1. Why are we so sure this was ivermectin resistance and not just, y’know, a really tenacious larva?
The patient got 240 µg/kg, waited a week, got another dose. That’s pretty standard. But the paper admits single-dose ivermectin failure happens sometimes even without resistance, some people just need 2-3 doses. So what’s the actual evidence here that this was genuine resistance in the parasite, rather than just a slow-to-clear infection in this particular patient?
We don’t have larval motility assays. We don’t have genetic data from the hookworm. We don’t even know for sure which species it was. Without that, calling this “ivermectin-resistant CLM” feels more like speculation than diagnosis. Could this just be confirmation bias because we want to see the first resistance case?
2. The dog deworming history is really thin—can we actually link it to this case?
The paper says community dogs got ivermectin yearly for 5 years. But there’s no data on hookworm prevalence in those dogs, no fecal egg count reduction tests, no molecular markers for resistance. We don’t even know if A. braziliense (the usual CLM culprit) was present in those dogs at all, most of the cited dog studies focus on A. caninum and A. ceylanicum.
So if the patient was infected with A. braziliense, and we have zero data on ivermectin susceptibility in that species in that community… isn’t the “resistance from dog MDA” storyline pretty speculative? Feels like the epidemiology is being stretched to fit the narrative.