A recent study published in the Morbidity and Mortality Weekly Report (MMWR) by the Centers for Disease Control and Prevention (CDC) has shed light on the long-term effects of Covid-19. The study found that approximately 16% of long Covid patients continue to experience symptoms more than 12 months after their initial infection.
The most common persistent symptoms reported were related to the head, eyes, ears, and nose, followed by fatigue and gastrointestinal issues. Interestingly, the study also revealed that even among participants who tested negative for Covid-19, the prevalence of extreme fatigue was 6.8%.
Lead author of the study, Juan Carlos Montoy, highlighted that symptoms often resolved and then re-emerged months later, suggesting that measuring symptoms at a single point in time could underestimate the true burden of the disease. Montoy also noted that the patterns of symptoms were similar between Covid-positive and Covid-negative groups, indicating that the burden after Covid may be high for other non-Covid illnesses as well.
The study collected data from 1,741 adults who had experienced symptoms similar to Covid-19 and self-reported their symptoms at three-month intervals for a year. Out of the participants, 1,288 tested positive for Covid and 453 tested negative. The researchers found that 21% of the Covid-positive patients reported getting infected again, while 38% of the Covid-negative patients reported a new infection during the study's duration.
The researchers emphasized the importance of conducting serial measurements of symptoms to better understand post-Covid conditions and to differentiate between symptoms that resolve and emerge over time. They also noted that the study's major limitation was the lack of information regarding the cause of acute symptoms in participants who did not test positive for Covid.
Overall, the study provides valuable insights into the long-term effects of Covid-19, highlighting the need for further research on post-illness processes for Covid and other conditions. It underscores the fluctuating nature of symptoms over time and emphasizes the importance of recognizing that these symptoms are not unique to Covid-19 or post-Covid conditions.