TB's persistent presence

Although tuberculosis cases have declined, the illness continues to be a serious threat -- both globally and domestically. Primary care physicians have an important role in the effort to control and prevent its reach.

By Kathleen Phalen Tomaselli, AMNews correspondent. Oct. 17, 2005.

The cycle may have started with an errant cough or sneeze in a grocery store or on a bus. At least that's how local health officials believe the Snohomish County, Wash., boy inhaled the Mycobacterium tuberculosis bacteria.

Once in his lungs, they reproduced slowly until something activated them. At one point, the boy might have been treated with the standard nine-month antibiotics regimen but stopped when he started feeling better. Thus, the tubercle bacillus remained hidden in his system and grew smarter.

This summer, the stealthy invader reactivated, making the boy sick again, the bug this time able to elude the first-line drugs. It also threatened to spread rapidly, leading health workers to scramble to find the boy's circle of contacts -- friends, teachers, family and co-workers, anyone who might have breathed in droplet nuclei of the bacteria when the boy coughed. During the same period, in the same county, a local day care center worker was also diagnosed with active TB. The contact web of the boy and worker grew: 50, 100, 200, 400.

"Our first priority is making sure an active case of TB gets treated and that the patient takes the complete therapy," says Chris Spitters, MD, MPH, TB control officer for the Snohomish County Health District in Everett, Wash. "The next highest priority is contact identification of exposed populations."

So goes the battle to prevent or contain a TB outbreak.

Each year 54 million people are infected with the tubercle bacillus, 6.8 million develop clinical disease and 2.4 million die. And even in the United States, this case is not unusual, Dr. Spitters says. "Certainly we frequently have high school, community college, university or middle school investigations, and the contact list can get quite large," he says. "We have to keep expanding the investigation; if someone in the household is infected, we have to look to their work and leisure environment. ... It can really consume resources."