Topics:
- The likelihood of developing long COVID
- The challenges in understanding long COVID
- The role of control groups in research
- Different prevalence estimates of long COVID
- The impact of media coverage on perceptions of long COVID
- Debate among scientists about long COVID
The Likelihood of Developing Long COVID
If you are infected with the coronavirus, how likely are you to develop long COVID? Tracy Beth Høeg at the University of California, San Francisco, and her colleagues suggest that the likelihood of developing long COVID has been overestimated. While some studies suggest that long COVID affects as many as half of all those infected, Høeg argues that these estimates are based on loose definitions of the condition or poor study design. The most authoritative studies suggest that only a few per cent of people are affected.
However, critics of this analysis argue that other well-designed studies support the idea that the virus often has lasting effects, and that the researchers have ignored these studies.
The Challenges in Understanding Long COVID
The scientific understanding of long COVID has been poor throughout the pandemic. Long COVID is a term used to describe any kind of lasting symptoms after COVID-19 infection. The symptoms can vary widely, and some doctors believe there are over 200 different symptoms associated with long COVID. The exact causes of long COVID are unknown, and it is uncertain whether factors such as the virus persisting in the body or immune system responses contribute to the condition. Long COVID also shares similarities with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), another syndrome of persistent tiredness that can develop after other infections.
The Role of Control Groups in Research
The difficulty in determining the prevalence of long COVID is partly due to the lack of control groups in some studies. Without a control group, it is challenging to compare the rate of long COVID symptoms in individuals who have had a COVID-19 infection with those who have not. Additionally, some studies that did have control groups found that the individuals in the control groups tended to be in better overall health than those diagnosed with COVID-19. This can skew the incidence of long COVID, as individuals with worse underlying health may be more likely to seek hospital testing if they develop COVID-19 symptoms.
Different Prevalence Estimates of Long COVID
One study conducted by the UK’s Office for National Statistics found that 5% of people had long COVID symptoms three to four months after infection, but so did 3.4% of people who hadn’t been infected. This suggests that 1.6% of people who contract the virus develop long COVID. However, other studies have reported higher prevalence rates, such as a study from Iceland that estimated 13% of people had at least one long COVID symptom eight months after infection.
The Impact of Media Coverage on Perceptions of Long COVID
Høeg argues that media coverage of research that produced high prevalence estimates has contributed to the perception that long COVID is more common than it actually is. Fear-based articles tend to attract more attention, perpetuating the idea that the condition is widespread.
Debate Among Scientists about Long COVID
The latest analysis on the prevalence of long COVID is unlikely to settle the debate. Scientists who advocate for more recognition and research on long COVID believe that the new claims undermine the experiences of people living with the condition. They argue that long COVID is a complex phenomenon and cannot be simplified into a single prevalence rate.
