Can you get sick from your own germs?

February 10, 2011 5:17 PM

Is it possible to reinfect yourself with your own germs when sick?

My friend and I are debating if one can make postpone getting better by reinfecting yourself with your old germs, such as using a toothbrush you had used 8 hours before etc.

If so, what special measure can you take to prevent this from happening? Boiling toothbrushes, hand sanitizer etc?

posted by JJkiss to health & fitness (13 answers total)

I was *just* reading something about this online, but I'm damned if I can remember where.

Short answer: no.
posted by gaspode at 5:19 PM on February 10, 2011

I agree with short answer. Your immune system is already working on those germs, and they are already in your body. So you aren't changing the odds much by reintroducing them.
posted by grizzled at 5:21 PM on February 10, 2011

@gaspode, it was probably Slate.
posted by heigh-hothederryo at 5:24 PM on February 10, 2011 [1 favorite]

I think it depends on what you're sick with. I have strep throat at the moment and I'm supposed replace my toothbrush about halfway through the course of antibiotics to avoid reinfecting myself.

Note to self: That's tonight.
posted by elsietheeel at 5:28 PM on February 10, 2011

If you're using antibiotics to kill off the infection your immune system may not be amped up enough to deal with fresh batches of germs. But if you're letting your body deal with it naturally then you should be ok.
posted by Hairy Lobster at 5:40 PM on February 10, 2011

Short answer: no.

Even as a short answer I think that's closer to wrong than right.

It's true that you very probably can't reinfect yourself with a cold virus or an influenza virus, but there are a lot more germs than simple common viruses. You most certainly can reinfect yourself with bacteria such as staphylococcus aureus, and quite easily for some virulent strains.

So I think the more correct short answer is "it depends on the germ".
posted by Justinian at 5:51 PM on February 10, 2011

Oh, yeah, it was Slate.

And I admit: I made the assumption that the OP was talking about "everyday" germs like the cold virus. Certainly you can reinfect yourself with S. aureus. Different mechanism.
posted by gaspode at 5:56 PM on February 10, 2011

If you're using antibiotics to kill off the infection your immune system may not be amped up enough to deal with fresh batches of germs. But if you're letting your body deal with it naturally then you should be ok.

This seems like a bit of a misunderstanding about how antibiotics and your immune system work. It's true that you probably won't reinfect yourself with a virus your immune system fights off, but you wouldn't (or at least shouldn't) be taking antibiotics to fight a virus in the first place. And you definitely can be reinfected with a lot of strains of bacteria even if your immune system fought it off before.
posted by Justinian at 5:58 PM on February 10, 2011

And I admit: I made the assumption that the OP was talking about "everyday" germs like the cold virus. Certainly you can reinfect yourself with S. aureus.

Unfortunately resistant s. aureus is turning into an every day germ. Which probably scares the bejeezus out of you just like it does me since you're in biomed? But I guess everyone can stipulate that you aren't going to reinfect yourself with a cold so it's all good.
posted by Justinian at 6:01 PM on February 10, 2011

S. aureus is (and always has been) part of normal flora. If you swabbed yourself (particularly your nose) you'd probably be able to isolate it right now. The one to worry about is methicillin-resistant s. aureus (MRSA).

And yes, it's hard to reinfect yourself with a virus or bacterial infection that you currently have. It is possible to pass these things back and forth, within families for example, because they have a nasty tendency to mutate.
posted by charmcityblues at 6:08 PM on February 10, 2011

Certain parasites that the body can't build immunity against will keep on reinfecting. Scabies, for example, they advise you to replace/ thoroughly wash in chemicals/burn bedsheets, clothes etc.
posted by Lucubrator at 6:11 PM on February 10, 2011

As a general rule: Viruses no (unless they mutate... which can happen), Bacteria yes.
posted by Brennus at 6:31 PM on February 10, 2011

I am going to take the other position. Yes. For everything. A virus gloms onto a cell and injects its DNA (or is it RNA? I forget.) into the cell, enslaving it to create more viruses. Meanwhile, the immune system is trying its best to kill all the viruses it comes into contact with. These things happen concurrently.

When we are immune to a virus, that doesn't stop the virus from doing its thing. It just allows the white blood cells to detect and stop the viruses more quickly. So even if you are immune to common cold virus #27b, if you get a nose full of it, they will start doing their thing. Your nose may get stuffed up and runny as the first wave of viruses reproduce, before the immune system devourers them.

If you haven't quite healed up from your initial infection, you have a lot of raw mucosal tissue in your respiratory tract that can easily be reinfected. This is how a cold lasts three weeks. Your immune system is killing everything it can get its hands on, but your stuffed nose is letting the viruses hang around.
posted by gjc at 6:42 PM on February 10, 2011