Ruling out sepsis should be doctors’ “default position”, said actor Jason Watkins, whose two-year-old daughter died of the condition.

Speaking about her to mark World Sepsis Day, The Crown actor described Maud, who died in 2011, as a “bubbly child” who was full of confidence and liked to sing on the bus.

The 60-year-old has joined forces with the UK Sepsis Trust to help raise awareness of the condition among the public and doctors.

Maud developed a chest infection, which was treated by her doctor with medication, around the new year.

After her condition did not improve, Watkins and his wife Clara Francis took her to A&E, where they were told she had a bad cold and croup before being discharged.

Maud died at home later that night.

It was only discovered later that she had developed sepsis, a life-threatening reaction to an infection that occurs when the immune system overreacts and starts to damage the body’s own tissues and organs.

“She was an amazing girl,” Watkins told the PA news agency.

“She sang a lot. We used to get on the bus and she used to sing all the time in her pram.

“She was just very bubbly and had a sense of humour and had confidence and directness about her.

“She was wonderful. It’s really heartbreaking that as our daughter Betty grows up she hasn’t got her sister to grow up with and all the things Betty is doing Maud won’t be able to do.

“My memories of her are often embroiled and mixed with the feelings of loss.”

Watkins said that since making the documentary Jason & Clara: In Memory of Maudie, which aired earlier this year and has been nominated for a Welsh Bafta, he has turned his attention to remembering “all the happy times”.

He said more must be done to make sure doctors in the UK get regular sepsis training to remind them of the range of symptoms.

He also called for better clinical practise in the way people are diagnosed with sepsis.

“The idea that sepsis has to be ruled out first,” he said.

“My thinking is that the diagnosis, particularly of children that arrive in A&E, needs to be looked at. Sepsis is a difficult thing to diagnose and one’s default really should be to rule it out first.

“Sepsis should be at the top of everyone’s list.”

Asked if Maud might still be alive if the default position then was to rule out sepsis first, Watkins said: “If sepsis had been at the top of the flagpole (when we took Maud into A&E), then she would have remained in hospital.

“Do I think she could have survived? I think if it was today that the hospital trust had the profile that some hospitals have of sepsis, I would say yes, because then, you know, she would have been assessed for sepsis and continued to have been assessed throughout her time in the hospital.”

Dr Ron Daniels, founder and joint chief executive of the UK Sepsis Trust, said doctors should have a “high index of suspicion” about sepsis.

He also called for more awareness among the general public so they are confident to ask health professionals: “Could it be sepsis?”

He told PA: “If there’s a risk of sepsis, it can present in so many different ways, so clinicians need to have a high index of suspicion. They need to look for sepsis and really be alert.

“To get this right demands that we have this partnership between the public who asks that question – could it be sepsis? – and health professionals who think sepsis.”

Meanwhile, he touched on the call for Martha’s rule – which was instigated by Merope Mills, an editor at The Guardian, after her daughter Martha died from sepsis.

Ms Mills and her husband Paul Laity raised concerns about Martha’s deteriorating health a number of times but they were not acted upon.

A coroner ruled that Martha would most likely have survived if doctors had identified the warning signs of sepsis and transferred her to intensive care earlier.

If introduced, Martha’s rule would give families a statutory right to get a second opinion if they have concerns about care.

Dr Daniels said: “Something we really want to highlight is families not being listened to by health professionals.

“This was a theme with Maud’s illness, this was a theme in the case of Martha Mills – that parental concern or relatives’ concern for adults is not often taken as seriously as it should be.

“There is variation between hospitals, there’s variation between regions, with some doing a lot better than others. And we have to standardise it. There shouldn’t be a postcode lottery.”

It comes as the charity released a number of tools to help raise awareness of sepsis.

The Sepsis Savvy resources, which can be accessed via sepsistrust.org/savvy, include a new video featuring Watkins and a mobile game giving information about the condition.

In adults, sepsis may feel like flu, gastroenteritis or a chest infection at first.

Early symptoms include fever, chills and shivering, a fast heartbeat and quick breathing.

Symptoms of sepsis or septic shock include feeling dizzy or faint, confusion or disorientation, nausea and vomiting, diarrhoea and cold, clammy and pale or mottled skin.

Any child who is breathing very fast, has a fit or looks mottled, bluish, or pale, or has a rash that does not fade when you press it, may have sepsis.

And a baby or child under five years old who is not feeding, vomiting repeatedly or has not had a wee or wet nappy for 12 hours, may have sepsis.

The UK Sepsis trust said the condition affects 245,000 people and claims 48,000 lives in the UK each year.