The latest update on the novel coronavirus aka COVID-19 situation is that there are over 44,000 confirmed cases all over the world.
At the time of writing, there have been over 1110 deaths due to the virus.
The situation is serious, yet much about the deadly virus remains unknown.
However, the latest new research by a team of Chinese scientists has suggested that the new coronavirus might have a long incubation period of up to 24 days.
Despite this possibility, the World Health Organisation (WHO) is not thinking of changing its recommended 14-day quarantine period at this point in time.
In the same vein, Singapore’s Health Ministry says that more evidence is required and that it’s hard to confirm from the paper if the outlier figure is due to an error or bias in the study’s methodology.
The Study
The Chinese Study was led by infectious diseases expert Zhong Nanshan.
It defined the incubation period as the duration of the transmission source to the onset of symptoms.
The study revealed that the median incubation period was three days based on the data of 1,099 patients from 552 hospitals in China.
The range of values was given as between zero and 24 days, however, it didn’t state how many patients experienced incubation periods at the top end of the range.
Dr Michael Ryan executive director of the WHO’s Health Emergencies Programme clarified that outliers need to be looked at very carefully.
“We’ve seen this in Ebola. We’ve seen very long incubation periods and then when we investigate, we find that there was a second exposure a week later, or two weeks later, and that’s when the actual infection occurred,” he said.
“There very often can be outliers, and they can be because of the recording of the exposure. We need to be really careful when we look at outlier figures.”
The Chinese study has been uploaded online but has yet to be peer-reviewed. This means that it should not be relied on to guide clinical practice or health-related behaviour.
To that end, the majority of the coronaviruses such as the severe acute respiratory syndrome (Sars) and the Middle East respiratory syndrome (Mers) coronaviruses, have an incubation period of two to 14 days.
