Worst thing that happened to me was the vermetid snail puncture bit... I was blindly reaching into the tank and doing it a bit too quickly and got stabbed right in the knuckle... got swollen... next day hand was red, told my wife not to worry about it (notice the stupidity/manliness starting)... hurt like hell had to sleep with my hand sticking up like a flag pole.. went to work... biologist there said he'd fear for his life if that were him... needless to say went to the docs.. hand was swollen like a sparring glove and curled/contorted in an odd way (cellulitis), had a lovely red streak that went halfway up my hand... broad spectrum antibiotics did the job. Never knew exactly what the bacteria in question was they couldn't grow out a specimen (or some dumb ass lab tech guy screwed things up).
Happened again some time later, I drew a circle with a marker around the wound to show the redness, had an appointment the next day, it was larger.. same thing with antibiotics, no issues with cellulitis.
Either way, those little vermetid snail harpoons are tough buggers, like really thick hypodermic needles, a glove wouldn't have done squat unless it was made with metal plates. Your skin is your most important organ that protects you in tanks! Be careful how you move and where you're grabbing. Wash your hands after you're done (with actual soap and hot water, not just run them under the sink for 5 seconds), and check for scrapes/cuts, I tend to put antibiotic ointment if I get any big scrapes.