Detection and epidemiology of Taenia solium in Northern Peru

Guezala Villavicencio, MC

Abstract

Taenia solium Taen/asis is prevalent in humans in developing countries, and an
imported disease in developed countries. It may cause severe or fatal illness when
humans ingest eggs and develop larval cysts in the central nervous system
(neurocysticercosis). This project has two parts: the development of a laboratory
diagnostic method to accurately detect Taenia solium carriers at the species-level,
and the use of a Geographic Information System (CIS) as a tool to study
transmission dynamics between human and pig hosts. A capture enzyme-linked
immunosorbent assay (ELISA) test that detects taeniid antigens (coproantigens) in
human faeces was developed and standardised to use antibodies against somatic
and secretory -excretory antigens produced by the tapeworm, achieving Taen/asis
detection 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 for
human T. solium Taen/asis. Porcine serosurveys (for T solium antibodies) and
total culling (for pig cyst counts) were performed within the framework of a large
intervention programme being applied in endemic villages in northern Peru.
Necropsy data for the entire porcine population was obtained, the whole carcass
being examined for T. solium cysts. The number and characteristics of the cysts
were recorded. All data, along with geographic location of the tapeworm carriers
and pigs, were entered in a GIS model developed using ArcGis 10. The results for
porcine cysticercosis and human Taen/asis were plotted on maps and spatial
relations among human and pig hosts were established. Correlation between the
hosts' locations was analyzed using binary logistic regressions performed in SPSS
11.0. The model showed a visual spatial relationship between the locations of
hosts. An approximate influence area for Taenia solium was established at 300
meters around human tapeworm carrier household locations, and confirmed by
logistic regression (p< 0.005). Pigs living inside this area may be a source of new
tapeworms. Using this model, focused control measures can be established in
high risk areas, targeting treatment or elimination of possible sources of infection.

Citation

Guezala Villavicencio, M. Detection and epidemiology of Taenia solium in Northern Peru. (Thesis). Salford : University of Salford

• Thesis Type: Thesis
• Deposit Date: Oct 3, 2012
• Award Date: Jan 1, 2011