Table 2.
Characteristics of Household Contacts With Resistance to Mtb Infection (0 mm TST cutoff), for All Levels of Exposure and for Highly Exposed HHCs
| All Levels of Exposure | High Exposure | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Resistant | Not Resistant | Resistant | Not Resistant | |||||||||
| Total | % (column) | n | % (row) | n | % (row) | Total | % (column) | n | % (row) | n | % (row) | |
| Total | 572 | 71 | 12% | 501 | 88% | 263 | 26 | 10% | 237 | 90% | ||
| Qualitative exposure variable | ||||||||||||
| Low exposure | 75 | 13% | 18 | 24% | 57 | 76% | ||||||
| Medium exposure | 234 | 41% | 27 | 12% | 207 | 88% | ||||||
| High exposure | 263 | 46% | 26 | 10% | 237 | 90% | 263 | 26 | 10% | 237 | 90% | |
| HHC demographics | ||||||||||||
| Countrya | ||||||||||||
| Botswana | 28 | 5% | 10 | 36% | 18 | 64% | 15 | 6% | 5 | 33% | 10 | 67% |
| Brazil | 9 | 2% | 0 | 0% | 9 | 100% | 7 | 3% | 0 | 0% | 7 | 100% |
| Haiti | 38 | 7% | 3 | 8% | 35 | 92% | 19 | 7% | 1 | 5% | 18 | 95% |
| India | 159 | 28% | 16 | 10% | 143 | 90% | 68 | 26% | 7 | 10% | 61 | 90% |
| Kenya | 6 | 1% | 0 | 0% | 6 | 100% | 5 | 2% | 0 | 0% | 5 | 100% |
| Peru | 0 | 0 | - | 0 | - | 0 | - | 0 | 0 | - | ||
| South Africa | 304 | 53% | 29 | 10% | 275 | 90% | 145 | 55% | 12 | 8% | 133 | 92% |
| Thailand | 28 | 5% | 13 | 46% | 15 | 54% | 4 | 2% | 1 | 25% | 3 | 75% |
| Sex | ||||||||||||
| Male | 233 | 41% | 35 | 15% | 198 | 85% | 97 | 37% | 8 | 8% | 89 | 92% |
| Female | 339 | 59% | 36 | 11% | 303 | 89% | 166 | 63% | 18 | 11% | 148 | 89% |
| Age, y | ||||||||||||
| <15 | 113 | 20% | 18 | 16% | 95 | 84% | 38 | 14% | 4 | 11% | 34 | 89% |
| 15+ | 459 | 80% | 53 | 12% | 406 | 88% | 225 | 86% | 22 | 10% | 203 | 90% |
| Employed | ||||||||||||
| Yes | 145 | 25% | 17 | 12% | 128 | 88% | 69 | 26% | 9 | 13% | 60 | 87% |
| No | 425 | 74% | 54 | 13% | 371 | 87% | 193 | 73% | 17 | 9% | 176 | 91% |
| Refused | 2 | 0% | 0 | 0% | 2 | 100% | 1 | 0% | 0 | 0% | 1 | 100% |
| Highest education | ||||||||||||
| None | 107 | 19% | 15 | 14% | 92 | 86% | 49 | 19% | 7 | 14% | 42 | 86% |
| Primary | 207 | 36% | 23 | 11% | 184 | 89% | 93 | 35% | 7 | 8% | 86 | 92% |
| Secondary | 214 | 37% | 29 | 14% | 185 | 86% | 99 | 38% | 11 | 11% | 88 | 89% |
| College/University or higher | 44 | 8% | 4 | 9% | 40 | 91% | 22 | 8% | 1 | 5% | 21 | 95% |
| Relationship of index patient to HHC | ||||||||||||
| Spouse | 42 | 7% | 5 | 12% | 37 | 88% | 35 | 13% | 5 | 14% | 30 | 86% |
| Cohabitant | 34 | 6% | 7 | 21% | 27 | 79% | 15 | 6% | 4 | 27% | 11 | 73% |
| Child | 78 | 14% | 8 | 10% | 70 | 90% | 34 | 13% | 3 | 9% | 31 | 91% |
| Mother | 66 | 12% | 6 | 9% | 60 | 91% | 36 | 14% | 2 | 6% | 34 | 94% |
| Father | 40 | 7% | 2 | 5% | 38 | 95% | 16 | 6% | 1 | 6% | 15 | 94% |
| Sibling | 104 | 18% | 8 | 8% | 96 | 92% | 45 | 17% | 4 | 9% | 41 | 91% |
| Missing/other | 208 | 36% | 35 | 17% | 173 | 83% | 82 | 31% | 7 | 9% | 75 | 91% |
| Comorbidities | ||||||||||||
| HIV | ||||||||||||
| Positive | 45 | 8% | 5 | 11% | 40 | 89% | 26 | 10% | 3 | 12% | 23 | 88% |
| Negative | 444 | 78% | 50 | 11% | 394 | 89% | 208 | 79% | 18 | 9% | 190 | 91% |
| Missing | 83 | 15% | 16 | 19% | 67 | 81% | 29 | 11% | 5 | 17% | 24 | 83% |
| Diabetes | 19 | 3% | 2 | 11% | 17 | 89% | 9 | 3% | 2 | 22% | 7 | 78% |
| COPD | 7 | 1% | 0 | 0% | 7 | 100% | 3 | 1% | 0 | 0% | 3 | 100% |
| Asthma | 18 | 3% | 2 | 11% | 16 | 89% | 7 | 3% | 0 | 0% | 7 | 100% |
| HHC behavioral factors | ||||||||||||
| Ever smoke tobacco | 139 | 24% | 13 | 9% | 126 | 91% | 76 | 29% | 6 | 8% | 70 | 92% |
| Currently smoke tobacco | 116 | 20% | 12 | 10% | 104 | 90% | 64 | 24% | 5 | 8% | 59 | 92% |
| HHC use substancesb | 44 | 8% | 1 | 2% | 43 | 98% | 21 | 8% | 0 | 0% | 21 | 100% |
| HHC drank alcohol | 38 | 7% | 3 | 8% | 35 | 92% | 22 | 8% | 0 | 0% | 22 | 100% |
| Index patient characteristicsc | ||||||||||||
| Index patient’s cavitation | ||||||||||||
| Yes | 199 | 35% | 27 | 14% | 172 | 86% | 118 | 45% | 15 | 13% | 103 | 87% |
| No | 190 | 33% | 20 | 11% | 170 | 89% | 74 | 28% | 6 | 8% | 68 | 92% |
| Unknown | 183 | 32% | 24 | 13% | 159 | 87% | 71 | 27% | 5 | 7% | 66 | 93% |
| Index patient’s AFB resultd | ||||||||||||
| Negative | 229 | 40% | 27 | 12% | 202 | 88% | 58 | 22% | 5 | 9% | 53 | 91% |
| Scanty positive | 56 | 10% | 6 | 11% | 50 | 89% | 38 | 14% | 5 | 13% | 33 | 87% |
| (1+) | 52 | 9% | 4 | 8% | 48 | 92% | 33 | 13% | 1 | 3% | 32 | 97% |
| (2+) | 70 | 12% | 10 | 14% | 60 | 86% | 42 | 16% | 3 | 7% | 39 | 93% |
| (3+) | 120 | 21% | 16 | 13% | 104 | 87% | 83 | 32% | 8 | 10% | 75 | 90% |
| Unknown | 45 | 8% | 8 | 18% | 37 | 82% | 9 | 3% | 4 | 44% | 5 | 56% |
Abbreviations: AFB, acid-fast bacilli; COPD, chronic obstructive pulmonary disease; HHC, household contact; HIV, human immunodeficiency virus; Mtb, Mycobacterium tuberculosis; TST, tuberculin skin test.
a TST was not performed in Peru due to reagent shortage. All countries followed the same protocol, and there was no other substantial difference across countries in terms of study procedures.
b In the past 12 months, has the household contact used any other substances (eg, marijuana, cocaine, etc.).
c Based on testing before or at study enrollment, whichever result was highest.
d Numbers included in this section are of HHCs who have an index patient with given characteristic, not the number of index patients itself.