Long COVID has variable incidence and clinical presentations: our 6-country collaborative study

Area of Science:

• Infectious Diseases
• Immunology
• Public Health

Background:

• Long COVID is a persistent, multi-organ inflammatory condition following acute COVID-19.
• Viral particle retention in organs is a suspected cause of Long COVID.
• The incidence and presentation of Long COVID vary significantly across different countries.

Purpose of the Study:

• To investigate the incidence and common symptoms of Long COVID across multiple countries.
• To highlight the need for expanded international collaboration for Long COVID research.
• To emphasize the importance of long-term observational studies for Long COVID.

Main Methods:

• Collaborative investigation across 6 countries (4 in Europe, 2 in North America).
• Data collection on the incidence of Long COVID.
• Analysis of frequently reported signs and symptoms associated with Long COVID.

Main Results:

• Long COVID incidence ranged from 17% (Ukraine) to 46% (Mexico), averaging 25% across the studied countries.
• The most frequent general symptoms reported were fatigue (47%), hair loss (39.2%), and myalgia (35%).
• No two countries shared the same top three clinical signs or symptoms, indicating variability in presentation.

Conclusions:

• Expanded international collaboration is essential to understand Long COVID prevalence, incidence, pathogenesis, and identify biomarkers.
• Development of new treatments, rehabilitation strategies, and organ-specific approaches for Long COVID is needed.
• Long-term observational studies are critical to assess potential increased cancer risk associated with Long COVID.