Gnathostomiasis

MICROBIOLOGY

• Human infection arises from the third larval stage of an immature nematode.
• Roundworm of vertebrate animals.
  • Gnathostoma with 13 known species, 6 of which are known to cause human infection.
    • Gnathostoma spinigerum or Gnathostoma hispidum is the usual species infecting humans.
    • Others cause human disease: G. nipponicum, G. malaysiae, G. binucleatum and G. doloresi.
  • The lifecycle includes intermediate/paratenic hosts (freshwater fish, eels, frogs, snakes and birds) and definitive hosts (domesticated pigs, cats, dogs and wild animals); see lifecycle.
    • Food-borne parasites, humans are accidental hosts.