Table 4.
Cases, Annual Incidence Rates, and Rate Ratios of the Most Serious Group B Streptococcus Infections by Patient Characteristicsa
| Patient Characteristics | Patients Aged 18–64 y | Patients Aged ≥65 y | Patients Aged ≥18 y | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Cases | Annual Rate per 100 000 | Rate Ratio (95% CI) | Cases | Annual Rate per 100 000 | Rate Ratio (95% CI) | Cases | Annual Rate per 100 000 | Rate Ratio (95% CI) | |
| All patients | 542 | 68 | … | 142 | 100 | … | 684 | 73 | … |
| Demographics | |||||||||
| Year of study | |||||||||
| 2014 | 136 | 52 | 1.0 | 49 | 109 | 1.0 | 185 | 60 | 1.0 |
| 2015 | 203 | 72 | 1.4 (1.1–1.7) | 45 | 95 | .9 (.6–1.3) | 248 | 82 | 1.4 (1.1–1.6) |
| 2016 | 203 | 82 | 1.6 (1.3–2.0) | 48 | 104 | .9 (.6–1.4) | 251 | 78 | 1.3 (1.1–1.6) |
| Sex | |||||||||
| Female | 259 | 64 | 1.0 | 74 | 91 | 1.0 | 333 | 69 | 1.0 |
| Male | 283 | 72 | 1.1 (.9–1.3) | 68 | 112 | 1.2 (.8–1.6) | 351 | 77 | 1.1 (1.0–1.3) |
| Raceb | |||||||||
| White | 346 | 54 | 1.0 | 112 | 89 | 1.0 | 458 | 60 | 1.0 |
| Black | 178 | 152 | 2.8 (2.3–3.4) | 27 | 199 | 2.2 (1.5–3.4) | 205 | 157 | 2.6 (2.2–3.1) |
| Other | 18 | 40 | .7 (.5–1.2) | 2 | … | … | 20 | 41 | .7 (.4–1,1) |
| Ethnicityc | |||||||||
| Not Hispanic or Latino | 525 | 69 | 1.0 | 139 | 98 | 1.0 | 664 | 74 | 1.0 |
| Hispanic or Latino | 16 | 41 | .6 (.4–1.0) | 1 | … | … | 17 | 43 | .6 (.4–.9) |
| Body mass indexd | |||||||||
| Underweight | 16 | 132 | 3.4 (1.9–6.0) | 7 | … | ... | 23 | 170 | 3.8 (2.4–6.1) |
| Normal weight | 115 | 39 | 1.0 | 31 | 102 | 1.0 | 146 | 45 | 1.0 |
| Overweight | 117 | 45 | 1.1 (.9–1.5) | 35 | 77 | .8 (.5–1.2) | 153 | 50 | 1.1 (.9–1.4) |
| Obesity | 330 | 117 | 3.0 (2.4–3.8) | 72 | 232 | 2.3 (1.5–3.5) | 402 | 129 | 2.9 (2.4–3.5) |
| Class 1 | 119 | 77 | 2.0 (1.5–2.6) | 33 | 161 | 1.6 (1.0–2.6) | 152 | 87 | 1.9 (1.5–2.5) |
| Class 2 | 83 | 111 | 2.8 (2.1–3.8) | 20 | 308 | 3.0 (1.7–5.3) | 103 | 126 | 2.8 (2.2–3.7) |
| Class 3 | 128 | 247 | 6.3 (4.9–8.2) | 19 | 476 | 4.6 (2.6–8.3) | 147 | 263 | 5.9 (4.6–7.4) |
| Chronic medical conditions | |||||||||
| Diabetes mellitus | |||||||||
| No | 216 | 30 | 1.0 | 66 | 60 | 1.0 | 282 | 34 | 1.0 |
| Yes | 326 | 486 | 16.1 (13.5–19.1) | 76 | 240 | 4.0 (2.9–5.6) | 402 | 409 | 12.0 (10.3–14.0) |
| Chronic renal disease | |||||||||
| No | 441 | 57 | 1.0 | 95 | 72 | 1.0 | 536 | 59 | 1.0 |
| Yes | 100 | 401 | 7.0 (5.6–8.7) | 47 | 473 | 6.6 (4.7–9.4) | 147 | 421 | 7.1 (5.9–8.5) |
| Coronary artery disease | |||||||||
| No | 460 | 60 | 1.0 | 81 | 70 | 1.0 | 541 | 62 | 1.0 |
| Yes | 82 | 279 | 4.6 (3.7–5.8) | 61 | 236 | 3.4 (2.4–4.7) | 143 | 259 | 4.2 (3.5–5.1) |
| Stroke | |||||||||
| No | 503 | 65 | 1.0 | 112 | 89 | 1.0 | 615 | 68 | 1.0 |
| Yes | 39 | 165 | 2.5 (1.8–3.5) | 30 | 181 | 2.0 (1.4–3.0) | 69 | 171 | 2.5 (1.9–3.2) |
| COPD | |||||||||
| No | 491 | 67 | 1.0 | 112 | 94 | 1.0 | 603 | 70 | 1.0 |
| Yes | 51 | 86 | 1.3 (1.0–1.7) | 30 | 129 | 1.4 (.9–2.1) | 81 | 98 | 1.4 (1.1–1.8) |
| Neoplasm | |||||||||
| No | 515 | 67 | 1.0 | 132 | 114 | 1.0 | 647 | 73 | 1.0 |
| Yes | 27 | 86 | 1.3 (.9–1.9) | 10 | 39 | .3 (.2–.7) | 37 | 66 | .9 (.6–1.3) |
| Health behaviors | |||||||||
| Current smoker | |||||||||
| No | 353 | 58 | 1.0 | 127 | 100 | 1.0 | 480 | 65 | 1.0 |
| Yes | 189 | 98 | 1.7 (1.4–2.0) | 15 | 100 | 1.0 (.6–1.7) | 204 | 98 | 1.5 (1.3–1.8) |
| Alcoholism | |||||||||
| No | 511 | 69 | 1.0 | 136 | 99 | 1.0 | 647 | 74 | 1.0 |
| Yes | 31 | 56 | .8 (.6–1.2) | 6 | … | … | 37 | 60 | .8 (.6–1.1) |
Abbreviations: CI, confidence interval; COPD, chronic obstructive pulmonary disease.
aIf group B Streptococcus (GBS) was isolated from >1 clinical site in the same patient, the most life-threatening or deepest site of infection was considered the most serious infected site. Rates were not calculated if the number of GBS cases was <10.
bRace was missing for 3 patients.
cEthnicity was missing for 7 patients.
dUnderweight was defined as body mass index (BMI; calculated as weight in kilograms divided by height in meters squared) <18.5, normal weight as BMI 18.5–24.9, overweight as BMI 25.0–29.9, obesity as BMI ≥30.0, class 1 obesity as BMI 30.0–34.9, class 2 obesity as BMI 35.0–39.9, and class 3 obesity as BMI ≥40.0; BMI was missing for 8 patients.