How long after infection do symptoms appear? SARS-CoV-2 (COVID-19)

Are people infectious during this time?

India

healthysoch

New Delhi, April 03, 2020 :

What do we know?

The best current estimate of the COVID-19 incubation period is 5.1days, with 99% of individuals exhibiting symptoms within 14 days of exposure.¹ Fewer than 2.5% of infected individuals show symptoms sooner than 2 days after exposure.¹
The reported range of incubation periods is wide, with high-end estimates of 24,²11.3,³ and 18days.⁴
Individuals can test positive forCOVID-19 despite lacking clinicalsymptoms.^2,5-8
Individuals can be infectious while asymptomatic,^7-10and asymptomatic individuals can have similar amounts of virus in their nose and throat as symptomatic individuals.¹¹
Infectious period is unknown, but possibly up to 10-14 days.^12-14
On average, there are approximately 4¹⁵to 7.5⁴days between symptom onset in successive cases of a single transmission chain.
Most individuals are admitted to the hospital within 8-14 days of symptom onset.¹⁶
Patients are positive for COVID-19 via PCR for 8-37 days after symptom onset.¹⁶
Individuals may test positive via PCR for 5-13 days after symptom recovery and hospital discharge.¹⁷The ability of these individuals to infect others is unknown.
According to the WHO, there is no evidence of re-infection with SARS-CoV-2 after recovery.¹⁸
Experimentally infected macaques were not capable of being reinfected after their primary infection resolved.¹⁹

What do we need to know?

What is the average infectious period during which individuals can transmit the disease?
Are individuals infectious after hospital discharge and clinical recovery, or are positive PCR tests only detecting non-infectious virus?
Can individuals become re-infected after recovery? If so, how long after?

(Source: DHS Science and Technology, Master Question List for COVID-19 (caused by SARS-CoV-2), Weekly Report, 18 March 2020)SARS-CoV-2 (COVID-19)

Author :Dr K K Aggarwal, President CMAAO