1/n. How has transmission varied after the (world's largest) lockdown in India? When should we exit the lockdown and how do we do it safely?
Read on as we explore these questions and more in our latest #COVIDー19 study from #AIIMS & #IISER #MedTwitter
📌doi.org/10.1101/2020.0…
Read on as we explore these questions and more in our latest #COVIDー19 study from #AIIMS & #IISER #MedTwitter
📌doi.org/10.1101/2020.0…
2/n.
📌significant transmission drop after #lockdownindia, but Rt as of 22 Apr still above 1
📌smaller and later #secondwave if (regional) lockdowns relaxed farther after peak has passed
📌expanded #testing an effective exit strategy, will influence degree of return to normalcy
📌significant transmission drop after #lockdownindia, but Rt as of 22 Apr still above 1
📌smaller and later #secondwave if (regional) lockdowns relaxed farther after peak has passed
📌expanded #testing an effective exit strategy, will influence degree of return to normalcy
some observations from the study-
📌Contagion seeding
here is a fig showing how COVID-19 was seeded in India by imported cases (✈️~550 cases; stage1) in March. Imported cases started dropping a day after flight ban, however local transmission had begun and kept growing (stage2)
📌Contagion seeding
here is a fig showing how COVID-19 was seeded in India by imported cases (✈️~550 cases; stage1) in March. Imported cases started dropping a day after flight ban, however local transmission had begun and kept growing (stage2)
4/n.
📌#Transmission trend in #India
-spike in late Mar (tablighi cluster) - compare w mobility drop on 23 March
-continuous down trend from Apr (effect of #lockdown+)
-last estimated Rt=1.15 on 22 Apr (above threshold of 1)
When will we reach Rt<=1❓(some states alrdy have)
📌#Transmission trend in #India
-spike in late Mar (tablighi cluster) - compare w mobility drop on 23 March
-continuous down trend from Apr (effect of #lockdown+)
-last estimated Rt=1.15 on 22 Apr (above threshold of 1)
When will we reach Rt<=1❓(some states alrdy have)
5/n.
📌#Testing (efficacy)
Fig: full, partial, no lockdown=olive, purple, blue resp; cases dec with inc testing->more so as LD is relaxed.
Reason? each case infects more ppl in open society, so each detection prevents more.
‼️ Testing has higher benefit when lockdown relaxed
📌#Testing (efficacy)
Fig: full, partial, no lockdown=olive, purple, blue resp; cases dec with inc testing->more so as LD is relaxed.
Reason? each case infects more ppl in open society, so each detection prevents more.
‼️ Testing has higher benefit when lockdown relaxed
6/n.
📌#Testing (feasibility)
-Cost of increasing testing capacity < cost (💵 🫂 🧠) of lockdown
-As you test more, you can relax more restrictions (fig)
-🔼 Test+Trace --> 🔼 degree of return to normal
eg: SKorea,Taiwan..
‼️ Better to invest in testing at a MASSIVE scale ASAP📈
📌#Testing (feasibility)
-Cost of increasing testing capacity < cost (💵 🫂 🧠) of lockdown
-As you test more, you can relax more restrictions (fig)
-🔼 Test+Trace --> 🔼 degree of return to normal
eg: SKorea,Taiwan..
‼️ Better to invest in testing at a MASSIVE scale ASAP📈
7/n.
📌How to relax lockdowns?
-Lockdown must now be seen in a regional (and not national) sense.
-Monitoring the reproduction number (Rt) is a simple yet effective tool to guide when to relax and tighten restrictions.
jamanetwork.com/journals/jama/…
nytimes.com/2020/04/06/opi…
📌How to relax lockdowns?
-Lockdown must now be seen in a regional (and not national) sense.
-Monitoring the reproduction number (Rt) is a simple yet effective tool to guide when to relax and tighten restrictions.
jamanetwork.com/journals/jama/…
nytimes.com/2020/04/06/opi…
8/n.
-Restrictions will need to be dynamic wrt intensity (how strict), area (where its needed) and time (when its needed).
-To guide such a flexible policy, RAPID SURVEILLANCE is needed.
-Inc #testing coverage comes in again! - ensures any resurgence is detected asap.
-Restrictions will need to be dynamic wrt intensity (how strict), area (where its needed) and time (when its needed).
-To guide such a flexible policy, RAPID SURVEILLANCE is needed.
-Inc #testing coverage comes in again! - ensures any resurgence is detected asap.
9/n. doi.org/10.1101/2020.0…
Some COVID-19 stats 🇮🇳
📌R0 for India : 2.083
Data from AIIMS:
📌Asymptomatics : 60.7% (n=140)
📌Reporting lag : mean of 3.4 days (n=53)
Some COVID-19 stats 🇮🇳
📌R0 for India : 2.083
Data from AIIMS:
📌Asymptomatics : 60.7% (n=140)
📌Reporting lag : mean of 3.4 days (n=53)
