Leon Cox was dubbed a "medical miracle" after he was given little chance of survival when he contracted a severe case of the potentially lethal infection.

But after being told he would not see out the night, his mother gave permission for revolutionary extracorporeal membrane oxygenation (ECMO) therapy to be administered.

A machine took over the work of his heart and lungs and after 18 days of treatment he showed signs of improvement.

Leon is now a picture of health after also overcoming pneumonia and kidney problems that resulted from the disease – and has just blown out the candle on his first birthday cake.

His mother, Jade Emerson, 19, of Cleethorpes, North East Lincolnshire, believes he caught whooping cough – which is at its most severe in babies under six months – while travelling on a bus when he was only two weeks old.

He began vomiting and suffering from an extreme cough. The disease takes it name from the whooping sound that sufferers usually make after coughing.

As his symptoms worsened he was taken to Diana, Princess of Wales Hospital, Grimsby, where doctors first diagnosed the illness and transferred him to Sheffield Children's Hospital.

Ms Emerson said: "We were told he would not last the night. I was given the choice whether or not to go ahead with the treatment, which hadn't worked on a baby so young with whooping cough before."

The family were so concerned he would not survive they arranged a christening at his bedside in the Sheffield hospital.

Leon was then airlifted to Freeman Hospital, Newcastle – one of only three centres in the UK to offer the treatment – and was initially put on a life support machine.

Ms Emerson said: "The doctors were straight with us the moment his condition worsened. They didn't think he had much of a chance, even with the treatment.

"When they mentioned the treatment they told us to expect the worst because it could cause pneumonia and make his blood thin. We sorted out the christening as we thought it would be a lovely memory if he didn't make it."

She added: "I'm not really religious but I spent a few days in hospital chapels writing things down to help me cope."

ECMO is considered a last resort therapy due to its high cost and technical demands. A machine takes over the work of the heart and lungs and can provide oxygenated blood for several weeks.

Leon has not been in hospital since February and his family are hoping he will be given a clean bill of health at an appointment next month.

Ms Emerson said: "It knocked his immune system and he has had bronchitis and chickenpox, and we are worried what else might affect him later in his
life.

"But I am happy I can hold him and he is here for his first birthday. We just hope he grows stronger and becomes a normal healthy boy."