hands, Mi Feng, an official with China’s National Health Commission, told a press conference.

Doctors in China and experts abroad have not expressed alarm about China’s outbreaks, given that many other countries saw similar increases in respiratory diseases after easing pandemic measures, which China did at the end of last year.