viral infectious diseases

Viral infectious diseases are illnesses caused by viruses, tiny infectious agents that invade human cells to reproduce. They can spread through contact with infected individuals, contaminated surfaces, or fluids like blood and saliva. Symptoms vary widely, from mild to severe, including fever, cough, fatigue, or more serious issues. Some viruses, like the flu or cold, resolve quickly, while others, like HIV or COVID-19, may require ongoing treatment or cause long-term health effects. Preventive measures include vaccination, good hygiene, and avoiding close contact with infected people. Understanding and controlling viruses help reduce their spread and impact.