The 32-bed ward has been closed to new admissions and restricted to visitors and non-essential staff since Friday, when the bug was first detected.

Initially up to nine patients and six staff were affected, but a review yesterday confirmed more people had succumbed to the contagious virus.

Tasmanian Health Organisation North chief executive John Kirwan said while precautions remained in place at the hospital to contain the transmission of the illness, there was evidence of its spread in the wider community.

Scottsdale is one of the main towns where the bug is having a widespread effect.

Mr Kirwan urged the public to only visit patients in the hospital if it was essential.

He warned the virus had the potential to impact on wider hospital services with a number of staff now affected.

Anyone who has been in contact with the virus should not visit the hospital, or attend work or school until at least 48 hours after symptoms stop.

Symptoms typically include nausea, vomiting, abdominal cramps and diarrhoea.

Low-grade fever, chills, headache and muscle aches are also associated with it.

The illness is usually self-limiting and resolved without treatment.

However, those at greater risk are the very young and the elderly. 

Anyone with severe symptoms should seek medical attention and if visiting the hospital, should phone in advance to ensure staff take the necessary precautions.

The Emergency Department can be reached via the LGH switchboard on 63487111.