I collect found white feathers, from seagulls. I am hesitant to use them for my creative projects as I worry that they may contain microscopic parasites, insects etc... I would like to know how to disinfect them. Does anyone have any suggestions? Thanks.

I'm guessing here, but I would try some alcohol on them. Maybe put it in an old spray bottle and spray them, then let them dry. Try not touching them, let them dry naturally so they stay the same shape.

I agree with unluckynut - alcohol should be fine as it evaporates quickly.