The donor of a blood product that is positive for bacteria on culture should be evaluated to identify the probable cause. Circumstances of the collection and the type of organism isolated can help guide the evaluation.


Differential diagnosis:

(1) false positive (contamination after collection or laboratory error)

(2) contamination with skin flora

(3) bacteremia associated with pneumonia, urinary tract infection, bacterial endocarditis, osteomyelitis or other infection

(4) subclinical chronic bacteremia with Yersinia non-pestis species, Salmonella, or Neisseria meningitidis

(5) subclinical bacteremia with bowel or other carcinoma (Streptococcus bovis, Clostridium septicum)

(6) bioterrorism attack


Because donors are screened for current health status the chance of donating with an active infection is low.


Bacteria that could indicate a bioterrorism attack:

(1) Bacillus anthracis

(2) Yersinia pestis

(3) Francisella tularensis

(4) Clostridium botulinum

The presence of multiple donors being affected is further evidence of an attack.


Features about the collection suggesting contamination with skin flora:

(1) failure to adequately clean the skin prior to collection

(2) contamination of cleaned skin prior to collection (such as by palpating the vein)

(3) skin disorder at the venipuncture site making cleaning difficult

(4) failure to use a diversion pouch system

(5) difficulty with the venipuncture or collection


Bacteria seen with skin contamination:

(1) coagulase negative Staphylococcus

(2) Corynebacterium species (diphtheroids), Propionibacterium acnes

(3) alpha hemolytic streptococci

(4) Bacillus species non-anthracis


Reasons to suspect infection in a donor:

(1) isolation of the same organism on a carefully collected blood culture from the donor

(2) history of a previous product donation with the same organism

(3) signs and symptoms of infection


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