Australians are more at risk of the food poisoning that killed a Queensland mother and daughter if they're travelling overseas, doctors say.
Autopsies on the bodies of Noeline Bischoff, 54, and her 14-year-old daughter Yvana have shown they likely died from a rare form of food poisoning after eating fish in Bali.
Ms Bischoff's brother Malcolm Bischoff has said scombroid poisoning caused their deaths, and the fact both suffered from asthma likely contributed to the severe reaction they had.
The Australian Medical Association says scombroid, or histamine poisoning is a rare form of food poisoning and it's extremely uncommon for it to cause serious illness.
It's caused by elevated levels of histamine being present in fish, which can cause an allergic reaction.
The severity of that reaction can be extremely serious in people with asthma.
AMA federal president Steve Hambleton says severe illness or death is very uncommon.
"People with asthma are more sensitive to histamines and probably in this case, the two people with mild asthma showed a very, very severe reaction," he told ABC radio.
He said the handling of fish was a critical factor, and the disease could arise if it was improperly cooled or left to thaw for too long.
"You can't taste it, and symptoms start to occur about 30 minutes after consumption."
Dr Hambleton said most people developed relatively mild illness, and symptoms could include a rash, feeling flushed, headaches, abdominal pain and feelings of anxiety.
"In this case, the reaction went on to be much more serious."
He said common anti-histamine drugs might have made a difference if the Bischoffs had been rapidly diagnosed.
He said 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."
