the economic impact of the common cold is poorly understood in much of the world. in the united states, the common cold leads to 75 million to 100 million physician visits annually, costing at least $7.7 billion per year (by conservative cost estimates). americans spend $2.9 billion on over-the-counter (otc) drugs. americans spend an additional $400 million on prescription medicines for symptomatic relief. more than one-third of people who saw a doctor received an antibiotic prescription. the use of antibiotic prescriptions has implications for antibiotic resistance. an estimated 22 million to 189 million school days are missed each year due to a cold. as a result, parents missed 126 million workdays to stay home to care for their children. when added to the 150 million workdays missed by employees suffering from a cold, the total economic impact of cold-related work loss exceeds $20 billion per year. this accounts for 40% of time lost from work in the united states.