Volume 22, Number 7—July 2016
Dispatch
Increased Mortality Rates Associated with Staphylococcus aureus and Influenza Co-infection, Maryland and Iowa, USA1
Table 1
Characteristics of patients in cohorts demonstrating increased mortality rates associated with Staphylococcus aureus and influenza co-infection, Maryland and Iowa, USA*
Characteristic | Positive influenza test, n = 32 | Negative influenza test, n = 163 | Odds ratio 95% CI | p value |
---|---|---|---|---|
Female sex | 12 (38) | 67 (41) | 0.86 (0.39–1.88) | 0.704 |
Age ≥18 y | 24 (75) | 112 (69) | 1.37 (0.58–3.25) | 0.479 |
Hospital admission within previous 12 mo | 12 (38) | 75 (46) | 0.70 (0.32–1.53) | 0.376 |
Previous MRSA infection or colonization |
4 (13) |
33 (20) |
0.56 (0.18–1.72) |
0.307 |
Co-occurring conditions | ||||
Cancer | 3 (9) | 24 (15) | 0.60 (0.17–2.12) | 0.579 |
Cerebrovascular disease | 0 (0) | 6 (4) | UTD | 0.592 |
Chronic pulmonary disease | 11 (34) | 41 (25) | 1.56 (0.69–3.51) | 0.282 |
Heart disease | 4 (13) | 20 (12) | 1.02 (0.32–3.22) | 1.000 |
Diabetes | 6 (19) | 15 (9) | 2.28 (0.81–6.41) | 0.123 |
Liver disease | 0 (0) | 6 (4) | UTD | 0.592 |
Renal disease | 5 (16) | 8 (5) | 3.59 (1.09–11.79) | 0.042 |
Charlson Comorbidity Index score, median (IQR) |
1 (0–2) |
1 (0–3) |
0.89 (0.75–1.07) |
0.641 |
Methicillin resistance | ||||
MRSA | 16 (50) | 93 (57) | 0.75 (0.35–1.61) | 0.462 |
MSSA | 15 (47) | 66 (40) | 1.30 (0.61–2.78) | 0.503 |
Unknown |
1 (3) |
4 (2) |
1.28 (0.14–11.86) |
1.000 |
First positive S. aureus culture collected ≤2 d after hospital admission |
24 (75) |
78 (48) |
3.27 (1.39–7.70) |
0.005 |
Year of first positive S. aureus culture | 0.038 | |||
2003 | 1 (3) | 3 (2) | Reference | |
2004 | 1 (3) | 10 (6) | 0.30 (0.01–6.38) | |
2005 | 7 (22) | 25 (15) | 0.84 (0.08–9.38) | |
2006 | 0 (0) | 25 (15) | UTD | |
2007 | 2 (6) | 14 (9) | 0.43 (0.03–6.41) | |
2008 | 12 (38) | 26 (16) | 1.39 (0.13–14.73) | |
2009 |
9 (28) |
60 (37) |
0.45 (0.04–4.81) |
|
Antimicrobial drugs received | ||||
Vancomycin | 25 (78) | 128 (79) | 0.98 (0.39–2.44) | 0.960 |
Linezolid | 7 (22) | 26 (16) | 1.48 (0.58–3.77) | 0.414 |
Quinolone | 19 (59) | 50 (31) | 3.30 (1.51–7.21) | 0.002 |
Macrolide | 13 (41) | 58 (36) | 1.24 (0.57–2.69) | 0.588 |
Aminoglycoside | 2 (6) | 41 (25) | 0.20 (0.05–0.87) | 0.018 |
Cephalosporin |
20 (63) |
105 (64) |
0.92 (0.42–2.02) |
0.836 |
30-d in-hospital deaths |
9 (28) |
18 (11) |
3.15 (1.27–7.86) |
0.021 |
*Values are no. (%) patients except as indicated. MRSA, methicillin-resistant Staphylococcus aureus; UTD; unable to determine because calculation includes zero; IQR; interquartile range; MSSA, methicillin-susceptible S. aureus. |
1Presented in part at ID Week, October 17-21, 2012, San Diego, CA, USA. Abstract 36846.
2Current affiliation: Infectious Disease Specialists, P.C., Sioux Falls, South Dakota, USA.