Queensland Health is implicating the animal nursery at the Brisbane Ekka as the possible source of several e-coli infections.

Four people who visited the Royal Queensland Show and allegedly attended the nursery in question are being treated for infections, but have so far not been hospitalised.

One 33-year-old woman and three children aged thirteen, eleven and six were not previously known to each other, but reportedly visited the nursery on Animal Boulevard within hours of each other.

Authorities say anyone who visited the Show and is now showing symptoms of e-coli infection (including stomach pain, diarrhoea, fever or vomiting) should see a doctor. In very rare cases e-coli infection can lead to the fatal haemolytic uraemic syndrome.