Table 2.
Characteristics of All Infants and Infants With An Invasive Culture for Staphylococcus aureusa
| Characteristic | MSSA (N=2825) |
MRSA (N=1063) |
P Value |
|---|---|---|---|
| Gestational age, weeks | .72 | ||
| <25 | 723 (26) | 270 (25) | |
| 26–28 | 966 (34) | 345 (32) | |
| 29–32 | 660 (23) | 2659 (24) | |
| 33–36 | 253 (9) | 107 (10) | |
| ≥37 | 219 (8) | 82 (8) | |
| Birth weight, g | .42 | ||
| <1000 | 1480 (52) | 528 (50) | |
| 1000–1499 | 689 (24) | 284 (27) | |
| 1500–2499 | 387 (14) | 145 (14) | |
| 2500–3499 | 194 (7) | 82 (8) | |
| >3500 | 73 (3) | 24 (2) | |
| Apgar score | .24 | ||
| 0-3 | 147 (5) | 49 (5) | |
| 4-6 | 512 (19) | 215 (21) | |
| 7-10 | 2087 (76) | 762 (74) | |
| Race/ethnicity | <.001 | ||
| White | 1329 (49) | 467 (45) | |
| African American | 681 (25) | 330 (32) | |
| Hispanic | 564 (21) | 201 (19) | |
| Other | 151 (6) | 37 (4) | |
| Male | 1555 (55) | 575 (54) | .60 |
| Inborn | 2236 (80) | 783 (74) | <.001 |
| Cesarean section | 2033 (73) | 741 (71) | .16 |
| Small for gestational age | 541 (19) | 207 (20) | .84 |
| Congenital anomaly | 363 (13) | 150 (14) | .30 |
| Age at 1st positive culture, days |
.01 | ||
| <7 | 324 (11) | 123 (12) | |
| 7–14 | 659 (23) | 292 (27) | |
| 15–28 | 905 (32) | 348 (33) | |
| >28 | 937 (33) | 300 (28) | |
| Previous surgical procedure |
476 (17) | 186 (18) | .63 |
| Inotropic supportb | 0 (0, 2) | 0 (0, 2) | .61 |
| Oxygen supportb | 8 (1, 20) | 5 (1, 15) | <.001 |
| Ventilator supportb | 5 (0, 16) | 5 (1, 13) | .06 |
| Antibiotic exposureb | 4 (1, 11) | 4 (1, 10) | .62 |
| Anti-MRSA antibiotic exposureb |
0 (0, 4) | 0 (0, 3) | .52 |
Abbreviations: MRSA, methicillin-resistant S. aureus; MSSA, methicillin-susceptible S. aureus.
a
Except where indicated, data are presented as no. (%). Invasive cultures = blood, cerebrospinal fluid, abscess and sterile sites. For infants with more than one infection, only the first invasive infection was evaluated.
b
Median (25th, 75th percentiles) number of days with exposure prior to first invasive Staphylococcus aureus infection.