#COVIDMS The need for testing and isolating


We are failing, not just because health case systems are being over run, but the tragedy is that we have stopped testing and so do not know who has got the virus and who has not.

This study based on modelling suggests that about 86% of the people infected are not being detected because their symptoms are very mild and so they go unnoticed. At present we are essentially capturing the people who end up in hospital . This says the actual death rate is lower that the figures suggest, which are skewed to hospital admissions.

But it also says that there are many people who do not know they are infected, and therefore are not isolating, and are therefore infecting people.

This mechanism for this situation is being changed slowly. I know that we are sending our equipment to testing centres to increase capacity. But in the interim the best way to stop getting the disease and the best way to not spread, it is to isolate. Those at particular risk will of course remain at risk when the risk is encountered, unless a vaccine is developed which is unlikely to happen quickly or we discover drugs that affect the virus. There seems to be some progress but that is matched with failure too. Therefore to protect yourself, think as every one as being a potential viral spreader unless you know they are not and ensure social distancing.

Substantial undocumented infection facilitates the rapid dissemination of novel coronavirus (SARS-CoV2).Li R, Pei S, Chen B, Song Y, Zhang T, Yang W, Shaman J.Science. 2020 Mar 16. pii: eabb3221 Estimation of the prevalence and contagiousness of undocumented novel coronavirus (SARS-CoV2) infections is critical for understanding the overall prevalence and pandemic potential of this disease. Here we use observations of reported infection within China, in conjunction with mobility data, a networked dynamic metapopulation model and Bayesian inference, to infer critical epidemiological characteristics associated with SARS-CoV2, including the fraction of undocumented infections and their contagiousness. We estimate 86% of all infections were undocumented (95% CI: [82%-90%]) prior to 23 January 2020 travel restrictions. Per person, the transmission rate of undocumented infections was 55% of documented infections ([46%-62%]), yet, due to their greater numbers, undocumented infections were the infection source for 79% of documented cases. These findings explain the rapid geographic spread of SARS-CoV2 and indicate containment of this virus will be particularly challenging.

This suggest to contain COVID we need a radical change in policy

COVID-19 epidemic in Switzerland: on the importance of testing, contact tracing and isolation.Salathé M, Althaus CL, Neher R, Stringhini S, Hodcroft E, Fellay J, Zwahlen M, Senti G, Battegay M, Wilder-Smith A, Eckerle I, Egger M, Low N. Swiss Med Wkly. 2020 Mar 19;150:w20225. Switzerland is among the countries with the highest number of coronavirus disease-2019 (COVID-19) cases per capita in the world. There are likely many people with undetected SARS-CoV-2 infection because testing efforts are currently not detecting all infected people, including some with clinical disease compatible with COVID-19. Testing on its own will not stop the spread of SARS-CoV-2. Testing is part of a strategy. The World Health Organization recommends a combination of measures: rapid diagnosis and immediate isolation of cases, rigorous tracking and precautionary self-isolation of close contacts.

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  • TONY F
    March 20, 2020 at 3:15 pm Edit

    Just to be clear – you are asking people to live in a jungle for a year? How realistic is that?


    My thoughts go against yours on this matter actually: damage control. We are more likely to be infected that not, so we are better off preparing our defenses than crossing fingers and hopping for the best.

    March 20, 2020 at 3:56 pm Edit
    Dear Tony I am asking people to think. We are certainly not prepared and doing what we can to slow things down, whilst we prepare, is the key issue. We are seeing triaging in Italy. Who get option of treatmeent who does not. If people have been infected and are clear they should be doing what they can, but do you know if you are immune or not? No. If we believe what we are told this will apear in a couple of weeks. We all have a social responsibility.

    We have been taking about social distancingbut are people doing it…Not really and if some a-hole hadn’t coughed in my MrsMD’s face from six inches, I wouldnt be stuck in isolation but there you go. Is it a cold is it a killer? I will remove any thoughts

    I have also added the correct reference. My apologises

    March 20, 2020 at 4:27 pm Edit
    It needs to stress that the first signs are actually GI problems before the respiratory complications following infection. This might give us more time to treat.


    Reference please

    March 20, 2020 at 3:56 pm Edit

  • Hey,

    I know this will be pure speculation, but how likely do you think this disease has been around in Europe early January or even at the end of 2019?

    We heard about the first case in China at the start of December 2019, but if so many of us might be asymptomatic is it not likely that a substantial portion of people got infected in Europe much earlier? And here, especially in the UK, we won’t screen for new types of viruses. We’ll just do a standard x-ray and ask for people to stay at home so we would never have classified critically ill patients as having suffered a “new strain of virus.

    • It is called COVID-19 because it, the disease, appeared in 2019. The causative virus has a different name. I think it appeared in about November and with global travel it must has been circulating for some time, before the SH1 hit the fan. If the alert had been given and heeded and planes had been grounded for a few weeks, I suspect this could have been better contained by with the Chinese New Year and school holidays in 2020 we have done our best to spread as best we can. In our desire to keep business working we have done more harm. I have just watched a programme about the 1918 pandemic which was made a couple of years ago, how little we were prepared. No doubt Hollywood are writing the script….Will Dustbin Hoffman come back to save the World again, if only it were so simple.

  • The PCR machines were taken from my unis life sciences dept this week too, and we are much further north, so appears to be a national policy.
    They should have taken the staff with them as most researchers are just feeling helpless with no labs to work in.

    • Yep, but this is my opinion should have happened weeks ago. I know where ours have gone. North of London so they may meet yours. People who use then have been asked to volunteer to run them 24/7. So if you are proficient in the Thermofisher cycler please volunteer, I’m too deskilled and probably too old. I feel abit like a lump trapped at home but at least we can read and feed the info to the front line. We had planned on developing a test to check who had been infected and had got the reagents made but because we have not got off the ground quick, too busy doing MS stuff, this has been vetoed with the lock down we had last week.

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