Another main purpose of this work was to analyze the relationship between seroprevalence and the prevalence of adult worms of A. cantonensis in the different areas. Furthermore, the association between seroprevalence and several parameters that may be involved in the occurrence of this nematode was studied. The present study represents the first immunological screening of antibodies against A. cantonensis in wild animals. More than half of the studied rodents were seropositive, suggesting a high prevalence of this nematode on Tenerife. In fact, the seroprevalence of A. cantonensis in R. rattus was higher than the prevalence observed by parasitological analysis previously on Tenerife, and in different endemic areas as Antilles, Taiwan, China and Jamaica. However, this difference could be due to the intrinsic differences between these diagnostic approaches, since not only the presence of the parasite can be detected by this immunological assay, but also past contacts with it. The high seroprevalence of IgG antibodies against A. cantonensis observed in our study could be explained by the fact that introduced rats in Tenerife are known to predate upon snails that have been described previously as intermediate hosts of A. cantonensis, such as Plutonia sp. and Hemicycla sp. Furthermore, our study suggests the presence of A. cantonensis in two new areas, Aguamansa and Pico del Ingle��s, increasing our knowledge about the real distribution of this parasite in the Canary Islands. However, these results need to be interpreted with caution. Although Eamsobhana et al. have reported 100% diagnostic Metaproterenol Sulfate specificity and sensitivity on testing human sera with 31-kDa glycoprotein by ELISA, it is not necessarily the same in rats. The presence of a linear correlation between seroprevalence of IgG antibodies against A. cantonensis and Rimonabant Hydrochloride helminthological prevalence of A. cantonensis in the different areas could indicate a high level of sensitivity of the 31-kDa glycoprotein on testing rats sera by ELISA. Therefore, and considering the fact that 31-kDa glycoprotein is among the principal antigens recognized by rats, experimental studies should be carried out to determine the sensitivity and specificity of this glycoprotein for rats. On the other hand, the discrepancy between the prevalence based on the presence of adult worms and the seroprevalence observed in this study could be explained by the presence of antibodies due to a past infection and due to the reason that not all the rats that acquire the larvae develop the adult form of the parasite. It is also possible that rodents produce antibodies against this nematode before the parasite has reached the lungs. Rattus rattus and R. norvegicus are the main definitive hosts for A. cantonensis. This fact emphasizes importance of our study from the public health point of view, due to the high density and wide distribution of these rodent species on the Canary Islands.