Introduction
The Kudoa genus comprises more than 90 myxosporean parasitic species capable of infecting various marine fish[1]. In Japan, K. septempunctata was recently associated with food poisoning caused due to the consumption of infected raw olive flounder [2,3]. Until recently, infection potential of other members of the genus Kudoa in humans was unknown. However, in the past decade, Japanese researchers have reported foodborne diseases after the consumption of K. hexapunctata -infected adult or juvenile Pacific bluefin tuna (PBT) (Thunnus orientalis ) [4]. Until recently,K. hexapunctata was classified as an intraspecific variant ofK. neothunni , but it has now been established as a separate species [5,6]; differing in spore shape, 28S rDNA sequences, and potential to cause myoliquefaction, which is absent inK. hexapunctata . Although previous in vitro study suggested that K. hexapunctata causes food poisoning[4], currently it is not listed as a food poisoning-related pathogen in Japan. Here, we report food poisoning in 10 patients after consumption of juvenile PBT infected with K. hexapunctata .