Lateral-Flow Antibody Detection Device for the Diagnosis of Human Fascioliasis Using Simulated Whole-Blood Samples.

Abstract

Fascioliasis, which is caused by Fasciola hepatica and Fasciola gigantica (F. gigantica), is a public health problem worldwide. Stages infective to humans occur on aquatic plants and in water. The gold standard for diagnosing human infection depends on finding fluke eggs in stool samples. However, this method has low diagnostic sensitivity; eggs from other trematode species might be misidentified as those of Fasciola, and eggs are not voided in ectopic infections. Therefore, serological analysis can support the diagnosis of human fascioliasis. We evaluated whether a new fascioliasis immunochromatographic test kit, which detects specific IgG antibodies using F. gigantica excretory-secretory antigen, can be used for rapid diagnosis from whole blood. The kit ("the fascioliasis whole-blood test kit") was evaluated under laboratory conditions using 250 whole-blood samples (WBSs), of which 41 were from fascioliasis cases. Results based on simulated WBSs and the corresponding serum samples were compared and showed almost perfect agreement (percent agreement = 97.2%; kappa value = 0.9145). The diagnostic sensitivity and specificity of the test using simulated WBSs were 97.6% and 96.2%, respectively. Comparable values when serum samples were tested were 100.0% and 93.3%, respectively. This kit represents a significant advance because it does not require extensive training of personnel, is easy to use, and can support diagnosis at the bedside or in local and remote hospitals with limited facilities. The kit may also contribute significantly to epidemiological surveys.