Table 1.
Characteristics of Patients and Infection Pairs With Identical and Distinct Methicillin-Resistant Staphylococcus aureus Strains
| Patient Characteristics | Total N = 105 (%) |
Distinct N = 11 (%) |
Identical N = 94 (%) |
P |
|---|---|---|---|---|
| Female | 64/105 (61) | 6/11 (55) | 58/94 (62) | .75 |
| Age, years, median (range) | 1.8 (0.3–18.5) | 1.2 (0.6–17.2) | 1.9 (0.3–18.5) | .23 |
| Medicaid | 79/101 (78) | 9/10 (90) | 70/91 (77) | .69 |
| African-American race | 76/104 (73) | 10/11 (91) | 66/93 (71) | .28 |
| Weight for age >97%a | 18/101 (18) | 3/11 (27) | 15/90 (17) | .41 |
| Day care attendanceb | 28/76 (37) | 4/9 (44) | 24/67 (36) | .72 |
| Eczema | 24/104 (23) | 3/11 (27) | 21/93 (23) | .71 |
| Number of SSTI episodes, median (range) | 2 (2–7) | 3 (2–4) | 2 (2–7) | .04 |
| S. aureus Isolate Pair Characteristics | Total N = 143 (%) |
Distinct N = 11 (%) |
Identical N = 132 (%) |
P |
| Related body site of 2 infections in pair | 59/143 (41) | 2/11 (18) | 57/132 (43) | .12 |
| Interval between infections, days, median (range) | 127 (11–1645) | 212 (23–1121) | 124 (11–1645) | .09 |
| Antibiotic was prescribed for 1st infection in pair | 115/136 (85) | 7/10 (70) | 108/126 (86) | .19 |
| Antimicrobial therapy for 1st infection in pair | .96c | |||
| Clindamycin | 61/115 (54) | 4/7 (57) | 57/108 (53) | |
| Trimethoprim–sulfamethoxazole | 50/115 (44) | 3/7 (43) | 47/108 (44) | |
| Otherd | 3/115 (3) | 0/7 (0) | 3/108 (3) | |
| Unspecified | 1/115 (1) | 0/7 (0) | 1/108 (1) | |
| Prescribed antibiotic to which isolate was susceptible for 1st infection in pair | 101/136 (74) | 6/10 (60) | 95/126 (75) | .28 |
Abbreviation: SSTI, skin and soft-tissue infection.
aWeight for age was determined using the Centers for Disease Control and Prevention Growth Charts for the United States.
bChildren ≤5 years included, N = 76.
cχ2 test; all others analyzed by Mann–Whitney (continuous variables) or Fisher's exact test (categorical variables).
dOther antimicrobial therapy prescribed: ciprofloxacin (1), amoxicillin–clavulanate (2).