Investigating the Role of Onchocerca ochengi in Epilepsy Development: A Gerbil Model Study

Abstract

Background: Onchocerca volvulus infection is linked to onchocerciasis-associated epilepsy (OAE) in humans, but the role of Onchocerca ochengi in epilepsy development remains unexplored. This study aimed to investigate whether O. ochengi infection contributes to epilepsy development.

Methodology/Principal Findings: Gerbils were implanted with O. ochengi worm masses (test group) or underwent sham surgery (control group). Behavioral and physical assessments were performed between days 15–19 using multiple tests, including the elevated plus maze, open-field, object recognition, and hanging wire tests. On day 21, gerbils were sacrificed, and body/organ weights were recorded, along with worm mass survival. Implantation of 15 worm masses resulted in 100% mortality in the test group, while implantation of 10 worm masses resulted in 53.3% mortality, with all control animals surviving. At day 21, worm mass survival averaged 1.4 out of 10, with a viability score of 93.3%. Test animals showed significant reductions in body weight and increased spleen weight compared to controls, but no significant behavioral differences were observed.

Conclusions/Significance: While O. ochengi infection caused notable physical effects, including high mortality and changes in body/organ weights, no behavioral evidence of epilepsy was observed. The high mortality rate and limited observation period restrict the interpretation of these findings. Further studies with larger cohorts and longer observation periods are needed to assess the potential role of Onchocerca spp. in epilepsy development. To the best of our knowledge, this study represents the first attempt to establish an animal model for OAE.