# Asymptomatic infection rates **URL:** \ **Category:** The Quarantine Zone\ **Tags:** covid-quarantine\ **Created:** [April 5, 2020, 8:17pm UTC](https://boards.straightdope.com/t/asymptomatic-infection-rates/851145 "2020-04-05T20:17:16Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![Mama\_Zappa](https://avatars.discourse-cdn.com/v4/letter/m/71e660/32.png) [@Mama\_Zappa](https://boards.straightdope.com/u/Mama_Zappa)\ **Post date:** [April 7, 2020, 2:24pm UTC](https://boards.straightdope.com/t/asymptomatic-infection-rates/851145/21 "2020-04-07T14:24:30Z")
> [@running\_coach](#): > > [Seroprevalence](https://www.merriam-webster.com/dictionary/seroprevalence) > > Just so you know, **DSeid** is a doctor and not in the habit of making up words. Well, we’re NOT doctors, and he might be having some fun at our expense because we wouldn’t be able to tell 😃 (actually I already knew seroprevalance to be a real word…) I’m not in a hot spot, otherwise I’d love to volunteer for it. The friend (housemate) who brought back a bad cold from Philly and shared with me, in early January, is convinced that COVID is a real possibility because she truly felt wretched for several weeks, including a brief improvement before worsening. Me, not so much: my cold, while unpleasant, did not follow typical COVID symptoms. No fever, the cough was productive which I gather is not typical (maybe in an asthmatic it behaves differently?), and I didn’t feel all that ill for all that long - just my sleep was disrupted from the coughing. Not clear from the article: does the CDC plan to do followups on those whose blood lights up, to see if they are still showing antibodies a few months later? ---
**Author:** ![PoppaSan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/poppasan/32/189_2.png) [@PoppaSan](https://boards.straightdope.com/u/PoppaSan)\ **Post date:** [April 7, 2020, 2:40pm UTC](https://boards.straightdope.com/t/asymptomatic-infection-rates/851145/22 "2020-04-07T14:40:19Z")
How difficult would it be to do the antibody tests along with, um … say a blood drive? Donate blood, get a free rapid Covid test, and do the antibody test on those testing negative? ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [April 7, 2020, 9:36pm UTC](https://boards.straightdope.com/t/asymptomatic-infection-rates/851145/23 "2020-04-07T21:36:07Z")
> [@PoppaSan](#): > > How difficult would it be to do the antibody tests along with, um … say a blood drive? Donate blood, get a free rapid Covid test, and do the antibody test on those testing negative? It would be a reasonable [sample of convenience](https://www.statisticshowto.com/convenience-sampling/) but would risk not being representative of the general population. ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [April 9, 2020, 9:27am UTC](https://boards.straightdope.com/t/asymptomatic-infection-rates/851145/24 "2020-04-09T09:27:37Z")
Nevertheless that seems how some of the first studies will collect samples. [First in a hard hit town in Italy.](https://www.lastampa.it/topnews/primo-piano/2020/04/02/news/coronavirus-castiglione-d-adda-e-un-caso-di-studio-il-70-dei-donatori-di-sangue-e-positivo-1.38666481) > [@](#): > > When Avis volunteers summoned them for blood donation, they were confident that they would find a high number of Covid positives19. Confirmation has come from the results of tests and swabs: out of 60 citizens of Castiglione D’Adda, one of the municipalities in the former red area of ​​Lodi, 40 tested positive without knowing it. All asymptomatic, escaped from official statistics: they came into contact with the disease, they did not develop it … So among a fairly small self-selected sample of apparently healthy asymptomatic blood donors in a region of Italy that is near peak COVID-19 two thirds had had asymptomatic infections. Small and self-selected appropriately emphasized, some may have had the same thought process **Mama Zappa** shares, but still … [Also apparently part of the U.S. planned approach.](https://www.sciencemag.org/news/2020/04/unprecedented-nationwide-blood-studies-seek-track-us-coronavirus-spread) > [@](#): > > The first one, which will be funded by the National Institutes of Health, is already underway in six metropolitan regions in the U.S. It was started in Seattle when that outbreak happened, then New York City, then we quickly kicked in the San Francisco Bay area, and now we’ve added Los Angeles, Boston, and Minneapolis. Colleagues at regional blood centers are each saving 1000 samples from donors each month—often it’s just a few days each month—and they’re demographically defined so we know the age, the gender, and, most important, the zip code of the donor’s residence. Those 6000 samples, collected each month starting in March and for the next 5 months, will be assessed with an antibody testing algorithm, which we’re still finalizing, that will help us monitor how many people develop SARS-CoV-2 antibodies over time. That will show us when we’re going from, say, a half a percent to 2% of the donors having antibodies. > > That will evolve into a national survey. With support from the U.S. Centers for Disease Control and Prevention [CDC], we’ll conduct three national, fully representative serosurveys of the U.S. population using the blood donors. That will be 50,000 donations in September and December of 2020 and November of 2021. We’re going to be estimating overall antibody prevalence to SARS-CoV-2 within each state, but also map it down within the states to regions and metropolitan urban areas, and look at the differences. … We want to compare the results we’re getting from our blood donor serosurveys in several geographies with colleagues who are doing different types of populations surveys. We’re collaborating closely with colleagues at UCSF and the University of Washington, and they’re doing population serosurveys by neighborhood door knocking and capturing samples from the hematology lab. … We’re cautious because blood donors are not a representative sample. … This also from that article which is consistent with the hypothesis that kids get so little identifiable or significant COVID-19 (and may be minimally contagious with it) because of their relative frequency and recency of multiple infections with the variety of other human coronaviruses that cause common colds. > [@](#): > > Q: What happens when SARS-CoV-2 infects a person who has antibodies to the other four coronaviruses that infect humans and cause the common cold? > > A: We were on a call today with the CDC about this. If we look at people who just went through a SARS-CoV-2 infection and have a burst of antibodies against the virus, they’ve also boosted their pre-existing antibodies against the classic cold coronavirus. And the earliest antibody responses that CDC researchers have seen in careful longitudinal studies to SARS-CoV-2 are actually those cross-reactive memory responses to the classic cold coronaviruses. > > Q: How might these cross-reactive antibody responses matter? > > A: The immune memory to previous infections may help control infection with those cold viruses and even ameliorate symptoms of SARS-CoV-2 infection. … ---
**Author:** ![Section\_Maker\_Jupe](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/section_maker_jupe/32/1424_2.png) [@Section\_Maker\_Jupe](https://boards.straightdope.com/u/Section_Maker_Jupe)\ **Post date:** [April 9, 2020, 3:58pm UTC](https://boards.straightdope.com/t/asymptomatic-infection-rates/851145/25 "2020-04-09T15:58:05Z")
Anyones ideas on the thought that California’ s (current) low infection fate is due to the virus passing through as early as Nov. 2019, and giving some degree of herd immunity? Blood antibody testing started on 3200 people. > **[New California antibody study could point to possible herd immunity to COVID-19](https://www.ksbw.com/article/new-study-investigates-californias-possible-herd-immunity-to-covid-19/32073873)** > > The hypothesis that COVID-19 first started spreading in California in the fall of 2019 is one explanation for the state's lower than expected case numbers. ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [April 9, 2020, 4:28pm UTC](https://boards.straightdope.com/t/asymptomatic-infection-rates/851145/26 "2020-04-09T16:28:22Z")
I would be completely unsurprised to read of a large number of Californians with evidence of past infection, perhaps asymptomatic or even labeled clinically as influenza or pneumonia not otherwise specified. I have no idea how antibody levels now can prove if that happened in March or in December. ---
**Author:** ![RitterSport](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/rittersport/32/6326_2.png) [@RitterSport](https://boards.straightdope.com/u/RitterSport)\ **Post date:** [April 9, 2020, 4:40pm UTC](https://boards.straightdope.com/t/asymptomatic-infection-rates/851145/27 "2020-04-09T16:40:04Z")
A slight hijack, hopefully not too off-topic – do they do these seroprevalence surveys for the flu? Once this is flattening out, will we be able to get good, apples-to-apples comparisons between how contagious SARS-COV-2 is compared to various flus. My layman’s impression is that it’s much more contagious, but I’ve never seen this kind of coverage for flu outbreaks, so it may be confirmation bias. ---
**Author:** ![CarnalK](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/carnalk/32/486_2.png) [@CarnalK](https://boards.straightdope.com/u/CarnalK)\ **Post date:** [April 9, 2020, 4:56pm UTC](https://boards.straightdope.com/t/asymptomatic-infection-rates/851145/28 "2020-04-09T16:56:16Z")
They do them for sure but I don’t know how regularly. There was a bunch of follow up seroprevalence surveys for H1N1, for instance. I would hope they’re doing that extensively this year so we can muddle out what was flu and what was covid-19 ---
**Author:** ![HoneyBadgerDC](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/honeybadgerdc/32/1033_2.png) [@HoneyBadgerDC](https://boards.straightdope.com/u/HoneyBadgerDC)\ **Post date:** [April 9, 2020, 5:03pm UTC](https://boards.straightdope.com/t/asymptomatic-infection-rates/851145/29 "2020-04-09T17:03:01Z")
> [@DSeid](#): > > I would be completely unsurprised to read of a large number of Californians with evidence of past infection, perhaps asymptomatic or even labeled clinically as influenza or pneumonia not otherwise specified. I have no idea how antibody levels now can prove if that happened in March or in December. . I had something in Nov, Dec where I was so shortwinded I couldn’t even shop. 100 steps I was ready to keel over. Dry cough, nose clear but not aware of a fever or Muscle aches. ---
**Author:** ![peccavi](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/peccavi/32/388_2.png) [@peccavi](https://boards.straightdope.com/u/peccavi)\ **Post date:** [April 9, 2020, 5:42pm UTC](https://boards.straightdope.com/t/asymptomatic-infection-rates/851145/30 "2020-04-09T17:42:43Z")
The IEEE has a nice layperson (well, layengineer) write-up on the testing methods and tests being rolled out for COVID-19, with links to detailed information on the who, what, where. [https://connect.ieee.org/Y0a0F0MUB00BQ0033PG0lHo](https://connect.ieee.org/Y0a0F0MUB00BQ0033PG0lHo) I am hoping the 5/13 minute tests for the virus are going to drastically increase the rate of testing for infection (the manufacturer claims 50,000 tests a day production rate). ---
**Author:** ![snowthx](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/snowthx/32/10660_2.png) [@snowthx](https://boards.straightdope.com/u/snowthx)\ **Post date:** [April 9, 2020, 5:56pm UTC](https://boards.straightdope.com/t/asymptomatic-infection-rates/851145/31 "2020-04-09T17:56:43Z")
> [@nearwildheaven](#): > > As a person who believes I had a mild case several months ago, if I hear about any antibody studies, I will be more than happy to roll up my sleeve and give them some of my blood. Same here. (Posting mainly to keep track of this thread) ---
**Author:** ![Yllaria](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/yllaria/32/3452_2.png) [@Yllaria](https://boards.straightdope.com/u/Yllaria)\ **Post date:** [April 9, 2020, 6:50pm UTC](https://boards.straightdope.com/t/asymptomatic-infection-rates/851145/32 "2020-04-09T18:50:58Z")
> [@Qadgop\_the\_Mercotan](#): > > And the seroprevalence rate of serum porcelain titers is still essentially zero. 😃 Does that mean that it’s never palindromic fibromyalgia? ---
**Author:** ![Stranger\_On\_A\_Train](https://avatars.discourse-cdn.com/v4/letter/s/13edae/32.png) [@Stranger\_On\_A\_Train](https://boards.straightdope.com/u/Stranger_On_A_Train)\ **Post date:** [April 9, 2020, 7:13pm UTC](https://boards.straightdope.com/t/asymptomatic-infection-rates/851145/33 "2020-04-09T19:13:13Z")
> [@Section\_Maker\_Jupe](#): > > Anyones ideas on the thought that California’ s (current) low infection fate is due to the virus passing through as early as Nov. 2019, and giving some degree of herd immunity? > Blood antibody testing started on 3200 people. > > [New California antibody study could point to possible herd immunity to COVID-19](https://www.ksbw.com/article/new-study-investigates-californias-possible-herd-immunity-to-covid-19/32073873) ”Herd immunity” requires a significant portion of the population (30% to 50% at least, depending upon the degree of infectiousness) to be immunized, either by vaccine or prior exposure. If 30% or more of the nearly 40 million population of California were infected, even assuming an asymptomatic rate of 80% would still be 8,000,000 people. If there is even only a 5% incidence of severe illness and net case fatality rate of 0.3% (which is about the low end of credible estimates) that would still be a net number of 400,000 new patients and 24,000 additional or premature deaths. If we saw an increase of severe acute respiratory distress across a period of three months that would have flagged epidemic surveillance systems as emergency rooms and ICUs registered an enormous unattributed spike in morbidity and mortality. And it isn’t as if California is walled off from the rest of the country. Los Angeles is a major tourist destination with Disneyland and Universal Studios being dense concentrations of crowds as well as a major transit center to international flights. The San Francisco Bay Area is obviously a major tech business hub with regular travel from and to China and other nations in Asia as well as domestic travel. Even without serology (which would not be able to tell you the timing of infections) it just doesn’t pass the smell test that the SARS-CoV-2 virus could have been circulating in North America undetected for several months before a sudden spike in severe illness and death. In reality, given the apparent infectiousness of SARS-CoV-2, you’d probably need an immunity level exceeding 50% to get a really significant attenuation of spread, especially as it appears that the virus may be spreading by aerosol routes instead of just intimate contact or fomites (droplets on surface transferred hand-to-mouth). It should be noted that San Francisco instituted “shelter-in-place” protocols a week before California implemented its “Stay At Home” order which was the most vigorous isolation direction in the US to that date. California has also been significantly deficient in getting wide scale testing available even for highly symptomatic patients for reasons largely left for another forum. So, despite a certain…political imperative to attribute the lower rates of infection and death to “herd immunity”, it seems more likely to be a combination of a lack of good testing samples and the effectiveness of isolation measures. Which, of course, argues for maintaining a lockdown until the risks of overwhelming health systems is mitigated to reduce unnecessary death. It should be noted that we are currently on [the tail end of a flu season that slightly exceeded the pneumonia & influenza mortality threshold for an epidemic](https://www.cdc.gov/flu/weekly/#S2) so any flu-like illness that was experienced in the Northern Hemisphere flu season of 2019-2020 was likely actually be the flu or some other endemic flu-like “common cold”. Stranger ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [April 9, 2020, 7:53pm UTC](https://boards.straightdope.com/t/asymptomatic-infection-rates/851145/34 "2020-04-09T19:53:03Z")
> [@Stranger\_On\_A\_Train](#): > > … It should be noted that we are currently on [the tail end of a flu season that slightly exceeded the pneumonia & influenza mortality threshold for an epidemic](https://www.cdc.gov/flu/weekly/#S2) so any flu-like illness that was experienced in the Northern Hemisphere flu season of 2019-2020 was likely actually be the flu or some other endemic flu-like “common cold”. > > Stranger EXCEPT that the unusual third hump occurred while lab confirmation of influenza went DOWN. (Same cite.) This can be seen specific to California even more so. [https://www.cdph.ca.gov/Programs/CID/DCDC/CDPH%20Document%20Library/Immunization/Week2019-2012\_FINALReport.pdf](https://www.cdph.ca.gov/Programs/CID/DCDC/CDPH%20Document%20Library/Immunization/Week2019-2012_FINALReport.pdf). Lab proven influenza admissions dropped while pneumonia admissions jumped really beginning in February. Interestingly California had a worse pneumonia year than usual and more so than the rest of the country seemed to have. It really does fit with COVID19 being there for while lost in the influenza statistics noise. No estimates of infection fatality rate can “credible” without data on the rates of undocumented and unsuspected infections in the general population, inclusive of those asymptomatic and minimally symptomatic to the degree of barely noticing it. That is the data this thread is anxiously waiting for. ---
**Author:** ![Stranger\_On\_A\_Train](https://avatars.discourse-cdn.com/v4/letter/s/13edae/32.png) [@Stranger\_On\_A\_Train](https://boards.straightdope.com/u/Stranger_On_A_Train)\ **Post date:** [April 9, 2020, 8:37pm UTC](https://boards.straightdope.com/t/asymptomatic-infection-rates/851145/35 "2020-04-09T20:37:04Z")
> [@DSeid](#): > > EXCEPT that the unusual third hump occurred while lab confirmation of influenza went DOWN. (Same cite.) This can be seen specific to California even more so. [https://www.cdph.ca.gov/Programs/CID/DCDC/CDPH%20Document%20Library/Immunization/Week2019-2012\_FINALReport.pdf](https://www.cdph.ca.gov/Programs/CID/DCDC/CDPH%20Document%20Library/Immunization/Week2019-2012_FINALReport.pdf). Lab proven influenza admissions dropped while pneumonia admissions jumped really beginning in February. Interestingly California had a worse pneumonia year than usual and more so than the rest of the country seemed to have. It really does fit with COVID19 being there for while lost in the influenza statistics noise. But that third hump starts in early March, which I would agree corresponds with the likely contagion of SARS-CoV-2 preceding the COVID-19 outbreak. The first peak appears in November and the second one peaking in late January/early February, which is consistent with previous trends (probably some relationship with students going back to school and passing viruses around). California has had an unusually cold and wet winter which it is still “enjoying” (I’m actually personally enjoying it but we usually have sunny warm weather by mid-February) so a higher incidence of pneumonia might be somewhat explained just by the environmental conditions even with a pathogen-specific outbreak. But I’ll go back to the reality that if SARS-CoV-2 were really making the rounds back in early November, we’d be seeing a very significant quantity of unexplained ARDS patients (not just typical pneumonia presentations but aggressive respiratory failures in patients without previous explicable morbidity) and it just isn’t there. New York is often cited as a special case for transmission for how dense the population is and how much the population uses public transit, but while the Bay Area is not comparable in strict density or the quantity of people on public transit, it is still dense enough with open plan workspaces and people in public spaces where people are on top of one another that you’d expect to see more flareups prior to when the epidemic was formally recognized, which is why San Francisco issued the “Shelter In Place” order so early. We don’t see any of that, and in fact the Bay Area has been remarkably quiet in terms of hospitalizations. For the virus spreading/herd immunity argument to make sense, the virus would have to have suddenly turned virulent, or a second much less virulent strain would have had to circulate first to provide immunity which was an early thesis but while several minor strains have emerged there isn’t any evidence that any are significantly less virulent than others. > [@DSeid](#): > > No estimates of infection fatality rate can “credible” without data on the rates of undocumented and unsuspected infections in the general population, inclusive of those asymptomatic and minimally symptomatic to the degree of barely noticing it. That is the data this thread is anxiously waiting for. Agreed, and that is why I picked 0.3% as a low end for the CFR. It could in fact be lower if the rate of asymptomatic cases is higher. However, from the best samples we have (primarily South Korea, but also some testing done in Germany, Iceland, and comprehensive testing of a town in Italy) the rate seems to be somewhere slightly above 1%. My totally off-the-cuff guestimate is that it’ll come in lower once we have a statistically significant sample of antibody testing, and maybe low enough to justify the more optimistic estimates of total deaths that we’re seeing but I wouldn’t make any plans on reducing isolation measures until there is solid data in hand. Stranger ---
**Author:** ![CarnalK](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/carnalk/32/486_2.png) [@CarnalK](https://boards.straightdope.com/u/CarnalK)\ **Post date:** [April 9, 2020, 9:00pm UTC](https://boards.straightdope.com/t/asymptomatic-infection-rates/851145/36 "2020-04-09T21:00:09Z")
> [@Stranger On A Train](#): > > But I’ll go back to the reality that if SARS-CoV-2 were really making the rounds back in early November, we’d be seeing a very significant quantity of unexplained ARDS patients (not just typical pneumonia presentations but aggressive respiratory failures in patients without previous explicable morbidity) and it just isn’t there. So what are the unexplained November ARDS numbers in California and what number would’ve been significant? ---
**Author:** ![Section\_Maker\_Jupe](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/section_maker_jupe/32/1424_2.png) [@Section\_Maker\_Jupe](https://boards.straightdope.com/u/Section_Maker_Jupe)\ **Post date:** [April 9, 2020, 10:42pm UTC](https://boards.straightdope.com/t/asymptomatic-infection-rates/851145/37 "2020-04-09T22:42:00Z")
Thank you all for this discussion. Stranger On a Train I would note that Feb in California is one the wettest months of the year. Even for SoCal. Systems usually swing north by March/April, but the"normal" storm track has been screwed up now going back 15 years or so? This year Feb was one of the driest on record. As I type this its is 55f out and been raining all day (and week) in Santa Barbara. Interesting April…(before Gray may and June gloom) edit to add: Questions: Is seasonal flu temperature related? My laymans understanding was that since more people were in close contact due to being indoors, that the infection rates spike because of that. So basically the flue/colds/virus’s are here year round? Mutation rate? Is it continual? A simple answer or reference link would be great!! Thank you. ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [April 10, 2020, 1:08am UTC](https://boards.straightdope.com/t/asymptomatic-infection-rates/851145/38 "2020-04-10T01:08:57Z")
> [@Section\_Maker\_Jupe](#): > > Thank you all for this discussion. Stranger On a Train I would note that Feb in California is one the wettest months of the year. Even for SoCal. Systems usually swing north by March/April, but the"normal" storm track has been screwed up now going back 15 years or so? > This year Feb was one of the driest on record. > As I type this its is 55f out and been raining all day (and week) in Santa Barbara. Interesting April…(before Gray may and June gloom) > > edit to add: > Questions: Is seasonal flu temperature related? My laymans understanding was that since more people were in close contact due to being indoors, that the infection rates spike because of that. So basically the flue/colds/virus’s are here year round? > > Mutation rate? Is it continual? A simple answer or reference link would be great!! Thank you. Seasonal flu considered more humidity than temperature related is my understanding. [The best mutation tracker](https://nextstrain.org/ncov/global?animate=2019-12-08,2020-04-05,0,0,30000&l=radial) I’ve seen even if I don’t quite understand it! [Their narrative.](https://nextstrain.org/narratives/ncov/sit-rep/2020-04-03) ---
**Author:** ![Absolute](https://avatars.discourse-cdn.com/v4/letter/a/b2d939/32.png) [@Absolute](https://boards.straightdope.com/u/Absolute)\ **Post date:** [April 10, 2020, 4:12am UTC](https://boards.straightdope.com/t/asymptomatic-infection-rates/851145/39 "2020-04-10T04:12:57Z")
The Germany study in Heinsberg has released some early results (the study is not complete). Translation available here: [Handelsblatt](https://translate.google.com/translate?sl=auto&tl=en&u=https%3A%2F%2Fwww.handelsblatt.com%2Fpolitik%2Fdeutschland%2Fcoronavirus-das-sind-die-wichtigsten-erkenntnisse-der-studie-im-kreis-heinsberg%2F25730508.html%3Fticket%3DST-1861008-Wq7dpmysW9Xx6t2EHkjp-ap2) > [@](#): > > How dangerous is the new virus? And how is it? Streeck, director of the Institute of Virology at the University of Bonn, was able to answer at least some of these questions with Laschet carefully before the end of the entire study period. The most important interim result: According to Streeck, the study shows that measures to contain the epidemic can be relaxed. > … > The infection rate is around 15 percent. This is an important number and will cause the spread to slow down, says Streeck. These first, but already scientifically representative interim results are a rather conservative calculation. > … > Immunity has been demonstrated in 14 percent of the residents of Gangelt, a municipality in the Heinsberg district. So far, it was only assumed that an existing illness protects against the virus, now this assumption can be proven. > … > The mortality rate , which is derived from the study results in Gangelt, is around 0.4 percent. Data from Johns Hopkins University, which records case numbers worldwide , shows that mortality in this area is five times higher. The study also concludes that strict hygiene regulations drastically reduce the risk of mortality. 15% of the population already infected and a 0.4% mortality rate seem quite favorable for the hypothesis that coronavirus is only moderately more deadly and a lot more contagious than the flu, and that the primary risk is not the mortality rate itself but the potential to overwhelm the healthcare system with an entire season’s worth of illness in the space of a a few weeks. ---
**Author:** ![Aspidistra](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/aspidistra/32/3894_2.png) [@Aspidistra](https://boards.straightdope.com/u/Aspidistra)\ **Post date:** [April 10, 2020, 5:23am UTC](https://boards.straightdope.com/t/asymptomatic-infection-rates/851145/40 "2020-04-10T05:23:13Z")
I just went to the worldometer site and looked up the testing and infection numbers for the last two days (8th April to 10th April) In that time, about 400,000 coronavirus tests were done in Germany, and 10,000 new cases of coronavirus were diagnosed. So, right now, around 2.5% of people who get tested for coronavirus in Germany, turn out to have a positive test. This doesn’t seem to be compatible with the claim that 15% of the general population are infected. I don’t think the district that this study took place in can be representative of the whole country [Previous page](https://boards.straightdope.com/t/asymptomatic-infection-rates/851145.md?page=1) [Next page](https://boards.straightdope.com/t/asymptomatic-infection-rates/851145.md?page=3)