Some WC melleri come in with filiarial worms that can be removed with ivermectin or surgery. Ivermectin WILL kill your chameleon if there are too many worms, or the worms are too large - the bodies of the dead worms will lead to a nasty internal infection.
Some of these worms may get large. At least one very experienced melleri keeper had an otherwise perfectly acclimated LTC adult melleri drop dead for no apparent reason. It was a very large worm, that did not die from panacur treatments, that did not lay eggs that show up in fecal tests (it's a filiarial worm, spread by mosquitos, likely).
It penetrated a major blood vessel or aorta or something - killed the thing directly!
The only way to remove these would be major surgery - not just under the skin, but inside the animals body cavity!
Unless these were treated with (probably MORE deadly on average) ivermectin, there's not a thing you can do. It might just be a lottery - IS your animal infected with a time-bomb worm? Is it not?
I think 6 animals were recieved in the same shipment - 2 died from these.
not that you needed any more convincing, but still, it's good to know.