B. Identifying Confirmed or Potential Tuberculosis Transmitters in a Health-Care Facility—Worker protection against tuberculosis infection is critically dependent upon rapid identification of any potential tuberculosis transmitters in a health-care facility. This high priority identification can be accomplished with an Admission Screening Plan (15). A qualified infection-control committee in each facility should review information about persons admitted to the facility and develop an Admission Screening Plan. The purpose of this Plan is to specify screening criteria for effectively identifying any individual that is a confirmed or potential tuberculosis transmitter. CDC has previously given the following guidance regarding diagnosing tuberculosis and determining the infectiousness of a person with active tuberculosis (10):
A diagnosis of tuberculosis should be considered for any patient with persistent cough or other symptoms compatible with tuberculosis, such as weight loss, anorexia, or fever. Diagnostic measures for identifying tuberculosis should be instituted for such patients. These measures include history, physical examination, tuberculin skin test, chest radiograph, and microscopic examination and culture of sputum or other appropriate specimens (16,97). Other diagnostic methods, such as bronchoscopy or biopsy, may be indicated in some cases (98,99). The probability of tuberculosis is increased by finding a positive reaction to a tuberculin skin test or a history of a positive skin test, a history of previous tuberculosis, membership in a group at high risk for tuberculosis (see section V.B), or a history of exposure to tuberculosis. Active tuberculosis is strongly suggested if the diagnostic evaluation reveals AFB in sputum, a chest radiograph is suggestive of tuberculosis, or the person has symptoms highly suggestive of tuberculosis (e.g., productive cough, night sweats, anorexia, and weight loss). Tuberculosis may occur simultaneously with other pulmonary infections, such as PCP....
The infectiousness of a person with tuberculosis correlates with the number of organisms that are expelled into the air, which, in turn, correlates with the following factors: a) anatomic site of disease, b) presence of cough or other forceful expirational maneuvers, c) presence of AFB in the sputum smear, d) willingness or ability of the patient to cover his or her mouth when coughing, e) presence of cavitation on chest radiograph, f) length of time the patient has been on adequate chemotherapy, g) duration of symptoms, and h) administration of procedures that can enhance coughing (e.g., sputum induction).
The most infectious persons are those with pulmonary or laryngeal tuberculosis. Those with extrapulmonary tuberculosis are usually not infectious, with the following exceptions: a) nonpulmonary disease located in the respiratory tract or oral cavity, or b) extrapulmonary disease that includes an open abscess or lesion in which the concentration of organisms is high, especially if drainage from the abscess or lesion is extensive (100).