SEROEPIDEMIOLOGICAL INVESTIGATION OF FASCIOLIASIS IN NORTHERN IRAN

Following an outbreak of fascioliasis in Anzali Harbor in 1988, 452 blood samples were collected using a multistage sampling method for hematological and serological studies. After determination of eosinophilia in the samples, antifasciolia antibodies in the sera were also determined using enzyme linked immuno sorbant assay (ELISA) and counter-current immuno electrophoresis (CCIE). 64.2% of the samples were collected from women and omitting the age effect and P<0.05, the rate of infection was 1.16 times more in women than in men as shown by hypereosinophilia and ELISA test results. Age distribution of seropositivity in both sexes with p<0.001 was statistically significant and the highest rate of seropositivity was seen among the below 20 age group in both sexes. The highest expected rate of seropositivity (24.12) was observed in location six (Taleghan area), but an average and more uniform distribution was seen in other locations. 50% of the samples using ELISA techniques and 34.95% using CCIE were positive indicating that point prevalence of the disease was in Anzali Harbor. It must be noted that all antibody positive samples showed hypereosinophilia as well and that ELISA technique was 52.6% more sensitive compared to CCIE. Of the 50% antibody positive cases, 13.7% had only IgG, 26.5% both IgG and IgM and 37.6% only IgM showing the chronic, subacute and acute condition of the disease respectively. The remaining 22% of the cases were IgA positive. In this investigation an incidence rate of 19% was obtained using ELISA technique which was indicative of a fasciolia epidemic in the region.