Background
Methods
Setting and patient population
Standard of care
Data collection and classification
Statistical analysis
Results
Description of cohort
Risk factors for infection
Variable | Total | Infected | Unadjusted OR | p-value | AOR | p-value1
| |
---|---|---|---|---|---|---|---|
(n = 228) | (row %) | (95% CI) | (95% CI)1
| ||||
(n = 102) | |||||||
Age of child (n = 224) | <1 year | 53 | 15 (28.3) | 1 | 0.05 | 1.43 (1.13–1.91) | 0.0022
|
1–2 years | 36 | 15 (41.7) | 1.81 (0.74–4.42) | ||||
2–3 years | 51 | 25 (49.0) | 2.44 (1.08–5.48) | 0.0072
| |||
3–4 years | 48 | 27 (56.3) | 3.26 (1.43–7.44) | ||||
4–5 years | 36 | 18 (50.0) | 2.53 (1.05–6.14) | ||||
Gender (n = 227) | Female | 109 | 46 (42.2) | 1 | 0.43 | ||
Male | 118 | 56 (47.5) | 1.24 (0.73–2.09) | ||||
Ethnicity | Xhosa | 101 | 30 (29.7) | 1 | <0.001 | 1 | 0.01 |
Colored | 125 | 70 (56.0) | 3.01 (1.69–5.36) | 2.51 (1.22–5.17) | |||
Previous TB treatment | No | 207 | 86 (41.5) | 1 | 0.002 | 1 | 0.08 |
Yes | 21 | 16 (76.2) | 4.50 (1.59–12.8) | 2.76 (0.84–9.12) | |||
HIV status (n = 217) | Negative | 209 | 96 (45.9) | 1.0 | 0.64 | ||
Positive | 8 | 3 (37.5) | 0.71 (0.16–3.03) | ||||
Weight-for-age z-score (n = 218) | More than −1 | 138 | 60 (43.5) | 1 | 0.14 | ||
−1 to −2 | 47 | 26 (55.3) | 1.61 (0.83–3.13) | ||||
Less than −2 | 33 | 11 (33.3) | 0.65 (0.29–1.44) | ||||
BCG scar visible (n = 222) | No | 40 | 14 (35.0) | 1 | 0.14 | ||
Yes | 182 | 87 (47.8) | 1.70 (0.83–3.47) | ||||
Type of residence (n = 217) | Tin shack | 33 | 8 (24.2) | 1 | 0.007 | ||
Brick House | 168 | 79 (47.0) | 2.77 (1.18–6.50) | ||||
Wendy House | 16 | 11 (68.8) | 6.87 (1.83–25.8) | ||||
Number of rooms in house | 1–2 | 61 | 28 (45.9) | 1 | 0.58 | ||
3–4 | 102 | 42 (41.2) | 0.83 (0.44–1.56) | ||||
>4 | 65 | 32 (49.2) | 1.14 (0.57–2.30) | ||||
Number of people living in house | ≤5 people | 109 | 47 (43.1) | 1 | 0.64 | ||
>5 people | 119 | 55 (46.2) | 1.13 (0.67–1.91) | ||||
Density of people living in house | ≤2 people per room | 153 | 72 (47.1) | 1 | 0.31 | ||
>2 people per room | 75 | 30 (40.0) | 0.75 (0.43–1.31) | ||||
Water source (n = 225) | Piped water in residence | 176 | 84 (47.7) | 1 | 0.06 | ||
Piped water from public source | 49 | 16 (32.7) | 0.53 (0.27–1.03) | ||||
Toilet | Flush toilet in house | 163 | 79 (48.5) | 1 | 0.07 | ||
Other | 65 | 23 (35.4) | 0.58 (0.32–1.05) |
Variable | Total | Infected | OR | p-value | AOR | p-value1
| |
---|---|---|---|---|---|---|---|
(n = 228) | (row %) | (95% CI) | (95% CI)1
| ||||
(n = 102) | |||||||
Age of source case (n = 219) | 16–25 | 55 | 31 (56.4) | 1 | 0.06 | 0.67 (0.45–1.00) | 0.052
|
26–35 | 86 | 40 (46.5) | 0.67 (0.34–1.33) | ||||
0.022
| |||||||
>35 | 78 | 28 (35.9) | 0.43 (0.21–0.88) | ||||
Gender of source case (n = 226) | Female | 138 | 62 (44.9) | 1 | 0.93 | ||
Male | 88 | 39 (43.3) | 0.98 (0.57–1.67) | ||||
Smoking status of source case (n = 225) | Non-smoker | 130 | 52 (40.0) | 1 | 0.09 | ||
Smoker | 95 | 49 (51.6) | 1.60 (0.94–2.73) | ||||
Alcohol use by source case (n = 225)3
| Never drinks | 166 | 65 (39.2) | 1 | 0.004 | 1 | 0.007 |
Drinks alcohol | 59 | 36 (61.0) | 2.43 (1.32–4.47) | 2.59 (1.29–5.22) | |||
Smear result of source case (n = 224) | Negative | 28 | 9 (32.1) | 1 | 0.17 | ||
Positive | 196 | 90 (45.9) | 1.79 (0.77–4.16) | ||||
Smear grade of source case (n = 217) | Negative | 28 | 9 (32.1) | 1 | 0.13 | ||
Scanty | 18 | 8 (44.4) | 1.69 (0.50–5.73) | ||||
1+ | 28 | 15 (53.6) | 2.44 (0.82–7.22) | ||||
2+ | 107 | 44 (41.1) | 1.47 (0.61–3.56) | ||||
3+ | 36 | 22 (61.1) | 3.31 (1.17–9.37) | ||||
HIV status of source case (n = 224) | Negative | 150 | 79 (52.7) | 1 | <0.001 | 1 | 0.06 |
Positive | 74 | 20 (27.0) | 0.33 (0.18–0.61) | 0.48 (0.22–1.04) | |||
CD4 count of source case if HIV-positive (n = 71) | <200 | 33 | 7 (21.2) | 1 | 0.46 | ||
>200 | 38 | 11 (28.9) | 1.51 (0.50–4.56) | ||||
Relationship of source case to child | Parents | 100 | 38 (38.0) | 1 | 0.34 | ||
Grandparent | 31 | 15 (48.4) | 1.53 (0.68–3.45) | ||||
Uncle or aunt | 66 | 33 (50.0) | 1.63 (0.87–3.06) | ||||
Other | 31 | 16 (51.6) | 1.74 (0.77–3.92) | ||||
Duration of exposure between source case and child | Less than a month | 30 | 13 (43.3) | 1 | 0.62 | ||
One month to six months | 92 | 38 (41.3) | 0.92 (0.40–2.11) | ||||
More than six months | 106 | 51 (48.1) | 1.21 (0.54–2.74) | ||||
Primary caregiver to child | Index case | 55 | 21 (38.2) | 1 | 0.26 | ||
Not index case | 173 | 81 (46.8) | 1.43 (0.77–2.65) | ||||
Frequency of contact between source case and child | Daily | 213 | 93 (43.7) | 1 | 0.23 | ||
Less frequently | 15 | 9 (60.0) | 1.94 (0.67–5.63) | ||||
Intensity of contact between child and source case | Sleeps in the same bed | 57 | 25 (43.9) | 1 | 0.67 | ||
Sleeps in the same room | 34 | 13 (38.2) | 0.79 (0.33–1.89) | ||||
Sleeps in the same house | 101 | 45 (44.6) | 1.03 (0.53–1.98) | ||||
Sleeps in a different house | 36 | 19 (52.8) | 1.43 (0.62–3.31) |
Risk factors for prevalent TB disease
Variable | Total | Disease | OR | p-value | Age-adjusted OR | p-value | |
---|---|---|---|---|---|---|---|
(n = 102) | (row %) | (95% CI) | (95% CI) | ||||
(n = 15) | |||||||
Age (n = 100) | <1 year | 15 | 4 (26.7) | 1 | 0.28 | n/a | n/a |
1–2 years | 15 | 3 (20.0) | 0.69 (0.12–3.79) | ||||
2–3 years | 25 | 6 (24.0) | 0.87 (0.20–3.77) | ||||
3–4 years | 27 | 2 (7.4) | 0.22 (0.03–1.38) | 0.011
| |||
4–5 years | 18 | 0 (0) | - | ||||
Gender | Female | 46 | 11 (23.9) | 1 | 0.02 | 1 | 0.04 |
Male | 56 | 4 (7.1) | 0.24 (0.72–0.83) | 0.29 (0.08–1.00) | |||
Ethnicity | Xhosa | 30 | 7 (23.3) | 1 | 0.13 | ||
Colored | 70 | 8 (11.4) | 0.42 (0.14–1.33) | ||||
Previous TB treatment | No | 86 | 14 (16.3) | 1 | 0.32 | ||
Yes | 16 | 1 (6.3) | 0.34 (0.04–2.81) | ||||
HIV status (n = 99) | Negative | 96 | 13 (13.5) | 1 | 0.04 | 1 | 0.01 |
Positive | 3 | 2 (66.7) | 12.8 (1.07–151.1) | 25.3 (1.63–393) | |||
Weight-for-age z-score (n = 97) | More than −1 | 60 | 10 (16.7) | 1 | 0.19 | ||
−1 to −2 | 26 | 1 (3.8) | 0.20 (0.02–1.65) | ||||
Less than −2 | 11 | 1 (9.1) | 0.50 (0.06–4.45) | ||||
BCG scar visible (n = 101) | No | 14 | 2 (14.3) | 1 | 0.95 | ||
Yes | 87 | 13 (14.9) | 1.05 (0.21–5.27) | ||||
Type of residence (n = 98) | Tin shack | 8 | 1 (12.5) | 1 | 0.84 | ||
Brick house | 79 | 12 (15.2) | 1.25 (0.14–11.1) | ||||
Wendy house | 11 | 1 (9.1) | 0.70 (0.04–13.2) | ||||
Number of rooms in house | 1-2 | 28 | 2 (7.1) | 0.04 | 1.39 (1.02–1.91) | 0.041
| |
3-4 | 42 | 4 (9.5) | 1.37 (0.23–8.03) | ||||
>4 | 32 | 9 (28.1) | 5.09 (1.00–26.0) | 0.021
| |||
Number of people living in house | ≤5 people | 47 | 5 (10.6) | 1 | 0.29 | ||
>5 people | 55 | 10 (18.2) | 1.87 (0.59–5.91) | ||||
Density of people living in house | ≤2 people per room | 72 | 12 (16.7) | 1 | 0.39 | ||
>2 people per room | 30 | 3 (10) | 0.56 (0.14–2.16) | ||||
Water source (n = 100) | House tap | 84 | 12 (14.3) | 1 | 0.65 | ||
No house tap | 16 | 3 (18.8) | 1.38 (0.34–5.60) | ||||
Toilet | Flush toilet in house | 79 | 12 (15.2) | 1 | 0.80 | ||
Other | 23 | 3 (13.0) | 0.84 (0.21–3.26) |
Variable | Total | Disease | OR | p-value | Age-adjusted OR | p-value | |
---|---|---|---|---|---|---|---|
(n = 102) | (row %) | (95% CI) | (95%CI) | ||||
(n = 15) | |||||||
Age of source case (n = 99) | 16–25 | 31 | 4 (12.9) | 1 | 0.81 | ||
26–35 | 40 | 5 (12.5) | 0.96 (0.24–3.94) | ||||
>35 | 28 | 5 (17.9) | 1.47 (0.35–6.12) | ||||
Gender of source case (n = 101) | Female | 62 | 11 (17.7) | 1 | 0.31 | ||
Male | 39 | 4 (10.3) | 0.53 (0.16–1.80) | ||||
Smoking status of source case (n = 101) | Non-smoker | 52 | 8 (15.4) | 1 | 0.88 | ||
Smoker | 49 | 7 (14.3) | 0.92 (0.31–2.75) | ||||
Alcohol use by source case (n = 101)1
| Never drinks | 65 | 6 (9.2) | 1 | 0.04 | 1 | 0.07 |
Drinks alcohol | 36 | 9 (25.0) | 3.28 (1.06–10.1) | 2.90 (0.90–9.31) | |||
Smear result of source case (n = 99) | Negative | 9 | 0 (0) | - | 0.35 | ||
Positive | 90 | 15 (16.7) | - | ||||
Smear grade of source case (n = 98) | Negative | 9 | 0 (0) | - | 0.05 | ||
Scanty | 8 | 0 (0) | - | ||||
1+ | 15 | 5 (33.3) | - | ||||
2+ | 44 | 9 (20.5) | - | ||||
3+ | 22 | 1 (4.5) | - | ||||
HIV status of source case (n = 99) | Negative | 79 | 8 (10.1) | 1 | 0.009 | 1 | 0.03 |
Positive | 20 | 7 (35.0) | 4.78 (1.45–15.5) | 4.07 (1.19–13.8) | |||
CD4 count of source case if HIV-positive (n = 18) | <200 | 7 | 3 (42.9) | 1 | 0.78 | ||
>200 | 11 | 4 (36.4) | 0.76 (0.11–5.28) | ||||
Relationship of source case to child | Parents | 38 | 5 (13.2) | 1 | 0.62 | ||
Grandparent | 15 | 4 (26.7) | 2.4 (0.55–10.6) | ||||
Uncle or aunt | 33 | 4 (12.1) | 0.91 (0.22–3.71) | ||||
Other | 16 | 2 (12.5) | 0.94 (0.16–5.45) | ||||
Duration of exposure between source case and child | Less than a month | 13 | 3 (23.1) | 1 | 0.35 | ||
One month to six months | 38 | 7 (18.4) | 0.75 (0.16–3.47) | ||||
More than six months | 51 | 5 (9.8) | 0.36 (0.07–1.77) | ||||
Primary caregiver to child | Index case | 21 | 2 (9.5) | 1 | 0.46 | ||
Not index case | 81 | 13 (16.0) | 1.82 (0.38–8.76) | ||||
Frequency of contact between source case and child | Daily | 93 | 12 (12.9) | 1 | 0.12 | ||
Less frequently | 9 | 3 (33.3) | 3.38 (0.74–15.3) | ||||
Intensity of contact between child and source case | Sleeps in the same bed | 25 | 3 (12.0) | 1 | 0.47 | ||
Sleeps in the same room | 13 | 1 (7.7) | 0.61 (0.06–6.54) | ||||
Sleeps in the same house | 45 | 6 (13.3) | 1.13 (0.26–4.96) | ||||
Sleeps in a different house | 19 | 5 (26.3) | 2.62 (0.54–12.7) |