7 ms·

Preliminary result of the Gangelt, Germany Covid-19 case cluster study [pdf]

64 points by chvid 7y ago

timkam 7y ago
Isn't this the report of the case study that was discussed with much controversy in German media, in particular because the researchers hired a high-profile marketing agency for promotion and held a press conference together with the prime minister of the federal state (NRW) before subjecting the findings to the scrutiny of the scientific community? Edit: link to newspaper article (German): https://www.sueddeutsche.de/gesundheit/heinsberg-studie-coronavirus-1.4876474 https://www.sueddeutsche.de/gesundheit/heinsberg-studie-coro... Note that Gangelt is a municipality in the Heinsberg district, so the article and the report refer to the same study by different names.
- sebslomski 7y ago
  Yes, lots of controversy about this study. All in all, it’s not too representative after all because of the outbreak in the festival. There’s currently a similar study going on in Munich, which represents a normal bigger city in Germany, which is expected to give more insights.
  - s9w 7y ago
    But the Munich study is still several weeks away. Which is frustrating. If the sky is falling like everyone is saying, intermediate results could be published daily. It's really not a difficult study to take such a test.
  - mannykannot 7y ago
    And the issue with the festival outbreak is that it skews the demographic distribution?
- luspr 7y ago
  However, the "controversy" has been overstated by the German media as well. Drosten, virologist who has been cited as one of the critics, called the Gangelt/Heinsberg study "very solid and robust" just yesterday: https://www.zdf.de/politik/maybrit-illner/christian-drosten-lobt-gangelt-studie-extrem-solide-und-robust-aus-sendung-vom-16-april-2020-100.html https://www.zdf.de/politik/maybrit-illner/christian-drosten-... Particulary, the death rate will be close to the estimate.
  - sokols 7y ago
    He also said that "..the data on the German town are definitely not representative for the country". https://twitter.com/c_drosten/status/1251034050883657729 https://twitter.com/c_drosten/status/1251034050883657729
    - s9w 7y ago
      The thing is that it's simply not exactly stated what kind of population they tested. Whether they were representative of that town or the German population. Of their sample was actually representative of the German population (which I heavily assume since they talked a lot about that) then the results will be quite robust.
      - pintxo 7y ago
        How would you create a representative sample for the whole population if all your samples are from a sub-population with a known cluster of cases?
        s9w 7y ago
        The cluster thing is obviously hard to remove. But the population.. that should be very doable. You'll just have to adjust the people you chose according to the general population. Not sure exactly how that goes down in practice. But in the press conference he stressed multiple times how this was representative and was done in cooperation with statisticians etc.
        pintxo 7y ago
        Problem here comes from the question "representative for what"? I can easily see this to be representative for the town in question. But I find it quite obvious that it cannot be representative for the whole country due to the initial difference in exposition.
        7y ago
- s9w 7y ago
  They weren't hired from what I heard. But rather personal friends.
  - jaynetics 7y ago
    Yeah... if you can make Deutsche Glasfaser and Gries Deco Company pay me 30k EUR each, I'm also more than happy to help you as a friend.
- odiroot 7y ago
  I think it's also political, Charité vs Uni Bonn and NRW vs Berlin. At the same time both Jens Spahn (central government) and Armin Laschet (local government) are front runners for the Chancellor's position.
  - JanSt 7y ago
    Spahn dropped out and supports Laschet as front runner
    - tobessebot 7y ago
      For now.
      - odiroot 7y ago
        Yeah, that's my feeling as well.
gwd 7y ago
Paper is short so worth reading, but some key points: * They had an outbreak in this village as a result of a festival event in mid-February * A random sample of 1000 from a population of 12,000 were sampled afterwards * The immunity within the population as a whole was at about 15%. * The fatality rate was 0.37% It's got this statement: > By adhering to strict hygiene measures it is to be expected that the virus concentration of an infected individual can be reduced to the point that the illness manifests more mildly, with simultaneous development of an immunity. But it seems like the that statement is just an assertion, not something specifically supported by the data they gathered in this study, because it goes on to say: > These favourable conditions are not present in a superspreading event (e.g. Karneval meeting, apres-ski bar in Ischgl, Austria).
- deleted 7y ago
  [deleted]
- tinus_hn 7y ago
  These statements are so odd they look like a translation error. Is there a German version of this paper?
  - luspr 7y ago
    Yes. Same url just drop the "_en": https://www.land.nrw/sites/default/files/asset/document/zwischenergebnis_covid19_case_study_gangelt.pdf https://www.land.nrw/sites/default/files/asset/document/zwis...
    - tinus_hn 7y ago
      The statements are similar so they are stating this community went through the worst case scenario and ended up with 0,37% fatality.
      - dr_zoidberg 7y ago
        If that mortaility rate is common, it would mean there are ~10x (or more) infected in the world... This sort-of coincides with the large asymptomatic reports. So what do we do from here on? Such numbers would surely raise the famous r0 infection rate, and it means this is far more contagious than reported/believed.
Tepix 7y ago
There is a large number of asymptotic cases which is quite encouraging. In their preliminary conclusion they write: "By adhering to strict hygiene measures it is to be expected that the virus concentration of an infected individual can be reduced to the point that the illness manifests more mildly, with simultaneous development of an immunity." I wonder how they came to that conclusion. It would be great if it turns out to be correct.
- point78 7y ago
  So wash your hands and gargle and your symptoms are mild?
  - rooam-dev 7y ago
    Interesting indeed, perhaps by reducing the quantity of virus we give more time to our body to prepare for the "invasion"?
    - Tepix 7y ago
      That's a theory I've heard before. I don't remember where, unfortunately. Does anyone have a source? The basic theory is that if you catch the virus, you want to have it in your nose first so your body has time to start a response before it reaches your lungs. If you get a large dose into your lungs at the start (perhaps because you work at a hospital with insufficient PPE) it's less likely to be mild.
      - usrusr 7y ago
        > The basic theory is that if you catch the virus, you want to have it in your nose first so your body has time to start a response before it reaches your lungs. That's a thought that has crossed my mind before: if it's better the farther up in the respiratory system the initial infection happens, then all that hand washing might be a bad idea, at least for the personal outcome. It depends a lot on wether you expect the full wave to eventually roll through until herd immunity or if you expect it to be stopped early, either by continued distancing until it's starved our by a vaccine.
ImaCake 7y ago
This monograph points to an IgG antibody assay with >99% specificity which means the false positive rate is tiny. Can anybody tell me if there is a commercial antibody test for Covid19 that advertises anything close to this? My thought is that they have done this with an ELISA. Using a commercially available (or custom made) antibody instead of using one of those terribly inaccurate chromatography strips.
danieltillett 7y ago
There are so many unknowns from this report that it is hard to make much from it. Some of the major questions. 1. How many people in this town ended up in hospital? How many are still in the ICU and likely to die? 2. Is the population sero tested representative of the town population? Was this population sampled biased by those who had obvious symptoms being more likely to participate? 3. Are the 15% positive representative of the German population or is it skewed to the young? 4. How was the accuracy of the serology test determined? >99% is impressively accurate if true.
- netjiro 7y ago
  > "(anti SARS-CoV2 IgG positive, specificity of the method >.99%)" This is a misprint. They meant to say 0.99 or 99%, not .99% That means it's very reliable that any positive signal originates from covid19 antibodies, instead of from something else. That does not mean that it's 99% accurate with regards to sensitivity.
  - cowmoo728 7y ago
    Preliminary data from China suggests that a non negligible percentage (maybe 5%) of recovered patients never produce the neutralizing antibody. https://www.medrxiv.org/content/10.1101/2020.03.30.20047365v1 https://www.medrxiv.org/content/10.1101/2020.03.30.20047365v... This would mean the antibody test alone cannot tell the full extent of community spread. There's a brief summary of antibody knowledge here. https://www.the-scientist.com/news-opinion/what-do-antibody-tests-for-sars-cov-2-tell-us-about-immunity--67425 https://www.the-scientist.com/news-opinion/what-do-antibody-...
- netjiro 7y ago
  15% positive is not representative of the total German population. This is a sample from a small town with a known cluster outbreak from a festival in mid Feb, where a significant amount of people are believed to have gotten infected.
postingawayonhn 7y ago
Not everyone is convinced that this study is accurate. "It is important to understand the sensitivity and specificity of the serological test used in the German studies to be sure the test is not picking up antibody to other corona viruses (4 different common cold causing coronaviruses have been isolated in humans during the past years and 3 more serious ones (SARSCoV1 and 2, and MERSCoV)." [1] It would be good to see more of these studies conducted in different areas by different teams to see if they come to similar conclusions. [1] https://www.sciencemediacentre.org/expert-reaction-to-unpublished-preliminary-findings-looking-at-the-presence-of-antibodies-to-sars-cov-2-virus-in-residents-of-gangelt-in-germany/ https://www.sciencemediacentre.org/expert-reaction-to-unpubl...

64 points by chvid 7y ago

Isn't this the report of the case study that was discussed with much controversy in German media, in particular because the researchers hired a high-profile marketing agency for promotion and held a press conference together with the prime minister of the federal state (NRW) before subjecting the findings to the scrutiny of the scientific community? Edit: link to newspaper article (German): https://www.sueddeutsche.de/gesundheit/heinsberg-studie-coronavirus-1.4876474 https://www.sueddeutsche.de/gesundheit/heinsberg-studie-coro... Note that Gangelt is a municipality in the Heinsberg district, so the article and the report refer to the same study by different names.

sebslomski 7y ago
Yes, lots of controversy about this study. All in all, it’s not too representative after all because of the outbreak in the festival. There’s currently a similar study going on in Munich, which represents a normal bigger city in Germany, which is expected to give more insights.
- s9w 7y ago
  But the Munich study is still several weeks away. Which is frustrating. If the sky is falling like everyone is saying, intermediate results could be published daily. It's really not a difficult study to take such a test.
- mannykannot 7y ago
  And the issue with the festival outbreak is that it skews the demographic distribution?
luspr 7y ago
However, the "controversy" has been overstated by the German media as well. Drosten, virologist who has been cited as one of the critics, called the Gangelt/Heinsberg study "very solid and robust" just yesterday: https://www.zdf.de/politik/maybrit-illner/christian-drosten-lobt-gangelt-studie-extrem-solide-und-robust-aus-sendung-vom-16-april-2020-100.html https://www.zdf.de/politik/maybrit-illner/christian-drosten-... Particulary, the death rate will be close to the estimate.
- sokols 7y ago
  He also said that "..the data on the German town are definitely not representative for the country". https://twitter.com/c_drosten/status/1251034050883657729 https://twitter.com/c_drosten/status/1251034050883657729
  - s9w 7y ago
    The thing is that it's simply not exactly stated what kind of population they tested. Whether they were representative of that town or the German population. Of their sample was actually representative of the German population (which I heavily assume since they talked a lot about that) then the results will be quite robust.
    - pintxo 7y ago
      How would you create a representative sample for the whole population if all your samples are from a sub-population with a known cluster of cases?
      - s9w 7y ago
        The cluster thing is obviously hard to remove. But the population.. that should be very doable. You'll just have to adjust the people you chose according to the general population. Not sure exactly how that goes down in practice. But in the press conference he stressed multiple times how this was representative and was done in cooperation with statisticians etc.
        pintxo 7y ago
        Problem here comes from the question "representative for what"? I can easily see this to be representative for the town in question. But I find it quite obvious that it cannot be representative for the whole country due to the initial difference in exposition.
        7y ago
s9w 7y ago
They weren't hired from what I heard. But rather personal friends.
- jaynetics 7y ago
  Yeah... if you can make Deutsche Glasfaser and Gries Deco Company pay me 30k EUR each, I'm also more than happy to help you as a friend.
odiroot 7y ago
I think it's also political, Charité vs Uni Bonn and NRW vs Berlin. At the same time both Jens Spahn (central government) and Armin Laschet (local government) are front runners for the Chancellor's position.
- JanSt 7y ago
  Spahn dropped out and supports Laschet as front runner
  - tobessebot 7y ago
    For now.
    - odiroot 7y ago
      Yeah, that's my feeling as well.

gwd 7y ago

Paper is short so worth reading, but some key points: * They had an outbreak in this village as a result of a festival event in mid-February * A random sample of 1000 from a population of 12,000 were sampled afterwards * The immunity within the population as a whole was at about 15%. * The fatality rate was 0.37% It's got this statement: > By adhering to strict hygiene measures it is to be expected that the virus concentration of an infected individual can be reduced to the point that the illness manifests more mildly, with simultaneous development of an immunity. But it seems like the that statement is just an assertion, not something specifically supported by the data they gathered in this study, because it goes on to say: > These favourable conditions are not present in a superspreading event (e.g. Karneval meeting, apres-ski bar in Ischgl, Austria).

deleted 7y ago
[deleted]
tinus_hn 7y ago
These statements are so odd they look like a translation error. Is there a German version of this paper?
- luspr 7y ago
  Yes. Same url just drop the "_en": https://www.land.nrw/sites/default/files/asset/document/zwischenergebnis_covid19_case_study_gangelt.pdf https://www.land.nrw/sites/default/files/asset/document/zwis...
  - tinus_hn 7y ago
    The statements are similar so they are stating this community went through the worst case scenario and ended up with 0,37% fatality.
    - dr_zoidberg 7y ago
      If that mortaility rate is common, it would mean there are ~10x (or more) infected in the world... This sort-of coincides with the large asymptomatic reports. So what do we do from here on? Such numbers would surely raise the famous r0 infection rate, and it means this is far more contagious than reported/believed.

Tepix 7y ago

There is a large number of asymptotic cases which is quite encouraging. In their preliminary conclusion they write: "By adhering to strict hygiene measures it is to be expected that the virus concentration of an infected individual can be reduced to the point that the illness manifests more mildly, with simultaneous development of an immunity." I wonder how they came to that conclusion. It would be great if it turns out to be correct.

point78 7y ago
So wash your hands and gargle and your symptoms are mild?
- rooam-dev 7y ago
  Interesting indeed, perhaps by reducing the quantity of virus we give more time to our body to prepare for the "invasion"?
  - Tepix 7y ago
    That's a theory I've heard before. I don't remember where, unfortunately. Does anyone have a source? The basic theory is that if you catch the virus, you want to have it in your nose first so your body has time to start a response before it reaches your lungs. If you get a large dose into your lungs at the start (perhaps because you work at a hospital with insufficient PPE) it's less likely to be mild.
    - usrusr 7y ago
      > The basic theory is that if you catch the virus, you want to have it in your nose first so your body has time to start a response before it reaches your lungs. That's a thought that has crossed my mind before: if it's better the farther up in the respiratory system the initial infection happens, then all that hand washing might be a bad idea, at least for the personal outcome. It depends a lot on wether you expect the full wave to eventually roll through until herd immunity or if you expect it to be stopped early, either by continued distancing until it's starved our by a vaccine.

ImaCake 7y ago

This monograph points to an IgG antibody assay with >99% specificity which means the false positive rate is tiny. Can anybody tell me if there is a commercial antibody test for Covid19 that advertises anything close to this? My thought is that they have done this with an ELISA. Using a commercially available (or custom made) antibody instead of using one of those terribly inaccurate chromatography strips.

danieltillett 7y ago

There are so many unknowns from this report that it is hard to make much from it. Some of the major questions. 1. How many people in this town ended up in hospital? How many are still in the ICU and likely to die? 2. Is the population sero tested representative of the town population? Was this population sampled biased by those who had obvious symptoms being more likely to participate? 3. Are the 15% positive representative of the German population or is it skewed to the young? 4. How was the accuracy of the serology test determined? >99% is impressively accurate if true.

netjiro 7y ago
> "(anti SARS-CoV2 IgG positive, specificity of the method >.99%)" This is a misprint. They meant to say 0.99 or 99%, not .99% That means it's very reliable that any positive signal originates from covid19 antibodies, instead of from something else. That does not mean that it's 99% accurate with regards to sensitivity.
- cowmoo728 7y ago
  Preliminary data from China suggests that a non negligible percentage (maybe 5%) of recovered patients never produce the neutralizing antibody. https://www.medrxiv.org/content/10.1101/2020.03.30.20047365v1 https://www.medrxiv.org/content/10.1101/2020.03.30.20047365v... This would mean the antibody test alone cannot tell the full extent of community spread. There's a brief summary of antibody knowledge here. https://www.the-scientist.com/news-opinion/what-do-antibody-tests-for-sars-cov-2-tell-us-about-immunity--67425 https://www.the-scientist.com/news-opinion/what-do-antibody-...
netjiro 7y ago
15% positive is not representative of the total German population. This is a sample from a small town with a known cluster outbreak from a festival in mid Feb, where a significant amount of people are believed to have gotten infected.

postingawayonhn 7y ago

Not everyone is convinced that this study is accurate. "It is important to understand the sensitivity and specificity of the serological test used in the German studies to be sure the test is not picking up antibody to other corona viruses (4 different common cold causing coronaviruses have been isolated in humans during the past years and 3 more serious ones (SARSCoV1 and 2, and MERSCoV)." [1] It would be good to see more of these studies conducted in different areas by different teams to see if they come to similar conclusions. [1] https://www.sciencemediacentre.org/expert-reaction-to-unpublished-preliminary-findings-looking-at-the-presence-of-antibodies-to-sars-cov-2-virus-in-residents-of-gangelt-in-germany/ https://www.sciencemediacentre.org/expert-reaction-to-unpubl...