Efficacy and Safety of Albendazole 400 mg for 30 Days in Adult Patients with Low Loa loa Microfilaremia: A Non-Inferiority Randomized Controlled Trial Compared to Ivermectin

BackgroundLoa loa infection is endemic in central African countries like Gabon and in West Africa. Treatment typically involves the use of ivermectin and albendazole, with albendazole often used to reduce microfilaremia in individuals with high microfilaremia before administering ivermectin. This study aims to evaluate the efficacy and safety of albendazole in patients with low microfilaremia. Methodology and principal findingsThe study was conducted from November 7 to April 1 across 31 villages in the Woleu-Ntem province of northern Gabon. Following a questionnaire, venous blood was collected in EDTA tubes for Loa loa diagnosis. Eligible individuals were randomized into two treatment groups and followed for 30 days. One group received daily albendazole tablets (400 mg), while the other received a single dose of ivermectin (200g/kg). The study reported a 33.0% prevalence of Loa loa infection in northern Gabon. In the per-protocol analysis, the mean microfilaremia decreased significantly by 82.3% and 90.4% in the ALB and IVM groups, respectively (p 0.001). The risk difference between the treatments was 8.1% [95% CI: 16.8; -0.6%]. For the intention-to-treat analysis, the mean microfilaremia decreased significantly by 82.4% and 90.8% in the ALB and IVM groups, respectively (p 0.001), with a risk difference of 8.4% [95% CI: 16.2; 0.6%]. Eosinophil rates decreased by day 30 in both groups, though not significantly different (p>0.05). Conclusions/SignificanceThe prevalence of Loa loa infection (33.05%) is notably high in northern Gabon. Albendazole demonstrated microfilaricidal activity in individuals with low Loa loa microfilaremia. However, its efficacy appears inferior to that of ivermectin and seems to diminish at very low microfilarial loads. Author summaryLoa loa infection is endemic in central African countries, including Gabon, and across West Africa. Despite the absence of specific treatments developed for Loa loa, current therapeutic approaches predominantly rely on diethylcarbamazine (DEC), ivermectin (IVM), and albendazole (ALB). Although ALB is more readily available, it is typically reserved for patients with high microfilaremia due to potential severe adverse effects following treatment with IVM. This study aimed to evaluate the efficacy and safety of ALB as an alternative treatment for patients with low microfilaremia compared to IVM. The findings suggest that ALB could serve as a viable alternative for the treatment of microfilaremic loiasis. Moreover, ALB treatment demonstrated adequate clinical efficacy and safety comparable to that of IVM.