Ensuring the health and safety of health care personnel (HCP) is paramount, and tuberculosis (TB) screening is a critical component of this. This guide provides a comprehensive overview of the Baseline Tb Screening Tool For Health Care Workers, aligning with best practices and guidelines to protect both HCP and patients.
Understanding State TB Regulations
It’s crucial to remember that the recommendations provided here are guidelines and do not supersede state or local TB regulations. These regulations are tailored to meet specific local needs and may vary significantly.
Always consult your state or local TB control program to confirm the specific TB testing regulations applicable in your region.
For easy access, here is a directory of State TB Programs.
Individual TB Risk Assessment for Health Care Personnel at Baseline
Health care personnel can be at a higher risk of TB infection due to potential occupational exposure. An increased risk is considered if any of the following risk factors are present in an individual HCP:
To accurately interpret TB test results and determine the level of risk for each health care worker, utilize an individual TB risk assessment tool. For HCP who are identified as lower risk and have an initial positive TB test result, a confirmatory second TB test (either a TB blood test or TB skin test) is recommended.
Recognizing TB Symptoms: An Essential Step in Baseline Screening
Symptom evaluation is a vital part of baseline TB screening. Active TB disease can manifest through various symptoms, including:
- Persistent cough lasting three weeks or more
- Chest pain
- Coughing up blood or sputum
- Unexplained weakness or fatigue
- Unintentional weight loss
- Loss of appetite
- Chills
- Fever
- Night sweats
Utilizing the Baseline TB Blood Test (IGRA) for Health Care Workers
The TB blood test, also known as Interferon Gamma Release Assay (IGRA), is a valuable tool for baseline TB screening in health care personnel. If using a TB blood test for baseline assessment, follow these steps:
- Administer the TB blood test strictly according to the recommended protocol.
- Interpret the result in conjunction with the individual TB risk assessment to accurately evaluate the test outcome.
- A negative result typically indicates no TB infection.
- A positive result in a low-risk HCP necessitates a second confirmatory test.
- If the second test is also positive (for low-risk HCP) or the HCP is at increased risk, TB infection should be considered, and further evaluation for TB disease is required.
- Document the test result meticulously in the HCP’s health record.
A significant advantage of using a TB blood test for baseline screening is that two-step testing is not necessary.
TB blood tests are particularly recommended for individuals who have received the Bacille Calmette-Guérin (BCG) vaccine, as the BCG vaccine can sometimes cause false-positive results with the TB skin test.
Implementing the Baseline Two-Step TB Skin Test (TST) for Health Care Personnel
When the Mantoux tuberculin skin test (TST) is chosen for baseline TB screening of health care personnel, two-step testing is the recommended approach.
Why Two-Step TB Skin Testing is Crucial for Baseline Screening
Two-step testing is specifically recommended for the initial TB skin test in adults who will undergo periodic TB testing, such as health care personnel. This is especially important in settings with low TB risk, where testing might primarily occur after a known exposure.
Latent TB infection can sometimes result in a negative reaction to a TB skin test, particularly when tested years after the initial infection. However, a subsequent TB skin test within a year of the first can trigger a positive reaction. This phenomenon, known as the “booster effect,” occurs because the first TST can stimulate the immune system’s memory, enhancing its response to the second test.
Without two-step testing, a boosted reaction might be incorrectly interpreted as a recent TB infection acquired between the first and second tests, rather than a reaction to a long-standing latent infection.
Step-by-Step Two-Step TB Skin Test Procedure
TB skin tests must be administered and interpreted by a designated, trained health care provider. Consult your state and local public health authorities to determine who is authorized to perform and read TB skin tests in your jurisdiction.
Step 1 of Two-Step TST
- Administer the first TB skin test following the proper protocol.
- Evaluate the result, using the individual TB risk assessment to aid in result interpretation.
- If negative, proceed to Step 2 and administer a second TB skin test 1 to 3 weeks after reading the first test.
- If positive and the HCP is at low risk, a second confirmatory test is required.
- If the second test is also positive (for low-risk HCP) or the HCP is at risk, consider TB infection and evaluate for TB disease.
- Document the result clearly.
Step 2 of Two-Step TST
- Administer the second TB skin test 1 to 3 weeks after reading the first test, again following proper protocol.
- Review the results. A positive result indicates likely TB infection, necessitating evaluation for TB disease. Use the individual risk assessment to guide interpretation. A negative result suggests no infection.
- Document the result.
Two-step testing is a crucial strategy to minimize the misinterpretation of a boosted reaction as a new TB infection.
What to do if the second TST reading is delayed beyond 72 hours:
- Administer a TB skin test as soon as possible, regardless of the time elapsed. Read the result within the standard 48–72 hour window.
- If a person does not return within 72 hours and the result is negative, the TB skin test must be repeated. TB skin tests can be safely repeated at any time without health risks.
When a second TB skin test is unnecessary:
- If the individual has documented proof of a negative TB skin test result within the previous 12 months, a single TB skin test is sufficient.
- This single test in this scenario acts as the second step of the two-step testing process.
Further Reading: Mantoux Tuberculin Skin Test Toolkit
Screening Health Care Personnel with a Pre-existing Positive TB Test Result
For health care personnel with a documented history of a prior positive TB test, baseline screening upon hiring (pre-placement) should include an individual TB risk assessment and a TB symptom screen. Repeating the TB test (TB blood test or TB skin test) is not necessary.
The Role of Chest X-rays in HCP with Prior Positive TB Tests
Generally, repeat chest x-rays are not required for HCP with a prior positive TB test unless they develop TB symptoms or as part of a pre-treatment evaluation for latent TB infection.
State and local regulations may specify documentation requirements. Consult your state TB program for specific regulations in your area.
Annual TB Symptom Screening for Ongoing Monitoring
Health care personnel with untreated latent TB infection should undergo an annual TB symptom screen. This annual screening is crucial for early detection of TB disease and to re-evaluate the necessity and benefits of treatment for latent TB infection.
Prioritizing Treatment for Latent TB Infection in Health Care Workers
Treatment for latent TB infection is strongly recommended for health care personnel. Short-course, rifamycin-based regimens are preferred due to their higher treatment completion rates.
Resources
For further information and resources on TB screening and management, please refer to the following:
State TB Programs
Individual TB risk assessment tool
Risk factors for TB
Bacille Calmette-Guérin (BCG) vaccine information
Mantoux Tuberculin Skin Test Toolkit
Treatment for latent TB infection guidelines
