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High Temperature and High Humidity Reduce the Transmission of Covid-19
- _bxg1 7y agoThis sounds great, but I don't know anything about SSRN. Can someone shed light on the credibility here?
- neural_thing 7y agosame as arxiv
- glouwbug 7y agoSure, but what about when it gets cold again? It may come back even worse
- tekmaven 7y agoIF this is the case, we should be way more prepared including possibly having a vaccine available.
- chucknthem 7y agoStill no vaccine for SARS 18 years later, what makes you think we'll have a vaccine for this?
- nate_meurer 7y agoSARS hasn't been seen in 15 years. Exactly whom did you expect would spend the time and money to develop a vaccine for it?
- sitkack 7y agoMaybe we should develop responses to pathogens that have the ability to wipe humanity off the galaxy. Given how close SARS and SARS-CoV-2 is, maybe the SARS vaccine could be applied to the current case.
- nate_meurer 7y agoI think that's likely, but it's understandably difficult to convince anyone to spend a few hundred million dollars to develop vaccine that might never be used.
- sitkack 7y agoSeems like a pretty good deal right now. Our economic system has structural pathologies that make it extremely difficult to meaningfully organize whole populations.
- nate_meurer 7y agoYeah, ok, I think I agree with this. I have to believe that a sustained effort to develop coronavirus vaccines would bear fruit, whether actual vaccines or merely processes and knowledge, even if the particular motivating disease was no longer in circulation.
- tasuki 7y ago> Maybe we should develop responses to pathogens that have the ability to wipe humanity off the galaxy. Not a bad idea, but isn't that a near-infinite set?
- AnimalMuppet 7y agoBy then, we should have enough testing kits, and authorities should be better prepared to handle it.
- Taek 7y agoNot to mention a better baseline immunity within the population, and more preparedness as a whole. Testing kit shortages, lack of information, no vaccine, etc. are all a function of how little time we've had to respond. If we can buy 3 months, that's a lot of bonus time to prepare.
- jmnicolas 7y agoEurope had about 3 months compared to China and is handling the situation much worse.
- seilrse 7y agoTrump won't have to worry about reëlection so we can handle this crisis like a responsible developed nation.
- darktimeline 7y agoTrump won't have to worry about reëlection so we can handle this crisis like a responsible developed nation.
- jmnicolas 7y agoI think this thing is so contagious that all the weak people will already be dead. The second wave might kill a few of the survivors that had their immune system weakened since the first wave, but it shouldn't be as much people as the first time.
- mrmuagi 7y agoSurely surviving the first wave will be a plus against a second wave as you already have some immunization?
- endorphone 7y agoIt can and will. For that matter, it's an RNA virus that is morphing as a function of the error factor of replication, so vaccines may be ineffective (for the same reason we continue to get the "common cold" again and again over our lives, as well as the flu -- the signature keeps changing). We will see. Though it's worth noting that there are a lot of very contrary signals on whether it attenuates with heat. Some find that it doesn't, while some do. The very origin of this -- Wuhan -- had very temperate conditions when the outbreak began, and transmission seems to be much worse in the US than in Canada.
- farseer 7y agoSpain seems to be an exception to this theory.
- seattle_spring 7y agoSpain is not hot at all this time of year.
- knapcio 7y agoThey say it “reduces” the spread. There may be other factors which affect the situation in Spain. Also it’s not that hot now in most places there ;p
- tomerico 7y agoMadrid has cold weather up until Tuesday - https://www.accuweather.com/en/es/madrid/308526/march-weather/308526 https://www.accuweather.com/en/es/madrid/308526/march-weathe... It’d be interesting to see if the warmer weather since Tuesday will reduce the number of new cases. If we assume a week between exposure to getting diagnosed, we would start seeing lowering rate of new infection starting from mid next week.
- baby 7y ago23C, thought it would be warmer now, what about Thailand?
- idgs 7y agoWeather in Spain in the en of february is cold most fo the times. March is a changeable weather, can have very cold weeks, some few days with 25C and very sunny. But cold also. May will be a hot month.
- chrisco255 7y agoMaybe that's why Singapore hasn't been badly impacted?
- X6S1x6Okd1st 7y agoSingapore is included in how they determined this result, therefore you shouldn't use this result to explain why singapore is doing better.
- chrisco255 7y agoAh fair enough. I guess we'll have to observe areas with similar climates and see if it holds. If so, I'm taking that tropical cruise after all. ;)
- 9nGQluzmnq3M 7y agoNo, Singapore is not in China and is thus not in the set of "100 Chinese cities". It's only mentioned in the paper in graphs of temperature and humidity of a whole bunch of countries.
- cVwEq 7y agoHere's the study on arxiv [1], if you're more inclined to use that system. [1] https://arxiv.org/ftp/arxiv/papers/2003/2003.05003.pdf https://arxiv.org/ftp/arxiv/papers/2003/2003.05003.pdf
- jclark_th 7y agoAnother paper saying something similar https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3550308 https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3550308
- svscam 7y agoHere's a likely related paper from 2007: https://jvi.asm.org/content/82/4/1899 https://jvi.asm.org/content/82/4/1899 In this study, a human immunodeficiency virus (HIV)-based pseudovirus system was employed to address these issues. Our results indicated that the SL-CoV S protein is unable to use ACE2 proteins of different species for cell entry and that SARS-CoV S protein also failed to bind the ACE2 molecule of the horseshoe bat, Rhinolophus pearsonii. However, when the RBD of SL-CoV S was replaced with that from the SARS-CoV S, the hybrid S protein was able to use the huACE2 for cell entry, implying that the SL-CoV S proteins are structurally and functionally very similar to the SARS-CoV S. These results suggest that although the SL-CoVs discovered in bats so far are unlikely to infect humans using ACE2 as a receptor, it remains to be seen whether they are able to use other surface molecules of certain human cell types to gain entry. It is also conceivable that these viruses may become infectious to humans if they undergo N-terminal sequence variation, for example, through recombination with other CoVs, which in turn might lead to a productive interaction with ACE2 or other surface proteins on human cells. Look at the authors: Zhengli Shi https://en.wikipedia.org/wiki/Shi_Zhengli https://en.wikipedia.org/wiki/Shi_Zhengli She is a researcher at the Wuhan Institute of Virology (WIV), which is part of the Chinese Academy of Sciences (CAS). Shi and her colleague Cui Jie found that the SARS virus originated in bats.
- svscam 7y agoPosts like this tend to get flagged quickly on HN. Meanwhile, you can freely conspiracy theorize all you like about the machinations of the CIA, NSA, etc., regardless of how little evidence you have. It's the same on other social media websites. Zero Hedge got deplatformed from Twitter for talking about this. The CCP is exerting a frightening chilling effect on public discourse, even in America.
- tic_tac 7y agoIt is extremely frightening, and it's important that we continue to fight for freedom of expression on all platforms. Unfortunately so many have an innate bias against the US that any criticism of it is considered fair game regardless of how conspiratorial or absurd.
- serioussecurity 7y agothis abjectly fails to deal with heteroscedasticity
- forkexec 7y agoThis isn't peer-reviewed. Maybe I have bad information, but cold plus high humidity caused it to persist on fomites longer (9+ days). Wouldn't heat plus low humidity be better than heat plus high humidity? What is/are the breakdown mechanism(s)?
- AstralStorm 7y agoHigh humidity reduces aerosol transmission, which is the more important vector. (By essentially washing down the vapor and additionally making people exhale less water. At least that's the theory behind it.)
- Animats 7y agoBut not by enough. This epidemic has a growth rate (R) of at least 2. The article claims "One degree Celsius increase in temperature and one percent increase in relative humidity lower R by 0.0383 and 0.0224, respectively." The March to July difference for New York City is only 19C. San Francisco, 9C. For both cities, humidity is relatively uniform year round. Even assuming this result is meaningful, it still leaves an R way above 1.
- _-___________-_ 7y agoThere are plenty of places that are hotter all year round, or have a larger temperature+humidity difference between seasons. Or was your comment only intended to address large US cities?
- kijin 7y agoIn many parts of China, it will be 30C hotter and 50%p more humid in the summer than it is now. The combination might reduce R to virtually nothing. In Japan, this could mean that it was the right decision to schedule the Olympics in the middle of summer after all.
- adrianN 7y agoI'm pretty sure that the Olympics will be cancelled. It's unlikely that we'll have a vaccine before then and Covid19 is well beyond containment at this point.
- kijin 7y agoAbe is dead set on hosting the Olympics one way or another, so he might try to reschedule it... to a time of year when R is higher. :(
- Fnoord 7y agoThere will be all kind of athletes ill. Especially sucks if you're part of a team. I mean, for individuals as well, but as team you rely on each other's strengths even more. Gonna be interesting for sure.
- filereaper 7y agoReally hoping this helps in India which so far has had really low reported cases.
- xxpor 7y agoTo be pedantic, COVID-19 is the disease, SARS-CoV-2 is the virus. It's like HIV vs AIDS.
- taneq 7y agoIf you reduce the transmission of the virus, do you not reduce the transmission of the disease?
- xxpor 7y agoI mean, that's why it's pedantic. Technically you can't "transmit" the disease. The disease consists of the effects on the body. Also, you can transmit the virus without having the disease, which is what makes it dangerous since you have no idea. It's like you can transmit HIV without having AIDS for years: >Acquired immunodeficiency syndrome (AIDS) is defined in terms of either a CD4+ T cell count below 200 cells per µL or the occurrence of specific diseases in association with an HIV infection That doesn't happen for a long time (or today, for a lot of people, never).
- taneq 7y agoWell, fair. My assessment was based on the assumption that the distribution of outcomes for a patient isn't affected by the source of the infection. If you had some hypothetical way of transmitting the virus only to hosts who would then develop symptoms of the disease, I guess you could argue that you could reduce transmissions of the virus while maintaining transmissions of the disease. That'd be impressively evil though.
- sb057 7y agoThe ME in MERS stands for Middle East, since outbreaks of it are always from camels. Such places are some of the hottest on the planet. MERS is another form of coronavirus. It is foolhardy to think spring and summer weather will save us.
- Leary 7y agoLooking at figure 4 in the paper gives me some comfort since the majority of the population centers in the northern hemisphere could approach a R of 1 in July.
- KKKKkkkk1 7y agoThis study fits a two-variable linear model to a high-dimensional nonlinear process.
- procinct 7y agoExcuse my ignorance but would a colder temperature but with rain help prevent due to the high humidity or does it require heat AND humidity?
- _-___________-_ 7y agoI am eagerly awaiting more studies into this subject. Something doesn't feel right about the relative lack of local transmission in e.g. Vietnam (temperatures over 30C at least in the south right now) compared to e.g. Italy (temperatures, what, 15C or lower in the north right now?). Cambodia's extremely low case count can easily be explained away by them not testing anyone, but Vietnam appears to be quite proactive with tracing and testing, yet still has a relatively low count and minimal transmission.
- virtualwhys 7y agoWhat doesn't feel right? The abstract states that high temperature and high humidity reduce transmission rates relative to colder climates, which corresponds with the high transmission rates during the northern hemisphere winter and early spring. And yes, lack of testing has resulted in some eyebrow raising numbers. Up in Da Nang now, both locals and foreigners are aware and taking it seriously -- scary times.
- _-___________-_ 7y agoSorry if I was unclear. I was trying to say that it seems clear to me intuitively that something other than "taking it seriously" is reducing the transmission rates in VN. It's just a "feeling" -- but this study seems to provide some (thin) evidence supporting it.
- realusername 7y agoVietnam has taken this epidemics 10x more seriously than Italy, that could just be the difference. They are testing as much as they can, everybody who had contact with infected people are tracked down and quarantined, streets where you had infected people are closed down and disinfected, almost everybody wear masks, you have temperature checks & hydroalcoholic gel available in public areas, schools are fully closed since early January.
- _-___________-_ 7y agoYes. However, there's also no travel restriction between Cambodia and Vietnam, significant cross-border traffic, and Cambodia is not "taking it nearly as seriously" as Vietnam is. If Vietnam had the transmission going on that Italy does, the case-tracking and quarantining would be a lot harder, and I just don't buy that the other things (masks, forehead temperature checks[0], hand sanitizer that hardly anyone knows how to use properly) have much of an impact. There has to be some much larger factor than those at play (and this study suggests what that factor could be). [0] I encourage people to ask or look what the reading is when getting these checks. About a third of the time when I get a forehead temperature check, the reading is totally nonsensical, like 31C, but the person just waves me through since it's under the threshold. I'm skeptical of the efficacy of a test that is this inaccurate.
- graycat 7y agoHow is the virus doing in Singapore, an island on the equator?
- gcc_programmer 7y ago105 data points (patient pairs). Linear regression. Not conclusive.
- known 7y agoTaiwan is doing good in containing Covid-19 despite its proximity to China
- notmyname259 7y agoI checked with a bunch of biologists and all of them find the results here to be merely correlational and misleading. Have asked to wait for more evidence
- bamboozled 7y agoIn the developed world a lot of people spend time indoors with air conditioning most of the summer anyway? Especially more frequently now thanks to climate change. Not sure how this changes a lot once it’s circulating already?
- inamberclad 7y agoHave the authors considered increased sunlight/UV radiation in warmer areas?
- ak39 7y agoExactly how does one take this body of scientific knowledge and act on it?
- maxhedrome 7y agoI feel like if you download that PDF you’ll get Chinese malware.... they already did it to the Mongolians... has anyone actually analyzed it yet?