Gallup: Almost 7 percent U.S. have a cold, 2.2 percent have flu in Oct WASHINGTON, Oct. 18 (UPI) -- Almost 7 percent of U.S. adults reported having a cold on any given day so far in October, up from 5.7 percent in September, a survey indicates. The Gallup-Healthways Well-Being Index asked about 500 U.S. adults each day this month whether they had a cold or the flu "yesterday." The survey found 2.2 percent of U.S. adults reported having influenza on any given day for the first half of October -- similar to the rates in October 2011 and October 2012, Gallup said. "It is possible that this measure of daily cold and flu prevalence underestimates the true rate, because those who were sick the day before may be less likely to respond to a phone survey than those who were not sick," Gallup said in a statement. Still, year-over-year comparisons provide useful information about the relative prevalence of flu in the U.S. population. Those in the East and West were slightly more likely than those in the Midwest and South to report having the flu or a cold, while younger adults were generally more likely than those who are older to report having the flu or a cold. Hispanics were the most likely racial or ethnic group to report having either the flu and a cold, lower-income Americans were more likely than higher-income Americans to report having either illness and men were more likely to report having a cold. The findings were consistent with what Gallup and Healthways found in previous years, except 2009, when H1N1 was the prevalent flu. The survey of 7,151 adults was conducted Oct. 1-14. The survey has a margin of error of 1 percentage point.