"If it was full of parasites, most likely the gecko would have been relatively easy to catch.
"If you have a broom, you can knock them off the wall and then catch them as they fall.
"It would have to have been packed with larval stages (of parasites), which might have been why it was so easy to catch."
Dowell died in "absolute agony" at the age of 34 in Brisbane's Mater Hospital last December after eating a gecko as a dare at a pre-Christmas party.
After feeling like he was hungover for days after the party, Dowell was taken to hospital where he began vomiting green bile, his urine turned black, and his stomach was so bloated he looked six months pregnant.
His lungs had also started to fill with fluid, fluid leaked from his stomach, and "his testicles were swollen up to grapefruits and there was fluid leaking from them".
A doctor told news.com.au Dowell had all the symptoms of a stomach obstruction coupled with fluid in his interabdominal cavity and scrotal oedema.
The doctor said the other symptoms were of liver failure, and they sounded extreme for salmonella poisoning.
Dowell died in surgery, leaving behind his partner Allira and three daughters.
Barton said while reptiles commonly carried salmonella, geckos were also host to other parasites.
"Asian house geckos carry the larval stage of various things, pentastomes which go into the lungs of snakes, nematodes or roundworms and the larval tapeworms that go into cats," she said.
"Spirometra is in snakes, frogs and geckos and go into mammals like cats and quolls and attack and grow.
"Heavy infections of parasites can cause abdominal blockage … or something got into the liver and blocked a duct, but that fast?
"That rapid a response, the gecko would have to have been packed with larval stages, which might have been why it was so easy to catch."
When an adult Spirometra tapeworm is present in the small intestine of cats and dogs, it may grow as long as 1.5m.
Cases of human infection by the Spirometra have been reported, with a 26-month-old baby having a 42cm worm in the lung and a 70-year-old man with a 20cm larva in his stomach, both in Vietnam.
Despite Australia being home to 200 different species of native geckos, the Asian house gecko is the most invasive species of lizard on earth.
Since the 1960s, the Asian house gecko has become resident in homes in Queensland and warm parts of Australia where some householders complain about it leaving droppings and making a noise.
Spirometra tapeworm, or zipper worm, also known as "the gecko tapeworm", is more common in cats than dogs, with pets becoming infected by ingesting intermediate hosts such as geckos, other lizards, mice, rats or frogs.
Dr Barton's 2015 study "Helminth parasites of the introduced Asian House Gecko" was the first report of helminths, or gastrointestinal parasitic "worms", infecting the invasive Asian house gecko in Australia.
Dr Barton told news.com.au the other recent death of an Australian man who had ingested a garden slug as a dare was another example of why it was a bad idea to ingest creatures.
Sam Ballard swallowed the slug as a 19-year-old taking up a drinking game dare and became infected with the parasite Angiostrongylus cantonensis, known as rat lungworm.
He contracted eosinophilic meningo-encephalitis and became a non-verbal quadriplegic. Last November, he died.
Dr Barton cited the case of a toddler who died from the same disease several decades ago.
"Don't eat things you are not meant to," she said.
"There was a little boy in Brisbane who went out to get the milk bottles.
"A snail had left a larval parasite in its slime trail and the boy … got rat lungworm and died.
"These particular parasites are a problem.
"In their life cycle, they wander through the host, go through the tissues and get lost as they try to find their way to the lungs and end up in the meninges (the protective layers of the brain and spinal cord)."
The Australian Reptile Park's head keeper, Dan Rumsey, told news.com.au while Asian house geckos chase and eat moths and insects in homes, it was best to wash your hands after touching them.
"Typically, they are about 8cm long and are highly invasive. They like urban habitats," he said.
"Reptiles carry salmonella, it's just a bacteria they can harbour on their skin.
"In the US a few years ago there were cases of salmonella poisoning from turtles.
"You should always wash your hands after handling any animal."
Following Dowell's death on December 11 last year, his family said he suffered mass organ failure and "basically rotted from the inside out".
More than six months later, Dowell's family are still searching for answers, but no inquest into his death will be held.
The Queensland Coroner's Court said in a statement, "After consideration of the hospital records, the coronial registrar finalised the investigation by authorising the cause of death certificate to issue without coronial autopsy."
Brisbane's Mater Hospital offered Dowell's family its sympathy but would not comment "due to patient confidentiality".
