Investigating the Invasive Contamination of Lymnaeidae Snails with Trematodes According to Species and Sampling Location in Lorestan province, Iran, Middle East

Radicine snails are of considerable medical and veterinary importance as termatodes’ vectors such snails are responsible for transmission of the zoonotic trematodes including Schistosoma turkestanicum and Fasciola gigantica in Iran. This study investigates Lymnaedae infestation with termatodes considering species and sampling location ۱.۷۰۰ snails were collected from the suburbs of Borujerd, Khorram Abad, and Dorud in Lorestan, Iran from April to August ۲۰۱۸ Round snails were separated and Snails species were identified based on measuring length, width, spire, valve using a shape of the radula as identification keys. To separate the radula, the soft tissue of snails was removed from the shell using forceps and incubated in a ۷% potassium solution for ۲۴ hours at room temperature. The isolated radula was placed in ۱۵% acetic acid. Then it was placed in Mallory's dye solution for ۳ minutes and washed with the oxalic acid solution. After dehydrating with ۹۶-degree ethanol, it was examined with a light microscope. To investigate trematode larvae in snails, ۱۰% of them (a total number of ۱۷۰ Lymnaeidae snails) were selected for this investigation by using the crushing method on a slide. The morphological results showed in Dorud and Borujerd, the highest distribution of Lymnaea gedrosiana was ۲۴.۰۹% and ۱۹.۷۲%, and the lowest distribution of Bulinus truncatus was ۴.۷۲% and ۴.۴۸%, respectively. Lymnaea species were the most abundant in plain villages, while Bithynia and Physa were seen more in mountain villages. In Khorram Abad, the highest distribution is related to Lymnaea truncatula (۲۰.۱۵%), and the lowest is related to Lymnaea stagnalis (۵.۵۶%). The genera Bithynia and Physa show a significant increase in mountainous Khorram Abad villages compared to the Borujerd and Dorud. The total rate of Lymneidae snails infection with termatodes was ۳۲.۹۴%, which includes ۱۸.۲۳% of samples in Borujerd, ۸.۲۳% in Dorud, and ۶.۴۷% in Khorramabad. According to chi-square with (p<۰.۰۵), a significant difference was seen in the rate of Lymneade snails’ trematode infection. In this regard, the Borujerd region showed the highest rate of infection while Khorram Abad revealed the lowest.

Keywords:

Lymnaeidae snails , trematodes , radix gedrosiana , Lymnaea auricularial , Schistosomamiasis