Evaluation the Role of House Lizards (Hemidactylus frenatus) in Transmitting Parasitic and Bacterial Pathogens to Humans

Background The common house lizard ( Hemidactylus frenatus ) thrives in human dwellings in tropical regions, raising concerns about its role as a reservoir for zoonotic pathogens. This study aimed to assess the potential of these synanthropic reptiles in transmitting parasitic and bacterial infections to cohabiting humans in Hajjah Governorate, Yemen. Methods Biological samples were collected from 30 house lizards and 60 symptomatic human residents sharing the same households across six districts. Parasitological examination of fecal/stool samples was performed using direct smear and iodine staining. Bacterial culture, Gram staining, and biochemical profiling were used for pathogen identification. Statistical analysis employed Pearson's correlation coefficient to examine associations between pathogen prevalence in lizards and humans. Results Parasitological analysis revealed high prevalence of Entamoeba spp. (33.33%) and Giardia lamblia (26.39%) in lizards, with corresponding findings of Entamoeba histolytica (51.7%) and G. lamblia (21.7%) in humans. Bacterial cultures showed significant overlap, with Salmonella Typhi (21.15% in lizards, 18.33% in humans) and Shigella spp. (19.23% and 18.33%, respectively) being predominant. A strong positive correlation was found between parasite prevalence in lizards and humans (r = 0.824, p = 0.012) and for overall bacterial profiles (r = 0.79, p = 0.007). Conclusions The study demonstrates a significant overlap in enteric pathogens between house lizards and humans, with strong epidemiological correlations. This suggests that H. frenatus likely acts as a reservoir and potential vector for zoonotic transmission in domestic settings. Public health interventions should incorporate reptilian control and heightened hygiene awareness to mitigate this transmission route. Trial registration Not applicable.