Comparison of guidelines on selected preventive measures for protection against Mycobacterium tuberculosis in hospitals separated by topics

Guidelines/recommendationsWHO [6, 7]USA [4, 12, 24, 26]UK [5, 8, 25]Germany [3, 9, 13, 23]
Spatial requirements
 NPI roomsYesYesYesYes
 Normal ventilation room allowedYesYes, if air-cleaning technologies (e.g. a portable HEPA filtration system) are availableYes, single rooms that are vented to the outside of the buildingYes, single rooms that are vented to the outside of the building
 Frequency of air exchange in NPI roomsMinimum 12 per hPrefer ≥12 per h (minimum ≥6 per h)“Adequate ventilation”Optionally 12 per h
 Frequency of air exchange in normal ventilation roomsNot addressedMinimum 2 per hNot addressedNot addressed
Personal protection
 Minimum standard of masksN95 or FFP2N95 or FFP2FFP2FFP2
 Masks when encountering MDR-TB patients
FFP3 not addressed>N95FFP3FFP3
 Masks during aerosol-generating procedures
FFP2>N95FFP2 [5], FFP3 [8]FFP2 [3] or at least FFP 2 [23]
Removal from isolation
 Sputum smear-positive patientsDiscussed, but no recommendation providedMinimum 2-week treatment, progressively decreasing M. tuberculosis load, then 3 microscopy-negative sputum smear-resultsOnly after at least 2-week treatment, and given a low initial smear (grade 2 or less), then 3 negative sputum smear resultsAfter 3-week treatment [23] or after 3-week treatment and 3 microscopy-negative sputum smear results [3], in each case dependent on clinical and radiographic improvement
 Sputum smear-negative patientsNot addressedAfter two negative results of the Xpert MTB/RIF testNo isolationAfter 3 microscopy- negative sputum results, depending on further medical consideration [3] or after 3-week treatment and clinical and radiographic improvement [23]
 MDR-TB patientsNot addressed (isolation only for culture-positive XDR-TB patients)After at least 1 negative cultureAfter 3 microscopy-negative smears at weekly intervals and ideally 1 negative cultureAfter 3 microscopy-negative smears, possibly after 1 negative culture [3] or definitely after 1 negative culture [23]
Screening for LTBI
 Serial testing of healthcare workersNot addressedAt the discretion of healthcare facilities; routine serial testing not recommendedNot addressed (BCG vaccination instead?)Yes, required by law (Ordinance of Occupational Health Care) in risk-prone healthcare facilities
 Upper-air or in-duct UV disinfection (UVGI)
YesYes, but not in lieu of ventilationNot addressedNoted as general option, but not recommended

WHO: World Health Organization; NPI: negative pressure isolation; HEPA: high efficiency particulate air; FFP: filtering face piece; MDR: multidrug-resistant; XDR: extensively drug-resistant; TB: tuberculosis; RIF: rifampicin; XDR: extensively drug resistant; LTBI: latent TB infection; BCG: bacille Calmette–Guérin; UVGI: ultraviolet germicidal irradiation.