As per literature, the time from when one is exposed to a COVID19 infected individual till the time they experience symptom onset is called the Incubation period. This period is believed to be between 3 to 14 days. As per records, COVID19 symptoms typically appear within 4 or 5 days after the exposure.
Harvard Health believes that a person with COVID-19 may be contagious (and can be a spreader) 48 to 72 hours (2-4 days) before they start to experience symptoms.
Source: Harvard Health
According to the data compiled by CDC, researchers believe that persons with mild to moderate COVID-19 may shed replication competent virus for upto 10 days following symptom onset. Therefore, if you are symptomatic for COVID-19, you can be a potential spreader for upto 10 days following symptom onset.
On the other hand, individuals with severe COVID-19, including immunocompromised persons, elderly and ones with an underlying condition, may shed replication competent virus for upto 20 days.
Source: Centers for Disease Control and Prevention (CDC)
What is the life cycle of a virus? When is one expected to show symptoms?
Viruses are considered to be one of the smartest disease-causing organism. They do not use their own machinery instead utilizes the host machinery to multiply in number. They enter the host system, uncoat (undress) itself to make itself available for the replication and gene expression, undergoes replication and exits the host. Obviously, a wide orchestra of proteins, receptors and biological cofactors governs each of these steps in the virus life cycle.
Let us map these steps to the disease progression.
When an individual is infected with COVID-19, the infection occurs during which the virus replicates and spreads throughout the body. It is important to note- that at this point when the virus is still undergoing replication chances of symptoms to show is almost NIL. This clearly suggests that once the incubation period ends – Symptoms appear- and the person is tested.
If this individual test positive for COVID-19, he will be considered Symptomatic.
When an individual is exposed to another individual who tested positive for COVID-19 but fails to show any symptoms even after a maximum of 5 days- should that person still get tested?
Answer- YES, because maybe this individual who was exposed to the COVID19 patient is asymptomatic for COVID-19. The process of virus infection and cycle remains same- just that even when the incubation period ends – Symptoms may not appear- and the person may still test positive.
If this individual test positive for COVID-19, he will be considered Asymptomatic.
