Assessment of Antihelminthic Efficacy of Mebendazole 500 mg against Soil- Transmitted Helminths in a High Risk Area of Cameroon

Background: The three major soil-transmitted helminths (STHs) (Ascaris lumbricoides, Trichuris trichiura and Necator americanus/Ancylostoma duodenale) cause the highest burden on public health particularly in the sub-saharian regions of Africa. Although albendazole (ABZ) or mebendazole (MEB) is widely used as preventive antihelminthic treatment, there still exist variation in the efficacy of these drugs and standard threshold efficacy limits are not yet well established for all the three STHs.

Aim: The objective of this study was to evaluate the efficacy of single dose Mebendazole (500mg) against these three STHs.

Methodology: A random control trial was conducted among school children residing in a high risk area of Cameroon. A toatal of 410 school-aged children in the Lolodorf neighbourhood were screened using the Kato katz technic followed by treatment of participants with a single dose of mebendazole (500 mg).Ten weeks post-treatment, children provided a single stool sample which was examined using the same diagnostic method. Efficacy was assessed by the Cure Rate (CRs) and Egg Reduction rate (ERRs).

Results: Globally, 259 (63.2%) were infected for one or more STHs.The highest CRs were observed for A. lumbricoides (93.9%) followed by hookworms (70.8%) and T. trichiura (60.7%), for an overall CR of 59.1%. CRs varied considerable by age for hookworms and by type of infection for T. trichiura and hookworms. The prevalence reduction rate was highiest for A. lumbricoides (91.4%) followed by hookworms (61.0%) and T. trichiura (46.3%). ERRs were highiest for A. lumbricoides (94.5%) while this values were low for hookworms (52.9%) and T. trichiura (39.9%). The ERRs were affected for T. trichiura and hookworms by pre-treatment egg count for sex, different classes of infection intensity and types of infection.

Conclusion: Our findings suggest the efficacy of single dose mebendazole 500 mg against A. lumbricoidesand to a lesser extent on hookworms with low drug effect on T. trichiura. Further development and validation of standard protocols for antihelminthic drugs efficacy has to be established.