Assessment of three major intestinal protozoan infections in Kermanshah, Iran: a pre- and post-COVID-19 study.

Intestinal parasitic infections continue to be a significant public health concern worldwide. This study examines the impact of the COVID-19 pandemic on the prevalence of three intestinal protozoa—Blastocystis, Entamoeba coli, and Giardia lamblia—among patients at the Imam Reza Health Complex in Kermanshah, Iran, from March 2017 to March 2024. Patient data were obtained from the Health Information System and analyzed across seven age groups using descriptive and inferential statistics. A total of 15,018 individuals participated in the survey, consisting of 7169 males and 7849 females. The overall prevalence of Blastocystis increased, while G. lamblia decreased significantly after the pandemic. E. coli prevalence showed no significant changes. Age-specific differences were noted: Blastocystis prevalence increased in children (≤10 years old), G. lamblia prevalence decreased in children (11–18 years old), and E. coli prevalence increased in adults (41–50 years old). Gender analysis revealed a significant rise in Blastocystis among male post-COVID-19, but no other gender-based differences were identified. Overall, the findings indicate limited changes in protozoan prevalence during the pandemic, suggesting sustained community hygiene practices. The study highlights the role of Blastocystis as a notable exception and underscores the importance of hygiene in controlling parasite transmission. Broader investigations are recommended to validate these findings and broaden insights across healthcare settings.