Development of a species-specific coproantigen ELISA for human taenia solium taeniasis

Taenia solium causes human neurocysticercosis and is endemic in underdeveloped countries where backyard pig keeping is common. Microscopic fecal diagnostic methods for human T. solium taeniasis are not very sensitive, and Taenia saginata and Taenia solium eggs are indistinguishable under the light microscope. Coproantigen (CoAg) ELISA methods are very sensitive, but currently only genus (Taenia) specific. This paper describes the development of a highly species-specific coproantigen ELISA test to detect T. solium intestinal taeniasis. Sensitivity was maintained using a capture antibody of rabbit IgG against T. solium adult whole worm somatic extract, whereas species specificity was achieved by utilization of an enzyme-conjugated rabbit IgG against T. solium adult excretory-secretory (ES) antigen. A known panel of positive and negative human fecal samples was tested with this hybrid sandwich ELISA. The ELISA test gave 100% specificity and 96.4% sensitivity for T. solium tapeworm carriers (N = 28), with a J index of 0.96. This simple ELISA incorporating anti-adult somatic and anti-adult ES antibodies provides the first potentially species-specific coproantigen test for human T. solium taeniasis

Serological Studies of Neurologic Helminthic Infections in Rural Areas of Southwest Cameroon: Toxocariasis, Cysticercosis and Paragonimiasis

A total of 188 people (168 and 20 with and without symptoms confirmed by clinicians, respectively, 84.6% under 20 years old) were selected on a voluntary basis in Cameroon. Soil transmitted helminthic infections were prevalent among persons surveyed as is common in developing countries, since eggs of Ascaris lumbricoides, Trichuris trichiura and hookworms were found from 56 (33.3%), 72 (42.8%) and 19 (11.3%) persons, respectively. Serological analyses revealed that 61 (36.3%), 25 (14.9%) and 2 (1.2%) persons were positive to the diagnostic antigens specific for toxocariasis, paragonimiasis and cysticercosis, respectively. Among 14 people with epilepsy, 5 persons were seropositive to the antigen of Toxocara and one of them was simultaneously positive to the antigens of Paragonimus. Serological confirmation of cysticercosis in two children is very important, and we suggest that further serologic surveys of cysticercosis be carried out in both children and adults in this area for the promotion of a better quality of life including control and early treatment

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