COMPARATIVE STUDIES ON THE DEVELOPMENT OF LARVAL ANGIOSTRONGYLUS CANTONENSIS IN PUERTO RICAN AND BRAZILIAN BIOMPHALARIA SNAILS.

Since the first report of angiostrongylosis cantonensis by Nomura and Lin (1945), Angiostrongylus cantonensis has been recognized as a causative agent of eosinophilic meningoencephalitis in humans in South Asian and Pacific areas (Roux et al., 1987; Purohit et al., 1991; Alibhoy et al., 1999; Cooke-Yarborough et al., 1999; Re and Gluckman, 2001). The diagnosis of the disease is usually based on clinical manifestations and immuno-serological test. Immuno-serological tests require a large amount of antigens. Therefore, it is a paramount importance to establish the life cycle of A. cantonensis in the laboratory. For this purpose, it is necessary to maintain the intermediate hosts in the laboratory. It is well known that various molluscan species can serve as intermediate hosts for A. cantonensis (Lim and Hyneman, 1965; Liat et al., 1965; Hori et al., 1976; Iwanaga et al., 1983). In general, snail species used to establish the life cycle of the parasite in the laboratory is Biomphalaria sp. that is easy to breed them. Although the larval development of A. cantonensis in Biomphalaria glabrata (Yousif and Lammler, 1977), Achatina fulica (Hori and Yamaguchi, 1982) and Ampullarium sp (Uchikawa et al., 1986) has been described, few detailed observations on the location of larvae and susceptibility of the pigmented and albino types of Biomphalaria snails are available. The present paper examines this relationship using laboratory colonies of the pigmented and albino types of Puerto Rican and Brazilian B. glabrata and pigmented B. straminea collected in Brazil. Only adult snails were used. The pigmented and albino types of Puerto Rican strains of B. glabrata were obtained from Puerto Rico via NIH in U.S. A. The Brazilian strains of snails were from the following areas in Brazil: Pigmented B. glabrata from Jaboatao, Pernambuco, albino B. glabrata from Belo Horizonte and pigmented B. straminea from Sao Lourenco da Mata. The snails have been reared in our laboratory by the modified method of Iwanaga and Tsuji (1972). Albino rats, Rattus norvegicus experimentally infected with A. cantonensis