Development of an immunochromatographic test for serodiagnosis of human sparganosis

Sparganosis is a parasitic zoonosis caused by the larval plerocercoid (sparganum) of tapeworms in the genus Spirometra. Humans become infected by ingesting raw or undercooked meat from second intermediate or paratenic hosts such as frogs, snakes, and wild boars by drinking water contaminated with cyclopoid copepods carrying the larval procercoid, or by applying frog meat poultices. The gold standard for diagnosis remains the molecular confirmation of plerocercoids in surgically removed specimens. However, because these larvae migrate in subcutaneous tissues and the central nervous system elicit a strong IgG antibody response, serological tests can provide valuable diagnostic support. Although several IgG antibody detection assays have been developed, they are often time consuming and require sophisticated equipment. To overcome these limitations, we developed an immunochromatography based diagnostic kit termed the "sparganosis whole-blood test kit" that employs a gold labeled secondary antibody and can be used directly on either whole blood or serum samples. When tested on simulated whole blood specimens, the kit achieved 100% sensitivity and 91.6% specificity; in paired serum samples, sensitivity and specificity were 100.0% and 84.1%, respectively. This rapid, user-friendly test can facilitate bedside diagnosis in high-risk populations (e.g., hospitalized patients), serve as a point-of-care tool in remote areas with limited medical infrastructure, and offer a noninvasive alternative when biopsy or excision is impractical.