481—59.2 (135B,135C) Definitions. For purposes of this chapter, the following definitions apply:
“Bacille Calmette-Guérin (BCG) vaccination” means a vaccine for TB. BCG is used in many countries with a high prevalence of TB to prevent childhood tuberculosis meningitis and military disease. BCG is not generally recommended for use in the United States because of the low risk of infection with Mycobacterium tuberculosis, the variable effectiveness of the vaccine against adult pulmonary TB, and the vaccine’s potential interference with tuberculin skin test reactivity.
“Baseline TB screening” means the screening of health care workers (HCWs) of health care facilities or hospitals and residents of health care facilities for latent tuberculosis infection (LTBI) and TB disease at the beginning of employment in a facility or hospital, or upon admission to a facility. Baseline TB screening includes a symptom screen for all HCWs and residents, and tuberculin skin tests (TSTs) or interferon-gamma release assay (IGRA) for Mycobacterium tuberculosis for those persons with previous negative test results for M. tuberculosis infection.
“Baseline TST”  or “baseline IGRA”  means the TST or IGRA, respectively, that is administered at the beginning of employment to newly hired HCWs or upon admission to residents of health care facilities.
“Boosting” means a phenomenon in which a person has a negative TST (i.e., false-negative) result years after infection with M. tuberculosis and then a positive subsequent TST result. The positive TST result is caused by a boosted immune response of previous sensitivity rather than by a new infection (false-positive TST conversion). Two-step testing reduces the likelihood of mistaking a boosted reaction for a new infection.
“Department” means the department of inspections and appeals.
“Employment”  or “employed”  means hired or retained for paid or unpaid work in a facility or hospital.
“Extrapulmonary TB” means TB disease in any part of the body other than the lungs (e.g., kidney, spine, or lymph nodes).
“Health care facility”  or “facility”  means a health care facility as defined in Iowa Code section 135C.1 or a long-term care service of a hospital as defined in rule 481—51.38(135B).
“Health care worker”  or “HCW”  means any paid or unpaid person working in a health care facility or hospital, including any person who is paid either by the health care facility or hospital, or paid by any other entity (i.e., temporary agency, private duty, Medicaid/Medicare or independent contractors), or any volunteer who volunteers in a health care facility or hospital on a consistent and regularly scheduled basis for five or more hours per week. Specifically excluded from the definition of “health care worker” are individuals such as visitors, building contractors, repair workers or others who are in the facility or hospital for a very limited purpose and are not in the facility or hospital on a regular basis.
“Hospital” means a hospital as defined in Iowa Code section 135B.1.
“Interferon-gamma release assay”  or “IGRA”  means whole-blood tests that can aid in diagnosing Mycobacterium tuberculosis infection.
“Laryngeal TB” means a form of TB disease that involves the larynx and may be highly infectious.
“Latent TB infection”  or “LTBI”  means infection with M. tuberculosis without symptoms or signs of disease having manifested.
“Mantoux method” means a skin test performed by intradermally injecting 0.1 mL of purified protein derivative (PPD) tuberculin solution into the volar or dorsal surface of the forearm.
“Patient” means a person admitted to a hospital.
“Pulmonary TB” means TB disease that occurs in the lung parenchyma, usually producing a cough that lasts greater than three weeks. Pulmonary TB is usually infectious.
“Purified protein derivative (PPD) tuberculin” means a material used in diagnostic tests for detecting infection with M. tuberculosis.
“Resident” means a person admitted to a health care facility or a long-term care service of a hospital as defined in rule 481—51.38(135B). For purposes of this chapter, “resident” does not include a patient admitted to a hospital.
“Risk classification” means the category the infection control team, or designated other staff, determines is appropriate for the facility or hospital as a result of the TB risk assessment.
“Serial screening” refers to TB screening performed at regular intervals following baseline TB screening. Serial TB screening, also called annual or ongoing TB testing, consists of two components: (1) assessing for current symptoms of active TB disease, and (2) testing for the presence of infection with M. tuberculosis by administering either a TST or single IGRA.
“Symptom screen” means a procedure used during a clinical evaluation in which persons are asked if they have experienced any departure from normal in function, appearance, or sensation related to TB disease (e.g., cough).
“TB patient” means a person who had undiagnosed infectious pulmonary or laryngeal TB while in a health care facility or hospital during the preceding year. “TB patient” does not include persons with LTBI (treated or untreated), extrapulmonary TB disease, pulmonary, or laryngeal TB that have met criteria for noninfectiousness.
“TB risk assessment” means an initial and ongoing evaluation of the risk for transmission of M. tuberculosis in a particular health care setting.
“TB screening” means an administrative control measure in which evaluation for LTBI and TB disease is performed through baseline and serial screening of HCWs in hospitals and health care facilities and residents of health care facilities.
“TB screening plan” means a plan that health care facilities and hospitals develop and implement that comprises four major components: (1) baseline testing for M. tuberculosis infection, (2) serial testing for M. tuberculosis infection, (3) serial screening for signs or symptoms of TB disease, and (4) TB training and education.
“Treatment for LTBI” means treatment that prevents the progression of M. tuberculosis infection into TB disease.
“Tuberculin skin test”  or “TST”  means a diagnostic aid for finding M. tuberculosis infection. The Mantoux method is the recommended method to be used for TST.
“Tuberculosis”  or “TB”  means the namesake member organism of M. tuberculosis complex and the most common causative infectious agent of TB disease in humans. In certain instances, the species name refers to the entire M. tuberculosis complex, which includes M. bovis and M. african, M. microti, M. canetti, M. caprae, and M. pinnipedii.
“Tuberculosis disease”  or “TB disease”  means a condition caused by infection with a member of the M. tuberculosis complex that has progressed to causing clinical (manifesting symptoms or signs) or subclinical (early stage of disease in which signs or symptoms are not present, but other indications of disease activity are present) illness.
“Two-step tuberculin skin test”  or “two-step TST”  means the procedure used for the baseline skin testing of persons who will receive serial TSTs to reduce the likelihood of mistaking a boosted reaction for a new infection.
[ARC 0484C, IAB 12/12/12, effective 1/16/13; see Delay note at end of chapter; ARC 0674C, IAB 4/3/13, effective 3/26/13; ARC 0761C, IAB 5/29/13, effective 7/3/13]