Helminth Infections in Rattus ratus and Rattus norvigicus in Tehran, Iran

BACKGROUND The aim of this study was to determine intestinal and liver helminth infections in Rattus rodents in Tehran Iran. METHODS Overall, 306 traps were put in 39 different regions in Tehran from 2009 to 2010. Rodents, including R. rattus and R. norvegicus were caught by live-traps. They become unconscious and the spinal cords were cut, afterwards the body was dissected and the stomach, small intestine, large intestine, liver, and cecum were studied separately. The dominant type and the prevalence rate of parasites in the rodents were determined based on the infected parts of their body. RESULTS After recognition of the helminthes' types, among the 120 total number of rodents, 39 belonged to males, while among the infected rodents, 57(47.5%) were female and 18(15%) were male. The prevalence of infection in Tehran was 62.5%. Seventy cases (58.33%) of helminth infections were observed in R. rattus and 5 cases (4.16%) were observed in R. norvegicus. The maximum prevalence (15.5%) was seen in the center and east part of Tehran, while the minimum (9.16%) was in the north part of the city. The helminthes types and the corresponding percentages were Hymenolepis nana fraterna (35.8%), Heterakis spumosa (17.5%), Hymenolepis diminuta (7.5%) and Capillaria annulosa (1.6%). The dominant rodent was Rattus rattus and among the identified helminthes, Hymenolepis diminuta and Hymenolepis nana fraterna are zoonotic ones. CONCLUSION The information presented here improves our understanding of the major parasitic infections that rodents harbor and can transmit to human and animal populations in Iran. To prevent infectivity of human, the hazard of the identified zoonotic species needs to be contemplated.