The third child has died after finding out that there is an unusual blood in a maternity hospital in Glasgow.
In January, it was pointed out that two people who were admired at the Prince's Royal Maternity Hospital died.
The NHS in Glasgow and Clyde said the third baby was very poor at birth and Staphylococcus aureus infection was one of the factors involved in the death.
The rest of the patients have not undergone disease tests since March.
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Staphylococcus aureus is a bacterium found on the skin and in a more dirty corridor about about one in four, and only diseases when it comes into the body.
In January, NHS Greater Glasgow and Clyde confirmed that a third child was being treated after the introduction of the bloodstream disease following the death of both babies.
Skin cleaning agent
At the time they set up an events management team (IMT) to review the issues. The IMT includes specialist clinics, veterinary doctors and nurses, occupational health nurses and colleagues from estates and facilities.
In a statement released on Wednesday, the health board said: "As mentioned earlier, we have been managing a number of issues affecting fluid diseases in Staphylococcus aureus in babies well. Early in the unit is the inaugural birthday of The Princess Royal Hospital.
"Unfortunately, three babies, who were very ill because of their early birth, died and there was a disease amongst the reasons why they died."
The health authority said a hospital and family screening program had been carried out as part of a number of measures taken to address the disease.
They said: "As a very unusual species, this is highly resistant to the antibiotics generally given for the use of S. Aureus and the skin cleaning agent used. T regularly in hospitals across the UK, we put in place several disease control measures, including prescribing different antibiotics and introducing a new skin cleaner.
The hospital said that when the child died, the hospital may not have known where the disease came from in the intensive care unit.