Self-Study Modules on Tuberculosis
Module 8: Tuberculosis Surveillance and Case Management in Hospitals
Identify Suspected or Confirmed TB Cases
Figure 8.5 Process for surveillance and case management
This is a flow chart that describes the four processes for
TB Surveillance and Case Management in Hospitals and Institutions:
- Identifying suspected or confirmed TB cases;
- Collect patient information;
- Conduct an initial interview;
- Plan for follow-up care.
Step 1, Identifying suspected or confirmed TB cases is highlighted.
Case Definition and Classification Criteria
The first step in the TB surveillance process is to identify suspected
or confirmed TB cases. A suspected case has a diagnosis that is
pending due to an incomplete medical evaluation. TB disease should
be considered when a patient presents with a persistent cough (that
is, a cough lasting for 3 or more weeks) or other signs or symptoms
compatible with TB disease (for example, bloody sputum, night sweats,
weight loss, or fever). The presence of any of the following will
increase the suspicion of TB disease:
- A positive AFB smear
- A positive tuberculin skin-test result
- An abnormal, unstable chest radiograph
A TB case is usually confirmed by a positive culture for
M. tuberculosis. However, in some cases, patients
are diagnosed with TB disease on the basis of their signs and symptoms,
even if their specimen does not contain M. tuberculosis (see
Module 3, Diagnosis of Tuberculosis
Infection and Disease). Other laboratory criteria that can be used
for diagnosis include a positive nucleic acid amplification test
(provided the test is used as approved by the Food and Drug Administration
[FDA]), or demonstration of AFB in a clinical specimen when a culture
has not been or cannot be obtained.
Table 8.2 presents the current classification used for describing
patients; it is based on the pathogenesis of TB. (See
Module 1, Transmission and Pathogenesis of Tuberculosis, and
Module 3, Diagnosis of Tuberculosis
Infection and Disease for more information on the pathogenesis or
diagnosis of TB disease.)
In most states, facilities are required by law to immediately report
suspected or confirmed TB cases (Class 3 or Class 5) to local or
state health departments. A case report form usually is completed
for every suspected or confirmed TB case by the infection control
practitioner or by a physician; in many jurisdictions, specific
legislation requires that this report be submitted within 24 hours.
Laws requiring that suspected TB cases be reported vary from jurisdiction
to jurisdiction. A significant period of time can occur before a
final diagnosis of TB is made. If the law does not require the reporting
of suspected cases in a jurisdiction, specific policies and procedures
regarding suspected cases should exist or be developed in the hospitals
and institutions where public health workers are assigned. Close
collaboration and effective communication with the infection control
practitioner and other key staff can ensure that suspected cases
are appropriately managed. At all times, laws and regulations on
patient confidentiality must be upheld (see
Module 7, Confidentiality in Tuberculosis Control, for further
Classification System for TB
||No exposure to TB
|No history of exposure, negative reaction to the tuberculin
||Exposure to TB
No evidence of infection
|History of exposure, negative reaction to a tuberculin skin
test (given at least 10 weeks after exposure)
No TB disease
|Positive reaction to the tuberculin skin test, negative
bacteriologic examinations (if done), no clinical or x-ray
evidence of TB disease
||Current TB disease
||Meets current laboratory criteria (for example, a positive
culture) or criteria for current clinical
||Previous TB disease (not current)
|| Medical history of TB disease, or
but stable x-ray findings for a person who has a positive
reaction to the tuberculin skin test, negative bacteriologic
examinations (if done), and no clinical or x-ray evidence
of current TB disease
||Signs and symptoms of TB disease, but evaluation not complete
The two basic methods for identifying suspected or confirmed TB
- Routine case reporting
- Active case finding
Routine case reporting is the required reporting
of suspected or confirmed TB cases to a public health authority.
In routine case reporting, physicians and other persons (for example,
infection control practitioners, pharmacists, laboratory staff)
submit reports of suspected or confirmed TB cases, as they are detected,
to a public health authority that collects and analyzes the information.
In active case finding, the TB program identifies
unreported cases of disease by actively searching for TB cases through,
for example, laboratory and pharmacy audits; active case finding
can be designed and implemented in several ways, depending on local
needs and practices. In addition to the public health worker's responsibilities
with cases routinely reported to the TB program, he or she may also
be doing active case finding to identify suspected or confirmed
TB cases that have not been reported.
Routine Case Reporting
Patient assessments and diagnoses are carried out by all health
care facilities and many residential institutions. When hospital
or institutional staff admit patients, it is important that they
- Be alert for TB symptoms
- Question patients about TB risk factors
- Request further evaluation for persons who may have undiagnosed
- Raise awareness about TB reporting laws
Immediately after they are admitted, patients with suspected or
confirmed TB should be brought to the attention of whomever has
lead responsibility for TB surveillance in the facility. Generally,
information about the diagnosis, the identification and location
of the patient, and possible barriers to adherence are reported
to this person. If infectious TB disease is suspected, the patient
should be isolated in accordance with the facility's infection-control
plan. Once a suspected or confirmed case is reported to the TB program,
the public health worker should help collect any information needed
to verify the case.
When a case report has been submitted, the public health worker
should check the TB program database to see if the case has been
reported previously. If so, he or she should obtain a print-out
of all the patient's past clinic visits, chest x-ray reports, adherence
history, bacteriology and susceptibility results, and medication
history, including the administration of directly observed therapy
(DOT). It is crucial that this information be given immediately
to the health care worker managing the case to ensure appropriate
medical treatment; if necessary, the patient should be asked to
sign a medical release form so this information can be shared with
his or her current providers. As confidentiality laws permit, this
information may also be shared with others providing direct care
to the patient (see Module 7, Confidentiality
in Tuberculosis Control).
Active Case Finding
Within a hospital or institution, public health workers can conduct
active case finding by
- Collaborating closely with the infection control practitioner
- Monitoring the use of negative-pressure isolation rooms that
may be used to isolate patients with suspected TB disease
In addition to these activities, public health workers may make
routine visits to the pharmacies and to the mycobacteriology and
pathology laboratories used by the facilities to which they are
assigned for TB surveillance.
With the collaboration of laboratory or pharmacy staff, public
health workers can use the information found there to
- Actively search for unreported TB cases
- Confirm suspected TB cases once the medical evaluation is completed
- Monitor the progress of reported TB patients (for example, through
sputum and culture conversion or prescription refills)
- Collect information on possible drug resistance and the adequacy
of the current regimen
Active case finding projects with laboratories or pharmacies require
a special agreement regarding the sharing of information; their
feasibility depends on local reporting and confidentiality laws
and regulations. In many areas, active case finding will be most
effective when targeted to specific laboratories or pharmacies with
the goal of reviewing specific data. For TB cases that have already
been reported by hospital or institution staff, laboratories and
pharmacies may already share information with the infection control
practitioner. If this is the case, the public health worker should
obtain such information from the infection control practitioner.
Laboratories. Most of the information the public
health worker needs to conduct active case finding is included in
the laboratory results. These records present the
results of every laboratory test that has been done on the patient,
such as AFB smear examinations, cultures, and drug susceptibility
tests. Test results related to TB are recorded in a computer database
or an AFB logbook, a logbook kept in the mycobacteriology
laboratory that contains the results of acid-fast bacilli (AFB)
smear examinations; it may be called a smear mycobacteriology log.
The logbook or database is usually updated daily. AFB smear results
and culture results should be reviewed periodically to identify
unreported suspected or confirmed TB cases, as well as new information
about reported cases. Local confidentiality laws and regulations
must be considered. Special agreements between the laboratories
and the health department regarding the sharing of information should
be established. The results of drug susceptibility testing should
be reviewed to identify drug-resistant cases of TB. At the same
time, the public health worker may also collect information about
the date of sputum and culture conversions from positive to negative;
this will help him or her to monitor each patient's progress.
For each result of interest, record the patient's
- Date of birth
- Medical record number
- Laboratory number
- Date of specimen collection
- Type of specimen
- AFB smear result (with quantification)
- Culture result (with species identification)
- Drug susceptibility pattern
- Case report number (if indicated)
If the culture result is pending on a suspected TB case, the case
should be classified as "Class 5, pending culture" until a diagnosis
of TB disease has been confirmed or ruled out by the patient's provider.
Any patient with a positive culture for M. tuberculosis
has a confirmed case of TB disease (Class 3).
Public health workers should be familiar with the average turnaround
times for laboratory examination. Results of AFB smears should be
available within 24 hours of specimen collection. Culture results
should be available within 10 to 14 days of specimen collection,
with drug susceptibility results available 1 to 3 weeks later. Results
showing resistance to any drug are usually verified, which can cause
a delay of several weeks. In addition, delays may occur in the reporting
of all laboratory results due to shipping and processing of specimens.
The results of drug susceptibility testing are often not available
until 1 to 3 weeks after the initial positive culture result. By
that time, the patient may have been discharged and be under the
care of another provider. It is very important to make the patient's
current provider aware of drug susceptibility test results as soon
as they are available. Laboratory staff should forward drug susceptibility
results promptly to the health department.
The pathology laboratory, a laboratory that performs
tests and examinations on tissue and biopsy specimens, will have
reports on any tissue specimens or biopsies that were submitted
for analysis (for example, when a case of extrapulmonary TB is suspected).
As with the mycobacteriology laboratory, the public health worker
should conduct periodic audits in the pathology laboratory to identify
all patients with positive AFB smears or other relevant results
from histologic exams.
Pharmacies. Pharmacy surveillance in hospital
or other institution pharmacies can also help to identify unreported
cases of TB disease (see Figure 8.6). In the absence of documented
culture-positive disease, a patient may still be diagnosed with
TB disease on the basis of clinical or x-ray evidence of current
TB disease. If this is the case, the patient's clinician will often
treat presumptively for TB. When patients are being treated for
TB based on a clinical diagnosis (i.e., no positive culture result),
pharmacy records can be an important active case finding tool. Information
found in the pharmacy records can be used to identify patients who
are placed on two or more TB medications (and therefore may have
active TB disease, not only TB infection). If feasible, on a periodic
basis the pharmacy may be able to print out a data sheet of any
patient on TB drugs for the public health worker. Local confidentiality
laws and regulations must be considered. Special agreements between
pharmacies and health departments regarding the sharing of information
should be established.
Figure 8.6 Example of active case finding: pharmacy surveillance.
This is a picture of a health care worker working with a pharmacist
to conduct active case finding through pharmacy surveillance.
In most areas of the country, the initial regimen for treating
TB disease should include four first-line TB drugs:
- Isoniazid (INH)
- Rifampin (RIF)
- Pyrazinamide (PZA) and either
- Ethambutol (EMB) or streptomycin (SM)
In areas where less than 4% of cases are resistant to INH (first
drug susceptibility test only), three drugs (INH, RIF, and PZA)
may be adequate for the initial regimen, provided the patient has
no risk factors for drug-resistant disease. If the bacilli are susceptible
to INH and RIF, the standard regimen includes 2 months of the above
initial regimen followed by 4 months of treatment with INH and RIF
alone (see Module 4, Treatment of
Tuberculosis Infection and Disease).
The focus of pharmacy surveillance is the identification of patients
who are placed on two or more first-line TB drugs.
The reason for specifying two or more drugs is because patients
who may be on isoniazid (INH) therapy only are most likely on a
regimen for the treatment for LTBI and not a regimen for the treatment
of TB disease.
Likewise, second-line TB drugs, which are drugs
used to treat TB resistant to first-line drugs, are generally not
included in TB pharmacy surveillance. Many second-line TB drugs
(for example, ciprofloxacin, amikacin) are used primarily to treat
diseases other than TB; therefore, pharmacy surveillance does not
usually include these drugs.
Participating pharmacies should allow the public health worker
to record the names of all patients receiving at least two of the
first-line medications listed above. The public health worker should
then check to see if the case has already been reported to the TB
program. Additional information from the patient's health care provider
may be necessary to determine if the patient has suspected or confirmed
Whenever active case finding has identified an unreported TB case,
the public health worker should alert the facility's staff and a
supervisor in the TB program. The public health worker should work
together with these persons to make sure a report is promptly submitted
and to assess the cause of the failure to report.
|Study Questions 8.8-8.10
8.8. Name three
things that will increase the suspicion of TB disease.
8.9. Under the classification system for TB, give the class
(0-5) for each type listed.
____ TB suspected
____ Current TB disease
____ Exposure to TB, no evidence of infection
____ Previous TB disease (not current)
____ No exposure to TB, not infected
____ TB infection, no disease
8.10. Explain the two basic methods for identifying suspected
or confirmed TB cases, and how they are put into practice.
8.11. How can public health workers use the information
found in laboratories and pharmacies?
8.12. What drugs are the focus of pharmacy surveillance?
|Case Study 8.2
A public health worker is conducting active case
finding in the laboratory of a small community hospital.
The AFB logbook contains the following entries:
|AFB Smear Result
||M. avium intracellulare
- Determine the classifications for each specimen using
the TB classification system and determine which specimens
the public health worker should follow up.
- What should the public health worker record?
- Specimen #362 was collected from a patient who is not
on the public health worker's list of current suspected
or confirmed TB cases in the hospital. What should be
|Case Study 8.3
Another public health worker is conducting active
case finding in a large residential facility for the mentally
ill. The public health worker goes to the facility's pharmacy
to review information about patients receiving TB medications.
For the current week, she notes that prescriptions of TB medications
were filled for the following patients:
||Medication Orders Filled
||Isoniazid, pyrazinamide, rifampin, ethambutol
- What patients should the public health worker record
for follow-up? Why?
- Patient P251 is not known to the TB program as a reported
suspected or confirmed TB case. What should be done?