Speaker
Description
Background: Onchocerciasis remains a major public health challenge in tropical regions despite decades of ivermectin-based Mass Drug Administration (MDA). While infection rates have declined, elimination still requires effective macrofilaricidal therapies targeting adult worms. Rifampicin (RIF), a potential macrofilaricide, has demonstrated superior anti-Wolbachia activity in vitro and in animals, but its clinical efficacy is uncertain. This study evaluated the safety and efficacy of 35 mg/kg/day RIF combined with 400 mg/day albendazole (ALB) as an alternative treatment.
Methods: A phase II randomized, controlled trial in Ghana enrolled 120 onchocerciasis patients into four groups: RIF+ALB for 7 days or 14 days, ALB alone for 14 days, or No-treatment (control). Participants were followed at 4-, 18-, and 20-months post-treatment to assess Wolbachia and microfilaridermia depletion, adult worm vitality and embryogenesis in female worms. All received 200 µg/kg ivermectin at 6 months post-treatment.
Results: High-dose RIF+ALB was safe, well tolerated, and associated only with mild, transient adverse events. Treatment with RIF+ALB for 14 days significantly reduced Wolbachia load in skin microfilariae at 4 months (47.9% reduction; p=0.018). Albendazole monotherapy showed significantly sustained reductions in skin microfilarial densities at 18 and 20 months’ time points (p<0.05). However, no significant macrofilaricidal effect or sustained Wolbachia depletion in adult worms was observed in any group.
Conclusion: High-dose RIF+ALB is safe but has limited macrofilaricidal efficacy in clinical settings. Albendazole alone shows promise as an alternative microfilaricidal treatment to ivermectin or as a complementary regimen. Further optimization of RIF as an anti-Wolbachia regimen is needed for onchocerciasis treatment.