TB Exposure Spurs Testing On StudentsBy Daniel C. Stevenson
Over the next few weeks, the Medical Department will test at least 150 students for exposure to tuberculosis, the result of a full-blown case of TB discovered in a student last fall. Any other student may also be tested for free by the Medical Department.
Nine students close to the original patient have already been tested, five of whom are undergoing antibiotic treatment for passive TB infection. Those students, along with the others who tested negative, are not contagious and pose no risk to other students.
Additional students who were associated with the original patient through her living group or small classes are now being tested because of the several cases in the first group.
"We expect the number of positive tests to be very small, but feel this additional testing is prudent," the Medical Department said in a press release.
"We don't think MIT students are more at risk than any others, but we're going to take it seriously. We're going to respond appropriately," said Senior Associate Dean for Undergraduate Education and Student Affairs Robert M. Randolph, calling the response a "conservative approach."
The community wasn't notified of the infection earlier partially because of "concern for the person who was ill,"Randolph said. Also, testing before last month would not have revealed very many infections because of the long time it takes for an infection to appear.
"This is the time that we can do something, and we're acting now,"Randolph said.
Randolph declined to identify the student.
Dorms to be tested Thursday
Representatives from the MedicalDepartment will meet with residents of Burton-Conner House and Next House on Thursday, and they will be able to administer the skin test if students want it.
Doctors met with residents of the Alpha Tau Omega house and administered the tests last night.
Another 90 students who were in small classes with the original patient will be getting mail asking them to get tested at the Medical Center.
Up to 400 students could be tested, but Randolph said he expects only about 150 tests.
MIT has notified the City of Cambridge of the infection and their treatment and testing plan, as required by law.
Case began in fall
The case began when a female student contracted TB from an unknown source, Randolph said. "It's not uncommon for people to be exposed to TB every so often," he said.
The student spent part of the summer and all of the fall term at MIT, during which time the infection developed into the full-blown TB disease. Only when someone is in the disease stage are they contagious, according to the Medical Department.
The student was treated and is now healthy and not infectious. According to the Medical Department, "we know of no one on the MIT campus who is now infectious and spreading further illness."
Immediately after the disease was discovered in the student, nine people who spent a lot of time near her were given the tuberculin skin test. One person, the student's boyfriend, tested positive at that time and was treated with an anti-tuberculous antibiotic.
Since the tuberculin immune reaction to passive infection can take six to 12 weeks to develop, those who initially tested negative were tested again last month, and five of them have now tested positive and are being treated with the antibiotic.
Any passive infections, including those among the student's close friends, almost certainly resulted from that student's infection.
The initial discovery of the disease and the treatment of all patients has been handled by the Medical Department, under the direction of Director Arnold Weinberg. The Medical Department isolated the TB and identified the strain. Weinberg is also the infectious disease specialist for the Medical Department.
Students interested in getting a free test should call the Medical Department at x3-4481 and request a tuberculin skin test, Weinberg said.
The test involved injecting 100 microliters of a purified protein derivative of the bacterium intradermally. The site of the injection is read and the result determined in 48 hours, Weinberg said.
First case in recent memory
This case is the first time in recent memory for an infectious disease outbreak at MIT, Randolph said. The Institute was not affected by the widespread measles outbreak at colleges in 1995.
TB is an infectious disease that is not highly contagious. It is spread when a person coughs, producing droplets of mucous which contain the TB bacterium. The bacterium is killed when the droplets are exposed to sunlight or settle on a surface, so another person can only be infected by inhaling many of the droplets. The chance of infection is low; even family members living in the same home have only a 20 percent chance of being infected.
Healthy people infected with TB do not normally develop the full-blown disease; rather, their immune system contains the bacterium. In this case, the student had a history of asthma.
The symptoms of full-blown TB include persistent fevers, cough, weight loss, and night sweats.
The strain of tuberculosis found in the student is not one of the newer, antibiotic-resistant strains, but an old, "very responsive" strain, Randolph said.