Cats are given a hard time in this blog; now it's the goldfish's turn.
The SMH reports that a drug resistant strain of salmonella has been proved (by Australian research no less) to live in fish tanks:
Australian researchers proved the link between gastroenteritis and fish tanks by showing that the strains of salmonella in patients and in their home aquariums were genetically identical.
Diane Lightfoot, a salmonella specialist at the University of Melbourne..said the study highlighted the need for care when cleaning tanks.
Fish were good pets, she said, "and fish tanks aren't to be feared. But commonsense hygiene is needed." This included washing hands after touching the water or gravel and making sure the water did not splash onto surfaces where it could contaminate food, she said.
To be fair to goldfish, the article does only refer to "tropical" fish, so maybe an unheated tank of the kind most goldfish have to put up with is not such a risk.