A HEALTH warning has been issued for those who have consumed food from Sumo Salad in the Sydney CBD following the diagnosis of Hepatitis A in an employee.

People who have eaten from the Kent St store between July 19-26 are being urged to seek out the Hepatitis A vaccine.

Those who bought food from the outlet between July 11-18 are encouraged to visit their GP if they begin to develop any symptoms including poor appetite, abdominal discomfort, jaundice and dark urine.

South Eastern Sydney Local Health District's Professor Mark Ferson said the disease was a viral infection of the liver.

"We urge anyone who may have been exposed to these food products to receive a Hepatitis A vaccination as quickly as possible to develop some protection from developing the infection,'' he said.

"People who have already received Hepatitis A vaccine or have had the disease would already be immune and will not need an injection.

"There is no specific treatment for Hepatitis A but the illness resolves after several days or weeks.''

As a precaution a clinic providing a free Hepatitis A vaccine will be available at Sydney Hospital tomorrow.

The clinic will be open between 3pm and 7pm.

A statement from Sumo Salad said the company was doing everything in its power to ensure the safety of its customers.

"Last night a public health warning was issued from the NSW Department of Health, which Sumo Salad have resolved,’’ it said.

"This was an isolated incident at one store in Westpac Place, Kent Street, Sydney.

"No other stores have been affected.

"The individual employee, who contracted the virus while overseas. is no longer working in the store - they had very limited contact with food.

"Sumo Salad is doing everything in its power to ensure our customers safety - this is our highest priority.

"We take our obligations to ensure our customers health and safety as paramount.

Sumo Salad is a national brand that promotes itself as ''the healthiest fast food franchise''.

It has stores across NSW, Victoria, South Australia, West Australia, Queensland, the ACT and NT.

Internationally, there are Sumo Salad stores in New Zealand, London, Dubai and Singapore.