alt Hacker Newshttps://pubmed.ncbi.nlm.nih.gov/9403981/
The article you referred to (and I've seen linked elsewhere in this thread) is about "regular" screwworm (Chrysomya bezziana). The recent outbreak is of New World Screwworm (Cochliomyia hominivorax). The article I've linked suggests that it is much harder to kill than regular screwworm (29% of calves developed myiasis even when treated with ivermectin).
Googling "Cochliomyia hominivorax and ivermectin" yields
"Ivermectin can be an effective treatment for myiasis, a condition caused by the larvae of certain dipterous flies, including Cochliomyia hominivorax (the New World screwworm). Studies have shown that ivermectin, when administered orally or topically, can help eliminate the larvae and reduce the severity of the infestation, especially in cases of orbital or oral myiasis. "