I.

Introduction

Common Cold, acute infectious disease of the upper respiratory tract, caused by more than 200 kinds of viruses. The common cold is the primary cause of absenteeism in schools and the workplace. According to the National Institutes of Health, American children have six to ten colds a year on average, while adults average two to four colds annually. Children probably have so many because they spend time in close contact in schools and daycare centers, making it easy for the virus to spread.