How Covid-19 gets transmitted: Mechanism explained; hotspots can be identified by Corona testing only

— By Dr KK Aggarwal

One can do COVID test every 48 hours once positive

No. It’s a waste of resources. Kanika Kapoor, Bollywood’s first coronavirus victim, has tested positive for Covid-19 for the fifth consecutive time in 10 days. She is presently admitted to Lucknow’s Sanjay Gandhi Post Graduate Institute of Medical Sciences.

Social distancing can not be intermittent

A new study conducted by Harvard School of Public Health researchers found that staggered intervals of social distancing could save more lives than the one-time social distancing guidelines issued by the United States government in response to the coronavirus pandemic. Federal authorities recently extended the advisory, which was issued March 16, until April 30.

The team proposed “intermittent” social distancing, in which authorities enforce distancing when cases rise above a set threshold and then lift measures when cases fall below a set threshold.

Digital mass surveillance does not help

Most of us have a smart watch of some kind. We’ve already shown that the heart rate from that data can be exquisitely helpful for picking up a flu outbreak before it actually happens.

Three is a big report on just using body temperature with a smart thermometer. So, with digital tracking at scale, hopefully we will pick up the outbreak before it happens, because if we get it at the earliest possible time, we can do very precise isolation and prevent that exponential growth in that community.

Face book, WhatsApp can not pick up any hotspot

Commands like “ I have fever”, “I have cough” “ I hope its not covid” “ I have lost my small” “I have lost my taste” etc if seen as a cluster postings can trace the hot spot.

Only testing can pick up hotspots

No, clusters can be identified by
1. Smart thermometers
2. Social site postings pattern
3. Spurt in low lymphocytes count noted by labs in an area
4. Spurt in bilateral pneumonias noted by Radiologists in an area
5. Spurt in ground glass appearances on chest CT noted by Radiologists in an area
6. Spurt of cases with fever and cough noted by GPs
7. Spurt of cases with loss of taste or small in an area
8. Spurts of cases of interstitial pneumonia noted by Radiologists on ultrasound in an area

Statins will help

There is no data that one should start stating but people on should not stop it. There are data on statins in non-COVID, in pneumonia and respiratory distress. And there was a lot of interest in that for a while, that it could decrease inflammation just like it decreases inflammation for cardiovascular disease. Then they did randomized studies and it was a bust.

They don’t seem to harm. So, we don’t have that out there, about the use of statins. But its protective or beneficial effect has to be considered suspect at this point.

You waste one PPE in home collecting one sample, there is no alternative

No, home kits are coming in US. You have to put this swab pretty far up your nose and then in the back of your throat, to the point where you gag. Otherwise you might get a false negative. You can take your own swab and send.

Drive-through stations are not the solutions

No, that’s a better potential solution, because then you save 2 days. You’re basically driving through, so you don’t have to wait for the kit to come to your house and then for it to go back to the central lab.
These are relatively inexpensive strategies that we were talking about.

We know every thing about shedding ands viability

What we don’t know about is shedding and viability. The virus has to be replication competent. Just because it’s sitting somewhere, if you touch it, the virus doesn’t have the ability to invade cells in your body, to hijack the cells, which is basically its pathogenicity.

These are the things that we don’t know, like why do some people shed virus so profoundly whereas others don’t?
A story was published in The Lancet, there was a couple hospitalized with severe infections. They had 372 contacts. Not a single one of them ever converted positive. May be that they didn’t shed. They were infected, but they’re non-shedders. And then there are these other asymptomatic people who are shedding.

PART 2

Special SERIES ONLY EVIDENCES
SARS-CoV-2 (COVID-19)

We present to you a series of daily questions related to various aspects of Covid-19, which summarizes what is known and what additional information is needed.

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

Transmissibility

How does it spread from one host to another? How easily is it spread?

What do we know?

• Pandemic COVID-19 has caused 214,894 infections and 8,732deaths72in at least 173 countries and territories (as of 3/18/2020).1,2,3
• There are 7,769 SARS-CoV-2 cases across 50 US states, with 118 deaths. (as of 3/18/2020)72; there is sustained community transmission of COVID-19 in theUS.4
• High-quality estimates of human transmissibility (R0) range from 2.2 to 3.1. 5-9 Early estimates of the attack rate in China range from 3%-10%, mainly inhouseholds.10
• SARS-CoV-2 is believed to spread through close contact and droplet transmission, 11 with fomite transmission12, i.e., germs left on surfaces, andclose-contact aerosol transmission alsoplausible. 13
• SARS-CoV-2 replicates in the upper respiratory tract (e.g., throat), and infectious virus is detectable in throat and lung tissue for at least 8 days. 14
• Pre-symptomatic15 or asymptomatic16 patients can transmit SARS-CoV-2; between 12%17 and 23%18 of infections may be caused by asymptomatic or pre-symptomatic transmission.
• SARS-CoV-2 is present in infected patient saliva, 19 lower respiratory sputum, 20 and feces. 21
• Social distancing and behavioral changes are estimated to have reduced COVID-19 spread by 44% in Hong Kong, 22 and a combination of non-pharmaceutical interventions (e.g., school closures, isolation) are likely required to limit transmission. 23
• Up to 86% of early COVID-19 cases in China were undiagnosed, and these infections were the source for 79% of documented cases. 24

What do we need to know?

• Capability of SARS-CoV-2 to be transmitted by contact with fomites (doorknobs, surfaces, clothing, etc.)
• Superspreading capacity needs to be refined
• Updated person to person transmission rates (e.g., R0) as control measures take effect
• What is the underreporting rate?25
• Can individuals become re-infected with SARS-CoV-2?
• What is the difference in transmissibility among countries?
• Is the R0 estimate higher in healthcare or long-term care facilities?

((The writer is President, CMAAO, HCFI and Past national President IMA))