BEIJING — More evidence is needed to confirm whether other routes of novel coronavirus transmission exist other than the respiratory droplets and contact transmission, Chinese medical experts said on Feb 5.

The respiratory droplets and contact transmission are the major routes of the coronavirus infection, and transmission via digestive tract and aerosol are yet to be confirmed, according to a newly issued diagnosis and treatment plan by the National Health Commission (NHC).

The majority of the cases are infected via respiratory droplets, Guo Yanhong, an official with the NHC, told a press conference. The positive test for the novel coronavirus nucleic acid in the feces of patients indicates the possibility of transmission via the digestive tract.

The description of transmission routes in the plan was summarized based on a continuously deepened understanding of the clinical illness, she added.

Aerosol transmission is known in the spread of respiratory infectious diseases, however, it is not clear for the moment and there is a lack of evidence for the possibility of aerosol transmission of the coronavirus, said Li Xingwang, an infectious disease expert with the Beijing Ditan Hospital and a member of China's national expert team against the coronavirus, at the press conference.

"We need to do more research," Li said.

Overall confirmed cases of novel coronavirus infection on the Chinese mainland had reached 24,324 by the end of Feb 4, and a total of 490 people have died of the disease.