Tehran University of Medical Sciences Iranian Journal of Public Health 2251-6085 37 2 2008 06 15 59 63 A Farahnak N Dabagh 2015 10 03 Background: Cercariae (larva of helminth parasites) are covered by a thick glycocalyx coat, which serves as an osmotic pro­tection during their free existence, and contain carbohydrates conjugated as glycoproteins, glycolipids and mu­co­polysaccharides. Although, limited studies have been made on life cycle of cercariae from fresh water snails, however, car­bo­hydrate studies on cercariae have not been done in Iran so far. This study was made to determine the cercariae speci­fica­tions from Lymnaea gedrosiana and evaluation of surface carbohydrates as receptors for host lectins in a host-parasite rela­tionship system as a model in human schistosomiasis including cercarial dermatitis in Khuzestan Province. Methods: For this purpose, snails were collected from Dezful region in Khuzestan Province and cercariae were obtained by shed­ding method and identified by valuable keys. Experimental infection was established in the Culex pipiens (Culicidae mos­quitoes) larvae for further identification and mode of adhesion. To detect the mode of adhesion, surface carbohydrates of cercariae were detected by lentil (Lens culinaris) lectins. Results: Examined snails were infected with xiphidiocerceria of trematodes and metacercariae were obtained from Culex pipiens. Also, Mannose monosaccharides- CH2OH (CHOH) 4CHO - were detected particularly on the glands of cercariae. Conclusion: Adhesion of cercariae to their host by lectins-carbohydrates bonds is the first stage of host-parasite relation­ship. This phenomenon could be happened for animal schistosome's cercaria in cercarial dermatitis. https://ijph.tums.ac.ir/index.php/ijph/article/view/2056 https://ijph.tums.ac.ir/index.php/ijph/article/download/2056/2037