Eating raw seafood is enjoyed by millions of people, not without hazard.
Factors affecting the frequency of hazards:
(1) salt water versus brackish water versus freshwater source
(2) proximity to sewage or industrial waste release
(3) reputable source with inspection
(4) storage and transport
(5) preparation
(6) handling after preparation including temperature control
Bacteria:
(1) Vibrio species
(2) Staphylococcus aureus
(3) Shigella species
(4) Salmonella species
(5) pathogenic E. coli
(6) Listeria monocytogenes
Viruses:
(1) viral hepatitis A
(2) viral hepatitis E
(3) norovirus
(4) enteroviruses
Parasites:
(1) Anisakis simplex
(2) Pseudoterranova decipiens
(3) Diphyllobothrium latum
(4) Gnathostoma species
(5) Capillaria philippinensis
(6) Clonorchis sinensis
(7) Opistorchis viverrini
(8) Metagonimus yokogawai
(9) Paragonimus
(10) Angiostrongylus cantonensis
(11) Spirometra erinaceieuropaei
(12) Fasciola hepatica
(13) Fasciolopsis buski
Other hazards:
(1) bones
(2) toxins
(3) squid spermatoceles
(4) fish bile
(5) mercury
