I asked Sean about the figure, and he said it was a "guesstimate", but his explanation of it sounded credible.
Sitting in the computer lab on Friday - the only internet connectivity in the building - I glanced around at the hundred-plus students present. About a dozen of them, by Sean's projection, would be HIV+. Did they know? Did their friends know, their family, their loved ones? Did their course convenors know, their tutors, seminar leaders? Was the doctor's note accompanying a late assignment for "gastro" the result of a late night partying, or the sign of something more sinister?
I couldn't help wondering what the comparable rate was among staff, too. Less, I would imagine - particularly among academics who reproduce by binary fission or cloning... but somewhere, among us, may be colleagues who, like our students, feel that they just can't disclose.
And in contributing to that culture of silence, each day, we fail them.