Ireland’s health authorities are investigating the outbreak of MRSA superbug which has affected 23 newborn babies at Mayo General Hospital, in Castlebar.

Methicillin-resistant Staphylococcus aureus (MRSA) is a bacterium responsible for several difficult-to-treat infections in humans, commonly referred to as the MRSA superbug.

The superbug was discovered as long as seven weeks ago according to the Irish Independent.

The health officials in Ireland remain mystified with the “cluster” of newborns affected, which is far above normal levels.

On average three babies per month are now testing positive for the bug. The infants tested positive for MRSA on their skin which is known as “colonization”. The bug only becomes life threatening if it enters the blood stream.

A spokesperson for the Health Service Executive (HSE) said “The maternity department staff, supported by the infection-control team, consultant medical staff and hospital management, are reviewing possible causes and implementing control measures.

“Control measures, including increased screening, strict implementation of the visiting policy, environmental cleaning and enhanced vigilance have been put in place.”

The outbreak was only made public as stricter visiting rules, in the maternity ward, were introduced.

Ireland’s HSE says that although the babies have tested positive none of the babies have become ill.

Tony Kavanagh, of MRSA and Families, said this situation is more “common than you would think. We were shocked initially when we heard of newborns having the infection but it has become very common.

“This is a very serious bacteria that can hit anyone in hospital. It's not just the elderly that are at risk, it is every patient from a newborn up.”