A SEROLOGIC STUDY OF HUMAN TOXOCARIASIS IN THE CANARY-ISLANDS (SPAIN)- ENVIRONMENTAL-INFLUENCES

The presence of anti-Toxocara antibodies in the human population of th e Canarian Archipelago was studied by means of an indirect enzyme-link ed immunosorbent assay with excretory/secretory antigen of infective-s tage larva. A total of 14,074 were analyzed, resulting in the followin g distribution and prevalence by location: southern Tenerife 6,435 (2. 5% positive), northern Tenerife 1,710 (6.7% positive), La Palma 1,214 (4.5% positive), La Gomera 264 (6.8% positive), El Hierro 204 (3.9% po sitive), Gran Canaria 2,875 (2.3% positive), Fuerteventura 277 (1.8% p ositive), and Lanzarote 1,095 (2.9% positive). The weighted average of the entire Archipelago was 3.4% positive. Neither age nor sex was fou nd to be significantly associated with positive serology. The influenc e of the different Canarian mesoclimates on the spreading of this zoon osis is demonstrated, with significant differences being found between humid and arid islands. Likewise, a significant positive correlation was found between De Martonne's humidity-aridity index and percentage of people with evidence of parasite exposure on the different islands.