The time period between exposure to the novel coronavirus and symptoms is an average of 5.2 days; however, it varies greatly among patients.

A Chinese team that published a paper in the New England Journal of Medicine (NEJM) stated that their findings support a 14-day medical observation period for people exposed to the pathogen.

According to the WHO, the incubation period ranged from 2-10 days before symptoms like fever, cough, shortness of breath and acute respiratory distress appeared.

Since its emergence in Wuhan in December, the number of cases of the new coronavirus have doubled every 7.4 days.

Each infected person then infected an average of 2.2 other people [the basic reproductive number, or R0 (pronounced “R-naught”].

In the present case, it is relatively low - close to seasonal flu (around 1.3), much less than measles (12 or higher) and comparable to SARS-epidemic of 2002-2003 (3).

The findings from the Chinese team reiterate the research by a team in the Netherlands that found an incubation period of 5.8 days, with large variations.

A 27-year-old Vietnamese man was infected by his father who had traveled to Wuhan. He showed symptoms in about three days, reported a letter published in NEJM.

Additionally, in the Chinese study, half of the 425 cases were above the age of 60, and none were under 15 years of age.

Dr KK Aggarwal

President CMAAO, HCFI and Past National President IMA