In order to protect the identity of the student neither UC Berkeley nor city public health officials said exactly when the student was diagnosed, only that the diagnosis occurred within the past few weeks and that the student remained in isolation. They also do not know where the student contracted the disease, but believe people on the Cal campus could have been exposed to it as far back as October.
"Realistically, I have to say that in my judgment that person probably wasn't infectious that far back. But, just to be safe we're identifying people who were in close contact," said Dr. Anna Bloxhom.
Bloxhom is the campus health center physician who diagnosed the student. She says it is not the diagnosis that is unusual.
"The thing that's maybe a little unusual in this case is the sheer number of people that had to be contacted. The reason for that is this is a student who attends classes and has been attending classes for a while and has attended a lot of classes in smaller rooms."
The case made headlines in Berkeley's student newspaper after more than 200 students and faculty members received emails from the city's public health department, warning them about possible exposure and advising them to get tested.
But, the advisory did not say where the potential exposure may have occurred, wether in a classroom or any other campus setting. It left many students with questions.
"It's definitely scary and I definitely would like to find out more about how it happened and who's affected," said student Ian Magruder.
"I guess it's a little irresponsible in a sense to not reveal where it was exposed, just as a warning," said student Jessica Wan.
There were more than 13,000 reported TB cases in the country in 2007. Berkeley sees an average of four to six every year, and one or two of those are from Cal's campus.
Health officials say it is nothing to be alarmed about as long as those exposed get tested.
"A third of the world's population is infected with tuberculosis and most of those people never become sick. It is a very slow-moving, slow-growing and actually highly-treatable disease," Bloxhom explained.
The university is asking that all those who received a warning about possibly being exposed come to the campus health center for a skin test. Doctors on campus want everyone to know that tuberculosis is an infectious disease that can be fatal if not treated.