Long Covid Studies
Overview of studies on the long-term effects of Covid-19.
Overview of studies on the long-term effects of Covid-19.
As of June 2021, there are a total of 3,723,234 people in Germany who have been or are currently infected with coronavirus. It is difficult to determine the frequency of Long Covid. A press release from the German Society for Respiratory Medicine (DGP) reports that about 10 % of these people are estimated to have to deal with the long-term effects of coronavirus.
Studies into the long-term effects of coronavirus have yielded a wide range of results. The following is a summary of individual studies into Long Covid:
Data on the long-term effects of coronavirus from the UK report protracted symptoms in 20 % of patients even 4 weeks after infection. Symptoms are still reported in 10 % of patients 6 months after infection. In particular, chronic fatigue may still be present 4 weeks after infection in as many as 35-34 % of cases and in as many as 16-55 % of cases 12 weeks after infection [1].
One study into Long Covid published in the Lancet involving 1,733 patients first diagnosed with COVID-19 in Wuhan, China between January and May found that 76 % of Covid-19 patients had at least one symptom six months after the onset of symptoms. The cohort study, which investigated the long-term effects of Covid-19 infection in patients in Wuhan, China, shows that the most common persistent symptom is fatigue or muscle weakness (63 % of patients), with patients also frequently suffering from sleep disorders (26 %). Anxiety or depression was reported by 23 % of patients [3].
A Long Covid working group from Ireland also found that persistent fatigue, dyspnoea and discomfort are common after acute Covid-19 infection. After an average of 75 days between diagnosis and follow-up, over 60 % of the study participants reported that they had "not fully recovered". However, none of the outcomes measured in this study were related to the initial severity of the disease [4].
A study from Bangladesh found that the incidence of Post- Covid-19 syndrome was 46 %. In all, 105 (30 %) patients showed at least one symptom following Covid-19, while 57 (16 %) patients showed multiple symptoms. Post-viral fatigue was the most common feature (117). Other symptoms included persistent cough (8.5%), dyspnoea after exertion (7 %), headache (3.4 %), dizziness (2.3 %) and sleep-related disorders (5.9 %) [5].