The incidence of community-acquired infections (CAs) and their relationship
to the incidence of nosocomial infections (NI), to our knowledge, is unkno
wn in elderly trauma patients. We prospectively collected data on 380 patie
nts greater than or equal to 65 years of age who were admitted >48 h to our
trauma center over a 2-year period. One hundred seventy-seven patients (47
%) developed an infection. A total of 147 (39%) patients were diagnosed wit
h an NI, and 67 (18%) were diagnosed with a CA. Of the 67 patients with CA,
37 (55%) went on to develop an NI. Patients with the combination of CA and
NI had the greatest mean ICU (28.6 days) and hospital length of stay (38.2
days). Mortality was increased significantly in patients with the combinat
ion of CA and NI (27%). Respiratory and genitourinary infections were the m
ost common CA. Patients with respiratory CAs accounted for the greatest pro
portion of NIs. Thus, community-acquired and nosocomial infections signific
antly increase morbidity and mortality in elderly patients post-injury. Pat
ients who present with a CA are at increased risk of acquiring an NI, which
is associated with the most significant increase in length of stay and mor
tality.