Seroprevalence of Angiostrongylus cantonensis in Wild Rodents from the Canary Islands

Abstract

Background Angiostrongylus cantonensis is a lungworm of rats (Muridae) that is the causative agent of human cerebral angiostrongyliasis. The life cycle of A. cantonensis involves rats and mollusks as the definitive and intermediate hosts, respectively. This study was designed to increase the knowledge about the occurrence and distribution of A. cantonensis in its definitive host in the Canary Islands, using parasitological and serological analysis in different areas and age groups.Methodology/Principal FindingsBetween 2009 and 2010, 54 black rats (Rattus rattus) from Tenerife were captured from six human-inhabited areas and sera samples were obtained. The lung nematodes were identified by morphological and molecular tools as A. cantonensis. The 31-kDa glycoprotein antigen was purified from A. cantonensis adult worms by electrophoresis and electroelution. Of the 54 tested rodents, 30 showed IgG antibodies against A. cantonensis 31-kDa antigen by ELISA. Therefore, the overall seroprevalence was 55.6% (95% CI: 42.4–68). Seroprevalent rodents were found in all the 6 areas. This 31-kDa antigen was not recognized by some sera of rats infected by other helminth species (but not A. cantonensis). Seroprevalence of IgG antibodies against A. cantonensis and prevalence based on the presence of adult worms showed significant correlation (R2 = 0.954, p<0.05).Conclusions/SignificanceThe present results could indicate a high prevalence of A. cantonensis in Tenerife and suggest the inclusion of two new zones in the distribution area of the parasite. The commonness and wide distribution of A. cantonensis in rats implies the presence of intermediate hosts, indicating that humans may be at risk of getting infected.

Intermediate Hosts of Angiostrongylus cantonensis in Tenerife, Spain

“…cantonensis or black rats carrying antibodies against A . cantonensis had been previously found in all the five locations [ 2 ].…”

“…The nematode Angiostrongylus cantonensis is the causative agent of human angiostrongyliasis, which in its severe form is characterized by eosinophilic meningitis (or meningoencephalitis), with marked cerebrospinal fluid (CSF) eosinophilia [ 1 ]. The life cycle of this nematode involves rats and molluscs as definitive and intermediate hosts, respectively, whereas humans are accidental hosts infected through the consumption of raw or undercooked molluscs that contain the infective third stage larvae (L3) [ 2 ]. Once the nematode has been ingested by a person, it can reach the central nervous system or, less frequently, the eye, causing eosinophilic meningitis or ocular angiostrongyliasis, respectively [ 3 ].…”

Phylogenetic relationship of the Brazilian isolates of the rat lungworm Angiostrongylus cantonensis (Nematoda: Metastrongylidae) employing mitochondrial COI gene sequence data

“…Currently, this mollusk is experiencing the explosive phase of invasion, since it has been found in 25 of the 26 Brazilian states and in the Federal District [12]. Humans are accidentally infected by eating raw and undercooked snails that contain the third stage larvae (L3) [13]. The infection can also occur by eating animals that act as paratenic hosts, such as shrimps, crabs, lizards, frogs and terrestrial planarians or through vegetables contaminated by the mucus of infected snails [4].…”

Brazilian Angiostrongylus cantonensis haplotypes, ac8 and ac9, have two different biological and morphological profiles

“…This nematode has been recognised as the primary etiologic agent of hundreds of cases of human eosinophilic meningoencephalitis, whose clinical manifestation is eosinophilic meningitis ( Alicata 1991 , Wang et al 2011 , Cowie 2013 ). Humans can act as accidental hosts and become infected by eating raw or uncooked mollusks or food contaminated with infective L3 larvae ( Martin-Alonso et al 2011 , Cowie 2013 ).…”