APPENDIX 2

Listeria monocytogenes instances of cross contamination during delivery or in the nursery. Disease Agent: At-Risk Populations: • monocytogenes • Pregnant women, newborns, and the elderly Disease Agent Characteristics: • Immunosuppressed transplant recipients and other individuals with impaired cellular immunity, includ- • Gram-positive, facultatively anaerobic, motile, ing those with HIV infection nonspore-forming, facultatively intracellular rod- • Individuals with chronic liver disease, diabetes, or shaped bacterium transfusional iron overload • Order: ; Family: Listeriaceae • Occupational risk for those who work with animals • Size: 0.4-0.5 mm ¥ 0.5-2 mm and silage (farmers, veterinarians, and others) • Nucleic acid: The genome of is 2905 kb of DNA. Vector and Reservoir Involved: • Growth enhanced by exposure to cold temperature and grows well at 4°C • No vector • Infected animals and food products derived from Disease Name: them serve as the reservoir. • Blood Phase: Priority Level: • Bacteremia without a primary source has been the • Scientific/Epidemiologic evidence regarding blood most common manifestation of listeriosis in compro- safety: Theoretical mised hosts. • Public perception and/or regulatory concern regard- • Asymptomatic bacteremia in platelet donors has ing blood safety: Absent been demonstrated. • Public concern regarding disease agent: Low Survival/Persistence in Blood Products: Background: • As an organism capable of growing at 4°C, L. monocy- • Stable in the population and most cases are sporadic togenes would be expected to grow in whole blood • Growing interest in this organism has resulted from and red blood cells, but experimental studies are foodborne outbreaks and concerns about food safety. lacking and it has not been isolated from these • Frequent cause of serious opportunistic septicemia products. and meningoencephalitis in at-risk populations • Several episodes of platelet contamination have been • Common veterinary pathogen reported, detected through quality control culture of apheresis platelets from asymptomatic donors. Common Human Exposure Routes:

• Most human listeriosis is a result of consumption of Transmission by Blood Transfusion: food contaminated with Listeria, including dairy • Theoretical; this is based on the occurrence of asymp- products, prepared meats and vegetables. Recovery tomatic or transient bacteremia and the ability of rates from 15-70% from many foods are documented, the organism to grow at 4°C or in platelets at room suggesting ingestion of the organism must be temperature. extremely common. • The organism is widespread in nature, found in soil, Cases/Frequency in Population: decaying vegetation, water and the fecal flora of many mammals. It has been found in the stool of 5% of well • Incidence of infection in the US (laboratory based): adults. 3.3 per million population per year • Other modes of transmission include from mother to Incubation Period: child transplacentally or through a colonized birth canal, via cross-infection in newborn nurseries, and • Acute gastroenteritis: 1-2 days (ingestion of 109 or transcutaneously after contact with infected animals. more organisms) • The incubation period for invasive disease is poorly Likelihood of Secondary Transmission: characterized but evidence from cases with recog- • Human-to-human transmission appears limited to nized ingestion suggests 11-70 days with a mean of vertical transmission from mother to fetus, and rare 31.

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Likelihood of Clinical Disease: • FDA-licensed tests currently in general use for bacte- riological quality control of apheresis platelets can • Often infection is asymptomatic or unrecognized, but detect this organism. L. monocytogenes will grow high-risk individuals develop severe systemic readily on blood enriched media and commercial manifestations. blood culture systems. Primary Disease Symptoms: • Serology: complicated by antigenic cross-reactivity with other and the possibility of having a • In healthy adults, the infection is mostly asymptom- culture-confirmed invasive disease without measur- atic, but gastrointestinal symptoms with mild fever able antibody production. Measurement of antibody may develop. Attack rates in foodborne outbreaks can to listeriolysin O has been used in outbreak settings. approach 75%. • Other research tests include PCR, real-time PCR, and • Septicemia, meningitis, and meningoencephalitis nucleic acid-based sequence amplification (NASBA) occur mostly in neonates, the elderly, patients with methods. defective cell-mediated immunity, and other high- risk patients. Currently Recommended Donor Deferral Period: • In pregnant women, inapparent infection in the • No FDA Guidance or AABB Standard exists. mother can manifest as abortion, stillbirth, and neo- • Prudent practice would be to defer donor until signs natal infection. and symptoms are gone and any course of treatment Severity of Clinical Disease: is complete.

• Ingestion of large numbers of organisms by healthy Impact on Blood Availability: people can result in self-limited, febrile gastroenteri- • Agent-specific screening question(s): Not applicable tis. • Laboratory test(s) available: Not applicable • Clinically recognized systemic disease is almost always severe in high-risk populations, but bacter- Impact on Blood Safety: emia with minimal clinical signs and symptoms can • Agent-specific screening question(s): Not applicable occur in healthy hosts. • Laboratory test(s) available: Not applicable Mortality: Leukoreduction Efficacy: • 10-30% in neonatal populations and among at-risk • Unknown populations with systemic disease Pathogen Reduction Efficacy for Plasma Derivatives: Chronic Carriage: • Specific data indicate that the multiple steps in the • Humans can carry L. monocytogenes asymptomati- fractionation process are robust and capable of inac- cally in the gastrointestinal tract for prolonged tivating and/or removing bacteria at concentrations periods. that may be present in plasma. • Intracellular organisms in macrophages may be able to survive for periods of time, but a role for chronic Other Prevention Measures: intracellular infection has not been established. • None Treatment Available/Efficacious: Suggested Reading: • Treatment with ampicillin with or without gentami- 1. Allain JP, Bianco C, Blajchman MA, Brecher ME, cin effective Busch M, Leiby D, Lin L, Stramer S. Protecting the • Trimethoprim-sulfmethoxazole is alternative agent blood supply from emerging pathogens: the role of pathogen inactivation. Transfus Med Rev 2005; Agent-Specific Screening Question(s): 19:110-26. • No specific question is in use. 2. Centers for Disease Control and Prevention. Prelimi- • No sensitive or specific question is feasible because of nary FoodNet data on the incidence of infection with the absence of recognizable risk factors. pathogens transmitted commonly through food— • Under circumstances of a common source outbreak, Selected sites, United States, 2003. Morb Mortal Wkly the need for specific donor screening questions Rep MMWR 2004;53:338-43. would need to be addressed. 3. Eder AF,Kennedy JM, Dy BA, Notari EP,Weiss JW, Fang CT, Wagner S, Dodd RY, Benjamin RJ; American Red Laboratory Test(s) Available: Cross Regional Blood Centers. Bacterial screening • No FDA-licensed blood donor screening test exists. of apheresis platelets and the residual risk of septic

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transfusion reactions: the American Red Cross expe- human platelet concentrates. Blood 1994;83:2698- rience (2004-2006). Transfusion 2007;47:1134-42. 706. 4. Guevara RE, Tormey MP,Nguyen DM, Mascola L. List- 8. Lorber B. Listeriosis. Clin Infect Dis 1997;24:1-9. eria monocytogenes in platelets: a case report. Trans- 9. McCullough J. Progress toward a pathogen-free blood fusion 2006;46:305-9. supply. Clin Infect Dis 2003;37:88-95. 5. Jaton K, Sahli R, Bille J. Development of polymerase 10. Vazquez-Boland JA, Kuhn M, Berche P,Chakraborty T, chain reaction assays for detection of Listeria mono- Domínguez-Bernal G, Goebel W, González-Zorn B, cytogenes in clinical cerebrospinal fluid samples. J Wehland J, Kreft J. Listeria pathogenesis and molecu- Clin Microbiol 1992;30:1931-6. lar virulence determinants. Clin Microbiol Rev 2001; 6. Jordan JA, Durso MB. Real-time polymerase chain 14:584-640. reaction for detecting bacterial DNA directly from 11. Walsh R, Gurevich I, Cunha BA. Listeria: a potential blood of neonates being evaluated for sepsis. J Mol cause of febrile transfusion reactions. J Hosp Infect Diagn 2005;7:575-81. 1993;24:81-2. 7. Lin L, Londe H, Janda JM, Hanson CV, Corash L. Pho- tochemical inactivation of pathogenic bacteria in

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