3 votes

As with any other poison, viruses are usually deadlier in larger amounts

2 comments

  1. skybrian
    Link
    I posted this because it seems like another example of how easy it is to treat things as binary when actually, it's more complicated than that. But I don't think it's all that useful except maybe...

    I posted this because it seems like another example of how easy it is to treat things as binary when actually, it's more complicated than that. But I don't think it's all that useful except maybe for a single person, living alone, who is not working, so they are effectively already quarantined?

    The risk of spreading it might vary depending on the dose, but it would be hard to prove and better to assume that that anyone who catches it is likely to spread it.

    Perhaps assuming infection is binary is a fiction, but it seems like a useful one.

    3 votes
  2. skybrian
    Link
    From the article: [...]

    From the article:

    The importance of viral dose is being overlooked in discussions of the coronavirus. As with any other poison, viruses are usually more dangerous in larger amounts. Small initial exposures tend to lead to mild or asymptomatic infections, while larger doses can be lethal.

    [...]

    Both small and large amounts of virus can replicate within our cells and cause severe disease in vulnerable individuals such as the immunocompromised. In healthy people, however, immune systems respond as soon as they sense a virus growing inside. Recovery depends on which wins the race: viral spread or immune activation.

    Virus experts know that viral dose affects illness severity. In the lab, mice receiving a low dose of virus clear it and recover, while the same virus at a higher dose kills them. Dose sensitivity has been observed for every common acute viral infection that has been studied in lab animals, including coronaviruses.

    Humans also exhibit sensitivity to viral dose. Volunteers have allowed themselves to be exposed to low or high doses of relatively benign viruses causing colds or diarrhea. Those receiving the low doses have rarely developed visible signs of infection, while high doses have typically led to infections and more severe symptoms.

    It would be unethical to experimentally manipulate viral dose in humans for a pathogen as serious as the coronavirus, but there is evidence that dose also matters for the human coronavirus. During the 2003 SARS coronavirus outbreak in Hong Kong, for instance, one patient infected many others living in the same complex of apartment buildings, resulting in 19 dead. The spread of infection is thought to have been caused by airborne viral particles that were blown throughout the complex from the initial patient’s apartment unit. As a result of greater viral exposure, neighbors who lived in the same building were not only more frequently infected but also more likely to die. By contrast, more distant neighbors, even when infected, suffered less.

    1 vote