Severe Acute SARS-CoV-2 Infection and Long COVID: What Do We Know So Far? New Challenges in Diagnosis and Management

Background/Objectives: The long-term impact of the COVID-19 pandemic is not just limited to socioeconomic aspects; there are also important health issues to consider. Among these, one of the most important and obvious is long COVID. Despite a significant amount of scientific work having been published, this condition is still semi-unknown. The objective of this study was to collect useful information for the clarification of some epidemiological, clinical, and laboratory characteristics of this disease. Methods: This was a single-center study carried out at the Infectious Diseases Clinic of the hospital “AUO delle Marche” on all patients hospitalized for COVID-19 between November 2021 and March 2022. Results: From the data, it emerged that, following the resolution of the acute phase of SARS-CoV-2 infection, the majority of people experienced health problems that persisted for at least 6 months. The manifestations and outcomes affect different systems; therefore, long COVID, like COVID-19, has systemic involvement and the clinical manifestations may be residues of the damage caused by the disease during the acute phase, or new manifestations whose pathogenesis is still a matter of discussion. Conclusions: The persistence of inflammation and the dysregulation of the immune system represent some of the pathogenetic hypotheses. Inflammation could therefore represent one of the physiopathogenetic mechanisms of long COVID, and it is possible that it is responsible for the clinical symptoms that appear in the months following the resolution of the acute phase of the disease.