Check these definitions for wound and other infections

The Atlanta-based Centers for Disease Control and Prevention (CDC) has created concise definitions for a variety of nosocomial infections. Here are some sample definitions of what the CDC says should be observed before the patient is diagnosed as having a nosocomial infection:

Surgical wound infection

Surgical wound infection includes incisional surgical wound infection and deep surgical wound infection.

Incisional surgical wound infection must meet the following criteria: Infection occurs at incision site within 30 days after surgery AND involves skin, subcutaneous tissue, or muscle located above the fascial layer AND any of the following:

1. Purulent drainage from incision or drain located above fascial layer.

2. Organism isolated from culture of fluid from wound closed primarily.

3. Surgeon deliberately opens wound, unless wound is culture-negative.

4. Surgeon’s or attending physician’s diagnosis of infection.

Deep surgical wound infection must meet the following criterion: Infection occurs at operative site within 30 days after surgery if no implant* is left in place AND infection appears related to surgery, AND infection involves tissues or spaces at or beneath fascial layer AND any of the following:

1. Purulent drainage from drain placed beneath fascial layer.

2. Wound spontaneously dehisces or is deliberately opened by surgeon when patient has fever (>38° C) and/or localized pain or tenderness, unless wound is culture-negative.

3. An abscess or other evidence of infection seen on direct examination, during surgery, or by histopathologic examination.

4. Surgeon’s diagnosis of infection.

Urinary tract infection

Urinary tract infection includes symptomatic urinary tract infection, asymptomatic bacteriuria, and other infections in the urinary tract.

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

1. One of the following: fever (>38° C), urgency, frequency, dysuria, or suprapublic tenderness AND a urine culture of >105 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 (>10 white blood cells [WBC]/ml3 or >3 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 >102 colonies/ml urine in nonvoided specimens.

e. Urine culture with <105 colonies/ml urine of single uropathogen in patient being treated with appropriate antimicrobial therapy.

f. Physician’s diagnosis.

g. Physician institutes appropriate antimicrobial therapy.

3. Patient <12 months of age has one of the following: fever (>38 degrees C), hypothermia (<37 degrees C), apnea, bradycardia, dysuria, lethargy, or vomiting AND urine culture of >105 colonies/ml urine with no more than two species of organisms.

4. Patient <12 months of age has one of the following: fever (>38 degrees C), hypothermia (<37 degrees C), apnea, bradycardia, dysuria, lethargy, or vomiting, AND any of the following:

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

b. Pyuria.

c. Organisms seen on Gram stain of unspun urine.

d. Two urine cultures with repeated isolation of same uropathogen with >102 organisms/ml urine in nonvoided specimens.

e. Urine culture with <105 colonies/ml urine of a single uropathogen in patient being treated with appropriate antimicrobial therapy.

f. Physician’s diagnosis.

g. Physician institutes appropriate antimicrobial therapy.

Asymptomatic bacteriuria must meet either of the following criteria:

1. An indwelling urinary catheter is present within seven days before urine is cultured AND patient has no fever (>38 degrees C), urgency, frequency, dysuria, or suprapubic tenderness AND has urine culture of >105 organisms/ml urine with no more than two species of organisms.

2. No indwelling urinary catheter is present within seven days before the first of two urine cultures with >105 organisms/ml urine of the same organism with no more than two species of organisms, AND patient has no fever (>38 degrees C), urgency, frequency, dysuria, or suprapubic tenderness.

Lower respiratory tract infection (excluding pneumonia)

Lower respiratory tract infection (excluding pneumonia) includes infections such as bronchitis, tracheobronchitis, bronchiolitis, tracheitis, lung abscess, and empyema.

Bronchitis, tracheobronchitis, bronchiolitis, tracheitis, without evidence of pneumonia, must meet either of the following criteria:

1. Patient has no clinical or radiographic evidence of pneumonia AND has two of the following: fever (>38 degrees C), cough, new or increased sputum production, rhonchi, wheezing, AND either of the following:

a. Organism isolated from culture obtained by deep tracheal aspirate or bronchoscopy.

b. Positive antigen test on respiratory secretions.

2. Patient <12 months of age has no clinical or radiographic evidence of pneumonia AND has two of the following with no other recognized cause: fever (>38 degrees C), cough, new or increased sputum production, rhonchi, wheezing, respiratory distress, apnea, or bradycardia AND any of the following:

a. Organism isolated from culture of material obtained by deep tracheal aspirate or bronchoscopy.

b. Positive antigen test on respiratory secretions.

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

Other infections of the lower respiratory tract must meet one of the following criteria:

(1) Organisms seen on smear or isolated from culture of lung tissue or fluid, including pleural fluid.

(2) Lung abscess or empyema seen during surgery or by histopathologic examination.

(3) Abscess cavity seen on radiographic examination of lung.

*A nonhuman-derived implantable foreign body (e.g., prosthetic heart valve, nonhuman vascular graft, mechanical heart, or hip prosthesis) that is permanently placed in a patient during surgery.

**Gram-negative bacteria or S. saprophyticus.