mostly what i've seen around here the past few years is that clinics have lots of signs that say things like "if you think you're sick or if you're coughing or sneezing, please take a mask and let the intake staff know", where they're likely to move extra-contagious people to isolation immediately.

as for meningitis, my recollection is that there's been at least one outbreak at at least one high school in the area nearly every year since i became a teacher, but it's usually a close-contact-spread kind, so it tends to be a small group of close friends or something like that.