I thought it was just a wound he got somehow else and it got infected with normal crap and that's why he needed antibiotics.
It looked like a knife slash or similar to me. Infected now, I suppose. Ends the same if it's not treated.
Well, this was certainly a gripping episode. It was just fascinating to watch Morgan's journey from complete insanity to normal to beginning the road to inner peace. I was pretty surprised when it was revealed that Eastman actually killed his family's murderer (definitely a Kodak moment). What a shame that Eastman had to die. And now we find out that Morgan's captive Wolf has been bitten. And he said "if I die." It seems that he's had the bite for a while-- I wonder if we'll start running into people who are immune to the virus.
Was that a bite though or just an ordinary wound that has gotten infected. He said he was looking for medicine.
For some reason, I thought it was a bite, but I'm probably wrong. Since everyone now alive has some degree of immunity from the virus, since they didn't die of the "flu," I thought it might be interesting if people with a greater degree of immunity-- whose immune systems can actually kill the virus-- started to turn up. It's already been speculated that Rick is immune, and there was Herschel who survived being bitten
when they amputated his foot.
That's they key thing there. They hacked off his lower leg before the active infection(s) could kill him and the dormant infections everyone has reanimated him. And it seems pretty likely, as it usually is in zombie fiction, that you'd have to do it quickly. Which is why it's very unlikely Rick is infected from the wound he suffered, to say nothing of the production reasons he won't lose his hand or that Kirkman regrets taking off Comic Rick's hand.
Rick's going to be fine, and I suspect it's not due to any "immunity" he has to the "walker virus" or whatever infection everyone has. The hand injury seemed more due to just it happening due to his ambitions in taking out the walkers and maybe play a role in slowing him down a bit; it's just another in a long list of injuries he's suffered.
Everyone on this show has been exposed to gobs and gobs of walker blood, entrails, offal and so forth. The gang were swimming in stagnant water that had walkers in it for untold lengths of time (the Food Bank last season) which is going to be filled with the infections from the walkers and it's unlikely everyone managed to not get some water in their mouths, in a minor cut, or whatever.
Remember, on an injury from a walker you do not die from any "walker virus" they carry you simply die from a nasty, immune system resistant infection. Sort of like getting surgery done at a hospital and there's some minor lapse in contamination control and people get a staph or other infection.
There's a lot of quibbles we could make about this, but it's possible this mundane infection doesn't survive long outside of the walker's body, or outside of any body, and the injury Rick got from the blade was no longer active enough to infect him.
These people are regularly coated in the blood of walkers and survive, where it's getting in their mouth, their eyes, in any cuts, scratches, scrapes, etc. they have and they survive.
Rick is going to be fine.