Blood worms and Drip system contamination

Quick question.

do alot of you guys experience issues when feeding strictly bloodworms to your fishes? i know i do. i feel if fishes eat pellets, leave them on the pellets...

and second question

what are the risks with community contamination with a drip system. would a uv light system and filters be enough to ensure bacteria and contamination is contained? i know nothing is foolproof but what steps would be recommended. i see some betta shops doent even care for drip systems. maybe to keep possible future contamination contained.