Listeria monocytogenes in platelets: a case report.
BACKGROUND
Efforts to reduce bacterial contamination in platelets (PLTs) have led to implementation of tests for bacterial detection before product release. Although relatively rare as a human pathogen, Listeria monocytogenes often causes serious illness and has a case-fatality rate of 20 percent.


METHODS
PLTs from an asymptomatic 58- year-old Hispanic male with a long history of PLT donation were culture-positive for the presence of L. monocytogenes. The pulsed-field gel electrophoresis (PFGE) pattern of the isolate matched two other L. monocytogenes isolates in the CDC National PulseNet database. Public health investigation found no evidence that the other two isolates were epidemiologically related to the PLT donor, who remained asymptomatic.


CONCLUSIONS
A cluster of listeriosis cases was detected by PFGE but the significance is unknown. Organisms of public health significance should be reported to health departments. Better surveillance and reporting are needed in the efforts to improve blood product safety.
Guevara
Ramon E
RE
Acute Communicable Disease Control Program, Los Angeles County Department of Health Services, Los Angeles, California 90012, USA. rguevara@ladhs.org
Tormey
Michael P
MP
Nguyen
Dao M
DM
Mascola
Laurene
L
D000368:Aged; D001782:Blood Donors; D001792:Blood Platelets / Q000382:microbiology*; D005260:Female; D006801:Humans; D008089:Listeria monocytogenes / Q000302:isolation & purification*; D008088:Listeriosis / Q000097:blood / Q000175:diagnosis* / Q000635:transmission; D008297:Male; D008875:Middle Aged; D017713:Platelet Transfusion