Table 2 TB transmission control measures and tuberculin skin test (TST) conversion: study details (n = 10)

Blumberg 1995. [27]

USA, 1992–1994.

3579 (B) and 2975–5153 (A1-A4).

HCWs; hospital, Atlanta

Administrative: Expanded and stricter respiratory isolation regimen. TB transmission control nurse. Expanded staff TB education.

Environmental: Rooms with negative pressure for respiratory isolation.

Personal: Submicron respirators for HCWs in isolation rooms.

(CDC 1990, 1994)

5 cycles:

B: 6 months

A1: 6 months

A2: 6 months

A3: 6 months

A4: 6 months

Aplisol or Tubersol, 5 TU.

Conversion: >  10 mm following prior negative test.

Jarvis, 1995. [28]

USA, 1989–1992.

Intervention:

152 (B) and 173 (A). HCWs; 2 hospitals, Miami, New York.

Controls:

22 (B) and 33 (A).

HCWs; third hospital, New York.

Administrative: Education of staff for earlier recognition, diagnosis and rapid isolation of TB patients. Restriction of patient movement. Expanded TB drug regimen.

Environmental: Increase in number of AFB isolation rooms. Negative pressure in these rooms. Negative pressure ventilated booths for aerosol generating procedures.

Personal: Respirators and submicron surgical masks.

(CDC 1994)

B: Up to 24 months

A: Not given

PPD not specified.

Conversion: > 10 mm (baseline unknown) or > 10 mm increase in induration (baseline known).

Maloney, 1995. [29]

USA, 1990–1992.

Intervention:

90 (B) and 78 (A). Staff on wards with TB patients; hospital, New York.

Controls:

254 (B) and 228 (A).

Staff on all other wards.

Administrative: Improved test based AFB isolation on admission. Expanded treatment regimen. More efficient and quicker laboratory diagnosis. Drug sensitivity probe added.

Environmental: AFB rooms with negative pressure. Portable chambers for cough inducing procedures.

Personal: Change from non-moulded to moulded surgical masks.

(CDC 1990).

B: 18 months

A: 14 months

PPD not specified.

Conversion: > 10 mm with negative prior test.

Wenger, 1995. [30]

USA, 1990–1992.

25 (B) and 27 (A). HCWs in HIV ward; hospital, Miami.

Administrative: Stricter respiratory isolation regimen. Sputum induction only in isolation rooms. Additional laboratory staff with faster results turnaround.

Environmental: Automatic door closers in isolation rooms. Negative pressure isolation rooms and HIV ward. Aerosolised pentamidine in TB isolation rooms.

Personal: Surgical submicron masks worn in isolation rooms. Dust-mist particulate respirators (late intervention).

(CDC 1990)

3 cycles:

B: 5 months

A1: 9 months

A2: 16 months

PPD not specified. 5 TU.

Conversion: > 10 mm and at least 6 mm increase over previous induration.

Bangsberg, 1997. [31] USA, 1992–1994.

126 (B1-B2) and 124–138 (A1-A3). Medical house staff; hospital, New York.

Administrative: Isolation of high risk patients. Specialised TB service for patients with HIV or known HIV risk factors and suspicion of pneumonia.

Environmental: Negative pressure rooms. UVGI in emergency and patient care areas.

Personal: Instruction and fit-testing on respirators to be worn by staff in care of isolated patients.

(CDC 1993)

5 cycles:

B1:11–35 months

B2: 6 months

A1: 6 months

A2: 6 months

A3: 6 months

Aplisol or Tubersol, 5 TU.

Conversion: ≥6 mm increase to a value of at least 10 mm.

Louther, 1997. [32]

USA, 1991–1994.

898 (B) and 971 (A).

HCWs; hospital, New York.

Administrative: Early respiratory isolation of suspected TB cases.^b

Environmental: Negative pressure rooms. UVGI.

Personal: Face shield masks. Particulate and dust-mist-fume respirators.

(CDC 1994)

B^c: 24 months

A: 24 months

Aplisol, 5 TU 1991–1992; Tubersol, 5 TU 1993–1994. (2-step tested employees excluded; tests by outside physicians allowed.)

Conversion: > 10 mm increase over baseline within 2 years.

^bInterventions assumed to be same as described in Fella et al.[20] (See Table 1).

^c“Before” period simultaneous with introduction of intervention.

Behrman, 1998. [33] USA, 1993–1996.

Intervention:

50 (B) and 64 (A). Emergency Department employees; hospital, Philadelphia. Controls:

2514 (B) and 3000 (A). Other hospital employees.

Administrative: None.

Environmental: Respiratory isolation rooms meeting CDC standards. Improved ventilation with at least 25% fresh air in the Emergency Department. 100% non-recirculated air in Trauma area. Laminar flow away from registrars with droplet shields.

Personal: None.

(CDC 1990)

B: 12 months

A: 12 months

PPD not specified. 5 TU.

Conversion: > 10 mm following prior negative test (<  5 mm).

Blumberg, 1998. [34] USA, 1992–1997.

2144 (B) and 2123 (A). Rotating house staff (residents and fellows); hospital, Atlanta.

Administrative: Expanded and stricter respiratory isolation regimen. TB transmission control nurse. Expanded staff. TB education.

Environmental: Rooms with negative pressure for respiratory isolation.

Personal: Submicron respirators for HCWs in isolation rooms.

(CDC 1994)

B: 6 months

A: 54 months

Aplisol or Tubersol, 5 TU.

Conversion: > 10 mm following prior negative test.

Yanai, 2003. [35] Thailand, 1995–1999.

369 (B) and 164 (A1).

HCWs; hospital, Chaing Rai.

Administrative: Training of HCWs on TB transmission prevention. Faster case detection, TB diagnosis, treatment initiation and isolation. Infectious patients trained in cough and mask practice. One-stop outpatient TB service with faster throughput and referral out.

Environmental: TB isolation rooms with negative pressure attached to wards. Increased natural ventilation in high risk wards. Safety cabinets, air exhaust and ultraviolet air disinfection in laboratory.

Personal: N95 respirators for HCWs. Air purified respirators with high efficiency particulate filters for laboratory staff.

(CDC 1994)

3 cycles:

B: 24 months (1995 to 1997)

A1: 12 months

A2: 12 months

Tubersol, 5 TU. 2-step test.

Conversion: > 10 mm increase over negative prior test (<  10 mm).

da Costa, 2009. [15]

Brazil, 1998–2003.

406 (B) and 193 (A).

HCWs; hospital, Rio De Janeiro.

Administrative: Increased respiratory isolation, rapid diagnosis.

Environmental: None.

Personal: Worker education in use of respirators.

(Guidelines not specified)

B: 23 months

A: 16 months

PPD not specified. 2-step where possible.

Conversion: > 10 mm increase over previous TST in 2-step; or > 15 mm increase in 1-step.