EFFICIENCY OF A RAPID TEST FOR DETECTION OF TETRODOTOXIN IN PUFFER FISH

Abstract

The selling and importing of puffer fish species and their products was banned in Thailand in 2002, because of possible neurotoxic effects. However, the sale of their flesh is still happening in Thai markets. Standard methods for toxin quantification (HPLC and LC-MS) have significant limitations, therefore a lateral flow, immuno-chromatographic test (TTX-IC) was developed as a tool for rapid detection of toxin. A total of 750 puffer fishes (387 Lagocephalus lunaris(LL), and 363 Lagocephalus spadiceus (LS)) and 100 edible fishes were caught in Thailand from June 2011–February 2012. Screening of TTX from their flesh by TTX-IC revealed that 69 samples (17.8%) of LL possessed TTX at dangerous levels but LS and edible fishes did not. A selected 339 samples were quantified by LC-MS/MS, showing 50 LL possessed TTX at dangerous levels. Comparison of results with LC-MS/MS showed the TTX-IC to have 94.0% sensitivity and 92.4% specificity. The TTX-IC will be a useful tool for TTX screening of a large number of samples, reducing the testing required by LC-MS/MS, thus reducing costs. All positive cases found should be confirmed by standard methods.

Keywords:

• Lagocephalus spp.
• lateral flow
• puffer fish
• rapid test
• tetrodotoxin

ACKNOWLEDGMENTS

The authors acknowledge Thailand Research Fund (TRF) for their financial support of this work, the Regional Medical Sciences Center 4, Bureau of Quality and Safety of Food, National Institute of Health, and the Department of Medical Sciences for their contributions to the work, and Dr. Toni Whistler, International Emerging Infections Program, Thailand MOPH-U.S. CDC Collaboration, for her review and help editing the manuscript.

Notes

*Sensitivity (%) = (No. of TTX-IC positive/No. LC-MS/MS positive) × 100.

**Specificity (%) = (No. of TTX-IC negative/No. LC-MS/MS negative) × 100.