at the end of chapter 9, Atticus refers to the ingrained racism among the residents of Maycomb. how does he describe racism in this passage? To what does he compare it?

Atticus just hopes that he can get his children through the ordeal without having them catch "Maycomb's usual disease," when "people go stark raving mad when anything involving a Negro comes up." Atticus hopes that Jem and Scout will look to him for their answers rather than to the townspeople.