Emergence of Larval Protostrongylus boughtoni (Nematoda: Metastrongyloidea) from a Snail Intermediate Host, and Subsequent Infection in the Domestic Rabbit (Oryctolagus cuniculus)

Spontaneous Shedding of Metastrongyloid Third-Stage Larvae by Experimentally Infected Limax maximus

“…Whether any environmental factor(s) influence or stimulate shedding in naturally infected gastropods to higher levels than those reported here remains unknown. Shedding levels in experimentally infected protostrongylids tend to be considerably higher ranging from 21 -82 % of the worm burden released by the gastropods (Jenkins et al 2006, Kralka and Samuel, 1984, Kutz et al 2000. In general, the shedding levels did not appear to be dose dependent, however, between species comparisons in this study are probably not valid.…”

“…Release of L3 via gastropod faeces has not been reported previously. Detection of metastrongyloid L3 in mucus trails or exiting directly through the body surface of slugs has been reported (Ash, 1976, Bonetti et al 1998, Heyneman and Lim 1967, Jenkins et al 2006, Kralka and Samuel 1984, Kutz et al 2000, Qvarnstrom et al 2007. No L3 were detected in the mucus of A. cantonensis infected Limax flavus (Campbell and Little, 1988).…”

“…Excepting species infecting marine mammals or swine, the exposure route for most involve the ingestion of infective third-stage larvae (L3) contained in the tissues of a gastropod intermediate host or also in some species a paratenic host. (Barcante et al 2003, Boev 1975, Bonetti et al 1998, Giannelli et al 2015, Heyneman and Lim 1967, Jenkins et al 2006, Kralka and Samuel 1984, Kutz et al 2000, Monson and Post 1972, Ubelaker et al 1980. Recently gastropod L3 shedding has also been reported for a crenosomatid (Troglostrongylus brevior) (Giannelli et al 2015).…”

Bionomics of Larvae of Parelaphostrongylus Odocoilei (Nematoda: Protostrongylidae) in Experimentally Infected Gastropod Intermediate Hosts

“…Emergence of preinfective larvae has not been previously reported for any protostrongylid species, nor has it been considered a mechanism of host resistance (Cabaret, 1979;Kralka and Samuel, 1984;Kutz et al, 2000). Emergence of preinfective larvae of P. odocoilei, which occurred from both healthy and sick gastropods, likely reflects "spillover" at high infection intensities, or expulsion by the intermediate host.…”

“…Even at high infection intensities, the percentage of infective larvae that emerged from D. laeve never exceeded 50%, similar to Protostrongylus boughtoni and P. stilesi (Monson and Post, 1972;Boev, 1975;Kralka and Samuel, 1984). In contrast, 100% of L3 of U. pallikuukensis emerged from some slugs regardless of infection intensity (Kutz et al, 2000).…”