Bali deaths of Noelene and Yvana Bischoff from fish poisoning 'impossible to predict'

THE food poisoning that killed Queensland mother and daughter Noelene and Yvana Bischoff was an "unbelievably rare" occurrence, experts say.

THE food poisoning that killed Queensland mother and daughter Noelene and Yvana Bischoff was an "unbelievably rare" occurrence it would have been almost impossible to predict, health experts say.

Ms Bischoff, 54, and her daughter, 14, died in Bali last month after eating contaminated fish.

Autopsy results released on Tuesday showed that the pair likely died from scombroid poisoning, a fish toxin, while family members say the fact both suffered from asthma probably contributed to the fatal reaction they had.

The Travel Doctor - TMVC national medical adviser Dr Tony Gherardin today said it was "unbelievably rare" for two people to die from scombroid poisoning at the same time.

"It's not only extremely rare to get a fatal dose," Dr Gherardin said.

"It's unbelievably rare to get two fatal doses."

Scombroid poisoning can occur in tropical countries where fish are prepared in unsanitary conditions or are left to thaw for too long.

Although relatively uncommon, it is caused by elevated levels of histamine present in fish that cannot be tasted or smelt.

Most people have a mild reaction, but when combined with asthma Dr Gherardin said it could have resulted in a fatal allergic response that would have been almost impossible to predict.

"The Bischoff's both had this mild asthma," he said.

"It could have been a histamine dose that set off a massive allergic response."

Scombroid poisoning symptoms include a rash, abdominal pains and some swelling about half an hour after consuming contaminated fish.

Australian Medical Association president Steve Hambleton said common antihistamine drugs might have made a difference if the Bischoffs had been rapidly diagnosed.

He told ABC Radio Australians travelling overseas were at an increased risk of this type of food poisoning for a couple of reasons.

"Scombroid fish are more commonly served internationally, and we know it's got something to do with fish handling ... where there's less opportunity to refrigerate, there's increased opportunity for this illness to occur," he said.

Travel safety specialist Phil Sylvester from Travel Insurance Direct said the Bischoff's case was a sad reminder of the need to take precautions when eating fish overseas.

This includes looking to see that fresh seafood has been properly refrigerated or iced and that cooked foods are not in contact with raw foods.

Travellers should also avoid eating raw or undercooked seafood, he said, while the Centre for Disease Control and Prevention recommends visitors to developing nations avoid all shellfish due to bacterial problems.

Three main types of fish toxin poisoning:

1. Ciguatera poisoning

2. Scombroid poisoning

3. Shellfish poisoning

Top five tips when eating seafood abroad:

1. Start by looking at the cleanliness of the store, the display cases and the employees.

2. Look to see that fresh seafood is refrigerated or properly iced and that cooked foods are not in contact with raw foods.

3. A fish's eyes should be clear and bulge slightly. The flesh of whole fish and fillets should be firm and shiny, and fresh whole fish should have bright red gills.

4. Avoid eating raw or undercooked seafood.

5. Avoid eating shellfish from areas shortly after an algal bloom. America's Centers for Disease Control and Prevention recommends travellers to developing nations avoid all shellfish due to bacterial problems.

(Source: Travel Insurance Direct)