How many viruses could we eradicate?

February 10, 2013 10:54 PM

This may end up in a story, it may not... But this occurred to me the other day. We all learned in school that viruses need a host, bacteria do not. Therefore if we all voluntarily quarantined ourselves for two weeks, how many potential viruses could we wipe out?

The rules: We all do it. We all stock up our homes with enough food and drinks. We have sufficient distractions to not go stir crazy. No international travel, no school. Only close relations in the same homes, and once you're in, you're in for the full fortnight. All businesses close except pharmacies and hospitals. Only emergencies force us to interact at said hospitals or pharmacies and you must return home if possible.

Can this be reasonably calculated? What about a quarantine by definition, isolation for the full 40 days? Could we eradicate the cold? Flu?

posted by CarlRossi to science & nature (17 answers total)

Viruses need hosts in order to replicate, not necessarily in order merely to exist. Also, most viruses that humans can host will have close relatives that happily replicate in other species, and these things mutate frequently. So I would expect a two week universal quarantine to affect only the least hardy types, and that for not very long. IANAepidemiologist.
posted by flabdablet at 11:05 PM on February 10 [3 favorites]

You'd have to heighten your quarantine to an even greater degree than you think. Viruses that travel by air have been known to infect large buildings. The last person to die of smallpox was an accidental exposure of a person that worked two floors above a virology lab.

All businesses close except pharmacies and hospitals.

Hospitals are among the "filthiest" places you can visit. That's where the sick people are.
posted by Cool Papa Bell at 11:48 PM on February 10 [8 favorites]

More practically (ha), you could do a rolling quarantine of the whole planet: quarantine some small zone, then gradually expand it, with anyone entering the zone (either because they moved or the zone overtook them) being in isolation for X days.

I think there are two main ways viruses could slip through something like this. One is that, as flabdablet says, many viruses can exist, inert, outside of a host for a long time. Smallpox was nominally eradicated in 1979, but there are viable samples in freezers. Some viruses don't survive well outside their host though (HIV, for example).

The other is, I think most viruses occasionally produce atypical infections— it only takes one person who's an asymptomatic carrier for the disease to get it through the quarantine.

So far, eliminating a virus has only been done through mass vaccination, as was done with smallpox and (in many regions, but not yet all) polio.
posted by hattifattener at 1:20 AM on February 11

I have recently been wondering this EXACT QUESTION!

I don't have good answers, but I remember reading about an african country (Angola
maybe?) which asked everyone to just not have any sex for a month because HIV is most virulent in the first month that it is contracted. Thus distinctly reducing incidence of new infections. (If I have time I'll try and find the story later).
posted by Just this guy, y'know at 2:26 AM on February 11

Unfortunately there are plenty of viruses that cross over from animals to people- making this pretty impossible, in addition to the fact that you could never shut down the hospitals.
posted by Aliera at 2:37 AM on February 11 [1 favorite]

Unfortunately there are plenty of viruses that cross over from animals to people- making this pretty impossible, in addition to the fact that you could never shut down the hospitals.

These tend to be some pretty nasty viruses. Ebola and hantavirus are two examples with animal reservoirs. Influenza doesn't typically spread from an animal reservoir, but if we were able to eliminate the human influenza strains, pig or bird influenza would probably mutate to be able to spread between easily humans within years or tens of years. It return would be particularly lethal, as many fewer people would have any immunity to it.
posted by TungstenChef at 2:46 AM on February 11

Is 2 weeks the right amount of quarantine time? I thought viruses could live for years inside your body and reemerge later when conditions are different. HPV, Chicken Pox, HIV, etc. are all longer living viruses. For the ones that we think of as quicker - a cold, a stomach bug, influenza??? - is 2 weeks enough or would we need a month or more?
posted by CathyG at 5:35 AM on February 11 [1 favorite]

According to a FPP link, crabs are nearly extinct because of pubic hair shaving. This should encourage you.
posted by Obscure Reference at 6:32 AM on February 11

The difficulty is that most human disease viruses also infect animals. Flu, for instance, also affects ducks and swine.

One of the reasons that they targeted smallpox was that it didn't have an animal host. If the last human case was gone, then the disease was gone forever. But few diseases are like that.

If we did what you say, a lot of diseases would be gone ... for a while. And in a few months or a few years they'd come back again, as humans got reinfected by animals.
posted by Chocolate Pickle at 6:37 AM on February 11

Another problem is that some human virus infections are chronic. The infection doesn't necessarily end in two weeks, and a two week quarantine wouldn't result in you being virus-free. Think of Herpes Simplex, for instance: infection is pretty much for life. Human Papillomavirus (which causes warts) is another example.
posted by Chocolate Pickle at 6:40 AM on February 11 [2 favorites]

Therefore if we all voluntarily quarantined ourselves for two weeks, how many potential viruses could we wipe out?

None. Doesn't work that way.
posted by valkyryn at 6:56 AM on February 11 [1 favorite]

Obscure Reference: According to a FPP link, crabs are nearly extinct because of pubic hair shaving. This should encourage you.

Since genital shaving doesn't tend to be common in third-world countries, I'm calling bullshit on that claim.
posted by IAmBroom at 8:01 AM on February 11 [1 favorite]

None. I'm not even sure how you think this would eliminate any viruses. There's plenty of benign viruses inside you right now, just hanging out. They'll be there two weeks later. Plenty of viruses are zoonotic. New viruses appear seeming out of nothing – see the current theory on the origin of HIV. And virus particles are often just fine existing outside the body for quite a long time, waiting for a chance to infect and reproduce.
posted by chairface at 9:01 AM on February 11 [1 favorite]

Also, humans are human--there's no way a universal quarantine would be universally obeyed.
posted by snorkmaiden at 9:28 AM on February 11

Not that many. Some of the additional sources of infection include:

The environment: Multiple viruses can persist for months on surfaces, in water, or in soil. Polio and the common cold are examples.

Asymptomatic latency: HIV, HSV, HPV, and Hepadnavirus all have extended latency periods where a person is potentially infectious but asymptomatic.

Animal reservoirs: Influenza, Hantavirus, and hemorrhagic fevers all have significant animal reservoirs.
posted by CBrachyrhynchos at 11:57 AM on February 11

Did you get into the difference between the DNA and the RNA virus? You can do some research on your own, but basically, because of its structure, a RNA virus can mutate quickly, changing in virulence or transmissibility. Influenza does this. Because a DNA virus doesn't mutate as quickly, it's easier to target for elimination. Smallpox and HepB are two exampes

Because of this, and for all the reasons given by others above, the only way to effectively quarantine people would be to put them in their own idividual bubble and hope the benign RNAs within them don't mutate. And don't expect to ever come out of your bubble, because the world will be waiting for you. Best to keep up herd immunity.

Now go wash your hands.
posted by BlueHorse at 5:49 PM on February 11

I think most answerers here are missing the question, which was not "could this eliminate all viruses?" but "what viruses could this eliminate?". Pointing out the existence of viruses that this wouldn't eliminate is irrelevant. There's some subset of viruses which (a) don't remain viable outside a human host and (b) go from first exposure to end of transmissability in less than two weeks. How many viruses are those? In what ways would those viruses (not other viruses) evade the quarantine?
posted by hattifattener at 12:33 AM on February 12