Table 1.
Characteristics of Cases of Invasive Staphylococcus aureus Disease, May 2016–April 2018
| Characteristic | Year 1 | Year 2 | Total |
|---|---|---|---|
| (05/16–04/17) | (05/17–04/18) | (05/16–04/18) | |
| N (%) | N (%) | N (%) | |
| Number of cases | 24 | 29 | 53 |
| Demographic Characteristics | |||
| Male | 15 (62.5) | 20 (69.0) | 35 (66.0) |
| Age | |||
| <1 year | 0 | 0 | 0 |
| 1–17 years | 2 (8.3) | 3 (10.3) | 5 (9.4) |
| 18–39 years | 6 (25.0) | 9 (31.0) | 15 (28.3) |
| 40–49 years | 5 (20.8) | 6 (20.7) | 11 (20.8) |
| 50–64 years | 10 (41.7) | 10 (34.5) | 20 (37.7) |
| ≥65 years | 1 (4.2) | 1 (3.4) | 2 (3.8) |
| Body mass indexa | |||
| <25 | 3 (13.6) | 6 (25.0) | 9 (19.6) |
| 25–29 | 7 (31.8) | 8 (33.3) | 15 (32.6) |
| ≥30 | 12 (54.5) | 10 (41.7) | 22 (47.8) |
| Type of infection | |||
| HO | 0 (0.0) | 1 (3.4) | 1 (1.9) |
| HACO | 15 (62.5) | 23 (79.3) | 38 (71.7) |
| CA | 9 (37.5) | 5 (17.2) | 14 (26.4) |
| Healthcare and Clinical Characteristics | |||
| Healthcare Exposures | |||
| Dialysis in past year | 2 (8.3) | 1 (3.4) | 3 (5.7) |
| Surgery in past year | 6 (25.0) | 13 (44.8) | 19 (35.8) |
| Hospitalized in past year | 14 (58.3) | 22 (75.9) | 36 (67.9) |
| Long-term care in past year | 3 (12.5) | 4 (13.8) | 7 (13.2) |
| Vascular catheter in past 2 days | 1 (4.2) | 2 (6.9) | 3 (5.7) |
| Underlying Conditionsb | |||
| Diabetes | 12 (50.0) | 14 (48.3) | 26 (49.1) |
| Alcoholism | 11 (45.8) | 12 (41.4) | 23 (43.4) |
| Obesity | 12 (50.0) | 10 (34.5) | 22 (41.5) |
| Hypertension | 5 (20.8) | 10 (34.5) | 15 (28.3) |
| Abscess/boil | 4 (16.7) | 3 (10.3) | 7 (13.2) |
| Chronic skin breakdown | 1 (4.2) | 6 (20.7) | 7 (13.2) |
| Chronic renal insufficiency | 2 (8.3) | 4 (13.8) | 6 (11.3) |
| Malignancy | 2 (8.3) | 3 (10.3) | 5 (9.4) |
| Asthma | 3 (12.5) | 2 (6.9) | 5 (9.4) |
| Chronic liver disease | 1 (4.2) | 3 (10.3) | 4 (7.5) |
| Decubitis/pressure ulcer | 0 | 4 (13.8) | 4 (7.5) |
| Chronic pulmonary disease | 1 (4.2) | 2 (6.9) | 3 (5.7) |
| Current smoker | 2 (8.3) | 1 (3.4) | 3 (5.7) |
| Myocardial infarction | 1 (4.2) | 1 (3.4) | 2 (3.9) |
| Atherosclerosis/vascular disease | 1 (4.2) | 1 (3.4) | 2 (3.8) |
| Stroke | 1 (4.2) | 1 (3.4) | 2 (3.8) |
| Congestive heart failure | 0 | 1 (3.4) | 1 (1.9) |
| Dementia | 1 (4.2) | 0 | 1 (1.9) |
| HIV/AIDS | 0 | 0 | 0 |
| Intravenous drug use | 0 | 0 | 0 |
| Other | 5 (20.8) | 6 (20.7) | 11 (20.8) |
| Any underlying condition | 23 (95.8) | 23 (79.3) | 46 (86.8) |
| Charlson index, median (range) | 2 (0–5) | 2 (0–9) | 2 (0–9) |
| Disease Syndrome(s)b | |||
| Bloodstream infection (BSI)c | 23 (95.8) | 23 (79.3) | 46 (86.8) |
| Implant involved (vascular catheter in past 2 days or other implant involved) | 2 (9.7) | 2 (8.7) | 4 (8.7) |
| BSI with other focusd | 20 (87.0) | 19 (82.6) | 39 (84.8) |
| BSI without other focus | 1 (4.3) | 2 (8.7) | 3 (6.5) |
| Pneumoniae | 4 (16.7) | 4 (13.8) | 8 (15.1) |
| Cellulitis or abscessf | 9 (37.5) | 7 (24.1) | 16 (30.2) |
| Osteomyelitisg | 9 (37.5) | 11 (37.9) | 20 (37.7) |
| Arthritis, joint infection, bursitish | 0 | 2 (6.9) | 2 (3.8) |
| Pericarditis or endocarditisi | 0 | 1 (3.4) | 1 (1.9) |
| Urinary tract infectionf | 0 | 0 | 0 |
| Necrotizing fasciitisf | 0 | 1 (3.4) | 1 (1.9) |
| Surgical site infectionj,d | 2 (8.3) | 4 (13.8) | 6 (11.3) |
| Other | 4 (16.7) | 16 (55.2) | 20 (37.7) |
| Prior infections: any SA | 15 (62.5) | 16 (55.2) | 31 (58.5) |
| Prior infections: any MRSA | 10 (41.7) | 15 (51.7) | 25 (47.2) |
| Current infection: MRSA | 18 (75.0) | 22 (75.9) | 40 (75.5) |
| Outcomes | |||
| Hospitalization during case event | 23 (95.8) | 24 (82.8) | 47 (88.7) |
| Amputation | 2 (8.3) | 2 (6.9) | 4 (7.5) |
| Deathk | 1 (4.2) | 3 (10.7) | 4 (7.7) |
Abbreviations: AIDS, acquired immune deficiency syndrome; CA, community-associated; HACO, healthcare-associated community-onset; HIV, human immunodeficiency virus; HO, hospital-onset; MRSA, methicillin-resistant Staphylococcus aureus; SA, Staphylococcus aureus.
aAmong cases ≥18 years of age.
bMultiple categories per case are possible.
cDefined as SA isolated from blood.
dSee Supplemental Table 1 for more details.
eDefined based on reported diagnosis in medical record or SA isolated from pleural fluid.
fDefined based on reported diagnosis in medical record.
gDefined based on reported diagnosis in medical record or SA isolated from bone.
hDefined based on reported diagnosis in medical record or SA isolated from synovial fluid.
iDefined based on reported diagnosis in medical record or SA isolated from pericardial fluid.
jDefined by review of medical record if SA was isolated from the site of a prior surgical procedure occurring at any time before the date of culture.
kTwo additional cases died at 33 and 34 days after the date of culture; for one case, the vital status after 30 days was unknown.