Passengers aboard the transcontinental train, the Indian Pacific, have been hit with a bout of severe viral gastroenteritis forcing them to be quarantined from other passengers.

Fairfax Media has been told that 10 passengers became sick on the train that arrived from Perth on Wednesday and three were taken to hospital.

A spokeswoman for Great Southern Rail, which operates the Indian Pacific, said staff on board had isolated the sick passengers to ensure the virus didn't spread.

A NSW Ambulance Service spokeswoman said seven ambulances met the train on arrival at Central to treat the sick passengers. Three were taken to St Vincent's and Royal Prince Alfred hospitals for treatment.

Great Southern Rail has said it has contacted passengers by email warning them about the virus and urging them to seek medical advice if they experience any symptoms.

The spokeswoman said the train has been disinfected.