toman's tuberculosis case detection, treatment and monitoring

Case detection
TOMAN’S TUBERCULOSIS
Infectious pulmonary tuberculosis is often not detected until a late stage, even
though the patient may have attended health facilities during the initial stages of the
disease. Physicians frequently do not suspect tuberculosis or do not request smear
examination in patients with cough, particularly if those patients present with nonrespiratory
ailments. It is estimated that as many as 5–10% of adults attending outpatient
health facilities in developing countries may have a persistent cough of more
than 2–3 weeks’ duration (1, 2). The proportion of smear-positive pulmonary tuberculosis
among these individuals depends on the prevalence of tuberculosis in the community.
Systematic identification of adults with persistent cough among outpatients
in general health facilities can detect a large proportion of sources of tuberculosis
infection (3). This reduces treatment delay and identifies infectious patients who are
a risk to the community and to other patients and staff at the health facility. Successful
treatment of these patients has a rapid effect on tuberculosis prevalence, mortality
(4), and transmission (1).
In heavily used facilities, paramedical or administrative staff should be largely
responsible for identification of persons with persistent cough and referral for smear
examination. This screening is a public health activity intended only to detect and
cure sources of infection, and is additional to diagnostic activities in persons consulting
spontaneously. Because the objective is primarily to benefit the community,
the procedure must be simple, convenient for the individual, and free of charge, and
should not detract from the patient’s original purpose in attending the clinic. It is
important to record the patient’s name and address: if the laboratory detects positive
smears the patient must be found immediately and treatment initiated.
Culture is not a priority test for systematic detection of cases. Persons who are positive
only on culture are less infectious than those who are also positive to microscopy.
Furthermore, culture is more expensive and complex than microscopy, and there is a
relatively long delay until the result is available.
The duration of cough chosen by a country as the threshold for recommending
smear examination depends on the prevalence of smear-positive tuberculosis, the
frequency of attendance at health facilities by the population, and the laboratory
resources available. If the prevalence of tuberculosis is very low, there is no role for
systematic case detection with smears in adults with cough (low cost-effectiveness
and high risk of false-positive results). Attendance at health facilities varies among
countries. People in more developed countries consult earlier and more often, and the
duration of cough selected as a basis for screening must be shorter; however, this
increases the proportion of patients with nonspecific cough and the workload of the
laboratory services, and reduces cost-effectiveness. Studies of prevalence of cough
among adults attending outpatient health facilities help determine the optimal duration
of cough at which to recommend sputum examination under routine conditions
(2, 5, 6).
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