Day 0: Infected
Day 0 -5:
Asymptomatic phase
Day 5 to 7 :
Onset of symptoms
D0 -D7: Window Period
(ONLY PCR IS POSITIVE
IN THIS PHASE) – To Prevent Community Spread, Check PCR for all close contacts of Index case, irrespective of symptoms
and Quarantine them,
if positive.
So,
First week Asymptomatic.
Second week – Crucial phase: Clinically Important Symptomatic Stage, when Few Patients may become Critically ill.
Day 14- D21: Third week
Decline Phase (STILL INFECTIVE)
D 21- D28: Fourth week
Convalescent Phase
(STILL INFECTIVE)
DURING First week:
Only PCR positive
AFTER First week :
After onset ofsymptoms
IgM becomes positive.
(Remains Positive From Day 7- D 21, that is during 2nd and 3rd weeks)
# we can confirm Covid by
Ig M Antibody testing
in All Symptomatic patients.
If Ig M Negative,
Then we can order PCR.
AFTER 2nd Week (Day 14):
IgG becomes positive
(appears by the End of
Second week)
Appearance of Ig G suggests
that the patient is in
DECLINE PHASE
(Day 14 -21)
(But, STILL INFECTIVE)
DURING 3rd week(Day 14 -21)
Both Ig M & Ig G are positive.
AFTER 3rd Week (Day 21):
IgM disappears..
Even after Ig M disappears,
patient can be INFECTIVE
Days 1-28:
Throughout Disease course
For 4 weeks..
patient is INFECTIVE :
SARS CoV2 RNA &
Antigens will be positive..
As Long as These tests are
positive, patient should be
in Isolation..
AFTER 4 weeks(Day 28):
SARS CoV2 RNA & Antigens disappear and Patients
Become NONINFECTIVE 😊
For Diagnosis of
Active Infection/ INFECTIVITY :
Check SARS CoV2 RNA &
Antigens at anytime..
(all 4 weeks of disease course)
Test for Ig M antibody
in all Symptomatic patients.
If +ve, Confirms Disease.
If -ve, Doesn’t Exclude Disease.
Ig G positivity, suggests –
Decline phase /Past infection.
Isolate them, until they are
PCR Negative