Talk:Optimal virulence

Unwanted word?

"... Once transmission occurs, the 10 pathogen must establish an infection to continue. ... " Uhhm wot's the "10" doing there? Old_Wombat (talk) 09:13, 12 October 2011 (UTC)

Trade-Off-Hypothesis

The chapter on the trade-off-hypothesis is extremely unclear. It is mostly defining what the trade-off-hypothesis is not. A proper definition would be better than the vague sentence that virulence depends on the parasites costs and benefits. — Preceding unsigned comment added by 2A02:908:1014:1F20:78B8:957D:1EC2:4FC (talk) 15:28, 3 April 2020 (UTC)

Edit request: Update to Transmission Trade-Off Model for Respiratory Viruses

I am the author of two peer-reviewed papers on the evolution of viral virulence and tropism (Shaw Stewart & Bach, 2021; Shaw Stewart, 2024). In compliance with Wikipedia's Conflict of Interest (COI) guidelines, I am submitting this request on the Talk page rather than editing the article directly.

I propose adding a short paragraph to the "Mode of transmission" section to expand on Paul Ewald's trade-off hypothesis. The proposed text details how temperature-dependent tropism serves as a biological mechanism that promotes host mobility in respiratory pathogens, and notes how this applies to the long-term evolutionary trajectory of direct respiratory viruses such as SARS-CoV-2.

Proposed text

In the "Mode of transmission" section, please insert the following text at the end of the first paragraph, immediately following the sentence: "...In such immobilized, crowded conditions pathogens can make individuals very sick and still jump to healthy individuals."

The biological mechanism underlying this trade-off for direct respiratory viruses (DRVs) has been conceptualized through the framework of "temperature-dependent viral tropism" (TDVT). According to this evolutionary model, endemic respiratory viruses have evolved an optimal thermal sensitivity that restricts aggressive replication to the cooler upper respiratory tract (approximately 33°C) while being inhibited at core body temperatures (37°C and above). This restriction prevents infection of vital internal organs, sparing the host from immobilization or rapid mortality, thereby maximizing the window for ambulatory transmission. Consequently, evolutionary pressure generally drives direct respiratory viruses—including the long-term trajectory of novel pathogens like SARS-CoV-2—toward attenuation and mildness, shifting them toward the clinical profile of a seasonal common cold over time.

References

• Shaw Stewart, P. D.; Bach, A. (2021). "Temperature dependent viral tropism: understanding viral seasonality and pathogenicity as applied to the avoidance and treatment of endemic viral respiratory illnesses". Reviews in Medical Virology. 31 (5): e2241. doi:10.1002/rmv.2241.{{cite journal}}: CS1 maint: article number as page number (link)
• Shaw Stewart, P. D. (2024). "Will COVID-19 become mild, like a cold?". Epidemiology & Infection. 152: e86. doi:10.1017/S0950268824001110.

Hybrid07 (talk) 16:06, 23 May 2026 (UTC)

Reply 20-JUN-2026

  Specification requested  

• Reasons for making this change were not provided with the request. A description of what the change entailed was given, however, a reason why the change was needed to be made was not offered.
• Four items are required for a successful COI edit request. In the section of text below titled Sample edit request, the four required items are shown as an example:

Sample edit request

1. Please remove the third sentence from the second paragraph of the Sun section:

"The Sun's diameter is estimated to be approximately 25 miles in length."

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2. Please add the following claim as the third sentence of the second paragraph of the Sun section:

"The Sun's diameter is estimated to be approximately 864,337 miles in length."

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3. Using as the reference:

Prisha Harinath (2023). The Sun. Academic Press. p. 1.

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4. Reason for change being made:

"The previously given diameter was incorrect."

Kindly open a new edit request at your earliest convenience when ready to proceed.
Regards,  Spintendo  16:43, 20 June 2026 (UTC)