Setting | Age profile | Recruitment start, recruitment end, follow-up end* | Long-est follow-up (years) | Epidemiological background | Latitude | TST no, dose | TST cut-off (mm) | Follow-up screen-ing | Diagnostic confirmation | TB endpoint (authors’ terminology) | Number recruited vaccinated, controls | TB cases in vaccinated, controls | Incidence rate ratio point estimate (confidence intervals) |
Saskatchewan native infants, Canada | Neonates | 1933, 1945, 1947 | 14 | Rapidly declining following period of very high burden55 | 50.8 n | None | N/A | X-ray | X-ray and clinical | TB | 306, 303 | 6, 29 | 0.19 (0.08 to 0.46) |
Native infants, USA | Neonates | 1938, 1940, 1946 | 8 | Rapidly declining following period of very high burden33 | 48.8 n and 43.2 n | None | N/A | X-ray, TST | Routine diagnosis after active follow-up ceased | Primary TB | 123, 139 | 4, 11 | 0.41 (0.13 to 1.29) |
New York infants, USA | Neonates | 1933, 1944, 1944 | 11 | Rapidly declining following period of very high burden56 | 40.7 n | None (for majority vaccinated before 1 month of age) | N/A | X-ray, TST | Microbiological or autopsy | None | 566, 528 | Not reported (TB-related deaths: 8, 8) | N/A (TB mortality: 0.93 (0.35 to 2.49)) |
Chicago hospital-delivered infants, USA | Neonates | 1937, 1956, 1956 | 19 | Very high burden, then rapidly declining23 57 | 41.9 n | None | N/A | Clinical, TST, X-ray | Clinical, TST, X-ray, autopsy (X-ray sufficient for diagnosis) | TB | 5426, 4128 | 18, 63 | 0.22 (0.13 to 0.37) |
Chicago household contact infants, USA | Neonates | 1940, 1955, 1955 | 15 | Very high burden, then rapidly declining23 57 | 41.9 n | None (if mother not the index) | N/A | Clinical, TST, X-ray | Clinical, TST, X-ray, autopsy (X-ray sufficient for diagnosis) | TB | 231, 220 | 3, 11 | 0.30 (0.08 to 1.07) |
Mumbai infants, India | Neonates | 1972, 1972, 1975 | 2.5 | Very high burden25 | 19.0 n | None | N/A | Clinical, TST | TST sufficient for diagnosis, although most TB diagnoses had X-ray changes | Primary TB | 396, 300 | 22, 27 | 0.63 (0.36 to 1.11) |
Agra preschool children, India | 0–5 years | 1979, 1979, 1984 | 5 | Very high burden27 | 27.2 n | One-stage, 1 TU PPD-RT23 | <10 | X-ray, sputum examination | Not stated | Radiologically active or probably active TB | 1259, 1259 | 10, 25 | 0.40 (0.19 to 0.83) |
Chicago housing project, USA | 0–12 years | 1942, 1955, 1955 | 13 | High burden23 57 | 41.8 n | Two-stage, Vollmer then 100 TU OT TST | Not stated | X-ray, TST | Unclear, presumed X-ray and clinical | Active pulmonary TB | 947, 944 | 0, 3 | 0.17 (0.01 to 3.32) |
Jeremie population-wide, Haiti | All ages, see figure 2 | 1965, 1966, 1969 | 3 | Very high burden58 | 18.6 n | One-stage, 5 TU PPD-S | <6 | X-ray, TST | Microbiological | TB | 635, 338 | 1, 5 | 0.11 (0.01 to 0.91) |
Native Americans in four states, USA | 0–19 years, see figure 1 | 1935, 1938, 1998 | 63 | Low and declining following a period of very high burden59 | 32.2 n to 58.8 n | Two-stage, 1 then 250 TU PPD | Not stated | X-ray, TST | X-ray during first 12 years, then microbiological, clinical and other tests | Radiological evidence first 11 years, then by case definitions | 1551, 1457 | 84, 280 | 0.27 (0.21 to 0.34) |
Georgia schools, USA | 6–17 years | 1947, 1947, 1967 | 20 | Low and declining following a period of high burden32 | 32.5 n | Two-stage, 5 and 100 TU PPD-RT19-20-21 | <5 | TST | Clinical, microbiological, X-ray, TST | TB | 2498, 2341 | 5, 3 | 1.56 (0.37 to 6.54) |
English cities, UK | 14–15½ years | 1950, 1952, 1972 | 20 | Low and declining following a period of high burden54 | 51.5 n to 53.5 n | Two-stage, 3 and 100 TU OT | <5 | Clinical, TST, X-ray | Clinical, microbiological, pathological | TB | 13598, 12 867 | 62, 248 | 0.23 (0.18 to 0.31) |
Puerto Rico children, USA | 1–18 years, see figure 2 | 1949, 1951, 1969 | 19.8 | Declining but substantial following a period of very high burden31 | 18.4 n | Predominantly (~76%) two-stage†, 1 then 10 TU PPD-RT19-20-21 | <6 | No active follow-up | Existing surveillance systems | TB | 50634, 27 338 | 186, 141 | 0.71 (0.57 to 0.89) |
Chicago mental health patients, USA | Adults up to 66 years | 1943, 1947, 1947 | 4 | High burden28 | 41.9 n | Two-stage, 100 TU OT | Not stated | Not stated | Not stated | Pulmonary TB | 20, 15 | 0, 1 (unconfirmed case) | Not estimated |
Chicago nursing students, USA | Presumed young adult | 1940, 1953, 1956 | 3 | High rates of exposure, higher in vaccinated38 | 41.9 n | Two-stage, 2 and 10 TU OT | <6 | TST | Clinical, X-ray, other tests (X-ray sufficient for diagnosis) | TB | 231, 263 | 2, 5 | 0.45 (0.09 to 2.34) |
Chicago medical students, USA | 20–37 years | 1939, 1952, 1964 | 4 | High rates of exposure38 | 41.9 n | Two-stage, 2 and either 10 or 100 TU OT | <6 | TST | Clinical, X-ray, microbiological | TB | 324, 298 | 0, 3 | 0.15 (0.01 to 3.00) |
Rand Mines, South Africa | 30.3±10.3 years‡ | 1965, 1968, 1968 | 3.6 | Very high burden60 | 26.2 s | None for most of trial, then one-stage for last 8 months | Not stated | X-ray | X-ray | TB | 8317, 7997 | 29, 45 | 0.62 (0.39 to 0.99) |
Muscogee and Russell Counties population-wide, USA | See figure 2 | 1950, 1950, 1970 | 20 | Low and declining burden | 32.5 n | One-stage, 5 TU PPD-RT-19-20-21 | <5 | None | Existing surveillance systems | TB | 16913, 17 854 | 32, 36 | 0.94 (0.58 to 1.51) |
Madanapalle population-wide, India | See figure 2 | 1950, 1955, 1971 | 21 | Very high burden, rapidly declining due to active case finding9 | 13.6 n | Predominantly one-stage (~95%), 5 TU PPD-RT-19-20-21† | <5 | X-ray | Clinical, X-ray, microbiological, other tests | Bacteriologically-confirmed TB | 5069, 5808 | 33, 47 | 0.81 (0.52 to 1.27) |
Lincoln State School, USA | Not stated‡ | 1947, 1947, 1960 | 12 | Declining but substantial following a period of very high burden40 | 40.2 n | Two-stage, 10 and 100 TU OT | Not stated | TST, X-ray | Clinical, microbiological, other tests | TB | 531, 494 | 12, 8 | 1.38 (0.56 to 3.38) |
Chengalpattu population-wide, India | See figure 2 | 1968, 1971, 1987 | 15 | Very high burden61 | 12.7 n | One-stage, 3 TU PPD-S | <8 | X-ray, sputum examination | Culture-positive on ≥1 sputum | Culture-confirmed TB | 78693, 39 025 | 380, 180 | 1.05 (0.88 to 1.25) |
*Italicised years indicate inferred/assumed dates/follow-up periods.
†Our assessment differs importantly from that of Mangtani et al4.
‡TB cases were aged 15–44, such that 'school' does not imply children.
OT, old tuberculin; PPD, purified protein derivative; TB, tuberculosis; TST, tuberculin skin test; TU, tuberculin units.