One can do COVID-19 test every 48 hours once positive

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

Social distancing cannot be intermittent

A new study by the Harvard School of Public Health researchers has suggested that staggered intervals of social distancing could save more lives than the one-time social distancing guidelines as currently issued by the United States government. Federal authorities have extended the advisory, which was issued March 16, until April 30.

The team proposed practicing intermittent social distancing, wherein distancing is enforced when cases rise above a set threshold and then measures can be alleviated when cases drop below a set threshold.

Digital mass surveillance does not help

Most of us have a smart watch of some kind. It has already been shown that the heart rate from that data can help pick up a flu outbreak before it actually happens.

There is a report on just using body temperature with a smart thermometer. With digital tracking at scale, it could be possible to pick up the outbreak before it happens, because if we get it at the earliest possible time, precise isolation can be done and we can prevent exponential growth in the community.

Face book, WhatsApp cannot 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 smell in an area
8. Spurt of cases of interstitial pneumonia noted by Radiologists on ultrasound in an area

Statins will help

There is no data that one should start statins but people taking these drugs should not stop them. Data are available on statins in non-COVID patients, in pneumonia and respiratory distress. There has been a lot of interest in for a while in that it could decrease inflammation just like it decreases inflammation for cardiovascular disease. But as randomized studies were done,  it was a bust.

They dont seem to harm. But their protective or beneficial effect has to be considered suspect at this point.

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

No, home kits are coming in US. A person has to put the swab far up in the nose and then in the back of the throat, to the point where you gag. Otherwise the result might be a false negative. One can take his own swab and send.

Drive-through stations are not the solutions

No, thats a better potential solution, because it saves 2 days. A person just drives through, and does not have to wait for the kit to come to his house and then for it to go back to the lab.

These are relatively inexpensive strategies.

We know everything about shedding and viability

We dont really know about shedding and viability. The virus has to be replication competent. Just because the virus is somewhere, if you touch it, the virus doesnt have the ability to invade cells in your body, which is its pathogenicity. We don’t know these things yet. We don’t know why do some people shed virus so profoundly whereas others dont?

A story was published in The Lancet.   A couple was hospitalized with severe infections. They had 372 contacts. None of them converted positive. It is possible that they didnt shed. They were infected, but theyre non-shedders. And on the other hand, there are 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.

Transmissibility

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

 What is known?

 COVID-19 has caused 214,894 infections and 8,732 deaths in at least 173 countries and territories (as of 3/18/2020).^1-3

• 7,769 SARS-CoV-2 cases have been identified across 50 US states, with 118 deaths (as of 3/18/2020); sustained community transmission has been identified 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%, particularly in households.¹⁰
• SARS-CoV-2 seems to spread through close contact and droplet transmission,¹¹ with fomite transmission¹², i.e., germs left on surfaces, and close-contact aerosol transmission is also possible. ¹³
• The virus 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-symptomatic¹⁵or asymptomatic¹⁶ patients can transmit SARS-CoV-2; some 12%¹⁷ to 23%¹⁸ of infections may be caused by asymptomatic or pre-symptomatic transmission.
• SARS-CoV-2 is present in the saliva of the infected patient,¹⁹ lower respiratory sputum, ²⁰ and feces.²¹
• Social distancing and behavioral changes seem to have diminished COVID-19 spread by 44% in Hong Kong,²² and a combination of non-pharmaceutical interventions such as school closures, isolation, etc., are needed to limit transmission.²³
• Up to 86% of early COVID-19 cases in China were undiagnosed, and these infections accounted 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
• Updated person to person transmission rates (e.g., R0) as control measures take effect
• Underreporting rate²⁵
• Possibility of re-infection with SARS-CoV-2
• Difference in transmissibility among countries
• Is the R0 estimate higher in healthcare or long-term care facilities?

References

1. CDC, Confirmed 2019-nCoV Cases Globally. https://www.cdc.gov/coronavirus/2019-ncov/locations-confirmed-cases.html.
2. Security, J. C. f. H., 2019-nCoV resources and updates on the emerging novel coronavirus. 2020.
3. WHO, Novel Coronavirus (2019-nCoV) Situation Report-5 25 January 2020. https://www.who.int/docs/defaultsource/coronaviruse/situation-reports/20200125-sitrep-5-2019-ncov.pdf?sfvrsn=429b143d_4.
4. Bedford T. Cryptic transmission of novel coronavirus revealed by genomic epidemiology. https://bedford.io/blog/ncov-cryptictransmission/.
5. Majumder M, Mandl K. Early transmissibility assessment of a novel coronavirus in Wuhan, China. SSRN 2020.
6. Park SW, Champredon D, Earn DJD, Li M, Weitz JS, et al. Reconciling early-outbreak preliminary estimates of the basic reproductive number and its uncertainty: a new framework and applications to the novel coronavirus (2019-nCoV) outbreak. 2020, 1-13.
7. Riou J, Althaus CL. Pattern of early human-to-human transmission of Wuhan 2019 novel coronavirus (2019-nCoV), December 2019 to January 2020. Eurosurveillance 2020, 25 (4), 2000058.
8. Wu JT, Leung K, Leung GM. Nowcasting and forecasting the potential domestic and international spread of the 2019-nCoV outbreak originating in Wuhan, China: a modelling study. The Lancet.
9. Zhao, Musa, Lin, Ran, Yang, Wang, et al. Estimating the unreported number of Novel Coronavirus (2019-nCoV) cases in China in the first half of January 2020: A data-driven modelling analysis of the early outbreak. Journal of Clinical Medicine 2020, 9 (2), 388.
10. WHO, Report of the WHO-China Joint Mission on Coronavirus Disease 2019 (COVID-19); World Health Organization: 2020.
11. CDC, Situation summary. https://www.cdc.gov/coronavirus/2019-nCoV/summary.html.
12. Jing C, Wenjie S, Jianping H, Michelle G, Jing W, Guiqing H. Indirect virus transmission in cluster of COVID-19 Cases, Wenzhou, China, 2020. Emerging Infectious Disease journal 2020, 26 (6).
13. Brosseau, L. M., COMMENTARY: COVID-19 transmission messages should hinge on science. http://www.cidrap.umn.edu/newsperspective/2020/03/commentary-covid-19-transmission-messages-should-hinge-science.
14. Woelfel R, Corman VM, Guggemos W, Seilmaier M, Zange S, Mueller MA, et al. Virological assessment of hospitalized cases of coronavirus disease 2019. 2020.
15. Zhen-Dong T, An T, Ke-Feng L, Peng L, Hong-Ling W, Jing-Ping Y, et al. Potential presymptomatic transmission of SARS-CoV-2, Zhejiang Province, China, 2020. Emerging Infectious Disease journal 2020, 26 (5).
16. Bai Y, Yao L, Wei T, Tian F, Jin DY, Chen L, Wang M. Presumed asymptomatic carrier transmission of COVID-19. JAMA.
17. Du Z, Xu X, Wu Y, Wang L, Cowling BJ, Meyers LA. The serial interval of COVID-19 from publicly reported confirmed cases. medRxiv 2020, 2020.02.19.20025452.
18. Liu Y, Funk S, Flasche S. The contribution of pre-symptomatic transmission to the COVID-19 outbreak; London School of Hygiene and Tropical Medicine: 2020.
19. To KKW, Tsang OTY, Yip CCY, Chan KH, Wu TC, Chan JMC, et al. Consistent detection of 2019 Novel Coronavirus in saliva. Clinical Infectious Diseases 2020.
20. Wang W, Xu Y, Gao R, Lu R, Han K, Wu G, et al. Detection of SARS-CoV-2 in different types of clinical specimens. JAMA 2020.
21. Ling Y, Xu SB, Lin YX, Tian D, Zhu ZQ, Dai FH, et al. Persistence and clearance of viral RNA in 2019 novel coronavirus disease rehabilitation patients. Chin Med J (Engl) 2020.
22. Cowling BJ, Ali ST, Ng TWY, Tsang TK, Li JCM, Fong MW, et al. Impact assessment of non-pharmaceutical interventions against COVID-19 and influenza in Hong Kong: an observational study. medRxiv 2020, 2020.03.12.20034660
23. Ferguson N, Laydon D, Nedjati-Gilani G, Imai N, Ainslie K, Baguelin M, et al. Impact of non-pharmaceutical interventions (NPIs) to reduce COVID-19 mortality and healthcare demand; 2020.
24. Li R, Pei S, Chen B, Song Y, Zhang T, Yang W, et al. Substantial undocumented infection facilitates the rapid dissemination of novel coronavirus (SARS-CoV2). Science 2020, eabb3221.
25. Imai N, Dorigatti I, Cori A, Riley S, Ferguson N. Estimating the potential total number of novel Coronavirus cases in Wuhan City, China. https://www.imperial.ac.uk/media/imperial-college/medicine/sph/ide/gida-fellowships/2019-nCoV-outbreak-report-17-01-2020.pdf.

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

 (To be continued)

Dr KK Aggarwal

President CMAAO, HCFI and Past National President IMA