Clinical pathology selected abstracts
September 2025—Severe acute respiratory syndrome coronavirus 2 infection can lead to post-acute sequelae, or a condition known as long COVID. The World Health Organization defines long COVID as any symptoms that typically present within three months of acquiring COVID-19 and that persist for at least two months. Long COVID generally manifests as fatigue, pulmonary symptoms, and cognitive dysfunction. The biological mechanisms of long COVID are not well understood. Changes in the serotonin system may lead to cognitive changes, while mitochondrial changes may lead to fatigue, and complement and platelet activation to vascular disease.