Detection and epidemiology of Taenia solium in Northern Peru

Taenia solium Taen/asis is prevalent in humans in developing countries, and animported disease in developed countries. It may cause severe or fatal illness whenhumans ingest eggs and develop larval cysts in the central nervous system(neurocysticercosis). This project has two parts: the development of a laboratorydiagnostic method to accurately detect Taenia solium carriers at the species-level,and the use of a Geographic Information System (CIS) as a tool to studytransmission dynamics between human and pig hosts. A capture enzyme-linkedimmunosorbent assay (ELISA) test that detects taeniid antigens (coproantigens) inhuman faeces was developed and standardised to use antibodies against somaticand secretory -excretory antigens produced by the tapeworm, achieving Taen/asisdetection sensitivity values of 96% and up to 100% specificity for Taenia solium.This simple and reliable ELISA is potentially very useful as a screening method forhuman T. solium Taen/asis. Porcine serosurveys (for T solium antibodies) andtotal culling (for pig cyst counts) were performed within the framework of a largeintervention programme being applied in endemic villages in northern Peru.Necropsy data for the entire porcine population was obtained, the whole carcassbeing examined for T. solium cysts. The number and characteristics of the cystswere recorded. All data, along with geographic location of the tapeworm carriersand pigs, were entered in a GIS model developed using ArcGis 10. The results forporcine cysticercosis and human Taen/asis were plotted on maps and spatialrelations among human and pig hosts were established. Correlation between thehosts' locations was analyzed using binary logistic regressions performed in SPSS11.0. The model showed a visual spatial relationship between the locations ofhosts. An approximate influence area for Taenia solium was established at 300meters around human tapeworm carrier household locations, and confirmed bylogistic regression (p< 0.005). Pigs living inside this area may be a source of newtapeworms. Using this model, focused control measures can be established inhigh risk areas, targeting treatment or elimination of possible sources of infection