Homeless risk TB microepidemics in Baltimore: JAMA report FWD

Tom Boland (wgcp@earthlink.net)
Tue, 24 Nov 1998 16:55:26 -0400


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FWD  Fox News - November 18, 1998

MICROEPIDEMICS OF TB PERSIST IN BALTIMORE


NEW YORK - "Microepidemics" of tuberculosis continue to occur in Baltimore,
Md., despite 15
years of public health efforts aimed at controlling the disease, according
to a report in The Journal of the American Medical Association this week.

Dr. William R. Bishai, of Johns Hopkins School of Hygiene and Public
Health, and colleagues
elsewhere in Baltimore estimate that approximately one third of the
tuberculosis cases detected in their city result from recently transmitted
disease, as opposed to disease that has been reactivated after a long
period of latency.

"Cases of TB have declined steadily over the past century, but there was a
very worrisome increase between 1985 and 1992," Bishai told Reuters Health.
"There was also an increase in drug-resistant TB."

"That taught us that we can't be too careful," Bishai continued. "We need
not to allow ourselves to become complacent about having controlled TB.
It's one of the few life-threatening infections you can catch by just being
in the same airspace with someone who has it."

Bishai and his associates used "DNA fingerprinting" techniques to study 182
Baltimore residents who were diagnosed with tuberculosis between January
1994 and June 1996.

Eighty-four patients (46 percent) had matching DNA strains, the researchers
found. They estimated that 32 percent of all cases resulted from recently
transmitted tuberculosis.

Twenty of these 84 patients, or 24 percent of all subjects, were also
linked on the basis of contact tracing, in which a public health official
interviews the person to find out if they know who might have exposed them
to tuberculosis. The investigators designated these patients as group 1.

The other 64 patients with matching DNA strains, designated group 2, could
not be linked on the basis of contact tracing. The remaining 98 patients,
designated group 3, presumably had reactivated disease, because they were
not linked on the basis of either DNA or contact tracing.

The study group found some "hot spots" of tuberculosis transmission in
Baltimore. In general, patients in groups 1 and 2 resided in "areas of low
socioeconomic status, high unemployment, high drug use, and poor housing
stocks," the study group determined.

In contrast, residences of group 3 patients "tended to be more widely
distributed and were associated with the lower middle-class neighborhoods
of the city."

Bishai's group explains in their report that Baltimore implemented a
tuberculosis control program in1981. The cornerstone is directly observed
therapy, in which patients take free tuberculosis medication under
supervision.

The overall incidence of tuberculosis in Baltimore has decreased by 58
percent since the program began, the researchers say, but they note that
the incidence of recent transmission is similar to that found in cities
with much shorter experience with directly observed therapy.

"I think directly observed therapy may have its limits and we're going to
need new tools," Bishai said in the interview with Reuters Health.
"Location-based screening is one, and optimally, a vaccine for TB and
better drugs for TB."

Location-based screening, Bishai explained, involves "taking our control
programs to high-risk
neighborhoods and looking for people who have symptoms of TB."

In an editorial, Dr. Peter F. Barnes, of the University of Texas Health
Center in Tyler, proposes that, in addition to offering preventive therapy,
communities should take three steps to reduce ongoing transmission of
tuberculosis:

- Pinpoint high-risk neighborhoods and sites, perhaps using DNA analysis.

- Use chest radiography or other screening techniques to identify
individuals with tuberculosis who have not yet sought medical attention,
particularly in "high-risk populations such as foreign-born persons from
countries with high incidence of tuberculosis and medically underserved
low-income persons."

- Consider installing "germicidal irradiation" systems to clean the air at
high-risk sites such as
homeless shelters.

END FORWARD
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distributed without profit to those who have expressed a prior interest in
receiving the included information for research and educational purposes. **

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FWD  Fox News - November 18, 1998 


<paraindent><param>right,left</param>MICROEPIDEMICS OF TB PERSIST IN
BALTIMORE 

</paraindent>


NEW YORK - "Microepidemics" of tuberculosis continue to occur in
Baltimore, Md., despite 15

years of public health efforts aimed at controlling the disease,
according to a report in The Journal of the American Medical
Association this week.


Dr. William R. Bishai, of Johns Hopkins School of Hygiene and Public
Health, and colleagues

elsewhere in Baltimore estimate that approximately one third of the
tuberculosis cases detected in their city result from recently
transmitted disease, as opposed to disease that has been reactivated
after a long period of latency.


"Cases of TB have declined steadily over the past century, but there
was a very worrisome increase between 1985 and 1992," Bishai told
Reuters Health. "There was also an increase in drug-resistant TB."


"That taught us that we can't be too careful," Bishai continued. "We
need not to allow ourselves to become complacent about having
controlled TB. It's one of the few life-threatening infections you can
catch by just being in the same airspace with someone who has it."


Bishai and his associates used "DNA fingerprinting" techniques to study
182 Baltimore residents who were diagnosed with tuberculosis between
January 1994 and June 1996.


Eighty-four patients (46 percent) had matching DNA strains, the
researchers found. They estimated that 32 percent of all cases resulted
from recently transmitted tuberculosis.


Twenty of these 84 patients, or 24 percent of all subjects, were also
linked on the basis of contact tracing, in which a public health
official interviews the person to find out if they know who might have
exposed them to tuberculosis. The investigators designated these
patients as group 1.


The other 64 patients with matching DNA strains, designated group 2,
could not be linked on the basis of contact tracing. The remaining 98
patients, designated group 3, presumably had reactivated disease,
because they were not linked on the basis of either DNA or contact
tracing.


The study group found some "hot spots" of tuberculosis transmission in
Baltimore. In general, patients in groups 1 and 2 resided in "areas of
low socioeconomic status, high unemployment, high drug use, and poor
housing stocks," the study group determined.


In contrast, residences of group 3 patients "tended to be more widely
distributed and were associated with the lower middle-class
neighborhoods of the city."


Bishai's group explains in their report that Baltimore implemented a
tuberculosis control program in1981. The cornerstone is directly
observed therapy, in which patients take free tuberculosis medication
under supervision.


The overall incidence of tuberculosis in Baltimore has decreased by 58
percent since the program began, the researchers say, but they note
that the incidence of recent transmission is similar to that found in
cities with much shorter experience with directly observed therapy.


"I think directly observed therapy may have its limits and we're going
to need new tools," Bishai said in the interview with Reuters Health.
"Location-based screening is one, and optimally, a vaccine for TB and
better drugs for TB."


Location-based screening, Bishai explained, involves "taking our
control programs to high-risk

neighborhoods and looking for people who have symptoms of TB."


In an editorial, Dr. Peter F. Barnes, of the University of Texas Health
Center in Tyler, proposes that, in addition to offering preventive
therapy, communities should take three steps to reduce ongoing
transmission of tuberculosis:


- Pinpoint high-risk neighborhoods and sites, perhaps using DNA
analysis.


- Use chest radiography or other screening techniques to identify
individuals with tuberculosis who have not yet sought medical
attention, particularly in "high-risk populations such as foreign-born
persons from countries with high incidence of tuberculosis and
medically underserved low-income persons."


- Consider installing "germicidal irradiation" systems to clean the air
at high-risk sites such as

homeless shelters.


END FORWARD

- 

** NOTICE: In accordance with Title 17 U.S.C. Section 107, this material is distributed without profit to those who have expressed a prior interest in receiving the included information for research and educational purposes. **


HOMELESS PEOPLE'S NETWORK  <<http://aspin.asu.edu/hpn/>  Home Page

ARCHIVES  <<http://aspin.asu.edu/hpn/archives.html>  read posts to HPN

TO JOIN  <<http://aspin.asu.edu/hpn/join.html> or email Tom <<wgcp@earthlink.net>

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