Medical personnel collect throat swabs from local residents in Tianjin Binhai New Area. Photo: AFP

China has reported four cases of dual infections of flu and COVID-19, and more such cases will occur as the country enters winter flu peak season, China's top respiratory expert Zhong Nanshan warned on Friday. 

Four people were found with both H1H3 flu and COVID-19, Zhong said at a health and technology innovation conference in Shenzhen, South China's Guangdong Province, on Friday. 

He said we will need rapid detection facilities to differentiate COVID-19 from flu. For ordinary residents, wearing facial masks is still a proper way to prevent both the flu and the coronavirus.

Although more cases of simultaneous infections of flu and COVID-19 will occur this winter, Zhong said current data shows that among China's 40 infectious diseases, the incidence of flu will drop significantly this year.  

Countries like the US have also reported dual flu-COVID-19 infections this winter. 

Johns Hopkins University said flu and COVID-19 share similar symptoms, and both illnesses can cause fever, cough, body aches, and pneumonia. 

Peng Zhiyong, director of the intensive care unit at Wuhan University's Zhongnan Hospital, told the Global Times on Friday nucleic acid tests are the best way to differentiate COVID-19 from flu. 

He warned that sporadic cluster infections cannot be ruled out this winter in China, but they will not be as bad as in the first half of the year as China has established fever clinics across the country and Chinese citizens are aware of the importance of masks. 

But this may not be the case in the US where the further spread of COVID-19 cannot be fully controlled as the US response to coronavirus has been too little, too late, he said. 

The 2019 flu season has sickened at least 19 million across the US, and led to 10,000 deaths and 180,000 hospitalizations. 

Although the US reported its first COVID-19 case in January, research shows that the US' winter flu could have been COVID-19, and the early spread of COVID-19 may have been far greater than experts had initially thought. 

Robert Redfield, director of the US Centers for Disease Control and Prevention (CDC), said in March that some COVID-19 deaths may have been diagnosed as flu-related in the US.

Some people believe US President-elect Joe Biden will be the US' hope in controlling the virus, and even Biden said they will beat the virus in a Thanksgiving speech on Wednesday. But Chinese analysts said that because Biden will not take office until January 20, his measures don't offer immediate help. He may also find it difficult to persuade many Americans to wear masks, as they have been brainwashed by President Donald Trump, who claimed that getting COVID-19 was just like getting a cold, and wearing masks was only political correctness.

Chinese experts warned that the epidemic in the US is likely to worsen considering the winter flu peak and upcoming Christmas holidays, when Americans usually gather to celebrate or hold reunions with their families.