The UK, South African and Brazilian variants of Covid-19 pose a “significantly higher” risk of hospitalisation and intensive care admission, a new study by the European Centre for Disease Prevention and Control (ECDC) has found.
The Health Protection Surveillance Centre (HPSC), National Virus Reference Laboratory, Irish Coronavirus Sequencing Consortium and All Ireland Infectious Diseases Cohort fed into the ECDC study, which reviewed more than 23,000 Covid-19 cases across Ireland, Cyprus, Estonia, Finland, Italy, Luxembourg and Portugal.
The study reviewed almost 20,000 cases involving variants of concern (VOC) and more than 3,000 cases involving other Covid strains that did not have mutations of concern (non-VOC) and compared how infection impacted on individuals and whether they required hospital treatment, were admitted to intensive care, or died.
The B117 variant, which originated in the UK, accounted for most of the cases reviewed (19,207), followed by the South African or B1351 variant (436), and the Brazilian or P1 variant (352) between September last and March this year. The UK variant was also the most prevalent in Ireland over the study period.
The three variants have been classified as ‘variants of concern’ because of their more infectious nature and ability to cause more severe illness and the study found that infection with the B117, B1351 or P1 variants increased the odds of being admitted to hospital or intensive care compared to those infected with Covid-19 strains that did not have mutations of concern.
The South African and Brazilian variants had the highest hospital admission rates of between 19% and 20%, followed by the B117 variant at 11%, compared to a 7.5% admission rate in those infected with a Covid strain that was not of concern.
A similar trend was evident among those requiring intensive care admission – 2.1% to 2.3% for the South African and Brazilian variants and 1.4% for the UK variant compared to 0.6% for non-VOC Covid cases.
The risk of hospital or intensive care admission was also higher for younger and middle-aged groups.
The risk of hospitalisation was two to three times higher for people aged between 20-59 years when infected with the B117 variant.
With the South African variant, the risk of hospitalisation was about 3.5 times higher for people aged 40-79 and the risk of being admitted to intensive care was “significantly” more likely in people aged 40-59 years.
In those infected by the Brazilian variant, the odds of requiring hospitalisation was three to 13 times higher in people aged between 20-79 years and the risk of intensive care admission was three to 14 times higher for those aged over 40.
The variants did not pose any greater risk of death, the study found. Of more than 23,000 cases reviewed, 184 people died and were aged between 41-99.
The increased risks, in particular for middle-aged groups, highlighted the need to “rapidly reach high levels of vaccine coverage”, continue public health measures, and enhance testing and tracing for variants of concern to reduce their spread, the study concluded.
Meanwhile, a new forecast tool for Covid-19 across Europe predicts an increase in infection rates in Ireland in the coming weeks.
The latest data from the ECDC forecast hub suggests that weekly Covid-19 case numbers could rise from almost 3,000 in the week to April 24 to about 3,500 by May 22.
The tool does not explain why rates may rise and is unlikely to take account of Government plans to further ease restrictions and open up the country.