Prevalence of Gastro-intestinal Parasites with Zoonotic Potential in Rodents Trapped from the Ngorongoro District, Arusha, Tanzania

Background: Rodents are prominent reservoirs for several pathogens that cause significant human infections, including parasitic zoonoses responsible for over 60% of human infectious diseases globally. This condition is exacerbated by climate and ecosystem changes, which facilitate the spread of rodents, ectoparasites and carried pathogens. This study aimed to determine the prevalence of zoonotic gastrointestinal parasites present in rodents of the Ngorongoro district, Tanzania, addressing an information gap at the human-wildlife interface.

Methods: A cross-sectional study was conducted in January to March 2022. A total of 606 rodents were live-trapped from indoor, crop fields, and peri-domestic areas, humanely euthanized by using Isoflurane, and examined for helminths and protozoa using simple flotation and formalin ethyl acetate concentration techniques (FECT).

Results: Nine gastrointestinal parasites were identified, with Trichuris spp. being the most prevalent helminth (12.7%), followed by Hymenolepis nana (11.5%), Hymenolepis diminuta (11.2%), Capillaria spp. (6.3%), Strongyloides spp. (6.1%), and Physaloptera spp. (5.4%). Among protozoa, Entamoeba spp. had the highest prevalence (15.5%), followed by Giardia spp. (6.8%) and Cryptosporidium spp. (2.5%). Overall, 46.9% of the rodents were infected with at least one type of gastrointestinal parasite. The study found no significant influence of sex, age, or habitat on the prevalence of gastrointestinal parasites. However, Mastomys sp and Rattus sp exhibited significantly higher parasite prevalence compared to Mus spp (p=0.040 and p=0.022, respectively). Additionally, Sale village had a notably higher prevalence compared to Orgosorok (p=0.00), Engarasero (p=0.022), and Malambo (p=0.002).

Conclusion: The occurrence of zoonotic parasites highlights the potential for rodent-borne diseases transmission to humans and domestic animals, necessitating enhanced public health awareness and rodent control measures.