No scientific proof of coronavirus 24-day incubation: health minister

Taipei, Feb. 12 (CNA) Health Minister Chen Shih-chung (陳時中) on Monday disputed one of the findings of a China-based study that found the incubation period of the 2019 novel coronavirus (2019-nCoV) could be as long as 24 days, saying it lacked scientific evidence.

The findings, published Feb. 10 by prominent Chinese epidemiologist Zhong Nanshan (鍾南山), were based on analysis of the medical records of 1,099 confirmed 2019-nCoV patients in China.

The study, which has not yet been peer-reviewed, found that the incubation period of the 2019-nCoV ranged from 0-24 days, Zhong and his research team said.

The incubation period was defined in the study as the duration from a patient's first contact with a transmission source to the onset of symptoms.

Chen, however, said the study relied solely on medical records, which may reflect different perceptions by patients and doctors regarding symptoms.

There simply was not sufficient scientific evidence to conclude that the incubation period of the 2019-nCoV could be up to 24 days, he said.

According to Taiwan's Central Epidemic Command Center (CECC), the consensus internationally is that the incubation period ranges from 2-10 days, and in 99 percent of cases, it is less than 14 days.

On the question of whether Taiwan's first asymptomatic patient was an indication that the incubation period could be longer than originally thought, CECC Deputy Commander Chuang Jen-hsiang (莊人祥) said a lack of symptoms is unrelated to the virus incubation period.

The asymptomatic patient, who was confirmed to be infected with 2019-nCoV on Feb. 9, is still not showing any symptoms, Chuang said.

On Monday, epidemiologist Zhong told the Chinese media that there was only one case in which the virus incubation period had stretched to 24 days, and people "shouldn't read too much into it."

"Using the timeline reported by one patient to determine how long the incubation period could last is not scientific," Zhong said.

The overall situation is more accurately reflected by the median incubation period of three days, the first quartile (two days), and third quartile (seven days), as found in the study, he said.