spp. is a liver fluke that infects humans and domestic animals. It is highly prevalent in some
Ecuadorian communities. Currently, diagnosis is based on the microscopic observation of eggs in faeces, but this has variable
sensitivity. More sensitive methods are needed for diagnostic testing.
The main objective of this work was to develop an enzyme-linked immunosorbent assay (ELISA) using crude
antigens from Amphimerus
spp. adult worms to detect anti-Amphimerus
IgG in human sera.
Crude somatic antigens were obtained from adult Amphimerus
spp. worms. Human sera from 119 patients were
tested: 48 from individuals with a confirmed Amphimerus
spp. infection, 78 from non-infected Ecuadorians living in the endemic
region, 60 from persons living in non-endemic areas (20 Ecuadorians, 20 Europeans, and 20 Africans), and 33 who had other
parasitic and non-parasitic infections.
Results were analysed using the receiver-operator characteristic (ROC) curve analysis with an area under
curve (AUC) value of 0.967. The accuracy of the ELISA was high. The sensitivity was 85.0% [95% confidence interval (CI): 80.3-89.7%] and the specificity was 71.0% (95% CI: 65.2-76.8%). Some cross reactivity was detected against Paragonimus mexicanus
, Schistosomiasis, Taenia solium
, Strongyloides stercoralis
spp., and Vampirolepis nana
We have developed the first ELISA technique that detects anti-Amphimerus
IgG in human sera with good
sensitivity, repeatability and reproducibility. However, more specific antigens are needed to further enhance performance of this
assay. Regardless, this ELISA test could be useful for early diagnosis and prompt treatment of human Amphimerus