High Parasitic Infections in the Laboratory Animals: Complications for the Research Outcomes and Zoonotic Importance

Laboratory animals are widely used for medical research; hence, their health status is a determinant of the outcome and success of the research. We aimed to investigate the possible infection of rodents with intestinal parasites in the Hamadan University of Medical Sciences animal house.

From October to November 2022, one hundred and twenty healthy laboratory rodents including 60 Wistar rats, 30 BALB/c mice, and 30 NMRI mice were randomly collected and examined for parasitic infections. The digestive tracts were removed and examined for infection by helminths and parasitic protozoa using naked eye inspection and microscopy.

75.8% (95% CI: 68.1-83.5%) of the rodents were infected by at least one helminth or protozoa. Protozoal infections (41.7%) with Giardia spp. (15%), Tritrichomonas spp.(10%), Blastocystis spp. (6.7%), Entamoeba spp. (5.9%), Cryptosporidium spp. (3.3%), and Eimeria spp. (0.8%) were observed relatively higher than helminthic infections (34.2%) with Syphacia obvelata (10.8%), Syphacia muris (10%), Aspiculuris tetraptera (7.5%), Hymenolepis nana (3.3%), and Hymenolepis diminuta (2.5%).

This study showed high parasitic infection without clinical signs in laboratory rodents. Therefore, monitoring these animals and improving their breeding conditions can eliminate the adverse effects of these parasitic infections in the animal research processes and improve the health of researchers and staff. .