Using Dot-ELISA Method to Study the Prevalence of Human Hydatidosis in People Referred to Blood Transfusion Center in Tehran, 2005-2006

Hydatidosis, which is seen in human and other hosts, is caused by the infective larval stage of Echinococcus granulosus. In most cases, diagnosis of hydatid cyst is not easy due to a long term incubation period and lack of specific clinical symptoms, and remains asymptomatic for years in some patients. The aim of this study was using the easy and sensitive serologic technique of Dot-ELISA to determine the prevalence of hydatid cyst in individuals referred to Blood Transfusion Center in Tehran between 2005 and 2006. Patients and This cross-sectional study was done on 1100 people who were referred to Blood Transfusion Center and the results were analyzed by running t-test and Chi-square test. B antigen is one of the principal specific and heat resistant compounds of hydatid cyst. To perform Dot-ELISA test,this antigen was purified from the sheep hydatid fluid. In addition, by using SDS-PAGE method, the 8-12 kDa molecular weight proteins of this antigen were determined. 1gµ of purified B antigen was dotted on the nitrocellulose disk and 1/250 diluted serum samples were added. Then, the incubation was performed against the HRP conjugated antihuman. In the final step, DAB stain was added as an indicator. Brown sediment indicated a positive result. From 1100 tested blood samples, 18 (1.63%) were hydatid positive, which can indicate the cryptic hydatid cyst infection in the ordinary people of Tehran. The observed rate of hydatid infected individuals is statistically significant, considering the studied population as a representative of Tehran's population. Owing to the long incubation period of the disease, the cyst is usually diagnosed in old patients at the stage when surgical treatment is necessary. The surgery complications might be unendurable in old age patients. Consequently, it is suggested that screening programs be run to detect and treat the patients at the primary stage of the infection. This study shows 1.63% of people referred to Blood Transfusion Center in Tehran have positive serum for hydatid cyst.