Long COVID

In non-reinfected survivors, sequelae declined substantially between years 2, 3, and 4. Without confirmed reinfection, long-term symptoms continued to improve across years 2 to 4. Among reinfected participants, long COVID symptoms one year after reinfection were less common than symptoms one year after the initial infection. Post-COVID syndrome shares characteristics with other post-acute infection syndromes caused by Ebola, polio, and Epstein-Barr virus. Long COVID is compared to chronic fatigue syndrome and related post-viral syndromes in which an acute infection can be the final overload on an already strained system. Common sequelae after reinfection were reduced compared with after initial infection, but the study could not fully separate this from reinfection status effects. The study used the WHO definition of long COVID based on symptom timing, duration, and absence of another diagnosis. Long COVID is defined as a condition after probable or confirmed SARS-CoV-2 infection, usually starting three months from onset, with symptoms lasting at least two months and not explained by another diagnosis. Participants in the study had long covid defined by WHO criteria after a positi…