Three students have come down with tuberculosis at Salisbury University, and the school is now asking about 385 students and staff members who may have come in contact with the infected students to get tested for the disease.

Dr. James Cockey, the deputy health officer for Wicomico County, Md., where the 8,770-student university is located, said that testing has not yet determined whether the three students contracted tuberculosis from the same source.

“Everybody wonders that,” he said. “On a probability basis, it is likely that there is transmission from one to the other.”

He said that tuberculosis bacteria cannot spread as easily across a campus as a virus like the cold or flu. It takes several hours of exposure to become infected — like sharing a dorm room, working in the same room or taking a long car ride with an infected person, Cockey said.

Once someone is infected, the bacteria might remain in his or her system for years or even decades without making the person sick. Cockey said that the bacteria only makes someone sick when his or her immune system is weakened.

That means that the three Salisbury University cases — which were diagnosed in October, then March 21, then last week — might all be linked, and that others who have become infected might not know it yet.

If skin testing or blood testing proves that other students have picked up the bacteria, they will likely receive a four- to nine-month course of prophylactic antibiotics, Cockey said.

He said that the student who first got sick at Salisbury University is no longer infectious and has returned to normal activities.

The university is working on figuring out ways to compel students who took classes with the sick students to get skin tests. About 385 people have received letters since October saying they might have come in contact with someone with tuberculosis, Cockey said.

At first, not many students who received the letters showed up for skin tests. Now, more students are concerned enough to come in for a free test, he said.

“Now that there have been three cases and everybody’s talking about it, we expect and we have experienced greater participation,” Cockey said.

The university has said that any student who received the letter and did not get tested for the bacteria cannot register for classes again next fall, Cockey said. Officials might come up with other ways to compel students to get tested, he said.

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