The U.S. flu season is off to a very early start. It’s hitting the South and West now

The US flu season has started earlier than usual and is intensifying, with high activity reported in seven states, up from two the previous week. The rise matters as doctors expect infections to spread further during Thanksgiving travel and gatherings, although it is not yet clear whether this season will be worse overall.

Louisiana currently has the highest activity, while California, Oregon, South Carolina, Tennessee, Texas and Washington are also reporting high levels. The CDC estimates at least 2.6 million illnesses, 36,000 hospitalisations and 2,100 deaths so far this season; the flu hospitalisation rate in mid-October was the highest for that point in autumn in more than 15 years. Most cases are linked to a mutated H1N1 strain, but early data suggests this year’s vaccine can recognise it.