Table 1 Identified infections and the applied CDC definitions according to Garner et al. [14]

Respiratory tract infections

(n = 47; 29.4% of all patients)

RTI must meet one of the following criteria:

1. Rales or dullness to percussion on physical examination of chest AND any of the following:

a. New onset of purulent sputum or change in character of sputum

b. Organism isolated from blood culture

c. Isolation of pathogen from specimen obtained by transtracheal aspirate, bronchial brushing, or biopsy

2. Chest radiographic examination shows new or progressive infiltrate, consolidation, cavitation, or pleural effusion AND any of the following:

a. New onset of purulent sputum or change in character of sputum

b. Organism isolated from blood culture

c. Isolation of pathogen from specimen obtained by transtracheal aspirate, bronchial brushing, or biopsy

d. Isolation of virus or detection of viral antigen in respiratory secretions

e. Diagnostic single antibody titer (IgM) or fourfold increase in paired serum samples (IgG) for pathogen

f. Histopathologic evidence of pneumonia

Bloodstream infections

(includes laboratory-confirmed bloodstream infection and clinical sepsis)

(n = 12; 7.5% of all patients)

In our study we did not differ between primary and secondary bloodstream infections

Primary bloodstream infections:

Laboratory-confirmed bloodstream infection must meet one of the following criteria:

1. Recognized pathogen isolated from blood culture AND pathogen is not related to infection at another site

2. One of the following: fever (>38°C), chills, or hypotension AND any of the following:

a. Common skin contaminant isolated from two blood cultures drawn on separate occasions AND organism is not related to infection at another site; b. Common skin contaminant isolated from blood culture from patient with intravascular access device AND physician institutes appropriate antimicrobial therapy; c. Positive antigen test on blood AND organism is not related to infection at another site

Secondary bloodstream infections:

When an organism isolated from blood culture is compatible with a related nosocomial infection at another site, the bloodstream infection is classified as a secondary bloodstream infection. Exceptions to this are intravascular device-associated bloodstream infections, all of which are classified as primary

even if localized signs of infection are present at the access site.

Symptomatic urinary tract infection

(n = 6; 3.8% of all patients)

Symptomatic urinary tract infection must meet one of the following criteria:

1. One of the following: fever (>38°C), urgency, frequency, dysuria, or suprapubic tenderness AND a urine culture of > = 10^5 colonies/ml urine with no more than two species of organisms

2. Two of the following: fever (>38°C), urgency, frequency, dysuria, or suprapubic tenderness AND any of the following:

a. Dipstick test positive for leukocyte esterase and/or nitrate

b. Pyuria (310 white blood cells [WBC]/ml^3 or WBC/high-power field of unspun urine)

c. Organisms seen on Gram stain of unspun urine

d. Two urine cultures with repeated isolation of the same uropathogen with > = 10^2 colonies/ml urine in nonvoided specimens

e. Urine culture with < = 10^5 colonies/ml urine of single uropathogen in patient being treated with appropriate antimicrobial therapy

f. Physician's diagnosis

g. Physician institutes appropriate antimicrobial therapy

Encephalitis

(n = 5; 3.1% of all patients)

Encephalitis must meet one of the criteria:

1. Organism isolated from culture of brain tissue or dura

2. Two of the following with no other recognized cause: headache, dizziness, fever (>38°C), localizing neurologic signs, changing level of consciousness, or confusion, AND physician institutes appropriate antimicrobial therapy if diagnosis is made ante mortern AND any of the following:

a. Organism seen on microscopic examination of brain or abscess tissue obtained by needle aspiration or by biopsy during surgery or autopsy

b. Positive antigen test on blood or urine

c. Radiographic evidence of infection

d. Diagnostic single antibody titer (IgM) or fourfold increase in paired serum samples (IgG) for pathogen

Meningitis

(n = 1; 0.6% of all patients)

Meningitis must meet one of the following criteria:

1. Organism isolated from culture of cerebrospinal fluid (CSF)

2. One of the following with no other recognized cause: fever (>38°C), headache, stiff neck, meningeal signs, cranial nerve signs, or irritability, AND physician institutes appropriate antimicrobial therapy if diagnosis is made ante mortem AND any of the following:

a. Increased white cells, elevated protein, and/or decreased glucose in CSF

b. Organisms seen on Gram stain of CSF

c. Organism isolated from blood culture

d. Positive antigen test on CSF, blood, or urine

e. Diagnostic single antibody titer (IgM) or fourfold increase in paired serum samples (IgG) for pathogen