Table 1 Characteristics of undocumented migrants and uninsured legal residents (N = 760) and determinants of nasal MRSA carriage, in Amsterdam, the Netherlands, October 2018–October 2019 (univariable logistic regression analyses with Firth’s correction)
|  | Total (N = 760) | MRSA-negative participants (N = 745) | MRSA-positive participants (N = 15) | Univariable associations | ||||
|---|---|---|---|---|---|---|---|---|
Sociodemographic variables | n | % | n | % | N | % | OR | 95%CI |
Sex | ||||||||
 Male | 442 | 58% | 431 | 58% | 11 | 73% | Ref |  |
 Female | 317 | 42% | 313 | 42% | 4 | 27% | 0.54 | 0.18–1.62 |
 Other | 1 | 0.1% | 1 | 0.1% | 0 | 0% | * | * |
Age in years, median (IQR) | 40 | (31–50) | 40 | (31–50) | 35 | (32–48) |  |  |
Age, categorized | ||||||||
  < 35 years | 249 | 33% | 243 | 33% | 6 | 40% | Ref |  |
 35–49 years | 302 | 40% | 295 | 40% | 7 | 47% | 0.95 | 0.33–2.76 |
 50–64 years | 183 | 24% | 181 | 24% | 2 | 13% | 0.52 | 0.12–2.25 |
  ≥ 65 years | 26 | 3% | 26 | 3% | 0 | 0% | 0.71 | 0.04–12.90 |
Kruispost target population | ||||||||
 Undocumented migrant | 705 | 93% | 691 | 93% | 14 | 93% | Ref |  |
 Uninsured legal resident | 55 | 7% | 54 | 7% | 1 | 7% | 1.31 | 0.24–7.21 |
Region of birth | ||||||||
 Europe | 36 | 5% | 36 | 5% | 0 | 0% | Ref |  |
 Asia | 229 | 30% | 222 | 30% | 7 | 47% | 2.46 | 0.14–44.01 |
 Africa | 267 | 35% | 261 | 35% | 6 | 40% | 1.81 | 0.10–32.89 |
 North/South America | 227 | 30% | 225 | 30% | 2 | 13% | 0.81 | 0.04–17.20 |
Educational level | ||||||||
 No school | 33 | 4% | 33 | 4% | 0 | 0% | Ref |  |
 Primary school | 129 | 17% | 125 | 17% | 4 | 27% | 2.40 | 0.13–45.74 |
 Secondary school | 320 | 42% | 314 | 42% | 6 | 40% | 1.38 | 0.08–25.13 |
 Higher education | 274 | 36% | 269 | 36% | 5 | 33% | 1.37 | 0.07–25.28 |
Migration history | ||||||||
Year of leaving country of origin, median (IQR) | 2011 | (2003–2016) | 2011 | (2003–2016) | 2016 | (2009–2016) |  |  |
Year of leaving country of origin, categorized | ||||||||
  < 2010 | 335 | 45% | 330 | 45% | 5 | 33% | Ref |  |
 2010–2017 | 329 | 44% | 321 | 44% | 8 | 53% | 1.59 | 0.54–4.69 |
  ≥ 2018 | 88 | 12% | 86 | 12% | 2 | 13% | 1.74 | 0.38–7.89 |
Years since leaving country of origin, median (IQR) | 8 | (3–16) | 8 | (3–16) | 3 | (3–10) | 0.98 | 0.93–1.04 |
Year of arrival in the Netherlands, median (IQR) | 2013 | (2006–2017) | 2013 | (2006–2017) | 2016 | (2012–2018) |  |  |
Year of arrival in the Netherlands | ||||||||
  < 2010 | 279 | 37% | 276 | 37% | 3 | 20% | Ref |  |
 2010–2017 | 308 | 41% | 300 | 41% | 8 | 53% | 2.23 | 0.64–7.84 |
  ≥ 2018 | 167 | 22% | 163 | 22% | 4 | 27% | 2.17 | 0.53–8.91 |
Years since arrival in the Netherlands, median (IQR) | 5 | (2–13) | 6 | (2–13) | 3 | (1–7) | 0.97 | 0.91–1.04 |
Way of entering the Netherlands | ||||||||
 Expired tourist/working/student visa | 406 | 54% | 398 | 54% | 8 | 53% | Ref |  |
 Rejected asylum seeker | 135 | 18% | 133 | 18% | 2 | 13% | 0.88 | 0.21–3.65 |
 EU citizen | 40 | 5% | 39 | 5% | 1 | 7% | 1.78 | 0.30–10.41 |
 Illegally crossing borders | 117 | 16% | 113 | 15% | 4 | 27% | 1.86 | 0.58–5.94 |
 Legally/other visa**/work | 37 | 5% | 37 | 5% | 0 | 0% | 0.63 | 0.04–11.04 |
 Other/unknown | 18 | 2% | 18 | 2% | 0 | 0% | 1.27 | 0.07–22.80 |
Housing situation (multiple answers possible) | ||||||||
 Lives in BBB facility | 56 | 7% | 55 | 7% | 1 | 7% | 1.29 | 0.23–7.07 |
 Lives with friends/family | 401 | 53% | 394 | 53% | 7 | 47% | 0.79 | 0.29–2.12 |
 Lives in illegal rent | 169 | 22% | 166 | 22% | 3 | 20% | 0.97 | 0.29–3.23 |
 Lives in housing provided by charity | 64 | 9% | 63 | 8% | 1 | 7% | 1.11 | 0.20–6.09 |
 Lives on the streets | 60 | 8% | 59 | 8% | 1 | 7% | 1.19 | 0.22–6.55 |
 Lives in other housing# | 51 | 7% | 49 | 7% | 2 | 13% | 2.61 | 0.66–10.36 |
Number of housemates | ||||||||
 No housemates | 105 | 14% | 103 | 14% | 2 | 13% | Ref |  |
  < 3 | 335 | 45% | 329 | 45% | 6 | 40% | 0.82 | 0.19–3.57 |
 3–5 | 228 | 31% | 223 | 30% | 5 | 33% | 1.02 | 0.22–4.63 |
  ≥ 6 | 79 | 11% | 77 | 11% | 2 | 13% | 1.34 | 0.23–7.90 |
Antibiotic use | ||||||||
Current antibiotic use | 38 | 5% | 36 | 5% | 2 | 13% | 3.55 | 0.88–14.25 |
Recent antibiotic use | ||||||||
 Current or < 3 months ago | 89 | 12% | 87 | 12% | 2 | 14% | Ref |  |
 3–6 months ago | 54 | 7% | 53 | 7% | 1 | 7% | 0.98 | 0.13–7.64 |
  > 6 months ago or never used antibiotics | 454 | 63% | 447 | 63% | 7 | 50% | 0.59 | 0.14–2.50 |
 Does not remember when last using antibiotics | 125 | 17% | 121 | 17% | 4 | 29% | 1.30 | 0.27–6.23 |
Other potential risk factors | ||||||||
Has been abroad for > 24 h in the past 6 months | 186 | 25% | 183 | 25% | 3 | 20% | 0.85 | 0.26–2.82 |
Ever admitted/treated in a foreign hospital | 268 | 36% | 265 | 36% | 3 | 20% | 0.50 | 0.15–1.65 |
Ever had surgery abroad | 254 | 33% | 250 | 34% | 4 | 27% | 0.77 | 0.26–2.33 |
Ever received a blood transfusion | ||||||||
 No/unknown | 717 | 94% | 703 | 94% | 14 | 93% | Ref |  |
 Yes | 43 | 6% | 42 | 6% | 1 | 7% | 1.71 | 0.31–9.46 |
Ever (been) paid for sex | ||||||||
 No, never | 613 | 81% | 600 | 81% | 13 | 87% | Ref |  |
 Yes, ever paid | 123 | 16% | 121 | 16% | 2 | 13% | 0.92 | 0.23–3.58 |
 Yes, ever been paid | 24 | 3% | 24 | 3% | 0 | 0% | 0.91 | 0.05–15.72 |
Ever injected drugs | 16 | 2% | 15 | 2% | 1 | 7% | 4.88 | 0.84–28.19 |