I think the parasite culprit you're thinking of is Coccidia, but it could be a few others.
Major signs of parasites are sleeping during the day, not moving at all throughout the day, darker in color, smelly fecal, NOT eating, losing weight, not drinking, weak grip, falling, etc. Atleast through MY experience with coccidia/pinworms these were the symtoms I noticed my cham going though. If you see your cham has 2-3 of these symtoms it's best to get a fecal test done asap to know exactly whats wrong with your guy. It could be pinworms or other parasites. But coccidia is pretty much the most dangerous one / life threatening.
Cures would be getting whatever meds your vet prescribes your cham and sticking to it. Sometimes you'll have to make a hospital cage so your cham won't hurt himself by falling, and cleaning up would be a lot easier.
again, It really just depends on what your cham has. You can get parasites by all kinds of ways. Bearded dragons are the culprits of coccidia, anoles aswell if your cham consumed them.
You can get your crickets from a pet shop, the pet shop could have an effected beardie/chameleon then a loose house gecko or anole could eat a cricket thats been eating on the effected fecal, then when the anole/gecko poops ontop of the cage where the crickets are, they all gut load themselves with the parasite, or a worker throws the loose cricket back in the cricket container.
It's detrimental if you really think about it, but it happens.
Your best bet to really find out what is wrong is by getting a fecal sample. But before you do that, i'd recommend filling out the
https://www.chameleonforums.com/how-ask-help-66/ because it could be no signs of parasites and just your husbandry could be off.
Just copy / paste your answers here.
-Gabe