COVID-19
COVID-19 is an infection caused by the SARS-CoV-2 virus. It circulates worldwide and can range from an infection without symptoms to severe illness. Older adults, pregnant people and people with certain health conditions or weakened immune systems are more likely to become seriously ill. Some people develop persistent symptoms, known as Long COVID, after the initial infection.
Prevention: Mixed
Symptoms
- Fever, cough, sore throat or a runny nose
- Tiredness, headache and muscle aches
- Changes in taste or smell
- Shortness of breath; sometimes vomiting or diarrhea
Transmission
- Breathing in infectious particles released when an infected person breathes, talks, coughs or sneezes
- Close or prolonged contact, especially in crowded indoor spaces with poor ventilation
- Spread can happen before symptoms begin or without symptoms
Prevention
Vaccination helps reduce severe illness; follow applicable local recommendations. Improve ventilation, consider a well-fitting mask in higher-risk settings and reduce contact with others while unwell. Hand hygiene also helps.
Diagnosis and care
People at higher risk should seek advice promptly when ill, as treatment options depend on timing. Severe breathing difficulty or rapidly worsening illness needs urgent medical care.
Source
- COVID-19
Based on CDC information
Source language: English
Source reviewed: April 23, 2025
Source accessed: May 17, 2026
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