Coccidia is not technically a worm but a protazoan. It has a large family and includes crypto. From what I have read, it is mostly species specific but there have been a couple that I have read about that cross from one species to another. It is also location specific in a host....some go to the stomach, some to the intestinal tract, etc. It can cause dehydration in its host.
I don't think there is a medication that will actually kill it but I have read that coccidastatic medications will slow its reproduction so that the chameleon's immune system can get rid of it.
I have read that oocysts can stay dormant for years. Due to the hard shell protecting them, it is almost impossible to kill them when they are encysted in the lining of the intestines or other location in the body.
I haven't had much experience with it in my chameleons or other reptiles (thank goodness!)...but I did have a pair of WC globifers and one of them had it. Coincidentally, they were both on a sulpha drug for toe and ankle infections...so it was just continued.
I also had a WC oustaleti female who expelled "worms" in her stool. They turned out to be Apicomplexa Eimeria and I was asked to allow her to continue untreated so that they could get a male of the species so they could identify it. No male was retrieved until the necropsy several years after.
The oocysts expelled from the body are not always easy to kill. From what I've read dryness will kill them and ammonia will too...but it may need to be left on them for a long time. Disinfectants in the strength normally used won't kill them in most cases. Some are killed by UV light and some take extreme heat to kill. Steam can kill them if its over 160 degrees. Even freezing won't kill some of the species. Sorry I can't be more specific...but its a large family of parasites.
Its important to be clean and take care not to transfer the parasite from one tank to another. In some cases insects can spread the oocysts...so I would dispose of whatever is taken from the cage in such a way that it can't be reached by insects.
Here are some sites that you might like to read...
http://biology.unm.edu/biology/coccidia/home.html
http://biology.unm.edu/biology/coccidia/eimeriabiol.html
Hope this helps! Hope you get rid of it in your lizard!