COVID-19 disease overview and current prevention measures

COVID-19 is a contagious illness caused by the SARS‑CoV‑2 virus. The disease spread worldwide from January 2020, leading to the COVID‑19 pandemic. Common symptoms include fever, fatigue, cough, breathing difficulty, loss of smell and taste, with onset typically 1‑14 days after exposure. About one‑third of infections are asymptomatic. Among symptomatic patients, roughly 81 % experience mild to moderate illness, 14 % develop severe disease such as dyspnoea or extensive lung involvement, and 5 % become critical, facing respiratory failure or multi‑organ dysfunction. Older adults and those with underlying health conditions are at higher risk of severe outcomes, and some patients suffer long‑term effects known as “long COVID.”

Transmission occurs primarily through inhalation of infected respiratory particles, which can travel short distances or remain airborne for longer periods indoors. Contact with contaminated surfaces and subsequent touching of the face also contributes. Infected individuals can remain contagious for up to 20 days, even without symptoms. Diagnostic testing relies on nucleic‑acid detection methods such as RT‑PCR, transcription‑mediated amplification, and RT‑LAMP from nasopharyngeal swabs. Multiple vaccines have received approval and are being distributed globally, supporting mass vaccination campaigns alongside non‑pharmaceutical interventions like physical distancing, mask wearing, ventilation, and hand hygiene.

These measures continue to form the basis of public‑health responses aimed at controlling the spread and impact of COVID‑19 worldwide.