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Background & objectives: Parasitic diseases are one of the health problems of all societies and are considered as barriers to progress socioeconomic development, especially in most developing countries. This study evaluated the frequency of intestinal parasites in patients referred to hospitals affiliated with Ardabil University of Medical Sciences in 2018.
Methods: a total of 409 stool samples were collected from laboratories of Imam Khomeini and Bouali hospitals and then transferred to the parasitology lab in the medical and paramedical school. Samples were evaluated using direct, concentration and culture methods. Data were analyzed using SPSS software version 21.
Results: Out of 409 samples, 22 cases (5.4%) were infected with intestinal parasites. Among them, 5.3% and 5.4% of infected cases were men and women respectively. Also, the rate of infection to the protozoans and helminths was 3.7% and 1.7% respectively. Among the positive cases, the highest percentage of infection was related to Giardia and Blastocystis.
The infection rate of each parasite among all patients and positive cases was 1.2% and 22.7% respectively.
Conclusion: The present study showed that intestinal protozoan infection, especially Giardia lamblia and Blastocystis hominis are high in Ardabil city, and therefore special infection control measures are urgently needed.
 

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Background & objectives: Fishes are one of the most important sources of zoonotic parasites throughout the world. This study aimed to determine helminthic parasites of Fish caught in the Aras River.
Methods: During 2020-2021, a number of 100 fishes including 20 Cyprinus carpio, 10 Hypophthalmichthys molitrix, 5 Hypophthalmichthys nobilis, 12 Silurus glanis, 5 Aspius aspius, 15 Ratilus rutilus, 3 Sander lucioperca, 22 Luciobarbus capito, and 8 Abramis brama were caught. All parts of the fish body (scales, gills, eyes, muscles, gastrointestinal tract) were examined for Helminthes parasites. After clearing and temporarily staining with Lactophenol-Azokarmin, morphological characters of worms were analyzed using a calibrated microscope equipped with a camera.
Results: After examining and evaluating the samples, 18 (18%) of the fish were infected with at least with one helminthic parasite. The species and percent of infection were as follows: Ligula intestinalis plerocercoid: Cyprinus carpio 40%, Ratilus rutilus 13.33%, Abramis brama 12.5% in the abdominal cavity. Bothriocephalus sp.: Cyprinus carpio 5% in the intestine. Diplozoon sp.: Cyprinus carpio 5% and Ratilus rutilus each 6.7% in gills. Dactylogyrus sp.: Cyprinus carpio 10%, Abramis brama 12.5% in gills. Clinostomum sp. metacercariae: Cyprinus carpio 5% infected with metacercaria in gills and abdominal cavity.
Conclusion: Among the investigated types of fish, the highest level of infection with helminthic parasites was found in common carp. Also, among the helminthic parasites found, the highest frequency is related to Ligula intestinalis, followed by Dactylogyrus