People eating raw fish from Australia's south coast might contract a tapeworm that has been found in an Australian for the first time, a university says.

People who enjoy eating raw fish, like tuna, are most at risk of being infected by a tapeworm that has been found in an Australian for the first time.

Analysis at Murdoch University has revealed a South Australian 3-year-old was infected with a Pacific Broad Tapeworm, commonly found in fish-eating mammals but not people in Australia.

The disease linked with the nutrient-stealing parasite can cause diarrhoea, vomiting and anaemia.

Parasite expert Andrew Thompson says more research needs to be done to find out what fish species off South Australia's coast may be harbouring the Pacific Broad Tapeworm but it has been identified in around 20 fish globally so far, including tuna.

"The organism has also been found in coastal waters off South America, southern Africa and Oceania, but to our knowledge, no human case has been reported from the Australian region to date," he said.

Professor Thompson said he expects there will be more human cases of the tapeworm in Australia, and that people consuming raw, pickled or smoked fish from waters along the country's southern coastline are most at risk.

He also suggested climate change could be contributing to fish with the parasite swimming closer to the coast than they have previously.

"It is possible that temperate water currents off southern Australia are changing thus affecting the distribution of the fish hosts of the parasite," he said.

The Eyre Peninsula toddler who has had the tapeworm was regularly eating raw fish caught by his father before he was diagnosed and successfully treated in 2015.

Pathologists investigating his worm passed it on to Murdoch University to identify, as it was leaving much larger segments in the boy's stools than those left by a more common strain.