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: including,
- 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 details).
Classification System for TB
|0||No exposure to TB
|No history of exposure, negative reaction to the tuberculin skin test|
|1||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|
|3||Current TB disease||Meets current laboratory criteria (for example, a positive culture) or criteria for current clinical case definition|
|4||Previous TB disease (not current)||Medical history of TB disease, or
Abnormal 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
|5||TB suspected||Signs and symptoms of TB disease, but evaluation not complete (diagnosis pending)|
The two basic methods for identifying suspected or confirmed TB cases are
- 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 TB
- 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 TB disease.
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:
|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: