Figure 2. Potential routes of infection of the human central nervous system (CNS) by the rat lungworm, Angiostrongylus cantonensis. Note that the normal life cycle involves (1) consumption of molluscs by rats, then (2) excretion of nematodes in rat feces, which are then (3) consumed by molluscs. Human infection can occur when uncooked infected molluscs are eaten (4a) or, more rarely, when uncooked contaminated paratenic (transport) hosts (4C) or vegetable matter (4b) is consumed. Adapted from Wang et al. (2008).