recent arrival of giant snails to Orchidland

[Midnight Rambler]

While they can have rat lungworm in the slime, there is much less in the slime of African snails than the semi-slug, Parmarion. That's why the disease only really took off after that arrived around 10-15 years ago (it also has very small babies which can be accidentally swallowed), while the giant African snails have been here (and been infected) for decades.