Tuberculosis tests for Cambridgeshire factory workers
Up to 500 workers at Cambridgeshire vegetable factories whose colleagues were diagnosed with tuberculosis are being screened for the disease.
Last month Public Health England (PHE) confirmed 17 staff at two sites in the Chatteris area had been diagnosed with the disease since 2012.
Workers are being offered X-rays and blood tests at a factory in the town.
The PHE said there was "no evidence" tuberculosis could be caught from consuming the factories' vegetables.
Six people employed at two factories in the area were diagnosed with TB in 2012, nine last year and two so far this year.
Details of the infections came to light when Paul Bullen, leader of UKIP on Cambridgeshire County Council, said he had "heard rumours" about people contracting the disease.
Although no new cases have been reported, PHE has set up a two-day screening programme at fruit and vegetable packing plant ERMS in Chatteris.
Dr Kate King, PHE consultant in communicable disease control, said: "The screening is taking place because staff at the factory spend long periods of time in close proximity to each other, either travelling to work or in the work place.
"I would like to stress that transmission of the infection is not related to the type of business at the factories, and there is absolutely no evidence to suggest TB transmission can occur from consumption of vegetables from the factories.
"The factories have been fully supportive of their staff and the public health response."
All those previously diagnosed had been treated and were no longer infectious, the PHE said.
Anyone newly diagnosed, or identified as having abnormal results from the screening process, would be referred to the relevant TB services for treatment, Dr King said.