Both influenza and the common cold are viral respiratory infections (they affect the nose, throat, and lungs). Viruses are spread from person to person through airborne droplets that are sneezed out or coughed up by an infected person. In some cases, the viruses can be spread when a person touches an infected surface (e.g., doorknobs, countertops, telephones) and then touches his or her nose, mouth, or eyes. Influenza is commonly referred to as “the flu.” From November to April each year, 5% to 15% of Canadians are stricken with influenza. Although most people recover fully, depending on the severity of the flu season, it can result in an average of 20,000 hospitalizations and approximately 2000 to 8000 deaths annually in Canada. Deaths due to the flu are found mostly among high-risk populations, such as those with other medical conditions (such as diabetes or cancer) or weakened immune systems, seniors, or very young children. There are 3 types of influenza viruses: A, B, and C. Type A influenza causes the most serious problems in humans. There are over 200 different known cold viruses, but most colds (30% to 40%) are caused by rhinoviruses. Children catch approximately 8 colds per year, adults catch roughly 4 per year, and seniors about 2 per year. Many people confuse the flu with a bad cold. People infected with an influenza or cold virus become contagious 24 hours after the virus enters the body (often before symptoms appear). Adults remain infectious (can spread the virus to others) for about 6 days, and children remain infectious for up to 10 days.