I do not know why she swallowed a fly. I almost died watching this video.
There are lots of unknowns about this.video which shows a doctor pulling a botfly larvae, more disgustingly known as a maggot, from inside the swollen lip of a woman. there are only limited details about the medical condition from the original post on YouTube, where the patient had consulted a doctor due to a swollen and itchy lip.
Its not clear where and why she got that infection that made her lip swollen. this video was originally posted on YouTube, and is now gaining traction viral.
Similar story by the HUFFINGTON post, we found out that flies can lay their eggs in orifices of anyone.