 According to the director of the Center for Disease Control and Prevention's influenza branch in January 2018, it was the first flu season where "we've had the entire continental US" show the same "widespread" flu activity, excluding the District of Columbia and Hawaii.Twenty-six of those states were classified by the CDC as having "high" activity in January 2018.In January 2018, analyzing the reason for the spike, "The Atlantic" noted that the flu season was possibly worse because the dominant circulating strain was the H3N2 strain, which for unknown reasons tends to hit humans harder than other strains and result in worse flu seasons when dominant.