Prevalence of Angiostrongylus cantonensis in terrestrial mollusks of Port Island, Hyogo Prefecture, Japan

Angiostrongylus cantonensis, also known as the rat lungworm, is a parasitic helminth that infects both rodents and snails as its definitive and intermediate hosts, respectively. In 2012, Sakamoto and Uga found that 46% of examined rodents (19 of 41 infected) on Port Island were infected with A. cantonensis adult worms. Given the extent of infection, we investigated the prevalence of A. cantonensis in terrestrial mollusks of Port Island. Snails and slugs were collected in seven different sites of Port Island between August and September of 2015. These mollusks were then subjected to artificial digestion for nematode larval collection. Nematode larvae were found in 9% of examined snails (24 of 257 infected) and 23% of examined slugs (11 of 48 infected). Allopeas clavulinum and Lehmannia valentinana were positive for nematode larvae. In addition, the site harboring infected mollusks was near universities, residential buildings, and parks, which could lead to the transmission of parasites. Morphological examination revealed that the nematode larvae recovered were different from A. cantonensis. Further identification of the parasite is needed to assess the risks it poses on the environment, humans, and animals