Matt Hancock said he was “incredibly concerned” after it emerged the patients were suspected of dying after eating pre-packaged hospital sandwiches and salads from the same supplier, The Good Food Chain – bringing the number of fatalities to five.
The affected products have since been withdrawn from hospitals and Public Health England (PHE) said evidence suggested all the deaths occurred before the items were removed from circulation on 25 May.
“I have been incredibly concerned by this issue and strongly believe that we need a radical new approach to the food that is served in our NHS,” said Mr Hancock, who withdrew from the Tory leadership race earlier this week.
“Staff, patients and families deserve so much better – our NHS should be at the forefront of supporting people to make healthy choices. I have instructed the NHS to conduct a root and branch review of hospital food.”
The listeria infection is a rare a form of food poisoning and usually causes a mild illness in healthy people. However, it can have more serious consequences among those with pre-existing medical conditions, pregnant women and those with a weak immune system.
The first three victims who died in the recent outbreak were at Manchester University NHS Foundation Trust and Aintree University Hospital NHS Foundation Trust in Liverpool.
It is understood that of the last two listeria deaths, one died after the first three confirmed cases.
The other patient died before the three cases that were reported last week, but has only just been discovered to be linked to the same strain of the bacteria.
The trusts where the latest two victims were receiving treatment have not yet been named, but PHE said there are seven trusts across the country dealing with listeria cases.
The first case showed symptoms on 25 April and sandwiches and salads were withdrawn on 25 May, as soon as a link with the cases was suspected.
PHE said investigations into the outbreak are ongoing and are being conducted in partnership with the Food Standards Agency (FSA).
The Good Food Chain, which supplied 43 NHS trusts across the UK, has voluntarily ceased production while the investigation is carried out. The business was supplied with meat produced by North Country Cooked Meats, which has since tested positive for the outbreak strain of listeria and also stopped production.
The Good Food Chain said in a statement: “Our thoughts and deepest sympathies are with the families of those who have died and anyone else who has been affected by this outbreak. The underlying cause of it remains unclear.
“We understand that the investigations being carried out are complicated and will involve a number of stakeholders, but we hope the authorities will pursue their inquiries with all urgency so the wider industry can learn any lessons as soon as possible, and so those affected do not have to wait too long for answers.
“For our part, we are co-operating fully and transparently with the FSA and other authorities, and will continue to do so.”
Shadow health secretary Jonathan Ashworth said it was “time for a review of hospital food and the adoption of minimum standards”.
Food Standards Scotland said there continues to be no listeria cases in Scotland.