My nephew he's 2 yrs. had a fever of a 104 by the armpit, has a stiff neck, and now he's not peeing. the hospital ruled it as a flu. what could it be?

ER visit now: Fever and stiff neck could signal a life threatening illness. Please take the child to the hospital emergency room immediately.

Needs in person eval: A 2 year old who is not peeing. That's a problem. With a fever of 104 with a stiff neck is concerning. And he is likely dehydrated too, and that's why he's not peeing. I would have him seen again, even if just to get him hydrated and to rule out meningitis.