The number of people being treated in a hepatitis A outbreak linked to a bakery has risen from nine to 42.

JB Christie bakery in Airdrie, North Lanarkshire, closed temporarily at the weekend after public health officials identified several people who had bought products at its outlets in the town and in nearby Coatbridge and fallen ill.

The bakery resumed trading on Tuesday after carrying out “additional control measures” and disposing of all fresh ingredients and any food that could transmit infection.

NHS Lanarkshire said there are currently no public health concerns regarding the safety of food produced by the bakery. It urged people to follow good hand hygiene and to remain aware of the possible symptoms of hepatitis A.

Dr Femi Oshin, NHS Lanarkshire consultant in public health medicine, said: “While our investigations continue, we want to remind people that although the risk of contracting the infection is low, anyone who has experienced a flu-like illness, loss of appetite, nausea, fever, abdominal pains or jaundice should contact their GP or, if out of hours, contact NHS24 by dialling 111.

“The investigation and assessment at the bakery indicated that products produced and sold between Monday March 20 and Thursday April 13 may have been affected, which is why we are advising anyone who ate bakery products which were produced by JB Christie between these dates, and who experiences the above symptoms, to contact their GP or, if out of hours, contact NHS24 on 111.

“A special helpline has been set up to help the public with general information about hepatitis A and about this outbreak. The free phone number for the helpline is 0800 028 2816 and it is open from 8am to 10pm daily.

“The bakery fully cooperated with our investigation and undertook additional control measures agreed by NHS Lanarkshire and North Lanarkshire council, which enabled it to resume trading on Tuesday May 2.”

Hepatitis A is a viral infection that leads to inflammation of the liver and can cause severe illness. The infection clears with time and usually there are no long-term effects, although a very small proportion of people could develop serious complications.

It can take 15-50 days from the time the virus enters the body to the development of symptoms, so new cases are likely to continue to be identified in the coming weeks.

All 42 cases have had a medical assessment and of those patients who required hospital admission, almost all have been discharged.