what is the worst parasite the snail can get

Question: what is the worst parasite the snail can get
- Keywords:
  parasite,
  snail
Asked by miamia to Catshark, Brown garden snail on 7 Dec 2017.
- Tomeu the snail answered on 7 Dec 2017:
  
  Well, unfortunately I sometimes have lungworm, which can be passed onto dogs if they eat me. And it is not very nice. My relative, the Biomphalaria snail is much worse – responsible for transmitting schistosomiasis, a fairly nasty tropical disease, for which scientists are trying to find a solution (not present in the UK, phew)

Question: what is the worst parasite the snail can get