Covid-19 contact tracing study finds children key to spread
princeton.edu
princeton.edu
Which is that it's impossible to determine the direction of transmission. Just because someone (a child or young adult) developed symptoms first doesn't mean they actually got infected first, they might have actually gotten infected at the same time as their supposed contact. When the South Korean study removed cases of shared exposure, the new study found those children did not in fact transmit very much. https://twitter.com/apsmunro/status/1311616493445165058
This Twitter discussion does not make me think they did anything differently than the South Korean study that was later corrected: https://twitter.com/apsmunro/status/1312301601156194304
Not only does the study not show that, the press release doesn't even claim that - it contains two separate claims, that superspreading is important, and that children are involved in spread. It's only the use of a comma in the headline that - through incompetence or dishonesty - suggests that!
Mods, could we have the title changed, please?
EDIT: Mods changed the title already, thanks mods!
> The researchers found that the chances of a person with coronavirus, regardless of their age, passing it on to a close contact [were] 9% in the household.
https://dontforgetthebubbles.com/evidence-summary-paediatric...
At this point, a study which concludes the opposite has to bring the proverbial extraordinary evidence.
We aren't even close to that point. There's a heckuva lot that we still don't know about this virus. That paper was update, what, 30 June? They even admitted that they were using their earlier conclusions to create filters for the new literature they were reviewing- in effect building their own echo chamber.
As long a the study is competently run and has reasoned conclusions it should be considered.
(a) The original title of this article is 'Largest COVID-19 contact tracing study to date finds children key to spread, evidence of superspreaders' -- I edited it to fit within the HN character limit
(b) The actual article is published in Science: https://science.sciencemag.org/content/early/2020/09/29/scie...
(c) This is a large study on 500k people in India. The researchers found that 71% of infected individuals did not infect any of their contacts, while a mere 8% of infected individuals accounted for 60% of new infections -- providing evidence for so-called 'superspreaders'. Regarding children, the researchers found that 'These patterns of enhanced transmission risk in similar-age pairs were strongest among children ages 0-14 years and among adults ages ≥65 years', and that they 'identif[ied] high prevalence of infection among children who were contacts of cases around their own age' -- something that was also true in adults.
The overall case-to-fatality ratio was between 0.05% at ages 5-17 years to 16.6% at ages ≥85 years.
Some key limitations to keep in mind from the study:
> The contact tracing data analyzed included only 20% of all reported cases as index cases and represented only 19% of all contacts traced
So the observations, while important, are probably just part of a more complex picture.
> Another limitation was the lack of data on timing of exposure and symptoms onset in relation to testing dates; this necessitated assumptions about identification of true index cases.
This is important: some cases may not be "true positives" in the sense that the PCR test alone does not tell if you have the disease, or had the disease if you did not develop symptoms. Given the size of the population tested, admittedly doing that is difficult.
> Finally, while comorbidities data collected as part of COVID-19 mortality surveillance revealed clinical and epidemiological attributes of fatal cases, the fact that such data were not collected for all diagnosed cases prevented inference of the contribution of comorbidities to fatal outcomes.
Note that it's easy to read the Princeton press release as "children are spreading the disease to each other", but I don't think the Science paper is very good evidence for that hypothesis. Sadly the paper is making it pretty hard to get an answer to that question - the least they could have done was to make it obvious over what time their study data was extracted (answer, I think: for all time up to 1st Aug 2020), and also when schools were shut down in India (answer according to UNESCO: partial closure from 2nd March, still fully closed). Anyway, it seems perfectly consistent to me that the superspreaders are adults, and that clusters of children who interact with each other also interact with the same adults.
Therefore we must always keep a close eye on the circumstances where the data was taken and what we can and cannot conclude from that.
The reason is buried in the article, but ought to be in the headline: children are key to spread...within the household. In other words, parents and older siblings and other household members do not socially distance from children in their own household. Well, duh.
Mind you, iirc only elementary school children (<12) went back to school, middle and higher education remained taught from home until after the holidays.
My son's secondary school just introduced mandatory masks this week. They should really do that in more areas.
Sorry but I don't understand the distinction. One family member has Covid-19 -> spread to children -> spread to other family members -> other family members spread it outside, so in the in the end children are key to spread. Or am I missing something?
> Although they are not the wealthiest states in India, Andhra Pradesh and Tamil Nadu are among the states with the largest healthcare workforces and public health expenditures per capita, and are known for their effective primary healthcare delivery models. Both states initiated rigorous disease surveillance and contact tracing early in response to the pandemic. Procedures include syndromic surveillance and SARS-CoV-2 testing for all individuals seeking care for severe acute respiratory illness or influenza-like illness at healthcare facilities; delineation of 5km “containment zones” surrounding cases for daily house-to-house surveillance to identify individuals with symptoms; and daily follow-up of all contacts of laboratory-confirmed or suspect COVID-19 cases, with the aim of testing these individuals 5-14 days after their contact with a primary case, irrespective of symptoms, to identify onward transmission.
A low/medium income region with good healthcare infrastructure is a rarity and may potentially provide unique insights.
We have seen very different transmission patterns in high latitude versus subtropical regions. I wonder if a third pattern will emerge in tropical regions.
[1] https://science.sciencemag.org/content/early/2020/09/29/scie...
The same for RT-PCR -- I tested positive one month after first symptoms, but I also have good igg antibodies.
Didn't people do this RT-PCR testing for influenza before? Are RT-PCR tests for influenza still positive one month after first flu symptoms?
I mean, the quality of information you can google up as a COVID-19 patient is absolute shit, most of what google shows is sensationalized news articles directed at the non-positive, scared general public.
She should be fine, unless immunocompromised. RT-PCR tests do not tell, in absence of symptoms, if you are infectious. If you have symptoms, the presence of a positive test correlates with actual, infectious virus in your throat until 7 days with milder symptoms and 15 days with more severe symptoms.
See https://www.cebm.net/covid-19/infectious-positive-pcr-test-r...
Also bear in mind, in particular for your daughter, that viral RNA takes a lot to clear, even when her immune system has already defeated the virus (IOW: you're seeing the "debris after the battle" and not the virus): the milder the symptoms, the longer it takes to clear.
tl;dr: Your daughter should be fine at this point, in general terms.
Of course, as an obligatory disclaimer, IAAS (I am a scientist), IANAMD, this is not medical advice, etc etc.
The odds you die of C19 is overwhelmingly slim especially now with the therapeutics and better understanding of how to treat it. If you're old you are at higher risk (about 2% chance over 65) but thats the case of anything when you're old. Eventually something gets you as you are basically walking on a tight rope. Everybody dies.
Old scared politicians have fucked the younger generation out of self preservation and greed once again. Theres absolutely no reason to shut down society like this. Wear a mask and move on.
I'm quite curious to learn what stands out about these superspreaders. Their infection? Their behavior? Their genes? The timing of their interaction with others?
I think it’s a bit dangerous for an intelligent HN reader to go looking at scientific papers without properly taking a systematic approach to cover all bases. A much sounder, yet less exciting, method is to rely on the advice of expert organisations such as the WHO.
Oxford's CEBM is one (https://www.cebm.net) and someone else has posted another for transmission in children here.
The motivation was moral, but it seems such organisations are 'happy' to use misinformation to the public; that is, they can't fully be trusted.
Finding trustworthy, competent voices that one can follow is v.hard.
Academic papers, and the response of academics that have some trust [with you] already, are more useful than supranational organisations whose declarations might not be entirely aligned with promulgation of truth.
This thinking has circulated widely on social media, but I don't see evidence for it.
The current WHO line is pretty much the same - they do accept that it may help to wear a mask e.g. in supermarkets, but they're pretty clear that the evidence for community mask wearing being a net positive is thin.
The WHO is not a conspiracy.
For example, many other sources (which tend to elucidate their sources and reasoning more fully) claim, convincingly, that the evidence for community mask wearing being a net positive is quite strong. When WHO claims that it's weak, I lose trust in them.
(genuine question) please could you provide a link to that? I've seen one meta-study that people quote, but I've not seen any evidence that community mask wearing is a net positive in practice.
Do you "lie" (maybe by omission; at least going against the current {at the time} scientific consensus) by saying that 'public mask-wearing provides no benefit' [that's to my recollection their advice around February time when I was considering buying masks] in order to maintain supplies for medical personnel? Or, do you say 'masks limit transmission of ARIs' and risk leaving medical need of masks unfulfilled because mass panic has decimated the supplies?
I don't think it's necessarily wrong to lie there (akin to people who say "vaccines are perfectly safe" - the info leaflet disproves that), but it does mean if you're searching for a source of ground truth that you can't rely on them.
No conspiracy, other than that needed to protect global populations, is required. I think you'd agree with me that WHO are conspiring to protect the health of global populations. That they would hold this goal above the goal of providing information that is absolutely true is not especially surprising, I think.
FWIW: WHO updated the information later such that they offered different mask advice per country (to my recollection), which seems anomalous unless one considers that the advice is tailored according to whether countries had secured supplies. The advice for UK went from "masks do nothing" to "you should wear a mask".
Truth mixed with guilt would've probably been the best path: "Yes, masks might help reduce spread, but doctors and nurses on the front lines are the ones most in need. Please consider donating your spare supplies."
https://www.businessinsider.com/who-no-transmission-coronavi...
Add in the network effects of crosslinking different social circles (school, family, workplace) by children and adults then you get good conditions to spread disease.
Very careful wording here by the author, where the usage of "children" includes "adult children".