COVID-19: transmission, prevention and key facts

Essentials

Respiratory infection, the forms of which range from absence of symptoms to severe illness, with the possibility of prolonged effects.

Agent: SARS-CoV-2
Transmission or exposure: Respiratory

Situation and vulnerability

Age, certain chronic diseases and weakened immunity increase the risk of serious form. Prolonged symptoms may follow infection.

Signs and limits of their interpretation

Fever, cough, sore throat and fatigue are possible. Respiratory discomfort or significant deterioration of the general condition requires rapid help.

Diagnosis and monitoring

PCR and antigenic tests do not have the same performance. Negative antigenics may require repetition according to the package leaflet and recommendations; they do not guarantee the absence of infection.

Check these benchmarks in the WHO reference →

Prevention and care

Vaccination according to recommendations, renewed air and reduction of symptomatic contacts complement each other. People at risk may need early advice on treatments.

Practical issues

Does a positive PCR measure the infectiousness exactly?

No. Detection of a genetic target may persist; its interpretation depends on time, symptoms and context.

Preparing for an exchange with a professional

Start date of symptoms and tests
Vulnerability factors and treatment
Respiratory difficulties and evolution

Bring the full minutes and dates. This information facilitates evaluation; its collection must not delay an urgent appeal.

Individual decisionThe choice of a test, treatment or prevention depends on the local situation and recommendations. In case of distress, call 911.