Covid-19 is just as deadly as Ebola for people admitted to hospital in the UK, a leading expert has said as his team published a major British study of almost 17,000 patients.

The research found almost half of people admitted to hospitals in England, Scotland and Wales with coronavirus have no underlying health conditions, while obese people are almost 40% more likely to die than those who are not.

The work examines data from 16,749 Covid-19 patients in 166 hospitals between February 6 and April 18.

It found patients were typically aged 72, though those admitted to intensive care were typically 61.

Most people had symptoms for around four days before admission and stayed in hospital for an average of seven days.

Almost half (47%) had no underlying conditions, while 29% had heart disease, 19% had diabetes, 19% had non-asthmatic chronic pulmonary disease and 14% had asthma.

The study found that women were 20% less likely to die from Covid-19 than men, while being obese, having underlying health conditions and being older were linked to a higher chance of death.

Covid-19 symptom reported included cough (70% of patients), fever (69%), shortness of breath (65%) as well as coughing up mucus, sore throat, runny nose, wheeze, chest pain, muscle pain, joint pain, fatigue, abdominal pain, vomiting and diarrhoea.

Overall, 49% of patients were discharged alive during the study, 33% died and 17% continued to receive care.

Of the total number of patients, 17% required admission to high dependency or intensive care units and of these, 31% were discharged alive, 45% died and 24% continued to be treated in hospital.

Some people persist in believing that Covid-19 is no worse than a bad dose of flu. They are gravely mistaken

Of the remaining 83% treated on wards, 55% were discharged alive, 14% were still in hospital and 31% had died, with the average age of death being 82.

Only one in five (20%) of those who required a mechanical ventilator in intensive care were discharged alive and a further 27% remained in hospital. Just over half who needed mechanical ventilation died.

Professor Calum Semple, from the University of Liverpool and a consultant respiratory paediatrician at Alder Hey Children’s Hospital, and chief investigator on the study, said the data showed that coronavirus was just as fatal as Ebola for patients admitted to hospital.

He said: “I’m going to choose my words very carefully here. Covid is a very serious disease.

“Some people persist in believing that Covid-19 is no worse than a bad dose of flu.

“They are gravely mistaken. Despite the best supportive care that we can provide, the crude case fatality rate for people who are admitted to hospital – that is, the proportion of people ill enough to need hospital treatment who then die – with severe Covid-19 is 35 to 40% which is similar to that for people admitted to hospital with Ebola.

“People need to hear this, and get it into their heads, because the reason the Government is keen to keep people to stay at home until the outbreak is quietening down, is that this is an incredibly dangerous disease….It’s a really nasty disease.”

He said that, on the whole, the British public has heeded advice to stay in but there were “examples of selfishness, where people think it’s okay to meet up in the park and share a four-pack of beer and I’ve seen it happen”.

He also said younger people might think “This doesn’t bother me, Why should I be worried?”.

First of all, the most the most striking feature is that this seems to be a disease that affects men, much more than it affects women

But, he said: “They’re just as likely to catch it and transmit it.

“So, as far as the danger, I’ll stick to my guns. Covid is as dangerous as Ebola, because it’s highly transmissible, and it’s associated with a very high crude case fatality rate for those that go into hospital.”

Prof Semple also said coronavirus was “very different to influenza”.

He added: “First of all, the most the most striking feature is that this seems to be a disease that affects men, much more than it affects women.

“And this difference becomes more apparent the older you get, so in each and every age group, more men than women are affected.”

He said those who were obese with a body mass index (BMI) over 30 “do particularly badly from Covid disease, so they’re more likely to go on to the intensive care units and to go on to die”.

He added: “Nobody who is a big person is just a big person in isolation.

“But (the) disease will cause problems in their lungs, and hearts and kidneys for complex reasons because fat cells secrete chemicals that essentially increase the inflammatory state of the body.

“But also, if you’re a big person, you’re more likely to have had a tough childhood and a tough life being brought up in an environment where you’ve been exposed to multiple deprivations because socioeconomic status and deprivation is strongly associated with (obesity).”

He said all these factors make Covid-19 “a very tough ride” for the obese.

Dr Anne Marie Doherty, honorary consultant in critical care at the University of Edinburgh, said the high death rate seen on wards reflected efforts to keep some patients at the end of their lives out of intensive care and away from intrusive ventilation.

Where there was little change of meaningful recovery, “I don’t think we’re doing these people any favours by bringing them to their intensive care unit,” she added.

Prof Semple also dismissed news from Swiss authorities who say it is now safe for children under the age of 10 to hug their grandparents.

Scientists there have concluded that young children do not transmit the virus.

Prof Semple said he did not agree with this, adding: “Children are infected, and there is good evidence that children are infectious.”

However, he said only a very small number of children fall seriously ill, with under-18s accounting for less than 2% of the study sample and under-fives accounting for 0.8%.

The scientists also said people were presenting with symptoms other than cough and fever, adding: “The current case definition of cough and fever, if strictly applied, would miss 7% of our hospitalised patients.”