Talk:Transmission of COVID-19/Archive 2

Semi-protected edit request on 14 May 2021
I would like to suggest the addition of these sentences to the "Larger Droplets" section, AT THE END of the current text. I am a scientist who has published extensively on COVID-19 transmission, including the recent paper in The Lancet (https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(21)00869-2/fulltext) and Science (https://science.sciencemag.org/content/372/6543/689). The text to add would be:

Large droplets were hypothesized as the dominant mode of transmission of respiratory infections in close proximity by Dr. Charles V. Chapin in his seminal 1910 book "The Sources and Modes of Infection". The hypothesis was loosely based on the work of Carl Flugge in the 1890s, although Flugge did not separate large droplets from aerosols. Chapin's work was enormously influential, and e.g. Alexander Langmuir, the first and longtime Chief Epidemiologist of the CDC referred to Chapin in 1967 as "the greatest American epidemologist." Although it has become the dominant hypothesis for the transmission of respiratory diseases, a 2019 search of the literature revealed that large droplet transmission has never been demonstrated directly for any disease. . There is a lack of evidence supporting large droplet transmission for SARS-CoV-2 as well. Despite this lack of evidence, Public Health authorities like WHO and CDC quickly declared COVID-19 to be transmitted via droplets based on tradition. Jljimene (talk) 16:37, 14 May 2021 (UTC)


 * The matter seems worth mentioning and there seems to have been a shift from droplets to aerosol (I'm not really an expert). Still I guess that here would be better something shorter, leaving the history/generic part to other articles, with eventual wikilinks. Actually the article already has a full section about the subject just a bit lower. Personuser (talk) 18:41, 14 May 2021 (UTC)
 * Red information icon with gradient background.svg Not done: For the reasons mentioned. &#8213;  Qwerfjkl  (please use&#32; on reply) 21:56, 14 May 2021 (UTC)

This article is extremely verbose
I think that this could be written much simpler. However I think WP:GOCE may be able to assist us, because the article is relatively stable for now, and is very repetitive, and then we can go from there. --Almaty (talk) 16:10, 17 May 2021 (UTC)

Discussion at Talk:COVID-19 pandemic § Request for comment
You are invited to join the discussion at Talk:COVID-19 pandemic § Request for comment. There is currently an RfC regarding the way we describe transmission of the virus. We should probably resolve that RfC before we continue editing this page in a different direction. &#123;{u&#124; Gtoffoletto  &#125;}  talk 08:31, 21 May 2021 (UTC)
 * Gtoffoletto, that RfC is only about one sentence in the lead of the pandemic article, and not about this article. The preexisting consensus applies for this page, and edits to try and make fomites and "touching" a main method only come from one editor. --Almaty (talk) 11:09, 21 May 2021 (UTC)
 * Since many of the same sentences are used in this article I would suggest waiting for that RfC to close before making further edits. Also the sentences being discussed are the summary of this article so they are substantially related. -- &#123;{u&#124; Gtoffoletto  &#125;}  talk 12:35, 21 May 2021 (UTC)
 * No they are not the summary of this article. The proposed edits on that page, where you propose to state fomites are as common as other methods (they are not, if you read this article), are a misunderstanding and tunnel vision about one particular CDC page, and only part of that page. --Almaty (talk) 14:47, 22 May 2021 (UTC)

Restructure
I restructured the article, as the initial structure appeared to be based on the June 2020 WHO brief, now out of date. Feel free to respond to any of the below comments
 * Infectious period is likely to be one of the most important things a person may want to know when visiting this page, so it is now first, because it would be lost after the immense amount of words describing the modes. --  Almaty  ✉✎ 13:30, 24 May 2021 (UTC)
 * Asymptomatic transmission is a subheading here, unless anyone has any bright ideas, but it is also potentially worthy of a Level 1 heading. -- Almaty  ✉✎ 13:30, 24 May 2021 (UTC)
 * Clarified that the "respiratory route" that the UK government and the Annals review refer to is effectively the "droplets and airborne particles" of the CDC. -- Almaty  ✉✎ 13:30, 24 May 2021 (UTC)
 * Combined all airborne under this header, because all agencies combine them -- Almaty  ✉✎ 13:30, 24 May 2021 (UTC)
 * Renamed indirect and direct contact to "Other modes of transmission" as this is WHO brief terminology that isn't universal in the sources, particularly the CDC. Given fomites (surfaces) is uncommon, but more common than mother to baby or other very minor ones, brought this to the top of "other modes of transmission" -- Almaty  ✉✎ 13:30, 24 May 2021 (UTC)
 * Heading about clusters and other patterns, to be expanded -- Almaty  ✉✎ 13:30, 24 May 2021 (UTC)
 * Heading about vaccination, to be expanded -- Almaty  ✉✎ 13:30, 24 May 2021 (UTC)

GOCE copyedit request

 * [...] mainly in locations that are poorly ventilated (such as restaurants, choirs, gyms, nightclubs, offices, and religious venues) [...] I think the stuff in the parentheses can be left in the body of the article. — Tenryuu 🐲 ( 💬 • 📝 ) 03:49, 10 June 2021 (UTC)
 * In October 2020, it recognized that although current evidence [...] This sounds outdated. Any more current evidence, as of June 2021? — Tenryuu 🐲 ( 💬 • 📝 ) 03:49, 10 June 2021 (UTC)
 * ✅. — Tenryuu 🐲 ( 💬 • 📝 ) 17:58, 11 June 2021 (UTC)
 * ✅. — Tenryuu 🐲 ( 💬 • 📝 ) 17:58, 11 June 2021 (UTC)


 * The number of people generally infected by one infected person varies; with only 10 to 20% of people responsible for the diseases spread. Is everything past the semicolon an unfinished thought? Not sure how it connects with the fragment before. — Tenryuu 🐲 ( 💬 • 📝 ) 03:49, 10 June 2021 (UTC)
 * Yes this is because people often use the R0 to describe COVID, but it is actually "overdispersed" - namely few people transmit to many, but many transmit to none or only to household contacts. Do you think we should go into that further? --Almaty (talk) 04:35, 16 June 2021 (UTC)
 * English variant: What kind of English is this article using? American? British? Something else? — Tenryuu 🐲 ( 💬 • 📝 ) 03:49, 10 June 2021 (UTC)
 * I think this should be in British English as it was originally taken from COVID-19 pandemic which uses british english. --Almaty (talk) 04:35, 16 June 2021 (UTC)
 * However, virus-containing droplets may be able to be produced in other ways, in particular circumstances. What other ways are these? — Tenryuu 🐲 ( 💬 • 📝 ) 03:49, 10 June 2021 (UTC)
 * The WHO recommends the use of filtering facepiece respirators such as N95 or FFP2 masks in settings where aerosol-generating procedures are performed, while the CDC [...] Wikilinks removed, emphasis added. Which CDC is this? — Tenryuu 🐲 ( 💬 • 📝 ) 03:49, 10 June 2021 (UTC)
 * The US CDC. --Almaty (talk) 04:35, 16 June 2021 (UTC)
 * The CDC recommended that pet owners limit their pet's interactions with people outside their household [...] Same as above. — Tenryuu 🐲 ( 💬 • 📝 ) 03:49, 10 June 2021 (UTC)
 * §Clusters and other patterns: A few sentences here are used in the lede. I suggest rewording in either one so that they're more distinct from one another; maybe the lede? — Tenryuu 🐲 ( 💬 • 📝 ) 03:49, 10 June 2021 (UTC)

Looking forward to your responses,. — Tenryuu 🐲 ( 💬 • 📝 ) 03:49, 10 June 2021 (UTC)
 * I will consider this copyedit request to be complete. If you would like me to take another look at this, please reply to the questions above. — Tenryuu 🐲 ( 💬 • 📝 ) 17:58, 11 June 2021 (UTC)
 * Thanks very much indeed User:Tenryuu Unfortunately I have been busy IRL. Much appreciate the copy edit. I introduced a new Australian guideline showing how the terminology is utilised differently by varying groups do you think that is best in the lead, or in the body? Also responded to some questions above --Almaty (talk) 10:16, 16 June 2021 (UTC)

Infectivity starting from three days before symptoms not fully compatible with claims of asymptomatic infection
In second paragraph: ''Infectivity begins as early as three days before symptoms appear, and people are most infectious just prior to and during the onset of symptoms. /---/ People can spread the disease even if they are asymptomatic.'' It might be more accurate to say that people having symptoms can be retrospectively considered infective three days before symptoms appeared, but since symptoms might never appear they can become infective up to n days after exposure to virus. The main point is that reader shouldn't conclude that you can derive period of infectivity from time of symptoms appearing, because symptoms might never appear. This is not contradiction in itself, but might be confusing and it might be good idea to avoid this misunderstanding, since it can also lead to wrong decisions in practise. Kamma (talk) 14:06, 26 July 2021 (UTC)
 * The infectious period is based on the symptom onset date, or the test date if asymptomatic. You can't base it on the exposure date due to the incubation period being variable. -- Almaty  ✉✎ 12:28, 1 August 2021 (UTC)
 * Exactly. Currently the article leaves reader with impression that you can presume that if no symptoms appear three days after possible exposure to virus, you are not infected. It is not self evident to layman how last sentence about asymptomatic infection applies to first two sentences of the section. I think first sentence of the section should already say that there is both symptomatic and asymptomatic infection and then specify what this entails. By the way, in practise you don't know in advance if you are symptomatic or asymptomatic, therefore if no symptoms appear you always need to take into account the possibility of being asymptomatic -- this leaves you with exposure date combined with test date as only reliable data to base your estimation of infectious period on (also taking into account variable length of both incubation or infectious periods). Kamma (talk) 19:43, 15 August 2021 (UTC)

Transmission of a disease?
Hi, I was a little surprised to read about the "Transmission of COVID-19" because I was certain, that COVID-19 is a disease that we develop after the transmission of SARS-CoV-2 virus. --DanSy (talk) 19:02, 15 September 2021 (UTC)

Kissing photo
Please replace the kissing photo with one which is less intimate, there are many cultures where kissing has been a significant method of transmission, and where the kissing has not been oral-to-oral such as depicted in this somewhat distracting and confronting intimate engagement. — Preceding unsigned comment added by 150.101.157.18 (talk) 09:45, 17 September 2021 (UTC)

Is there any correlation between number/quantity/quality of viruses, and severity of symptoms?
Have any studies indicated a variation in severity of symptoms relating to number of viruses or transmission route or any other factor that could affect the viability of viruses in the host? (other than the obvious vaccination and previous infection antibodies) · · · Peter Southwood (talk): 16:25, 10 January 2022 (UTC)

Yes, see DOI 10.1093/cid/ciab903 for an intro, or the respective pages in the Master Question List of the DHS: https://www.dhs.gov/publication/st-master-question-list-covid-19. — Preceding unsigned comment added by 62.155.217.106 (talk) 13:51, 20 December 2023 (UTC)

Unclear claim commented out in intro
I have commented out the following clause from the introduction: as only 10 to 20% of people are responsible for the disease's spread,. It is unclear whether this refers to the percentage of the total population who transmit the virus (i.e., substantially those infected at any one time), or to the percentage of those infected who transmit it. There is use in the body of the article of the term "overdispersed", but I don't have the expert knowledge to evaluate whether that's the answer and hence to clarify it in the introduction. We are only using that source once. Rather than examine it and the sources for the passage in the body text myself and risk misleading the reader, I commented it out and request editors with more knowledge to establish whether that passage in the introduction is appropriate in the current state of knowledge and if so, make it clear. Yngvadottir (talk) 22:19, 4 April 2022 (UTC)

NYC Departement of Health recommendations re:sex & covid19
I rewrote the paragraph that mentioned the NYC Departement of Health (NYCDH) recommendations. One problem is that it presented all these things as something recommended by "health authorities" in general, not as things recommended by NYCDH. For example, I'm not sure that health authorities in general discouraged unvaccinated people or people over 65 from kissing or having casual sex.

Also, there were groups mentioned in the source, but not mentioned in the article, so I added them (e.g. immunocompromised people).

I also added the recommendation regarding face masks during sex (by the way, this is one of the reasons why I really don't think these NYCDH's recommendations are reflective of what recommendations are/were globally).

It's probably an outdated source, and I'm not even sure NYCDH still recommends all of these things. Maybe this is very anecdotal, and should be replaced with information from a more global source (what does WHO recommend for example?).

On the other hand it might be interesting to keep it, to show how recommendations changed over time (but the problem is that it seems quite NYC-centric). I'm not entirely sure what to do. Anyway, it was not possible to keep the paragraph as it was, because it didn't reflect correctly what the source actually says, in particular by omitting groups particularly at risk from severe disease. 85.169.195.108 (talk) 09:12, 27 August 2022 (UTC)

Confusing wording pertaining to aerosol/droplets.
"The dominant mode of transmission of the COVID-19 virus is exposure to respiratory droplets (small liquid particles) carrying infectious virus (i.e., airborne or aerosol transmission)."

The quoted sentence (as of Sept 10, 2023) is intransparent to the average reader, or possibly inherently intransparent. The paragraph should start with a definition of what a "droplet" is and if this is the same as an aerosol. Then there should be evidence which mode (aerosol / small / large droplets / range of a continuum etc) is predominant in which situation (e.g. depending on variant, exposure situation) and what evidence there is. In particular, the article https://en.wikipedia.org/wiki/Airborne_transmission provides insightful information on this topic that could be incorporated to some degree. 2A01:C22:D4FB:C00:B81D:22F4:1D15:D170 (talk) 19:20, 10 September 2023 (UTC)


 * I agree that the airborne transmission article is clearer and would support similar wording here. PieLover3141592654 (talk) 19:23, 25 October 2023 (UTC)