Evaluation of Taenia solium cyst fluid-based enzyme linked immunoelectro transfer blot for Neurocysticercosis diagnosis in urban and highly endemic rural population of North India

Background: Neurocysticercosis (NCC) is infection by cestode Taenia solium/pork tapeworm. Sero-diagnosis of NCC is still a challenge. Radiological imaging (CT/MRI) are cost intensive, requires technical expertise and resource intensive. Hence, its availability is restricted in endemic zone. Existing Enzyme electro immune transfer blot (EITB) antigens are difficult to make and is not standardized for endemic population. Therefore, there is a definite need for easy and reliable EITB tool.

Methods: T. solium metacestode were harvested from naturally infected swine post slaughter. The cyst fluid/vesicular fluid was aspirated and processed with ultracentrifugation and immune blot was performed with this antigen.

Results: A total of 406 cases [rural 256 (NCC 78, seizures other than NCC 108 and healthy controls 70); urban 150 (NCC 41, seizures other than NCC 59 and healthy controls 50)] were enrolled. Positive EITB (detection of band <50 kDa) was significantly associated with NCC patients of urban population only (p < 0.001) but not in rural populations (p = 0.292). However, identification of 15 kDa band had significant association with NCC both in urban and rural populations with overall sensitivity of 91.5% and specificity of 91.6%. Presence of 35 kDa band was associated with multiple NCC (p < 0.001). The study shows that 15 kDa reactive band on EITB is highly sensitive and specific for diagnosis of NCC in endemic population.

Conclusions: Presence of 35 kDa band on EITB was associated with infection by multiple cysticerci. The observations demand purification of cyst fluid antigens to develop simple and easy to execute test in field studies.