Welcome to the forum.
This question would be more proper on the HIV forum (see the statement at the top of the page). But hepatitis C rarely may be sexually transmitted, so we'll bend the rule.
Sharing of razors is one of those theoretical risks for transmission of HIV, hepatitis B and C, and other blood-borne viruses -- always listed as possible risks, but with few if any acqually documented cases. I am unaware of any actual proved cases of HIV being transmitted that way. It is true that HIV, as well as HCV, dies promptly upon drying, partly explaining the low risk.
I'm sure the blood supply in Chile has been adequately protected from contamination with HIV for at least the past 15 years, so you should have no worries about HIV. I'm less certain about hep C. However, if you remain concerned about it, why not talk to your brother about this? If he hasn't been tested for hep C or HIV recently, it could easily be done in both of you. In the meantime, you should not be worried at all.
Regards-- HHH, MD
Any testing for you is strictly for anxiety relief from the negative result. But if you want to wait for your brother's test results, that's fine too -- but it would be anxiety producing if he happens to have a positive test. But even if your brother happens to test positive for HIV or HCV, you are no measurable risk from having shared a razor a few times. And it sounds like that probably didn't happen anyway (did you ask him?). If not, what is this all about?
Anyway, stay mellow as you await the test results. That's all I'll have to say unless and until you want to report the actual test results.
I think I have convinced my brother to get tested. When you said "it could easily get done in both of you" are you referring to me get tested as a means for anxiety relief or is there actually enough risk to warrant my testing. I just tested negative for everything a week ago, as did my girlfriend and we have been having unprotected sex with an IUD for a while now. The anxiety of waiting for the proper waiting periods is agonizing for me, particularly the long one for hepC. I mostly worried about this stuff because I have been enjoying unprotected sex with my girlfriend, occasionally anally which I am aware is the rare possibility of hepC being spread. "In the meantime, you should not be worried at all" should be enough for me but my anxiety is high so if you could clarify whether or not you recommend testing for me, I would appreciate it. Again I fairly certain my brother never actually used my razor; the possibility is just very troubling.