Epidemiology of Human Fascioliasis in Iran

Fascioliasis has medical and veterinary importance in Iran. Human Fascioliasis had been limited to just ectopic cases or sporadic reports before 1988. In this year an outbreak of human fascioliasis was reported from Gilan province and peak of this epidemy was seen in spring 1989. Considering 100000 population of Bandar-e-Anzali total infected cases was estimated between 9800 and up to 20000 cases. Although infection was seen in different age groups, most cases were less than 35 years old. Next outbreak was started in 1998 and raised up to maximum in 1999. Various factors were probably affected these outbreaks, including scattered stray cows, raise of snail population, intermediate Fasciola species with unknown biologic characteristics, Lymnaea truncatula like snails, higher snail infection, raise of sea level, raise of summer rainfall, more contact with polluted water and popular consumption of local wild herbs, in 1988 (up to 91% of infected people had history of “Khalvash” consumption, which is one of these wild herbs belonged to Menta sp). In these years more cultured herbs were exported to Tehran. It is highly probable that a combination of these factors has caused outbreaks of human fascioliasis in Iran.