Can i get an infection from my guitar?

ive been playing 4 or 5 hours a day for the past 4 weeks. and i havnt changed my strings in a year. and i cut my index finger on the B string. there was ore blood than i anticipated and i started to panic.well itrs been a wek since then and the slit is turning greenish black. but i clean it everyday with alchohol and iodine. whats happening?