You may spread Novel Coronavirus even before you develop symptoms…

You may spread Novel Coronavirus even before you develop symptoms…

Last Reviewed : 12/17/2020
You may spread Novel Coronavirus even before you develop symptoms…


Incubation period is the time between exposure to an infection and when symptoms first appear. For COVID-19 infection, incubation period is around 5-6 days. It means that an individual typically develops symptoms 5-6 days after being exposed to the Coronavirus. Usually, affected individuals start spreading the virus after they develop symptoms. The most common symptoms include fever, cough, fatigue, sputum production and shortness of breath. Usually, fever and cough develop during the first week. If the illness persists beyond the first week, affected individuals start developing shortness of breath. Affected persons are most infective when they have fever and cough. However, some affected people start spreading the virus even before they develop any symptoms. Based on the article published in NEJM1, asymptomatic persons are potential sources of 2019-nCoV infection. Based on this article, a German businessman had attended meetings with a Chinese business partner who visited Germany. At the time of the meetings, none of the business partners had any symptoms. Three days after the meetings were over, German businessman developed sore throat, fever, chills and body aches. He was found to have confirmed COVID-19 infection. Five days later, the Chinese business partner also informed the company about COVID-19 infection. Three other colleagues were also found to have confirmed COVID-19 infection.

Followed by this case, there were several instances where people got infected by asymptomatic individuals. Although it does not happen with every infected person, it is obvious that infected people without symptoms can spread the disease to other individuals. This state is called as asymptomatic carrier state. It is not clear what percentage of the infected people spread the virus before they develop symptoms. Larger studies may be needed to figure out the exact number.

It is also highly possible that few asymptomatic individuals may remain in asymptomatic carrier state throughout the course of illness. Again, it is not clear what percentage of the patients remain as asymptomatic carriers. As Coronavirus became more rampant, it is obvious that asymptomatic carriers are playing a big role in spreading the disease. This is definitely concerning from public health perspective to contain the disease in the communities.



  • Rothe C, et al. Transmission of 2019-nCoV infection from an asymptomatic contact in Germany. N Engl J Med. 2020:2019–20.
  • J Microbiol Immunol Infect. 2020 Mar 4. pii: S1684-1182(20)30040-2. doi: 10.1016/j.jmii.2020.02.012. Asymptomatic carrier state, acute respiratory disease, and pneumonia due to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2): Facts and myths. Lai CC et al.
  • Int J Infect Dis. 2020 Mar 16. pii: S1201-9712(20)30146-6. doi: 10.1016/j.ijid.2020.03.027. Transmission of COVID-19 in the terminal stage of incubation period: a familial cluster. Li P et al.

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