The flu season is starting to hit full stride in Iowa, but the flu bug has been with us throughout the year. Tom Boo, an epidemiologist with the Iowa Department of Pubic Health, says the flu is the opposite of people, it likes the cold weather.He says flu is always here are very low levels, and like most respiratory viruses, it tends to circulate more in the winter in colder temperatures and as people move indoors and are crowded together. Dr. Boo says different strains of the flu are like Iowa snowbirds in reverse, traveling to climates that’re cooler. He says our winter is the summer in the southern hemisphere, so during our summer when it’s winter there, there’s lots of flu activity there. Boo says the best thing to do to avoid letting the flu bug get ahold is to get a flu shot.