Postacute COVID-19: An Overview and Approach to Classification.

Area of Science:

• Infectious Diseases
• Public Health
• Internal Medicine

Background:

• The COVID-19 pandemic has generated extensive research on acute infection.
• Emerging reports and public discourse highlight persistent symptoms following initial COVID-19 illness, termed post-acute COVID-19 or long COVID.

Purpose of the Study:

• To review the existing medical literature on post-acute COVID-19.
• To propose a classification system for post-acute COVID-19 manifestations.
• To examine long-term symptoms from other epidemic coronaviruses and discuss potential underlying mechanisms.

Main Methods:

• Literature review of clinical manifestations of acute and post-acute COVID-19.
• Analysis of reported symptoms in patients recovered from other coronavirus infections.
• Discussion of potential pathogenetic mechanisms.

Main Results:

• The concept of post-acute COVID-19 is emerging, with diverse persistent symptoms reported.
• A systematic classification of these manifestations is needed.
• Long-term sequelae are known from other coronavirus outbreaks, offering insights into potential COVID-19 mechanisms.

Conclusions:

• Post-acute COVID-19 is a significant emerging clinical syndrome.
• A standardized classification approach is crucial for research and clinical management.
• Understanding mechanisms, informed by prior coronavirus studies, is key to addressing long COVID.