Tuberculosis Infection Control in Healthcare Personnel
Excerpted from: Guidelines for Infection Control in Healthcare Personnel, 1998
On this page:
Background
- Prevention of Transmission
- TB Screening Program
- Follow-up Evaluation
- Postexposure management
- Preventive Therapy
- Work Restrictions
- BCG Vaccine
Nosocomial transmission of tuberculosis (TB) is well documented, but such transmission in the United States is generally low. However, the risk may be increased in health care facilities located in communities with
(a) high rates of HIV,
(b) high numbers of persons from TB-endemic countries, and
(c) communities with a high prevalence of TB infection.
In some areas in the United States, the incidence and prevalence of multidrug- resistant Mycobacterium tuberculosis (MDR-TB) have also increased, and nosocomial MDR-TB outbreaks have occurred. The increased risk of occupational acquisition of TB by health care personnel has been reported for decades, and it dramatically decreased after the introduction of effective antituberculous drugs. Skin-test conversion rates among health care personnel after routine skin testing have ranged from 0.11% to 10%. Among health care personnel with known exposure to an infectious patient with TB or involved in prolonged nosocomial outbreaks of TB, the skin-test conversion rates have ranged from 18% to 55%. Health care personnel with severely compromised immune systems, especially those infected with HIV and including those with malignancies or receiving immunosuppressive therapy, are at high risk for development of active disease after acquisition of tuberculous infection. It has been estimated that persons infected with M. tuberculosis and coinfected with HIV have an 8% to 10% risk per year for development of active TB, whereas immunocompetent persons infected with TB have a 10% life-time risk for active disease.
The transmission of TB in health care facilities has been primarily caused by incomplete implementation of recommended TB infection control measures. In 1994, the CDC published detailed recommendations for the prevention of transmission of TB in health care settings, "Guidelines for Preventing the Transmission of M. tuberculosis in Health Care Facilities, 1994." A summary of the recommendations pertaining to personnel health follows:
a. Strategies for prevention of transmission of TB
The risk of transmission of TB to or from personnel in a health care facility varies according to the type and size of the facility, the prevalence of TB in the community, the patient population served by the facility, the occupational group the person represents, the area of the facility where the person works, and the effectiveness of the facility's TB control program. A detailed risk assessment is essential in identifying the nature of TB control measures that are appropriate for a particular facility, as well as for specific areas and occupational groups within a facility.
A risk assessment should include the following:
(a) review of the community TB profile,
(b) review of the number of patients with TB who were treated in each area of the facility,
(c) review of the drug-susceptibility patterns of TB isolates from patients treated in the facility,
(d) an analysis of purified protein derivative (PPD) skin-test results of health care personnel by work area or occupational group,
(e) an evaluation of infection control parameters, including isolation policies, laboratory diagnostic capabilities, and antituberculous therapy regimens,
(f) an observational review of TB infection control practices, and
(g) evaluation of the function and maintenance of environmental controls.
Transmission of TB can be minimized by developing and implementing an effective TB control program that is based on a hierarchy of controls:
b. TB screening program(a) administrative controls,
(b) engineering controls, and
(c) personal respiratory protection.
A TB screening program for personnel is an integral part of a health care facility's comprehensive TB control program. The screening program should be based on the facility-specific risk assessment. It may be advisable to screen immunocompromised personnel every 6 months.
Baseline PPD testing of all personnel (including personnel with a history of bacille Calmette-Guérin [BCG] vaccination) during their preemployment physical examination or their application for hospital privileges will identify personnel who have been previously infected. For the baseline testing, a two-step procedure for personnel without a PPD test in the past 12 months can be used to minimize the likelihood of confusing reactivity from an old infection (boosting) with reactivity from a recent infection (conversion). Decisions concerning the use of the two-step procedure for baseline testing in a particular facility should be based on the frequency of boosting in that facility.
Criteria used for interpretation of a PPD-test reaction may vary depending on:
(a) the purpose (diagnostic or epidemiologic) of the test,
(b) the prevalence of TB infection in the population being tested,
(c) the immune status of the host, and
(d) any previous receipt of BCG immunization. Detailed recommendations for performing and interpreting skin tests have been published.
c. Follow-up evaluation
The risk assessment will show which health care personnel have the potential for exposure to M. tuberculosis and determine how frequently they should receive PPD testing. At a minimum, annual PPD testing is indicated for personnel with the potential for exposure to TB.
It is also important to obtain an initial chest radiograph for personnel with positive PPD-test reactions, documented PPD-test conversions, or pulmonary symptoms suggestive of TB. There are no data to support the use of routine chest radiographic examinations for asymptomatic PPD-negative personnel. In addition, personnel who have positive PPD-test reactions but also received adequate preventive treatment do not need repeat chest films, unless they have pulmonary symptoms suggestive of TB. Repeat chest radiographic examinations of such persons have not been shown to be beneficial or cost-effective in monitoring persons for development of disease. However, more frequent monitoring for symptoms of TB may be considered for personnel who had recent conversion of their PPD test and those persons who, if infected, are at increased risk for development of active TB (e.g., HIV-infected or otherwise severely immunocompromised persons). Routine anergy testing of HIV-seropositive individuals is limited in its usefulness; however, anergy testing may be useful in guiding individual decisions regarding preventive therapy in selected situations.
d. Management of personnel after exposure to TB
It is important to administer PPD tests to personnel as soon as possible after TB exposures are recognized. Such immediate PPD testing establishes a baseline with which subsequent PPD tests can be compared. A PPD test performed 12 weeks after the last exposure will indicate whether infection has occurred. Persons already known to have reactive PPD tests need not be retested. Personnel with evidence of new infection (i.e., PPD-test conversions) need to be evaluated for active TB. If active TB is not diagnosed, preventive therapy should be considered.
For workers with positive PPD-test results who were probably exposed to drug-susceptible TB, preventive therapy with isoniazid is indicated, unless there are contraindications to such therapy. Alternative preventive regimens have been proposed for persons who have positive PPD-test results after exposure to drug-resistant TB.
Personnel with active pulmonary or laryngeal TB may be highly infectious; exclusion from duty is indicated until they are noninfectious. If personnel are excluded from duty because of active TB, the facility should have documentation from their health care providers that personnel are noninfectious before they are allowed to return to duty. The documentation needs to include evidence that:
(a) adequate therapy is being received,
(b) the cough has resolved, and
(c) results of three consecutive sputum acid-fast bacilli (AFB) smears collected on different days are negative.
After personnel resume duty and while they remain on anti-TB therapy, periodic documentation from their health care providers is needed to show that effective drug therapy is being maintained for the recommended period and that their sputum AFB smear results continue to be negative. If personnel discontinue their treatment, they need to be evaluated for active TB; directly observed therapy may be considered.
Work restrictions are not necessary for personnel receiving preventive treatment for latent TB (positive PPD-test result without active disease) or for personnel with latent TB who do not accept preventive therapy. However, these personnel should be instructed to seek evaluation promptly if symptoms suggestive of TB develop.
g. Considerations for BCG vaccine
BCG has not been routinely used in the United States to protect health care personnel. Nevertheless, because of the resurgence of TB in the United States and new information about the protective effect of BCG, the role of BCG vaccination in the prevention and control of TB in the country has been reevaluated. The following is a summary of the joint statement by the Advisory Council for the Elimination of Tuberculosis and ACIP regarding the use of BCG in health care personnel.
Two recent metaanalyses of 18 and 26 BCG studies, respectively, indicate that the efficacy of BCG vaccine in preventing serious TB is high (>80%) in children and suggest 50% efficacy in adults. However, the protective efficacy of the vaccine in adolescents and adults, including health care personnel and HIV-infected children and adults, has not been determined.
BCG vaccination should not be used as a primary TB control strategy because:
(a) the protective efficacy of the vaccine in health care personnel is uncertain and
(b) even if vaccination is effective in an individual, other persons in the health care facility are not protected against possible exposure to and infection with drug-resistant strains of M. tuberculosis.
However, BCG vaccination may be indicated for health care personnel in a few geographic areas where the prevalence of MDR-TB is high, transmission of TB is likely, and TB infection control measures have been implemented but have not been successful in controlling nosocomial transmission. Consultation with local and state health departments is advisable when determining whether to provide BCG vaccination to health care personnel.
BCG vaccination often results in local adverse effects (such as muscular soreness, erythema, purulent drainage, and axillary or cervical lymphadenopathy) for as long as 3 months after vaccination; serious long-term complications (such as musculoskeletal lesions, multiple lymphadenitis, and disseminated BCG disease) are infrequent. The safety of BCG vaccination in immunocompromised populations (i.e., immunocompromised from immune deficiency diseases, HIV infection, leukemia, lymphoma, or generalized malignancy, or immunosuppressed as a result of therapy with corticosteroids, alkylating drugs, antimetabolites, or radiation) has not been determined by adequate epidemiologic studies. However, because of the possibility of disseminated BCG infection in such persons, BCG vaccination is not recommended for immunocompromised personnel. The safety of BCG vaccination in pregnant women has also not been evaluated; therefore, it is not recommended for pregnant personnel.
PPD testing is not contraindicated for persons who have received BCG vaccine and can be used to support or exclude the diagnosis of infection with M. tuberculosis. PPD-test reactivity caused by BCG vaccination wanes with time and is unlikely to persist longer than 10 years after vaccination in the absence of infection with M. tuberculosis. After a person has been vaccinated with BCG, the presence or size of a PPD-test reaction cannot be used to predict whether BCG will provide any protection against TB disease or to determine whether the reaction is caused by M. tuberculosis infection or the previous BCG vaccination. However, a BCG-vaccinated person who has a PPD-test reaction of 10 mm induration should be considered infected with TB, especially if the vaccinee
(a) is a contact of a person with infectious TB, particularly if the infectious person has transmitted M. tuberculosis to others,
(b) is from a country with high prevalence of TB, or
(c) is continually exposed to populations in which the prevalence of TB is high.
Recommendations
- General recommendations
- TB Screening Program
- Baseline PPD
- Follow-up PPD
- Preventive Therapy
- Postexposure management
- Work restrictions
- Immunocompromised personnel
- BCG Vaccination
1) Educate all health care personnel regarding the recognition, transmission, and prevention of TB. Category IB
2) Follow current recommendations outlined in the "Guidelines for Preventing the Transmission of Mycobacterium tuberculosis in Health-Care Facilities, 1994." Category
IB
1) Include all health care personnel who have potential for exposure to M. tuberculosis in a PPD skin-test program.. Category IA
2) Administer PPD tests by using the intracutaneous (Mantoux) method of administration of 5 tuberculin units (0.1 ml) PPD. Category IB
3) Do not routinely test personnel known to have conditions that cause severe suppression of cell-mediated immunity (such as HIV-infected persons with lowered CD4+ counts and organ-transplant recipients receiving immunosuppressive therapy) for cutaneous anergy at the time of PPD testing. Category IB
4) Ensure that the administration, reading, and interpretation of PPD tests are performed by specified, trained personnel. Category IA
c. Baseline PPD1) Perform baseline PPD tests on health care personnel who are new to a facility and who have potential for exposure to M. tuberculosis, including those with a history of BCG vaccination. Category IB
2) Perform two-step, baseline PPD tests on newly employed health care personnel who have negative results of initial PPD testing and have not had a documented negative PPD-test result during the preceding 12 months, unless the institution has determined that two-step testing is not warranted in its facility. Category II
3) Interpret baseline PPD-test results as outlined in the "Guidelines for Preventing the Transmission of Mycobacterium tuberculosis in Health-Care Facilities, 1994." Category IB
d. Follow-up (repeat) PPD1) Perform periodic follow-up PPD tests on all health care personnel with negative baseline PPD-test results who have the potential for exposure to M. tuberculosis. Category IA
2) Base the frequency of repeat PPD testing on the hospital's risk assessment, as described in the "Guidelines for Preventing the Transmission of Mycobacterium tuberculosis in Health-Care Facilities, 1994" and as provided by federal, state, and local regulations. Category IB
3) Exempt from follow-up PPD tests personnel with documented history of positive baseline PPD-test result or adequate treatment for TB. Category IB
4) Consider retesting immunocompromised health care personnel who have potential for exposure to M. tuberculosis at least every 6 months. Category II
5) Interpret follow-up-PPD test results as outlined in the "Guidelines for Preventing the Transmission of Mycobacterium tuberculosis in Health-Care Facilities, 1994." Category IB
6) Management of PPD-positive personnel:
e. Preventive therapya) Promptly evaluate personnel with positive PPD-test results for active disease and obtain an adequate history on TB exposure to help determine whether the infection is occupational or community acquired. Category IB
b) Perform chest radiographic examinations on personnel with a positive PPD-test result as part of the evaluation for active TB. If results of the initial chest radiographic examination are negative, do not repeat chest radiograph unless symptoms suggestive of TB develop. Category IB
c) Periodically remind all personnel, especially those with positive PPD-test results, about the symptoms of TB and the need for prompt evaluation of any pulmonary symptoms suggestive of TB. Category IB
d) Do not require routine chest radiographs for asymptomatic, PPD-negative workers. Category IB
1) Offer preventive therapy to the following personnel, regardless of age, who have conversion of their PPD test:
(a) recent converters,
(b) close contacts of persons with active TB,
(c) those with medical conditions that increase their risk for active TB,
(d) those with HIV infection, and
(e) injecting-drug users. Category IB
2) Offer preventive therapy to all other personnel (i.e., who do not have the above risk factors) with positive PPD reactions if they are younger than 35 years. Category IA
3) Provide preventive therapy to personnel through the occupational health program or refer them to the health department or their health care provider, as appropriate. Category IB
f. Postexposure management of personnel
1) As soon as possible after an exposure to TB (i.e., exposure to a person with pulmonary or laryngeal TB for whom proper isolation precautions were not implemented), conduct PPD testing on personnel who are known to have negative PPD-test results. If the initial postexposure PPD-test result is negative, repeat the PPD test 12 weeks after the exposure. Category IB
2) Do not perform PPD tests or chest radiographs on personnel with previous positive PPD-test results, unless they have symptoms suggestive of active TB. Category IB
1) Exclude personnel with infectious pulmonary or laryngeal TB from the workplace until the facility has documentation from their health care provider that they are receiving adequate therapy, their coughs have resolved, and that they have had three consecutive sputum smears collected on different days with negative results for AFB. After personnel return to work, obtain periodic documentation from their health care provider that effective drug therapy has been maintained for the recommended period and that sputum smear results remain negative for AFB. Category IB
2) Promptly evaluate for infectiousness those personnel with active TB who discontinue treatment before they are cured. Exclude from duty those who are found to remain infectious until
(a) treatment is resumed,
(b) an adequate response to therapy is documented, and
(c) sputum smear results are negative for AFB. Category IB
3) Consider directly observed therapy for personnel with active TB who have not been compliant with drug regimens. Category IB
4) Do not exclude personnel from the workplace who have TB only at sites other than the lung or larynx. Category IB
5) Do not restrict personnel from their usual work activities if they are receiving preventive therapy because of positive PPD-test results, even if they are unable or unwilling to accept or complete a full course of preventive therapy. Instruct them to seek prompt evaluation if symptoms suggestive of TB develop. Category IB|
h. Immunocompromised personnel
1) Refer personnel who are known to be immunocompromised to personnel health professionals who can individually counsel them regarding their risk for TB. Category II
2) At the request of immunocompromised personnel, offer but do not compel reasonable accommodations for work settings in which they would have the lowest possible risk for occupational exposure to M. tuberculosis. Consider the provisions of the Americans With Disabilities Act of 1990 and other federal, state, and local regulations in evaluating these situations. Category II
i. Bacille Calmette-Guérin vaccination
1) In settings associated with high risk for M. tuberculosis transmission:
a) Consider BCG vaccination of personnel on an individual basis, and only in settings where:
(1) a high proportion of isolates of M. tuberculosis are resistant to isoniazid and rifampin,
(2) there is a strong likelihood of transmission and infection with such drug-resistant organisms, and
(3) comprehensive infection control precautions have been implemented and have failed to halt nosocomial transmission of TB. Consult with the local and state health departments in making this determination. Category II
b) Do not require BCG vaccination for employment or for assignment of personnel in specific work areas. Category II
2) Counsel health care personnel who are being considered for receipt of BCG vaccination about the risks and benefits of both BCG vaccination and preventive therapy, including
(a) the variable data on the efficacy of BCG vaccination,
(b) the potentially serious complications of BCG vaccine in immunocompromised individuals, such as those with HIV infection,
(c) the lack of information on chemoprophylaxis for MDR-TB infections,
(d) the risks of drug toxicity with multidrug prophylactic regimens, and
(e) the fact that BCG vaccination interferes with the diagnosis of newly acquired TB infection. Category IB
3) Do not administer BCG vaccine to personnel in settings associated with a low risk for M. tuberculosis transmission. Category IB
4) Do not administer BCG vaccine to pregnant or immunocompromised persons with negative baseline PPD-test results. Category II
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Date last modified: June 26, 2006
Date last reviewed:
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