Human fatalities in Vanuatu after eating the xanthid crab, Daira perlata

This was the first case of the crab species, Daira perlata, being inplicated in toxic poisoning. Autopsies were not carried out on the two teenagers who died in 2000 after consuming a meal containing the crab, Daira perlata. Because it was not possible to test for toxicity at the hospital on Tanna Island, the remains of the crab from the meal were sent to the Australian Institute of Marine Science for testing. As these remains had been preserved in formalin which hinders subsequent toxin analysis, 4 specimens of the crab species were collected from the same location (Lenawha Reef) in the fortnight after the poisonings and analysed for toxins using 2 specific and sensitive binding assays but no toxin was detected. Three toxins are known to occur in crabs, saxitoxin, tetrodotoxin and palytoxin (assays available at the time do not detect palytoxin). To use sodium channel and saxiphilin receptor assays to see if paralytic shellfish toxins could be identified in this species of crab involved in human fatalities. Crabs are known to bioaccumulate toxins from the environment.

本案例为光手馒头蟹（Daira perlata）首次被证实与中毒事件相关。2000年，两名青少年食用含有该蟹的餐后身亡，相关尸检并未开展。由于塔纳岛（Tanna Island）的医院无法开展毒性检测，餐食中剩余的蟹样本被送往澳大利亚海洋科学研究所（Australian Institute of Marine Science）进行检测。由于该样本经福尔马林保存，会对后续的毒素分析造成干扰，研究人员在中毒事件发生后的两周内，从同一海域（勒纳瓦礁Lenawha Reef）采集了4份该蟹物种的标本，采用2种特异性且灵敏的结合检测法开展毒素分析，但未检出任何毒素。目前已知蟹类可富集三类毒素：石房蛤毒素（saxitoxin）、河豚毒素（tetrodotoxin）与岩沙海葵毒素（palytoxin），但当时可用的检测方法无法检出岩沙海葵毒素。本研究拟采用钠通道（sodium channel）与saxiphilin受体（saxiphilin receptor）检测法，探究此次致人死亡的涉事蟹物种体内是否可检出麻痹性贝类毒素。已知蟹类可从环境中生物富集毒素。