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Listeria monocytogenes in platelets: a case report
Ramon E Guevara1, Michael P Tormey, Dao M Nguyen
1Acute Communicable Disease Control Program, Los Angeles County Department of Health Services, Los Angeles, California 90012, USA. rguevara@ladhs.org
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.
Case Report:
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.
Conclusion:
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.
Insights
A platelet donor tested positive for Listeria monocytogenes, a bacterium causing severe illness. This finding highlights the need for improved blood product safety surveillance and reporting systems.
Area of Science:
- Microbiology
- Blood Transfusion Safety
- Infectious Disease Surveillance
Background:
- Bacterial contamination of platelet (PLT) products is a significant concern, prompting the implementation of pre-release testing.
- Listeria monocytogenes, though a rare pathogen, is associated with severe illness and a high mortality rate (20%).
Observation:
- A platelet donation from an asymptomatic individual tested positive for Listeria monocytogenes.
- Pulsed-field gel electrophoresis (PFGE) revealed the isolate matched two other Listeria monocytogenes strains in the national database.
- Despite the genetic match, public health investigations found no epidemiological link between the donor and the other cases.
Findings:
- A cluster of Listeria monocytogenes infections was identified through PFGE analysis.
- The clinical significance of this detected cluster remains undetermined.
- The asymptomatic carrier state in the platelet donor underscores potential challenges in routine screening.
Implications:
- This case emphasizes the critical need for enhanced surveillance and reporting mechanisms for organisms of public health significance.
- Improved blood product safety protocols are essential to mitigate the risk of transfusion-transmitted infections.
- The findings necessitate a re-evaluation of screening strategies for blood donors to detect potential pathogens like Listeria monocytogenes.
