The observation by the head of the World Health Organisation last Friday that the acute phase of the pandemic could end this year, if around 70% of the world gets vaccinated, is akin to light at the end of the Covid-19 tunnel. But, with the pandemic that turned life upside down well into its 27th month, new studies are also shedding light onto hitherto unknown complications from the infection. The latest research from the US, published by the BMJ on February 9, says almost a third (32 of every 100) of those aged 65 or older and infected with Covid-19 in 2020 developed at least one new condition that required medical attention in the months after initial infection, 11 more than those who did not get infected. Conditions involved a range of major organs and systems, including the heart, kidneys, lungs, and liver as well as mental health complications.
The US researchers used health insurance plan records to identify 133,366 individuals aged 65 or older in 2020 who were diagnosed with Covid-19 before April 1, 2020. These individuals were matched to three (non-Covid) comparison groups from 2020, 2019, and a group diagnosed with viral lower respiratory tract illness. The researchers then recorded any persistent or new conditions starting 21 days after a Covid-19 diagnosis (the post-acute period) and calculated the excess risk for conditions triggered by Covid-19 over several months based on age, race, sex, and whether patients were admitted to the hospital for Covid-19.
The results show that among individuals diagnosed with Covid-19 in 2020, 32% sought medical attention in the post-acute period for one or more new or persistent conditions, which was 11% higher than the 2020 comparison group. Compared with the 2020 comparison group, Covid-19 patients were at increased risk of developing a range of conditions including respiratory failure (an extra 7.55 per 100 people), fatigue (an extra 5.66 per 100 people), high blood pressure (an extra 4.43 per 100 people), and mental health diagnoses (an extra 2.5 per 100 people). Similar findings were found for the 2019 comparison group.
However, compared with the group with viral lower respiratory tract illness, only respiratory failure, dementia, and fatigue showed increased risk differences of 2.39, 0.71, and 0.18 per 100 people with Covid-19, respectively. Individuals admitted to hospital with Covid-19 had a markedly increased risk for most but not all conditions. The risk of several conditions was also increased for men, for those of black race, and for those aged 75 and older. This was an observational study, so it cannot prove a direct link between Covid-19 and new health problems. However, the researchers warn that with roughly 400mn people infected with coronavirus worldwide, “the number of survivors with sequelae (a condition which is the consequence of a previous disease or injury) after the acute infection will continue to grow.” These findings further highlight the wide range of important sequelae after acute infection with the Sars-CoV-2 virus. “Understanding the magnitude of risk for the most important clinical sequelae might enhance their diagnosis and the management of individuals with sequelae after acute Sars-CoV-2 infection. Also, our results can help providers and other key stakeholders anticipate the scale of future health complications and improve planning for the use of healthcare resources,” they conclude.
