Differential diagnosis of cystic and alveolar echinococcosis using an immunochromatographic test based on the detection of specific antibodies

Abstract

Human cystic and alveolar echinococcoses are zoonotic diseases caused by the larval stages of Echinococcus granulosus and Echinococcus multilocularis, respectively. As the diseases are co-endemic in many areas of the world, a simple and rapid test for the differential diagnosis of cystic echinococcosis (CE) and alveolar echinocoocosis (AE) is needed. Here, we describe the development of an immunochromatographic test (ICT) using crude hydatid cyst fluid and a recombinant 18-kDa protein (rEm18) as antigens for the detection of E. granulosus and E. multilocularis antibodies in serum samples. The ICT was evaluated with serum samples from 195 echinococcosis patients from different endemic areas in northwestern China. These included 144 from CE patients, 51 from AE patients, 67 from patients with other parasitic diseases, 13 from patients with serous hepatic cysts, and 60 from healthy individuals. The sensitivity and specificity of the ICT for CE were 91.0 and 96.9% and for AE were 98.0 and 99.3% with diagnostic efficiencies of 94.1 and 99.1%, respectively. No significant differences and high degrees of agreement were found between the ICT and an enzyme-linked immunosorbent assay for both CE and AE. Five serum samples from cysticercosis patients and one serum sample from a healthy control were found positive for CE with the ICT. These findings indicate that this test allows for discrimination between both forms of human echinococcosis. In conclusion, the ICT developed in this study is a promising tool for the simultaneous detection and discrimination of CE and AE. This test will be useful for serodiagnosis of CE and AE in clinical settings and screening programs.

Evaluation of Immunochromatographic Test for the Detection of Antibodies against Echinococcosis granulosus

“…No significant difference was found between ELISA and the immunochromatographic test for cystic echinococcosis. Positivity was detected in 1 of 60 healthy individuals and 5 of 25 cysticercosis patients who were evaluated by this test [ 16 ]. We found false-positivity in 2 of 50 healthy individuals and 4 of 15 taeniasis patients by immunochromatographic test.…”

Serological Diagnosis and Follow-Up of Human Cystic Echinococcosis: A New Hope for the Future?

“…Se reported in these studies varied from 64.8% to 100%. Reasons for false negative results depend on several factors comprising cyst location other than the liver [ 12 , 13 ], early (CE1) and inactive (CE4 and CE5) cyst stages [ 14 – 16 ], serum collection before treatment [ 15 , 17 ], single and small cysts [ 17 ], and HF antigenic source variability [ 18 ]. Additionally, E. granulosus complex comprises several genotypes that potentially express different antigenic sets.…”

Comparison of the Diagnostic Accuracy of Three Rapid Tests for the Serodiagnosis of Hepatic Cystic Echinococcosis in Humans

“…The use of Rapid Diagnostic Tests (RDTs) is particularly useful is resource-poor settings, and in the context of CE they may be suitable to complement imaging where diagnosis is uncertain. Several reports described the performance of commercial and experimental RTDs in the diagnosis of CE [ 10 – 15 ]; however, no study so far compared the performance of commercially available RDTs. Here we performed a comparison of the diagnostic performance and reproducibility of three commercially available RDTs for the diagnosis of CE and compared them with those of a commercial ELISA test routinely used in the parasitology diagnostic laboratory of San Matteo Hospital Foundation, Pavia, Italy.…”