Clinical features and outcome of Staphylococcus aureus infection in elderly versus younger adult patients.
OBJECTIVE
The purpose of this study was to more clearly determine whether the clinical features and outcomes of Staphylococcus aureus infections are different in elderly patients as compared with younger adults.


METHODS
Patients included in the database from our previous surveillance study on S. aureus infections were stratified into two groups by age: those 65 years or older were considered 'elderly' and those aged 16 to 64 years were defined as 'younger'.


RESULTS
Of 4334 patients with an S. aureus infection, 1546 (35.7%) were classified as elderly. Nosocomial infections were more prevalent in the elderly group (55.2% vs. 42.8%, p<0.001), while community-associated infections were more common in the younger group (19.0% vs. 33.5%, p<0.001). Elderly patients were more likely to have underlying diseases and co-morbid conditions. Pneumonia was the most common S. aureus infection in the elderly group and skin and soft tissue infection was the most common in the younger group. The 30-day mortality rate among elderly patients was more than twice as high as that in younger patients (22.7% vs. 8.7%, p<0.001). Old age (≥65 years) was confirmed to be a strong independent risk factor for death in the entire study population (adjusted odds ratio 1.66; 95% confidence interval 1.32-2.08; p<0.001), after adjustment for confounding variables.


CONCLUSIONS
Our study showed that the clinical features of elderly patients with S. aureus infection differed substantially from those of younger patients in terms of underlying diseases, co-morbid conditions, types of infection, and outcomes.
Division of Infectious Diseases, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon-dong, Gangnam-gu, Seoul, 135-710, Republic of Korea.
Cheol-In
CI
Kang
Jae-Hoon
JH
Song
Kwan Soo
KS
Ko
Doo Ryeon
DR
Chung
Kyong Ran
KR
Peck
D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001208:Asia / Q000453:epidemiology; D015331:Cohort Studies; D017714:Community-Acquired Infections / Q000453:epidemiology; D015897:Comorbidity; D003428:Cross Infection / Q000453:epidemiology; D018563:Disease Notification; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009026:Mortality; D011023:Pneumonia, Staphylococcal / Q000453:epidemiology; D011159:Population Surveillance; D011446:Prospective Studies; D012307:Risk Factors; D013203:Staphylococcal Infections / Q000453:epidemiology*; D013211:Staphylococcus aureus; D055815:Young Adult