University
Physicians At Grady On Cutting Edge of Infection Control and Research
for Tuberculosis
Physicians at
Grady Health System have developed a cutting-edge tuberculosis control
and research program to fight the disease burden of TB in Atlanta, which
in some areas rivals the rate of incidence found in developing countries.
"We care for a lot of patients
with TB, so we really have to be prepared and we must have excellent
TB infection control, which we do have at Grady," said Henry M. Blumberg,
M.D., associate professor of medicine with the Emory University School
of Medicine, Division of Infectious Diseases, and hospital epidemiologist
at Grady Memorial Hospital. "Our program has been recognized nationally
to be a leader in TB infection control."
With regards to research,
Emory is leading the way. In October 2001, the Emory University School
of Medicine received funding for a new, 10-year, $4 million study as
part of the Centers for Disease Control and Prevention (CDC) Tuberculosis
Epidemiology Studies Consortium. The Emory-Georgia Department of Health
and Human Resources partnership is one of 22 sites across the country
to receive funding for the CDC-sponsored epidemiology studies. The partnership
also involves Fulton and DeKalb county health departments and Grady
Health System.
Emory physicians, including
Sophie Lukashok, M.D. and collaborators Mark Feinberg, M.D., and Jon
Altman, M.D. at the Emory Vaccine Center, are also working on efforts
to develop new diagnostic tests for tuberculosis to replace the tuberculin
skin test for the diagnosis of tuberculosis
infection. Other applied research studies being carried out by Emory
investigators include molecular epidemiologic (DNA fingerprinting) studies
of TB isolates, or TB strains, recovered from patients in Atlanta. The
Emory University School of Medicine is also collaborating with the former
Soviet Republic of Georgia to examine TB rates and drug resistance as
well as transmission dynamics in that country.
Controlling tuberculosis
infection remains a major priority among Emory University physicians
at Grady Hospital. In an effort to prevent TB transmission in healthcare
facilities, Grady employs a hierarchy of TB infection control measures
including administrative, engineering and respiratory protection. The
most important include administrative controls, by which physicians
and other health care workers perform careful screening and early identification
of patients with TB. Patients with or at risk for TB are isolated upon
admission, and all health care employees are given TB skin tests annually.
Grady isolates between 1,200 to 1,500 patients each year with only about
10 percent of the patients who are isolated at Grady are diagnosed with
TB. This approach, however, results in the early identification of the
vast majority of patients seen at Grady who are subsequently diagnosed
with active TB.
Grady also has a 26-bed respiratory
isolation ward, which has increased efficiency in evaluating patients
admitted to respiratory isolation to "rule out" TB, and in treating
patients. There also are specially engineered, negative pressure rooms,
where air is passed through a filter before being re-circulated or exhausted
to the outside of the hospital.
Tuberculosis is especially
problematic among the patient population served at Grady with very high
rates of TB in the communities surrounding the hospital, which cared
for about 130 patients with active TB cases in 2001. In 2000, Georgia
TB cases increased to 703 cases from 665 in 1999 and Georgia was one
of only three states where the numbers of reported cases increased.
In 2001, however, TB rates in Georgia decreased by 18 percent, to a
total of 575 cases.
"TB remains a problem in
certain areas," Dr. Blumberg said. "There are very high rates of TB
in the inner city, and we're seeing as much TB as almost half of the
states in the U.S. at Grady."
Tuberculosis is a treatable,
communicable disease that has two general states: latent infection and
active disease. Only those who develop active tuberculosis in the lungs
or larynx can infect others, usually by coughing, sneezing, or otherwise
expelling tiny infectious particles that someone else inhales. Symptoms
of TB can include weight loss, fever, night sweats, and occasionally
blood in the sputum.
The southern United States
has the highest rates of TB in the U.S. and continues to have rates
of TB higher than the national average. In 2000, Georgia had the fifth
highest rate of tuberculosis in the country; by 2001, it had fallen
to seventh highest.
"The reasons for the high
rates of TB in Georgia and the south are mixed Ð some that we know and
some that need further investigation and elucidation," Dr. Blumberg
said. "Demographics, economics, and access to health care are key factors
making the rates of TB higher in African Americans. Other causes include
poverty and links to HIV, and a variety of other reasons as well."
In Atlanta, the facts are
startling. If Grady Memorial Hospital were a state, for example, it
would rank 28th in the country for the number of tuberculosis cases
reported. The epidemiology of TB is different in Atlanta and many southeastern
states compared to other parts of the nation with rates of tuberculosis
that are higher than the national average and, with most cases occurring
among U.S.-born persons who are African Americans, according to Dr.
Blumberg and Carlos del Rio, M.D., chief of medicine at Grady Hospital.
In a Nov. 15, 2001 letter
to the New England Journal of Medicine, Dr. del Rio and Dr. Blumberg
point out that the number of tuberculosis cases in Georgia increased
between 1998 and 2000 despite decreasing in the United States and most
states. The rates of disease in some areas of Atlanta, for example,
exceed 100 cases per 100,000 persons per year, similar to the rates
in developing countries. Tuberculosis also is not a Medicaid-eligible
disease in Georgia (as it is in all of the other high-incidence states),
thus Grady Health System has annually provided more than $1.5 million
of uncompensated care to patients with tuberculosis.
Patients with active TB are
initially treated with a four-drug regimen (Isoniazid, Rifampin, Pyranizamide,
Ethambutol) and therapy takes a minimum of six months. In addition,
directly observed therapy (DOT), which involves health department staff
directly observing a patient take medication, is typically considered
for all patients with active disease, since it is difficult to predict
a patient's adherence to therapy and data shows that DOT is the most
effective way to ensure patients are rendered non-infectious and cured
of the disease.
The best way to measure the
effectiveness of therapy for pulmonary TB is monitoring patients bacteriologically
through sputum examination at least monthly until conversion to negative
culture. If a patient's sputum cultures remain positive beyond two months
of therapy, there is a possibility of drug-resistance disease. When
multidrug resistant (MDR) disease is present, it is much more difficult
to treat patients and therapy has to be continued for up to two years.
Grady and the state of Georgia, fortunately, have relatively low rates
of MDR-TB; at Grady this is in the range of 1 percent.
Blumberg said Georgia is
starting to see more cases of foreign-born TB, but unlike many states,
the large majority of cases of TB still occur in U.S.-born persons.
In 2000, for example, 46 percent of tuberculosis cases in the United
States occurred among foreign-born individuals and by 2001, half of
the TB cases in the U.S. occurred among foreign-born persons. In Georgia,
however, the proportion of TB cases occurring among the foreign-born
was less than 25 percent.
"Within the next year, the
majority of the TB cases in the U.S. will be among the foreign born,"
Blumberg noted. "This just reflects the huge, global public health problem
associated with tuberculosis."
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