Prevalence of Sporozoan and Parasitic Enteropathogen Protozoans in Patients with Gastroenteritis in Iran

Parasitic gastroenteritis is one of the most common illnesses in humans worldwide. Most studies on gastroenteritis have focused on viral and bacterial infections, while parasitic enteropathogens and especially intestinal protozoan parasites may play a role that has not been well studied. The aim of this study is to identify the prevalence of enteropathogenic parasites and sporozoan protozoa in patients with gastroenteritis in selected hospitals in seven provinces of Iran.
Methods: In this cross-sectional study, randomly 4200 stool specimens were obtained from patients with gastroenteritis in selected hospitals. Primarily samples were examined directly for enteroparasites. The samples were filtered and concentrated by using the Paraseb Kit; and fixed, and stained by different methods including acid-fast staining, Auramin phenol fluorescence staining, and Giemsa staining were observed using light microscopy under various magnifications.
Results: The results revealed the overall rate of parasitic infection was 2.4% in the studied population. The highest rate of infection was observed in the 0-10 year age-group (47.2%). Among the infected patients, 59.5% were male and the rest were female patients.
In the studied regions, Tehran and Mazandaran had the highest and the lowest frequency with 41 (97%), and 2 (47%) cases respectively. Gastroenteritis was found in patients infected with Cryptosporidium, Microsporidium, Isospora and Cyclospora, 13 cases in total (0.3%) with 5 (0.12%), 4 (0.09%), 3 (0.07%) and 1 (0.02%) cases for all four parasites respectively. Parasitic enteropathogens were detected in 88 cases of all studied cases (2.09%). Among these observed parasitic enteropathogens, Giardia lamblia with 42 cases (1%) had the highest rate of infection, The observed frequency of infection for Blastocystis Hominis, Entamoeba histolytica, were 21 (0.5%), and 20 (0.47%) cases respectively while for the rest was 10 cases.
Conclusion: Despite a relatively low prevalence of sporozoans group, Giardia was the most prevalent agent for gastroenteritis (1%) parasitic infections in Iran, specifically in Tehran with the highest rate in children (0-10 year age-group). High frequency of Blastocystis hominis and co-infection of Giardia lamblia and Blastocystis hominis implies possible interactions between enteropathogens in a host, which require more studies to be clarified. The study also showed presented knowledge of personal and community health and hygiene needs to be more emphasized.