Evaluation of the Ability of Antigen B Originated from Echinococcus granulosus Sensu Stricto and E. canadensis for the Diagnosis of Confirmed Human Cystic Echinococcosis Using ELISA.

Background: Cystic echinococcosis (CE) is an important zoonotic parasitic disease worldwide. Application of species-specific antigen for serodiagnosis of human CE has not been utilized, so far. In this regard, AgB originated from Echinococcus granulosus sensu stricto (G1-G3) and E. canadensis (G6/G7) CE cysts, confirmed by molecular biology and sequencing was used for evaluation of their ability in the diagnosis of confirmed human CE. Methods: The hydatid cyst fluid (HCF) of E. granulosus sensu stricto and E. canadensis species were separately, used for preparation of AgB during 2017-2018 in Shiraz and Tehran, Iran. A total of 45 sera samples from confirmed CE patients, 102 sera from healthy people as negative control and 44 sera from other parasitic diseases, were used for measurement of the diagnostic ability of antigen B originated from E. granulosus sensu stricto and E. canadensis species of CE, alone or in 50%:50% mixture using ELISA method. Results: Overall, 38 (84.4%) out of 45 confirmed human CE were positive by ELISA using AgB originated from E. granulosus sensu stricto. This items for AgB originated from E. canadensis was 39 (86.6) out of 45 serum samples. A total of 39 out of 45 samples (86.6%) showed positivity by a mixture of antigen B originating from both species. The specificity of the above tests was calculated as 93.15%, 96.58%, and 93.84%, respectively. Conclusion: Due to the diversity of the cyst species in human population, application of AgB from prevalent species alone or in combination with other species is suggested. [ABSTRACT FROM AUTHOR]