It's all quite very simple. Most life forms were made by intelligent design, actually all were. Life forms cannot exist without consciousness (of various degrees) and intelligence giving them life. That includes us.

And it does not need to be God, but a manifestation of God, meaning, other intelligent beings just like us, just more advanced. Unless you think we are the only ones in this Universe...

Humans are just now learning how to edit DNA and create the perfect "human"... see CRISPR.

All life is intelligent. The theory of evolution tries to explains something we have not yet understood. That we are also creators. In its most basic form, see animal breeders.

I do not know who created this parasite, but be sure this is not the result of random accidents, but careful, intelligent planning where a new species is created in harmony with others so they co-exist in balance...