Differential Effect of Ivermectin on Intestinal Helminths in Multimmate Mouse (Mastomys natalensis).

Mastomys natalensis is a widespread rodent species in sub-Saharan Africa and is increasingly recognised as an important component of food systems in some communities. However, rodents may harbour gastrointestinal helminths with potential implications for animal health, food safety, and zoonotic disease transmission. Information on gastrointestinal helminth infections in M. natalensis and the response of these parasites to anthelmintic treatment is limited. This study investigated the prevalence and diversity of gastrointestinal helminths in M. natalensis and evaluated changes in helminth egg burden following treatment with Ivermectin. A total of 90 adult M. natalensis, comprising 43 males and 47 females, were captured, and their faecal samples were examined for gastrointestinal helminth eggs. Identified helminths were characterised and their prevalence was estimated with 95% confidence intervals. Following baseline assessment, the rodents were allocated to -treated and untreated control groups. Faecal egg counts, expressed as eggs per gram of faecal sample (EPG), were monitored every 14 days over an eight-week period. The change in egg burden was assessed using faecal egg count reduction (FECR). Five gastrointestinal helminth taxa were identified, of which Hymenolepis diminuta was the most prevalent (39%; 95% CI: 29.6-49.3%), followed by Physaloptera spp. (29%; 95% CI: 20.6-39.1%), Rodentolepis nana (12%; 95% CI: 6.8-20.3%), Strongyloides spp. (11%; 95% CI: 6.1-19.1%), and Trichuris spp. (9%; 95% CI: 4.6-16.7%). In the Ivermectin-treated rodents, mean EPG declined substantially across all five helminth taxa between baseline and weeks post-treatment. The highest egg reductions were observed for H. diminuta (96.4%) and Trichuris spp. (96.2%), followed by Strongyloides spp. (90.9%), Physaloptera spp. (85.5%), and R. nana (80.0%). The untreated control group showed comparatively little change in overall helminth egg burden. Sex-specific analyses showed substantial reductions in both males and females over the same period, except for, R. nana females, where egg counts showed an increase. These findings indicate the potential value of Ivermectin in reducing gastrointestinal helminth egg shedding by M. natalensis. Further studies with larger sample sizes, over a longer period, and appropriate experimental replication are warranted to validate treatment with the anthelminth and its implications for animal health, food safety, and potential zoonotic transmission.