If they stop for 24 hours with invermectin, it could be another roundworm.
I was tested for filariasis, and strongyloides. both were negative.
There are 1000 species of round worms.
I tested positive for Ascaris. The ELISA test means 205KDA
Testing positive for 205 generally means you have a round worm.
unless you tested positive for specific kda 49, 87, 21, etc, antigens, which is only done in a research lab, it is hard to know exactly what species you have.
The good news is that there are only a few meds and most have some effect on a round worm, irregardless of the type.
BOLDO slowed them down, Zinc Sulfate made them sick then explode, anti-parasitics kill them. Even within a species, certain drugs may not work. I tried all the usual drugs, non of them worked for me. I had to go off label.
If it is round, there are quite a few meds that could work. sometimes it takes 2 or 3 at a time to kill the critters.