Stopping coronavirus spreading in hospitals could have made ‘substantial’ reduction in first wave deaths as SAGE paper claims up to 40% of patients caught Covid AFTER admission
- Researchers said in-hospital spread prolonged the first wave by ‘several weeks’
- NHS struggles to contain the virus, which spreads silently, especially when busy
- Some caught the virus then developed symptoms after discharge, they said
Stopping the spread of coronavirus in hospitals could have led to a ‘substantial’ reduction in the number of deaths in the first wave, SAGE research has suggested.
A paper presented to the government advisory board found that as many as 40 per cent of hospital patients with Covid caught it after they were admitted.
The spread of the virus on wards has been a problem for the NHS throughout the crisis, with hospitals that have more Covid patients finding it harder to manage.
Although staff must wear protective equipment at all times and Covid and non-Covid patients are segregated, the virus can still spread from people who don’t have any symptoms or who get false negative test results.
The SAGE paper, published today, suggested that as many as 36,152 of around 90,000 people who were diagnosed with the virus in hospital between February and July 2020 had caught it in hospital.
This included people who became ill while an inpatient for another condition, or who developed Covid-19 shortly after being discharged and then ended up back in hospital. Some of the cases were only suspected, while others were confirmed by process of elimination.
Preventing the spread inside hospitals, the researchers said, could have had a ‘substantial’ impact on deaths because the patients were often old or frail.
And it could have shortened the first wave by several weeks because it was seeding outbreaks in the community when infected people were discharged.
The study, published by SAGE today, found that at times more than half of Covid patients in hospital appeared to have caught the virus after being admitted. The red bars represent the proportion of people who definitely caught the virus before they came in. The purple and blue represent varying levels of certainty about where people got infected, with the lightest blue representing people who were diagnosed more than two weeks after they got sent to hospital, meaning they definitely didn’t have it when they went in
The paper showed that even people who didn’t obviously catch the virus in hospital may have done so if they developed symptoms shortly after being admitted and then ended up back in hospital with Covid-19
The paper estimated that at least 8.8 per cent of Covid-19 hospital cases in England over the first wave of the pandemic may have been nosocomial, or hospital-acquired, infections.
The figures suggest that between February 2 and July 26, there were about 7,906 cases where patients tested positive 15 or more days after hospital admission.
Experts analysing the data said this figure increased to 14,635 cases (or 16.4 per cent), when factoring in positive Covid-19 tests eight or more days after hospital admission.
However, they add that when taking into account missed hospital-acquired infections – those with a symptom onset after discharge, or those with symptom onset prior to the defined cut-off – the numbers may have been as high as 31,000 in England over the first wave.
The experts said that while the proportion of Covid-19 cases linked to hospital transmission is considerable, this is relatively small at a population level.
The undated document said: ‘A simple calculation assuming 5 per cent of infections are hospitalised and of these hospital cases, if 25 per cent are due to nosocomial infection, the complete prevention of nosocomial transmission would have led to approximately 1 per cent impact on the number of infections in the English epidemic overall.
‘However, since hospitalised patients tend to be old and/or frail, the impact in terms of morbidity and mortality would nonetheless be expected to be substantial.’