Evaluation of the double diffusion, enzyme immunoassay and immunoblotting techniques, for the diagnosis of human hydatid disease in tropical areas

Evaluation of enzyme-linked immunosorbent assay (ELISA) and enzyme-linked immunoelectrotransfer blot (EITB) for immunodiagnosis of hydatid diseases in sheep

This study was undertaken to investigate antigenic characteristics of hydatid cyst fluid in sheep by SDS-PAGE method, to evaluate sensitivity and specificity of Enzyme-linked immunosorbent assay (ELISA) and Enzyme-linked immunoelectrotransfer blot (EITB) assay for diagnosis of sheep hydatidosis, and to determine seroprevalance of hydatidosis in sheep population in Elazig, Turkey. SDS-PAGE analysis of hydatid cyst fluids indicated that 6 specific-protein bands were detected at molecular weights of 29, 45, 58, 68, 98 and 116 kDa. EITB analysis showed presence of 29, 38, 42, 58, 62, 68, 98, 116, 120, 150 and 205 kDa bands in positive sheep sera, while 38, 58, 62, 68, 116 and 205 kDa bands were detected in negative sheep sera. Therefore, it was concluded that the 116 kDa band was specific for diagnosis of sheep hydatid disease by EITB assay. Sensitivity and specificity of EITB assay were determined as 88% and 84%, respectively, whereas corresponding rates for ELISA were 60% and 94%, respectively. Sensitivity of ELISA was 47.3% in hepatic cysts, 60% in pulmonary cysts, 69.2% in hepato-pulmonar cysts. Sensitivity ratios of ELISA were 67.8%, 75%, and 38.4% for fertile, sterile, and under-growth cysts, respectively. Sensitivity of EITB was found 84.2% in hepatic cysts, 80% in pulmonary cysts, and 92.3% in hepato-pulmonar cysts. Corresponding ratios for sensitivity of EITB for fertile, sterile, calcified, and under growth cysts were 92.8%, 75%, 100%, and 84.6%, respectively. In addition, seroprevalance of hydatidosis in sheep was found as 62% by ELISA and 66.4% by EITB in Elazig, Turkey and seroprevalance increased by age.

Renal echinococcosis: clinical study of 34 cases

PURPOSE

Hydatid disease, a cyclo-zoonotic parasitic infestation caused by the larval stage of the cestode Echinococcus granulosus, is prevalent worldwide. We reviewed the clinical findings of a large series of renal hydatidosis treated in an endemic area with special emphasis on diagnostic pitfalls.

MATERIALS AND METHODS

A retrospective 15-year review in a rural area of central Spain (600,000 population), with a global incidence of hydatidosis of 10 new cases per 100,000 population per year, revealed 34 with renal echinococcosis treated surgically (3 to 4% of officially confirmed cases of hydatidosis). Clinical, radiological and laboratory data were analyzed.

RESULTS

Renal hydatid disease mimicked other diseases. The combination of clinical history, imaging studies, and serological and urine investigation yielded a reliable pretreatment diagnosis in only 50% of cases and a presumptive diagnosis in 71%. Among imaging studies computerized tomography was the most valuable diagnostic examination. Moderate eosinophilia was found in half of the cases, while a third had scoleces in the urine. A diagnostic and therapeutic algorithm is presented.

CONCLUSIONS

Preoperative diagnosis of renal hydatid disease is difficult even in an endemic zone. Imaging studies are suggestive but usually inconclusive, and the differential diagnosis with a renal tumor or complicated cyst may not be made without surgery. Renal sparing surgery is possible in a significant proportion of cases, particularly when preoperative diagnosis has been considered. Significant surgical morbidity can be expected, and the risk of anaphylaxis and hydatid seeding, although low, should not be overlooked.