There are several parasites that infest bluegills and they are more prevalent during warm weather. This is because these "worms" have a very complicated life cycle that includes snails, the digestive tract of specific birds and the fish.
I know a bad infestation doesn't look very appetizing but these parasites *are not* a danger to humans. First because humans can not be a host (you could eat a handfull raw) and second because 350 degree grease tend to kill them.
I just add a little more pepper to the breading and *smile* when people say they won't eat 'gills in warm weather.
"Flyfishing is not a religion. You can make up your own rules as you go.".. Jim Hatch.. 2/27/'06