An infestation of ignorant ghetto behavior, which started off in America's ghettos, but spread to the suburbs where non-black people act all ignorant and call themselves and each other Nigga, which is spreading like a disease hence the term Negritis. Which was coined by Mexicans or Latinos.
Juan: Hey what up Nigga you wanna get hella faded?
Carlos: Why are you acting all ignorant and shit?
Juan: Calm down Nigga!
Carlos: I aint even black?! Looks like you got a bad case Negritis?