TB Cases at 25 Year Low
in Houston and Harris County in 1999 declined to their lowest levels
since 1975. The Houston Department of Health and Human Services
(HDHHS) recorded 456 new cases of TB in 1999, down from an all time
high of 786 cases in 1995. HDHHS has maintained a TB case registry
for more than 30 years. The lowest number of cases registered
was 441 in 1975.
M. desVignes-Kendrick, MD, MPH, HDHHS Director, credits the improvement
in TB rates to a dedicated crew of TB specialists. “The Houston
TB Control program initiated and perfected the national standard of
care for tuberculosis patients, directly observed therapy. Their
commitment to this treatment strategy is paying real dividends to the
residents of Houston.”
TB patients will normally feel better after two weeks of treatment and
tend, like most people taking medication, to not complete their course
of treatment. TB treatment requires six to 12 months of antituberculosis
medication. Failure to complete the six to 12 month course of
treatment results in multi-drug resistance. Multi-drug resistant
tuberculosis is much more difficult and expensive to treat.
Directly observed therapy (DOT) is a treatment strategy where medication
doses are delivered to the patient and the patient is observed taking
the medication. DOT doses are delivered daily for the initial
phase of treatment, then decreased to two or three times per week.
Patients who have drug resistant disease will continue daily DOT throughout
their course of treatment. Ninety percent of the 1999 TB cases
were placed on DOT. The multi-drug resistance rate for Houston
in 1999 was 0.2 percent.
HDHHS TB Control Program also employs directly observed preventive therapy
(DOPT) to patients with latent tuberculosis infection (positive tuberulin
skin test), but have not developed active disease. DOPT utilizes
the same strategy as DOT. DOT and DOPT staff deliver medications
on weekends and holidays. Patients who cannot be located for medication
delivery are referred to a special team to locate the patient and return
the patient to medical supervision. As of March 9, 2000, the Program
is delivering 1,083 doses of DOT and DOPT per week.
The HDHHS TB Control staff meets daily to discuss case status and assignments
for new TB investigations. For each new TB case, a contact investigation
is initiated within three days and efforts are made to test contacts
within a week.
TB cases began to rise in the 1980's due to declines in funding for
treatment and surveillance. Simultaneous to declines in funding,
increases in high risk populations living in congregate settings (prisons,
homeless shelters, refugee facilities) facilitated new infections.
AIDS also contributed significantly to rising cases of TB.
According to Kendrick, “Tuberculosis is the oldest and most resilient
killer on earth. I doubt we will ever completely eliminate it,
but the declining numbers we are seeing in Houston are very encouraging.”