That's a safe assumption YES, but its also the easy way out of describing what are some of the most highly evolved and successful organisms on this earth.
I certainly didn't mean to downplay the importance of cleanliness... But for example, if someone is to run a fecal on a Uroplatus gecko, they will likely find species of coccidian (like Sean said) that are undescribed and specific to Uroplatus... They can and will differ from other coccidians (even between congeners) in a number of morphological structures, different developmental patterns and site and host specificity. It is unlikely that they can cross family lines, but I am not completely ruling out the fact that they can possibly cross-infest within or between a genus/genera. Mechanisms of host-specificity can function on many levels (from ecological factors to specific nutritional requirements on down to something as specific as the pH of the host site).
The truth of the matter is that not much is known about Uroplatus parasites, and cross-infestation is more/less common in certain animal taxa. However, I am going to stick my neck out there and say that it is unlikely for Uroplatus to spread parasites to Rhacodactylus; undoubtedly so, if you are practicing good husbandry.
You will never rid your geckos of coccidians, you can only hope to maintain a balance between what the gecko’s immune system can handle and what is detrimental to their health (ie. bad husbandry, stress, ect. play a role in causing coccidian manifestation). In addition, little is known about coccidian ability to re-infest its host after oocycts have been shed in the feces. Such re-ingestion of sporulated oocyts via directly into the mouth from dirt/feces or via a cricket that has eaten feces may cause coccidiosis.
Other parasites such as strongyles and acarids are more easily treated and eliminated so I will not concern myself with them in this post.
Like I said, I never meant to take a lax stance on fecal checks and proper hygiene. I guess I was trying to say more simply what I just said. And this is my opinion, as there is a lot of ambiguity surrounding Uroplatus parasites. However, I’ve done my research. I, along with a PhD, am slowly (but surely) working on scientifically describing some of these exact coccidians I have spoke of.
I invite people to take a look at the link I have posted to see just how diverse Saurian coccidians are;
Saurian Coccidians
-----
Ben