Clinical and molecular features of human cystic echinococcosis in Tehran,Iran,2011-2019

Objective:To evaluate the clinical and molecular features of human cystic echinococcosis in Tehran,Iran.Methods:In this cross-sectional study,all human cystic echinococcosis patients admitted to Tehran’s hospitals from 2011 to 2019 were enrolled,and demographic characteristics,clinical findings,and laboratory data were collected.Formalinfixed,paraffin-embedded and fresh tissue samples of 175 cystic echinococcosis patients were evaluated for molecular characterization.The samples’isolated DNA was used to amplify cytochrome c oxidaseⅠand NADH dehydrogenase subunitⅠgenes.Also,the morphological features of fresh samples were examined.Results:In total,175 patients with a mean age of 45(9-98)years were admitted to Tehran’s hospitals diagnosed with cystic echinococcosis.Moreover,the highest(26.9%)and the lowest(2.9%)prevalence of cystic echinococcosis cases were in the 16-30 and 1-15 years range,respectively.Male/female ratio was 0.96(49.1%vs.50.9%).The liver was affected in 92 patients(52.6%),and two or more organs were infected in 7 patients(4.0%).The cysts’diameter varied from 1 to 25 cm,and 96.0%of the patients had a single hydatid cyst.All patients underwent radical surgery and the PAIR technique was applied for all cases.No significant difference was observed between the protoscolex hooks of pulmonary and hepatic cysts.G1-G3 had the highest percentage(99.4%)over other identified G6 genotypes(0.6%).Conclusions:The sheep-dog cycle plays an important role in transmitting the human cystic echinococcosis infection in Tehran.