November 13, 2002
Tuberculosis seems like such a relic of the Victorian age, it's almost surprising to find it's still with us. But Mycobacterium tuberculosis, the cause of this often-overlooked disease, is extremely well adapted to humans and re-emerged as major problem in this country during the onslaught of the AIDS epidemic as a frequently occurring opportunistic infection in those with damaged immune systems.
In the last decade, the tuberculosis attack rate has been falling again in most of the United States. But it remains a significant problem in many other parts of the world as well as right here in New Orleans. And it's a problem Tulane should be addressing, according to Newton Hyslop, chief of the section of infectious diseases.
"We as an institute should be working on tuberculosis," said Hyslop. "We're very close to the problem. With nearly 22 cases per 100,000 in New Orleans, this is serious stuff. It's infecting all ages, including children under 5 years of age in family outbreaks."
Hyslop's department has been involved in the fight against TB since 1990, when it took over the inpatient isolation unit at Charity Hospital. Researchers noticed that TB patients were often not adequately treated, were lost to follow-up, and sometimes reappeared at the hospital, sick once again. When they conducted a follow-up study of patients they'd seen between 1993 and 1994, they found that 18 percent had died and only 43 percent had completed treatment.
"The system was badly broken," said Hyslop. Since then, he and his colleagues have worked with the state health department and the state TB task force to fix it. They've been instrumental in reopening a sanatorium for TB patients and in hiring a TB patient coordinator at Charity. Michelle Fernandez is the third person to occupy the position.
Fernandez works with patients, nurses, house staff and state TB control programs to get and keep patients in treatment while monitoring their progress. TB is almost always curable, but successful treatment requires taking a complicated regimen of four different drugs daily for six months or more. When patients don't take all their pills they can develop drug-resistant strains of the disease, which can be trasnmitted to others.
Much of the challenge of controlling TB lies in the difficulty of keeping track of patients and in finding the people they might have exposed who, if found, are tested and offered treatment if appropriate. But the population in question is often transient, the health department is understaffed, and the disease is slippery because of a large number of latent cases and the long period between infection and the onset of symptoms.
"One way to evaluate the effectiveness of the contact tracing is to look at how many contacts are being found for each new case. You should be able to find eight or more people who might have been exposed, and we consistently find one or two," said program coordinator Steve Styron.
With funding from the Whetmore Foundation of New Orleans, Awewura Kwara, a freshly graduated fellow in infectious diseases, has completed two studies showing that cases are still eluding the Louisiana Office of Public Health's TB control program. In a study of extrapulmonary tuberculosis cases in New Orleans over a nine-year period, he found that only half of the patients had completed treatment and 24 percent had died, a figure Hyslop considers unacceptable.
Many of those who die of tuberculosis are co-infected with HIV. Many complications can ensue when trying to treat both infections. Deepthi Murthy, a second-year fellow in infectious diseases, is beginning a study of pulmonary tuberculosis to parallel Kwara's look at extrapulmonary TB. Murthy's study will closely examine the impact of HIV co-infection on treatment outcomes.
In another study, she also will look for microbiological markers in patients for whom standard treatment fails. Next, Hyslop would like to see the tuberculosis program become one of the units in national ongoing tuberculosis clinical trials sponsored by the Centers for Disease Control. Participating in these trials would not only help improve tuberculosis control locally, but would allow Tulane to have an impact on the global epidemic.
"One of the major goals of the World Health Organization and Centers for Disease Control is to eradicate tuberculosis," said Hyslop. "We want to participate in that effort."
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