Learn about Alexandra Michelle: her birthday, what she did before fame, her family life, fun trivia facts, popularity rankings, and more. Fun facts: before fame, family life, popularity rankings, and more.
Viruses cause such respiratory infections as the common cold (rhinovirus), the flu (influenza), some pneumonias and bronchiolitis (respiratory syncytial virus, or RSV). It can be difficult to determine whether you have a viral or bacterial infection because the symptoms are often similar.
Introduction. A cold is an upper respiratory infection caused by a virus. Colds tend to occur most often in winter, although scientists aren't sure why. In the United States, adults usually have 2 colds per year, and children have at least 6.ntroduction. A cold is an upper respiratory infection caused by a virus. Colds tend to occur most often in winter, although scientists aren't sure why. In the United States, adults usually have 2 colds per year, and children have at least 6.