# 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:** 18\ **Page:** 7
**Author:** ![Francis\_Vaughan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/francis_vaughan/32/3093_2.png) [@Francis\_Vaughan](https://boards.straightdope.com/u/Francis_Vaughan)\ **Post date:** [April 21, 2020, 4:46am UTC](https://boards.straightdope.com/t/asymptomatic-infection-rates/851145/121 "2020-04-21T04:46:32Z")
One would want to know why the 6% were not tested. But assuming they were just random people that somehow were not able to be tested, one would indeed assume that 12.5% of them would also test positive. The thing is - we don’t have to be perfect here. The point is to get R down really low. Test and quarantine can do this. We don’t expect R to be zero, we expect that it will be driven very low because we don’t give hot spots time to grow. That will contain, or even snuff out the contagion, even if we miss some. ---
**Author:** ![Francis\_Vaughan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/francis_vaughan/32/3093_2.png) [@Francis\_Vaughan](https://boards.straightdope.com/u/Francis_Vaughan)\ **Post date:** [April 21, 2020, 12:27pm UTC](https://boards.straightdope.com/t/asymptomatic-infection-rates/851145/122 "2020-04-21T12:27:47Z")
On the subject of the unexpectedly high numbers for previous Covid-19 infections, Medscape has this to say: [https://www.medscape.com/viewarticle/928954](https://www.medscape.com/viewarticle/928954) (Not sure of you need to register to read it, registration is free anyway.) TL;DR Lots of questions about the false positive rate of the serology test, even a small glitch will produce significant overestimates. Serology test used was a Chinese one that claimed specificity between 98.3 and 99.9%. 98.3 would account for pretty much all of the 50 people detected. Also questions about using Facebook to recruit subjects skewing the survey. On a survey that tried to estimate Covid-19 infections on the basis that during three weeks of March, anything 'flu like that wasn’t tested as 'flu was Covid-19, they have already revised their estimated number down from 28 million to 8.7 million after discovering the CDC pooled some numbers, invalidating the first calculation. False positives estimating a small population is always going to be a problem. With testing using whatever test kit that can be found, with no proper validation yet done, we might expect to see some wild numbers for a while yet. ---
**Author:** ![cmosdes](https://avatars.discourse-cdn.com/v4/letter/c/a587f6/32.png) [@cmosdes](https://boards.straightdope.com/u/cmosdes)\ **Post date:** [April 21, 2020, 1:56pm UTC](https://boards.straightdope.com/t/asymptomatic-infection-rates/851145/123 "2020-04-21T13:56:08Z")
> [@Francis\_Vaughan](#): > > One would want to know why the 6% were not tested. But assuming they were just random people that somehow were not able to be tested, one would indeed assume that 12.5% of them would also test positive. > > The thing is - we don’t have to be perfect here. The point is to get R down really low. Test and quarantine can do this. We don’t expect R to be zero, we expect that it will be driven very low because we don’t give hot spots time to grow. That will contain, or even snuff out the contagion, even if we miss some. Good points. Rather than derail the OP further than I have continuing this discussion, I think it important to note that the information in the video about the difference in asymptomatic infection rates between the two groups probably the most relevant part of the video to this discussion. So we’ll just leave it at that in this discussion. But you do make great points. Thanks. ---
**Author:** ![jshore](https://avatars.discourse-cdn.com/v4/letter/j/b5e925/32.png) [@jshore](https://boards.straightdope.com/u/jshore)\ **Post date:** [April 22, 2020, 1:37pm UTC](https://boards.straightdope.com/t/asymptomatic-infection-rates/851145/124 "2020-04-22T13:37:33Z")
> [@Francis\_Vaughan](#): > > False positives estimating a small population is always going to be a problem. With testing using whatever test kit that can be found, with no proper validation yet done, we might expect to see some wild numbers for a while yet. Yeah…I got sucked down the rabbit hole in looking at that Santa Clara County study the other night and I think we can say with pretty strong certainty that they screwed up the low side of their confidence intervals by not properly considering the uncertainty in the actual false positive rate based on what the manufacturer found for false positives in the sample that the manufacturer had studied. So, while it is true that their data is compatible with a prevalence of a few percent (and, hence, much higher than the known infection rate there), it is also compatible with an infection rate of 0% within 95% confidence intervals. So, in other words, it tells us very little about how much higher the prevalence of the virus might be compared to the known cases. ---
**Author:** ![Wesley\_Clark](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wesley_clark/32/20581_2.png) [@Wesley\_Clark](https://boards.straightdope.com/u/Wesley_Clark)\ **Post date:** [April 23, 2020, 8:36pm UTC](https://boards.straightdope.com/t/asymptomatic-infection-rates/851145/125 "2020-04-23T20:36:59Z")
Preliminary NY results are in. About 14% of people have had the virus. > **[New York antibody study estimates 13.9% of residents have had the...](https://www.cnbc.com/amp/2020/04/23/new-york-antibody-study-estimates-13point9percent-of-residents-have-had-the-coronavirus-cuomo-says.html)** > > The state's mortality rates remains persistently high at about 7.4%. The antibody testing indicates the actual death rate may be far lower. > [@](#): > > With more than 19.4 million residents, according to U.S. Census data, the preliminary results indicate that at least 2.7 million New Yorkers have been infected with Covid-19. > > The results differed across the state with the largest concentration of positive antibody tests found in New York City at 21.2%. On Long Island, 16.7% of the people tested were positive and in Westchester and Rockland counties, 11.7% of the tests were positive. Westchester County is where the state’s first major outbreak originated. The Covid-19 pandemic across the rest of the state is relatively contained with just 3.6% of positive test results. [https://twitter.com/NYGovCuomo?ref\_src=twsrc^google|twcamp^serp|twgr^author](https://twitter.com/NYGovCuomo?ref_src=twsrc%5Egoogle%7Ctwcamp%5Eserp%7Ctwgr%5Eauthor) > [@](#): > > Percent positive by demographic: > > Female: 12% > Male: 15.9% > > Asian: 11.7% > Black: 22.1% > Latino/Hispanic: 22.5% > Multi/None/Other: 22.8% > White: 9.1% If 21% of NYC has had the virus and its already killed 0.1% of the city, then thats an IFR of about 0.5%. So if the virus has a high R0, and you need 80% infected to reach herd immunity (and we dont’ get a virus or any effective medical treatments), thats about 1.3 million Americans who will die in the US from it. I’m assuming blacks and latinos have double the infection rates of whites due to them having less liquid assets to withstand unemployment and not having jobs that you can work from home as often. ---
**Author:** ![Wesley\_Clark](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wesley_clark/32/20581_2.png) [@Wesley\_Clark](https://boards.straightdope.com/u/Wesley_Clark)\ **Post date:** [April 23, 2020, 8:55pm UTC](https://boards.straightdope.com/t/asymptomatic-infection-rates/851145/126 "2020-04-23T20:55:15Z")
If you do the math and assume NY state has 6x higher infection rate (since their NY state death rate seems to be 6x higher than the death rate for the country as a whole) then that means the national infection rate is closer to 2-3% of the total population who have had it? Unless my math is wrong. The rest of NY state outside of a few highly populated counties is about 3.6%. So I’m wondering if the national rate of those who have been infected is only about 3% or so. ---
**Author:** ![Wesley\_Clark](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wesley_clark/32/20581_2.png) [@Wesley\_Clark](https://boards.straightdope.com/u/Wesley_Clark)\ **Post date:** [April 23, 2020, 9:05pm UTC](https://boards.straightdope.com/t/asymptomatic-infection-rates/851145/127 "2020-04-23T21:05:12Z")
Not sure if its true, but someone on reddit is claiming the death rate in NYC when you factor in all excess deaths, and claims the IFR based on the new NY numbers is closer to 1%. I’m not sure if the 1% figure counts all excess deaths (people who can’t get medical care for non covid issues, people who die at home who normally wouldn’t etc) so that would make the death rate 1.3-2.6 million when its all said and done. Isn’t that what scientists were claiming a month or two ago, about 1.3-2.5 million deaths? Again, unless my math is wrong and I’m not good at math. ---
**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 24, 2020, 12:17am UTC](https://boards.straightdope.com/t/asymptomatic-infection-rates/851145/128 "2020-04-24T00:17:24Z")
Interesting results and I must say I was expecting a larger number, like 50% plus. The various test products have different performance metrics so between that and the usual sample of convenience concerns of course it is another bit to be interpreted as part of a whole. More complicated as infection and death rates are just peaking now so knowing what portion of the curve this reflects is unknown. My understanding is that the tests in general reach best reliability days 11 to 24 after infection and that false negatives are overall about 13%. But who knows for this specific test? Given that deaths lag too it might be reasonable to consider deaths as reflective of these number of infections. Depending on the performance of the product. Both possibly representing the number of infections and the number who would die from those infections of a bit more than two weeks ago. So with those caveats - 21.2% of the 8.6 million NYC residents with a current deaths number of 11,267 would be a surprisingly high 0.6% IFR if indeed it was a representative sample, if they represented the same points of the still rapidly moving curve, and the product’s false negative rate was reasonable. That is a scary number if true. And if true then despite the fairly rapid drop in daily death rates (the 7 day moving average dropping 5d in a row and the one day dropping from a peak of 165/million/day on 4/16 to 16/million/d on 4/22) unlocking should be _very_ cautiously done, as the odds would be that herd immunity is likely a ways away. Since two weeks ago infections have roughly doubled (by confirmed infection rate numbers) to tripled (by death rate numbers) … so the number who will be immune by the time they fight off current infections by this preliminary data is somewhere between 28 to 42% based on this snapshot. Although no one knows how much is needed for herd immunity in any specific population, it’s a guess … 80% is a much higher guess than is generally made … but 28% would be lower than generally believed. Unfortunate if true. Again, more to come! ---
**Author:** ![Tamerlane](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tamerlane/32/7602_2.png) [@Tamerlane](https://boards.straightdope.com/u/Tamerlane)\ **Post date:** [April 24, 2020, 12:27am UTC](https://boards.straightdope.com/t/asymptomatic-infection-rates/851145/129 "2020-04-24T00:27:23Z")
> [@DSeid](#): > > Although no one knows how much is needed for herd immunity in any specific population, it’s a guess … 80% is a much higher guess than is generally made … but 28% would be lower than generally believed. The speculative number I was hearing from epidemiologists on NPR yesterday was ~60%. ---
**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 24, 2020, 12:51am UTC](https://boards.straightdope.com/t/asymptomatic-infection-rates/851145/130 "2020-04-24T00:51:15Z")
40 to 60 is what is the usual guess range. What need be emphasized though is that while these are educated people making educated guesses they are still guesses based on very little to base a guess off of. One of the big problems has been the tendency of some of those doing the modeling to fail to communicate the _huge_ uncertainties of their guesses. ---
**Author:** ![MichaelEmouse](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/michaelemouse/32/101_2.png) [@MichaelEmouse](https://boards.straightdope.com/u/MichaelEmouse)\ **Post date:** [April 24, 2020, 12:59am UTC](https://boards.straightdope.com/t/asymptomatic-infection-rates/851145/131 "2020-04-24T00:59:52Z")
Doesn’t the % depend on contagiousness? The higher the initial R, the greater the % required to get it below R1, no? If we presume 80%, about when should NYC have herd immunity? ---
**Author:** ![MichaelEmouse](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/michaelemouse/32/101_2.png) [@MichaelEmouse](https://boards.straightdope.com/u/MichaelEmouse)\ **Post date:** [April 24, 2020, 1:01am UTC](https://boards.straightdope.com/t/asymptomatic-infection-rates/851145/132 "2020-04-24T01:01:24Z")
n/m: Grue ate several of my posts then spit two back out. ---
**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 24, 2020, 1:19am UTC](https://boards.straightdope.com/t/asymptomatic-infection-rates/851145/133 "2020-04-24T01:19:56Z")
Another way to think of this information. Again antibody positivity now most likely captures infections up to about two weeks ago, some more some less. Two weeks ago the confirmed case number was about 150K in New York. This study says in fact 2.7M were infected at that time. That would mean that, according to this result, even with ample testing there were 18 times more infections than identified. ---
**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 24, 2020, 1:27am UTC](https://boards.straightdope.com/t/asymptomatic-infection-rates/851145/134 "2020-04-24T01:27:17Z")
I remain very anxious to see some real studies that do more than samples of convenience and have broad sampling by age and other demographic groupings. ---
**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 24, 2020, 2:06am UTC](https://boards.straightdope.com/t/asymptomatic-infection-rates/851145/135 "2020-04-24T02:06:42Z")
> [@MichaelEmouse](#): > > Doesn’t the % depend on contagiousness? The higher the initial R, the greater the % required to get it below R1, no? > > If we presume 80%, about when should NYC have herd immunity? Not just contagiousness, but also the number of asymptomatic carriers. With most really virulent diseases they tend to be self-limiting just because infected people don’t feel like going to work or socializing, and so the group of people who are most likely to be infected are in the household. If there are a large percentage of people who can actively shed the virus without recognizing symptoms and displaying clear signs like fever or sneezing, then the virus can continue to circulate unseen (without comprehensive testing), and the standard surveillance methods and self-isolation cannot be relied upon. Herd immunity should be thought of not as a barrier or a point at which the virus stops spreading, but a threshold at which the rate of spread is consistently declining which requires that most of the people an infected person comes into contact with have immunity. In some cases, like influenza, a herd immunity through vaccination can be effective even with only about a third of the population getting inoculated (and the vaccination being less than perfect). For poliovirus, the initial vaccine was only about 70% effective, and only about 70% of the population was vaccinated, so the effective immunity was about 50%, but that was sufficient to limit outbreaks of polio to the point that it did not achieve epidemic proportions. For Varicella zoster, the virus that causes chickenpox, we never had effective herd immunity prior to a vaccine even though the vast majority of the adult population was exposed and could no longer express the virus in significant quantity; its prevalence in human populations was persistent enough that it infected nearly every person on the planet. In addition to asymptomatic human carriers, we know for certain that the virus can infect a number of different cat species (but apparently not dogs) and potentially other animals that people are in regular contact with, which means it may have a persistent reservoir even if we could eradicate it from the human population. And of course, if the immunity conferred by exposure or vaccination only last a few years or less, the virus may be sufficiently endemic in other populations to spillback into the developed world, which means we need to think of vaccination in terms of both a global program and surveilling domestic animal populations for indications that the virus is circulating. There so many unknowns about how the SARS-CoV-2 virus operates in the human body, but here’s some additional bad news: [_Washington Post_: “A mysterious blood-clotting complication is killing coronavirus patients”](https://www.washingtonpost.com/health/2020/04/22/coronavirus-blood-clots/). This new effect explains some of the odd behaviors and may be a clue as to why the presentation of COVID-19 is so severe in a small segment of the population and has little effect on others, but the worrisome observation is this: \*Increasingly, doctors also are reporting bizarre, unsettling cases that don’t seem to follow any of the textbooks they’ve trained on. They describe patients with startlingly low oxygen levels — so low that they would normally be unconscious or near death — talking and swiping on their phones. Asymptomatic pregnant women suddenly in cardiac arrest. Patients who by all conventional measures seem to have mild disease deteriorating within minutes and dying at home. With no clear patterns in terms of age or chronic conditions, some scientists hypothesize that at least some of these abnormalities may be explained by severe changes in patients’ blood. … Autopsies have shown some people’s lungs fill with hundreds of microclots. Errant blood clots of a larger size can break off and travel to the brain or heart, causing a stroke or heart attack. On Saturday, Broadway actor Nick Cordero, 41, had his right leg amputated after being infected with the novel coronavirus and suffering from clots that blocked blood from getting to his toes. Lewis Kaplan, a University of Pennsylvania physician and head of the Society of Critical Care Medicine, said every year doctors treat people with clotting complications, from those with cancer to victims of severe trauma, “and they don’t clot like this.” “The problem we are having is that while we understand that there is a clot, we don’t yet understand why there is a clot,” Kaplan said. “We don’t know. And therefore, we are scared.”\* So not only may there be many asymptomatic people and animal reservoirs, but even if we have an effective antibody test that allows us to identify people who are (presumably) immune we cannot necessarily predict who will have a benign response to infection and who may be likely have profound illness or mortality. I don’t think we can assume any level of herd immunity and testing will protect vulnerable people until we have a better understanding of how the virus functions in the body and how long any conferred immunity will last. 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:** [May 29, 2020, 2:45am UTC](https://boards.straightdope.com/t/asymptomatic-infection-rates/851145/136 "2020-05-29T02:45:39Z")
A few bits to share that I think justify updating this thread. 1. From _BMJ Thorax_ another [cruise ship study](https://thorax.bmj.com/content/early/2020/05/27/thoraxjnl-2020-215091). > [@](#): > > We describe what we believe is the first instance of complete COVID-19 testing of all passengers and crew on an isolated cruise ship during the current COVID-19 pandemic. Of the 217 passengers and crew on board, 128 tested positive for COVID-19 on reverse transcription–PCR (59%). Of the COVID-19-positive patients, 19% (24) were symptomatic; 6.2% (8) required medical evacuation; 3.1% (4) were intubated and ventilated; and the mortality was 0.8% (1). **The majority of COVID-19-positive patients were asymptomatic (81%, 104 patients)**. Bolding mine. These do seem to be truly asymptomatic rather than presymptomatic individuals, but I am not sure if that can be stated with complete confidence. Also unclear the age range of those on the ship … my WAG is that a cruise of the Antarctic Peninsula following “a route similar to that taken by the British explorer, Ernest Shackleton, in 1915–1917” _might_ have a different demographic than a Carnival Cruise. Also noted that antibody studies done during an acute phase were falsely negative but follow up testing in not reported. 2) [Wuhan](https://onlinelibrary.wiley.com/doi/10.1002/jmv.25904). Population 11M. Workers required to be tested before being able to return to work. Very useful as this study was done not during a rapid rate of rise. Studies done while a population is on the curve are problematic as antibody positivity lags infection by 2 weeks or more. > [@](#): > > 50,008 confirmed cases and 2,579 deaths were from Wuhan … people have been allowed to resume working since April 8 if meeting a set of COVID-19-associated tests including SARS-CoV-2 nucleic acid test (NAT) of nasopharyngeal swabs, chest CT scan or a SARS-CoV-2-specific serological test. … there were 98 (98/1,021, 9.60%) from resuming group that were IgG positive and IgM and NAT negative. None of these people had a history of COVID-19, or suspect symptoms. These IgG+IgM-NAT- individuals with no history of COVID-19 probably suggested a recovered asymptomatic SARS-CoV-2 infection. … If one assumes that the 9.6% with past asymptomatic rate that means the true number of infected individuals in Wuhan was about 1.1M and the death rate (using the number quoted in the article) was 2,579/1,100,000 = 0.2%. Double it for assumed under-reporting of deaths maybe? Asymptomatic infections are being reported as 21 times more than “confirmed cases.” 3) [Spain](https://www.lamoncloa.gob.es/serviciosdeprensa/notasprensa/sanidad14/Documents/2020/130520-ENE-COVID_Informe1.pdf) study done 4/27 to 5/11. Information from reading the tables put into a Google translator and doing some simple calculations (40202 asymptomatic of which 2.5% were positive, so on). Positive IgG in: 1005 asymptomatic individuals, 46% of all who were positive; 568 with 1 to 2 symptoms, 26%; so on. Very few had been confirmed by PCR infections (247 of the over 60K). Overall > [@](#): > > The estimated prevalence of IgG antibodies against SARS-Cov2 in Spain is 5.0% (95% CI: 4.7% -5.4%), being very similar in men and women (5.0% (95% CI: 4.6% -5.4%) versus 5.1% (95% CI: 4.7%).In relation to age, the prevalence is lower in babies, children and young people, remaining quite stable in older age groups. > > The proportion of positives is higher in residents of large cities (\> 100,000 inhabitants) 6.4% (CI95%: 5.8-7.1) Using 5% with a deaths/million at the same time of about 530/million (0.05%) and IFR was running, very crudely about 1%. 4) [England.](https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/888254/COVID19_Epidemiological_Summary_w22_Final.pdf)(Page 22.) Current week is week 22. > [@](#): > > … After making adjustments based on the latest information on the accuracy of the assay\*, the overall adjusted prevalence in London increased from 1.3% in week 13 to 10.6% in weeks 15-16 and 14.8% in week 18. … Given that the antibody response takes at least two weeks to become detectable, those displaying a positive result in week 18 are likely to have become infected before mid-April … Mid-April numbers for confirmed cases was about 1500/million (0.15%) and total deaths 2 weeks later (presumptively from infections up to that date) about 327/million (0.03%). Plugging in that’s 99 times more infected than confirmed cases and an IFR of 0.2%. 5) [Sweden.](https://www.folkhalsomyndigheten.se/nyheter-och-press/nyhetsarkiv/2020/maj/forsta-resultaten-fran-pagaende-undersokning-av-antikroppar-for-covid-19-virus/) > [@](#): > > The Public Health Authority has launched a survey to measure and estimate how many in the community have had covid-19. Blood samples are collected from laboratories in clinical chemistry and clinical immunology in nine regions: Jämtland, Jönköping, Kalmar, Skåne, Stockholm, Uppsala, Västerbotten, Västra Götaland and Örebro. > > The collection takes place during eight weeks in the spring of 2020. A total of 1,200 samples are collected each week for analysis of antibodies. Antibodies show that the immune system recognizes the SARS-CoV-2 virus. > > The analyzes for week 18 (a total of 1,104 analyzed samples) show, as expected, the largest proportion of positive antibody tests in Stockholm. A total of 7.3 percent of the blood samples collected from people in Stockholm were positive in the antibody study, which can be compared with a total of 4.2 percent in Skåne and 3.7 percent in Västra Götaland. > > The numbers reflect the state of the epidemic earlier in April, as it takes a few weeks for the body’s immune system to develop antibodies. > > Regarding age differences, the results show that it was most common with antibodies to covid-19 among people between 20 and 64 years. In total, 6.7 percent of the samples in this group were positive, which can be compared with 4.7 percent in the age group 0-19 years and 2.7 percent in the age group 65-95 years. Confirmed cases in Sweden in mid April about 1200/million (0.12%) and deaths 2 weeks later about 250/million (0.025%). About 59 times more with evidence of infection than confirmed infections and an implied IFR of 0.3%. FWIW. ---
**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:** [June 8, 2020, 4:27am UTC](https://boards.straightdope.com/t/asymptomatic-infection-rates/851145/137 "2020-06-08T04:27:57Z")
New article synthesizing various studies. They attempted to separate true asymptomatic from pre and mild. [https://www.acpjournals.org/doi/10.7326/M20-3012](https://www.acpjournals.org/doi/10.7326/M20-3012) > [@](#): > > Asymptomatic persons seem to account for approximately 40% to 45% of SARS-CoV-2 infections The bottom line though is less interesting than the whole review inclusive of their speculation that very high rates of asymptomatic infection in a prison population might be due to protective effects from recent common cold causing coronaviruses. ---
**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:** [June 8, 2020, 10:53pm UTC](https://boards.straightdope.com/t/asymptomatic-infection-rates/851145/138 "2020-06-08T22:53:04Z")
Another update. [60%](https://www.reuters.com/article/us-health-coronavirus-usa-navy-exclusive/exclusive-u-s-navy-test-shows-60-percent-of-carrier-crew-have-coronavirus-antibodies-idUSKBN23F29Z) of the tested crew of the Theodore Roosevelt have antibodies. > [@](#): > > A U.S. Navy investigation into the spread of the coronavirus aboard the Theodore Roosevelt aircraft carrier has found that about 60 percent of sailors tested had antibodies for the virus, two U.S. officials told Reuters on Monday, suggesting a far higher infection rate than previously known. … > > … More than 1,100 aboard tested positive for the virus as of April, less than 25 percent of the crew. … about 400 volunteers participated in the serology tests, lower than the 1,000 volunteers that were sought, but enough to provide statistically relevant data about how the virus spread aboard one of world’s largest warships. > > The Roosevelt has about 4,800 personnel on the ship. Interpret with caution of course. [Previous page](https://boards.straightdope.com/t/asymptomatic-infection-rates/851145.md?page=6)