Table 2.
Unconditional logistic regression analysis of child, parental, domestic and environmental characteristics associated with S. aureus colonisation in Umtata participants
| Explanatory variable | Colonised a, n (%) | Not colonised, n (%) | OR [95% CI] | p-value | aOR [95% CI] | p-value |
|---|---|---|---|---|---|---|
| AD: case | 31 (28) | 27 (24) | 7.54 [2.92–19.47] | 0.000 | 8.02 [1.28–50.37] | 0.026 |
| Sex: male | 21 (19) | 46 (42) | 0.74 [0.33–1.67] | 0.469 | 0.83 [0.32–2.16] | 0.696 |
| Child characteristics | ||||||
| Breastfeeding | 10 (9) | 25 (23) | 0.69 [0.29–1.63] | 0.395 | 1.46 [0.48–4.47] | 0.503 |
| Allergic rhinitis | 1 (1) | 6 (7) | 0.43 [0.05–3.79] | 0.449 | Excluded | |
| Asthma § | 0 (0) | 0 (0) | Omitted d | Excluded | ||
| Food allergy | 5 (5) | 6 (5) | 1.69 [0.48–5.95] | 0.413 | Excluded | |
| Mode of delivery: vaginal | 29 (26) | 57 (51) | 0.9 [0.36–2.29] | 0.833 | Excluded | |
| Incomplete immunisation status | 2 (2) | 2 (2) | 1.97 [0.27–14.58] | 0.506 | Excluded | |
| Antibiotic exposure | 33 (30) | 58 (52) | 1.71 [0.57–5.12] | 0.34 | 1.54 [0.39–6] | 0.536 |
| Large family size b | 15 (14) | 35 (32) | 0.71 [0.32–1.57] | 0.395 | 0.94 [0.36–2.44] | 0.903 |
| Animal exposure c | 27 (24) | 65 (59) | 0.3 [0.11–0.83] | 0.021 | 0.53 [0.11–2.54] | 0.429 |
| Fossil fuel exposure | ||||||
| Electricity + gas | 31 (28) | 38 (34) | 4.08 [1.59–10.44] | 0.003 | 0.35 [0.05–2.47] | 0.295 |
| Kerosene + paraffin | 28 (25) | 36 (32) | 2.88 [1.22–6.77] | 0.015 | 0.69 [0.19–2.49] | 0.571 |
| Indoor fire | 1 (1) | 3 (3) | 0.63 [0.06–6.27] | 0.694 | Excluded | |
| Outdoor fire | 10 (9) | 39 (35) | 0.31 [0.13–0.73] | 0.008 | 0.54 [0.17–1.67] | 0.283 |
| Wood + coal | 3 (3) | 28 (25) | 0.14 [0.04–0.49] | 0.002 | 0.14 [0.02–0.99] | 0.048 |
| Maternal factors | ||||||
| Allergic rhinitis | 0 (0) | 4 (4) | Omitted d | Excluded | ||
| Asthma | 1 (1) | 1 (1) | 1.95 [0.12–32] | 0.641 | Excluded | |
| Atopic dermatitis | 1 (1) | 1 (1) | 1.95 [0.12–32] | 0.641 | Excluded | |
| Food allergy | 1 (1) | 2 (2) | 0.96 [0.08–10.93] | 0.973 | Excluded | |
| Smoking | 0 (0) | 1 (1) | Omitted | Excluded | ||
| Pregnant smoker | 0 (0) | 1 (1) | Omitted | Excluded | ||
| Animal exposure c | 31 (28) | 65 (59) | 0.55 [0.18–1.64] | 0.28 | 1.93 [0.37–10.16] | 0.438 |
| Paternal factors | ||||||
| Allergic rhinitis § | 0 (0) | 3 (3) | Omitted | Excluded | ||
| Asthma § | 1 (1) | 2 (2) | 0.96 [0.08–10.93] | 0.973 | Excluded | |
| Atopic dermatitis § | 0 (0) | 1 (1) | Omitted | Excluded | ||
| Food allergy § | 0 (0) | 1 (1) | Omitted | Excluded | ||
| Smoking | 5 (5) | 10 (9) | 0.94 [0.3–2.98] | 0.267 | Excluded | |
AD atopic dermatitis, OR odds ratio, aOR adjusted odds ratio, CI confidence interval; § No within group variance; a Colonisation with Staphylococcus aureus; b Large family size is arbitrarily defined as 7 or more members within a household; c Animal exposure refers to farm animals; d Independent variables omitted due to dependency in the regression model