The following correction was printed in the Guardian's Corrections and clarifications column, Thursday March 15 2007

We stated in the article below that the "superbug" MRSA is a virus. It is a bacterium. This has been corrected.

A baby is believed to be the youngest ever victim of the MRSA bug, after contracting the bacterium and dying at 36 hours old, a coroner concluded yesterday.

Luke Day, of Woodbridge in Suffolk, died in February 2005, but might have been saved had hospital staff recognised signs of his illness, an internal inquiry found. Doctors at the Ipswich hospital had not properly co-ordinated his care, the inquest heard. He should have been tested for infections when his temperature and blood sugar were found to be low, and he was "lethargic and slightly floppy".

The coroner, Peter Dean, said there were signs of illness 20 hours after the birth, and alarm bells should have rung. "These were opportunities where Luke could have been taken into intensive care," he said. "Whether the outcome would have been different, we really cannot know. But what we do know is that at least if Luke had been given the chance, then the family would know that everything that could have been done had been done."

The hearing in Ipswich was told a pathologist found traces of MRSA in the baby's organs; however, experts could not be certain it was MRSA that killed him. A post mortem found septicaemia due to the staphylococcus bacterium, but did not specify if it was MRSA. Dr Dean ruled that it was likely that MRSA was responsible for Luke's death. However despite extensive searches at Ipswich hospital, the MRSA source remained unknown.

The inquest heard Luke weighed a healthy 7 lbs 7 oz at birth on February 2, 2005. However, his mother, Glynis, 19, had pre-eclampsia, a high blood pressure condition, and had a convulsion during the delivery.

An internal inquiry at the hospital later found staff had failed to properly recognise signs that the baby might have been ill up to 16 hours before his death. It said Luke appeared "lethargic and slightly floppy" 12 hours before he died. But he was left in a cot on a normal maternity ward, rather than being moved to intensive care and given antibiotics.

Senior midwife Jane Gosling said she was attending to the mother when she noticed the child was "cold to the touch". He was transferred for emergency resuscitation, but declared dead 30 minutes later. The report said that there were deviations from clinical guidelines, and that a paediatrician should have been called due to his low temperature and blood sugar; some of the clinical guidelines were ambiguous, but there was "no over-arching co-ordination of Luke's care". The hospital has since carried out two reviews.

Ms Day said yesterday she knew immediately something was wrong when she heard her child grunting: "They should have done more." Luke's father, Kevin Fenton, 26, said: "We are glad of the verdict, even though it has taken more than two years to come out."

The family is considering legal action against the hospital.