Ciguatoxin in moray eels raising the risk for seafood safety in Viet Nam

Abstract

Recently, suspected ciguatera fsh poisoning (CFP) cases caused by the consumption of moray eels, popular seafood for locals and tourists, have been reported in Viet Nam. However, little is known about ciguatoxins (CTXs) in these marine fsh. In May 2020, 119 specimens of six moray eel species were collected for CTX detection from Ly Son Island (site 1), Ninh Hai Coast (site 2), Phu Quy Island (site 3), and Spratly Islands (site 4), where suspected CFP from moray eel consumption have occurred. CTX-1B was detected by liquid chromatography–mass spectrometry (LC/MS) analysis in 12 specimens belong-ing to four Gymnothorax species: (G. fmbriatus, G. favimarginatus, G. javanicus, and G. undulatus), accounting for about 10% of the total specimens. Remarkably, CTX-1B levels detected in all toxic specimens were beyond the safety threshold of 10 pg/g CTX-1B equivalent. The highest occurrence was observed at site 4 (15.6%) (n = 45), followed by site 1 (10.0%) (n = 40) and site 2 (6.3%) (n = 16); whereas no CTX-1B was detected in any specimens (n = 18) from site 3. These results, for the first time, report the presence of CTX-1B, indicating a CFP risk in Viet Nam from consumption of moray eels.