642 - 645 Fontanilla IKC.pmd

The 5’ end of the small subunit ribosomal RNA gene was used to determine whether 3rd larval stage Angiostrongylus cantonensis are present in populations of the giant African land snail Achatina fulica from French Polynesia. Two populations, one from Moaroa Valley, Tahiti (n=5) and the other from Haapiti Valley, Moorea (n=10), were examined. All snails from Tahiti were infected with nematodes, with parasite load ranging from 12 to 28. A total of 92 nematodes were found, of which 91 were positively identified as A. cantonensis. No nematodes were found in the snails from Moorea. We report for the first time the presence of A. cantonensis in A. fulica snails from French Polynesia, indicating a viable route of human infection of A. cantonensis in the region through the handling of A. fulica or consumption of the snail or contaminated food crops associated with the snail. Angiostrongylus cantonensis has a pantropical distribution (Marquardt et al., 2000) and is a major concern from a human health perspective as it causes food-borne eosinophilic meningoencephalitis (EME) or cerebral angiostrongyliasis (Kliks & Palumbo, 1992, Prociv et al., 2000). The life cycle of A. cantonensis involves a gastropod intermediate host and a murid rodent definitive host; the parasite is not highly specific to its intermediate host, and it has been known to infect a wide range of gastropods (Anderson, 2000). The consumption of contaminated salad crops or raw/undercooked snails (Kliks & Palumbo, 1992, Marquardt et al., 2000) has led to sudden outbreaks or isolated cases of eosinophilic meningoencephalitis due to 3rd larval stage A. cantonensis infection (Kliks & Palumbo, 1992). Some of these outbreaks were attributed to the giant African land snail, Achatina fulica (Kliks & Palumbo, 1992), which Alicata (1966) suggested as primarily responsible for the spread of the parasite to Southeast Asia and the Pacific due to the ease with which the snail established itself into these areas via human-aided means. The ability of the parasite to readily infect A. fulica, as shown in Brazil (Maldonado Jr. et al., 2010) and in China (Lv et al., 2009), highlights the risk of human infection of A. cantonensis through this snail. Larval stages of A. cantonensis are difficult to identify with certainty morphologically (Wallace & Rosen, 1969), rendering surveys of Angiostrongylus incidence in intermediate hosts difficult. Molecular techniques provide a reliable alternative method for nematode identification that can be applied to all life stages. The small subunit (SSU) or 18S ribosomal (r) RNA gene has become the molecule of choice for