There may have been plenty of cough and cold products in the Christmas stockings of residents in the Lone Star State, as Texas markets continue to top the Walgreens Flu Index list for flu activity, the Deerfield, Ill.-based chain announced Wednesday morning. As many as nine of the top 10 markets exhibiting flu activity were in Texas, though flu incidence may be gaining traction across the nation as gains in flu activity were recorded from San Diego to Lafeyette, La.