Listeriosis in bone marrow transplant recipients: incidence, clinical features, and treatment

Listeria monocytogenes Infections in Hematopoietic Cell Transplantation Recipients: Clinical Manifestations and Risk Factors. A Multinational Retrospective Case-Control Study from the Infectious Diseases Working Party of the European Society for Blood and Marrow Transplantation

Listeriosis is rare after hematopoietic stem cell transplantation (HCT). Little is known about listeriosis in this population. In this retrospective international case-control study, we evaluated 41 listeriosis episodes occurring between 2000 and 2021 in HCT recipients (111 transplant centers in 30 countries) and assessed risk factors for listeriosis by comparisons with matched controls. The 41 listeriosis episodes (all due to Listeria monocytogenes [LM]) occurred in 30 allogeneic (allo)-HCT recipients and 11 autologous (auto)-HCT recipients at a median of 6.2 months (interquartile range [IQR], 1.6 to 19.3 months) post-HCT. The estimated incidence was 49.8/100,000 allo-HCT recipients and 13.7/100,000 auto-HCT recipients. The most common manifestations in our cohort were fever (n = 39; 95%), headache (n = 9; 22%), diarrhea, and impaired consciousness (n = 8 each; 20%). Four patients (10%) presented with septic shock, and 19 of 38 (50%) were severely lymphocytopenic. Thirty-seven patients (90%) had LM bacteremia. Eleven patients (27%) had neurolisteriosis, of whom 4 presented with nonspecific signs and 5 had normal brain imaging findings. Cerebrospinal fluid analysis revealed high protein and pleocytosis (mainly neutrophilic). Three-month mortality was 17% overall (n = 7), including 27% (n = 3 of 11) in patients with neurolisteriosis and 13% (n = 4 of 30) in those without neurolisteriosis. In the multivariate analysis comparing cases with 74 controls, non-first HCT (odds ratio [OR], 5.84; 95% confidence interval [CI], 1.10 to 30.82; P = .038); and lymphocytopenia <500 cells/mm3 (OR, 7.54; 95% CI, 1.50 to 37.83; P = .014) were significantly associated with listeriosis. There were no statistically significant differences in background characteristics, immunosuppression, and cotrimoxazole prophylaxis between cases and controls. HCT recipients are at increased risk for listeriosis compared to the general population. Listeriosis cause severe disease with septic shock and mortality. Neurolisteriosis can present with nonspecific signs and normal imaging. Lymphocytopenia and non-first HCT are associated with an increased risk of listeriosis, and cotrimoxazole was not protective.

Infections in Allogeneic Stem Cell Transplantation

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) has become a widely used modality of therapy for a variety of malignant and nonmalignant diseases. Despite advances in pharmacotherapy and transplantation techniques, infection remains one of the most severe and frequently encountered complications of allo-HSCT.

This chapter will address the risk factors for development of infection following allo-HSCT, including those related to the host, the conditioning regimen, and the graft, as well as the timing of opportunistic infections after allo-HSCT. The most common bacterial, viral, fungal, and parasitic infections, as well as issues surrounding their diagnostics and treatment, will be discussed. Finally, this chapter will address vaccination and other preventative strategies to be utilized when caring for patients undergoing allo-HSCT.

Central nervous system infections in cancer patients and hematopoietic stem cell transplant recipients

Central nervous system (CNS) infections in cancer patients present a diagnostic and therapeutic challenge for clinicians. While CNS infections are not frequent complications of cancer, its therapies, or hematopoietic stem cell transplantation, the importance of CNS infections lies in their propensity to result in profound morbidity and substantial mortality in this vulnerable patient population. With an expanding population of patients with malignant disease undergoing more potent and aggressive therapies and with the advent of newer immunomodulatory agents, the incidence of CNS infectious complications is likely to rise. This chapter will summarize the clinical and diagnostic evaluation of potential infections of the CNS in these patients and will discuss particular pathogens of interest with regard to this at-risk patient population.

Serving high-risk foods in a high-risk setting: survey of hospital food service practices after an outbreak of listeriosis in a hospital

BACKGROUND AND OBJECTIVES

Prepared ready-to-eat salads and ready-to-eat delicatessen-style meats present a high risk for Listeria contamination. Because no foodborne illness risk management guidelines exist specifically for US hospitals, a survey of New York City (NYC) hospitals was conducted to characterize policies and practices after a listeriosis outbreak occurred in a NYC hospital.

METHODS

From August through October 2008, a listeriosis outbreak in a NYC hospital was investigated. From February through April 2009, NYC's 61 acute-care hospitals were asked to participate in a telephone survey regarding food safety practices and policies, specifically service of high-risk foods to patients at increased risk for listeriosis.

RESULTS

Five patients with medical conditions that put them at high risk for listeriosis had laboratory-confirmed Listeria monocytogenes infection. The Listeria outbreak strain was isolated from tuna salad prepared in the hospital. Fifty-four (89%) of 61 hospitals responded to the survey. Overall, 81% of respondents reported serving ready-to-eat deli meats to patients, and 100% reported serving prepared ready-to-eat salads. Pregnant women, patients receiving immunosuppressive drugs, and patients undergoing chemotherapy were served ready-to-eat deli meats at 77%, 59%, and 49% of hospitals, respectively, and were served prepared ready-to-eat salads at 94%, 89%, and 73% of hospitals, respectively. Only 4 (25%) of 16 respondents reported having a policy that ready-to-eat deli meats must be heated until steaming hot before serving.

CONCLUSIONS

Despite the potential for severe outcomes of Listeria infection among hospitalized patients, the majority of NYC hospitals had no food preparation policies to minimize risk. Hospitals should implement policies to avoid serving high-risk foods to patients at risk for listeriosis.

Qualitative studies of the food safety knowledge and perceptions of transplant patients

Organ and stem cell transplant patients are at risk for foodborne illness due to disease and medically induced immunosuppression. The food safety knowledge and informational needs of these groups have not been documented in the literature. The objectives of this study were to assess transplant patients' food safety knowledge and perceptions, to probe the likelihood of practicing safe food handling behavior, and to test an educational strategy for future food safety interventions aimed at transplant patients. Subjects were organ or stem cell transplant patients, or their family care providers. Research was conducted in inpatient or outpatient facilities at a large, Midwestern United States comprehensive cancer and transplant center. Differences in survey data between the organ and stem cell transplant groups were determined by Student's t tests. Ethnographic methods were used to analyze qualitative focus groups and interview data for themes. Organ transplant patients had less motivation to follow food safety recommendations than did stem cell transplant patients, and they were more likely to consume risky foods. Stem cell transplant patients overall had a better understanding of their susceptibility to foodborne illness and had better prepared themselves with the knowledge and behavior changes needed to protect their health. Educational materials aimed at communicating food safety information for transplant patients were evaluated by patients and judged acceptable. This study found that organ transplant and stem cell transplant patients are distinct patient populations, with differing perceptions regarding the seriousness of foodborne illness and willingness to adopt preventative food handling practices. Population differences should be accounted for in food safety educational strategies.

Acute Myelogenous Leukemia and Febrile Neutropenia

Aggressive chemotherapy has a deleterious effect on all components of the defense system of the human body. The resulting neutropenia as well as injury to the pulmonary and gastrointestinal mucosa allow pathogenic micro-organisms easy access to the body. The symptoms of an incipient infection are usually subtle and limited to unexplained fever due to the absence of granulocytes. This is the reason why prompt administration of antimicrobial agents while waiting for the results of the blood cultures, the so-called empirical approach, became an undisputed standard of care. Gram-negative pathogens remain the principal concern because their virulence accounts for serious morbidity and a high early mortality rate. Three basic intravenous antibiotic regimens have evolved: initial therapy with a single antipseudomonal β-lactam, the so-called monotherapy; a combination of two drugs: a β-lactam with an aminoglycoside, a second β-lactam or a quinolone; and, thirdly, a glycopeptide in addition to β-lactam monotherapy or combination. As there is no single consistently superior empirical regimen, one should consider the local antibiotic susceptibility of bacterial isolates in the selection of the initial antibiotic regimen. Not all febrile neutropenic patients carry the same risk as those with fever only generally respond rapidly, whereas those with a clinically or microbiologically documented infection show a much slower reaction and less favorable response rate.

Once an empirical antibiotic therapy has been started, the patient must be monitored continuously for nonresponse, emergence of secondary infections, adverse effects, and the development of drug-resistant organisms. The averageduration of fever in serious infections in eventually successfully treated neutropenic patients is 4–5 days. Adaptations of an antibiotic regimen in a patient who is clearly not responding is relatively straightforward when a micro-organism has been isolated; the results of the cultures, supplemented by susceptibility testing, will assist in selecting the proper antibiotics. The management of febrile patients with pulmonary infiltrates is complex. Bronchoscopy and a high resolution computer-assisted tomographic scan represent the cornerstones of all diagnostic procedures, supplemented by serological tests for relevant viral pathogens and for aspergillosis. Fungi have been found to be responsible for two thirds of all superinfections that may surface during broad-spectrum antibiotic treatment of neutropenic patients. Antibiotic treatment is usually continued for a minimum of 7 days or until culture results indicate that the causative organism has been eradicated and the patient is free of major signs and symptoms. If a persistently neutropenic patient has no complaints and displays no evidence of infection, early watchful cessation of antibiotic therapy or a change to the oral regimen should be considered.

Early invasive Listeria monocytogenes infection after orthotopic liver transplantation: case report and review of the literature

Infection with Listeria monocytogenes is rare, with a reported annual incidence of 4.4 cases per million individuals. It is caused by a gram-positive rod-shaped bacterium (Listeria monocytogenes) that can be found in soil, vegetation, water, sewage, and silage and in feces of humans and animals. It is a facultative intracellular pathogen with the ability to survive and multiply in phagocytic host cells, even in adverse environmental circumstances. Listeriosis has rarely been reported after orthotopic liver transplantation, and transplant physicians are often unfamiliar with the clinical presentation of this rare but virulent infection, which accounts for 20%-30% mortality in affected individuals. We present a case of invasive Listeria infection causing bacteremia and peritonitis in the early postoperative period after cadaveric liver transplantation in a previously asymptomatic patient.

Bacteriemia por Listeria monocytogenes: análisis de 110 casos

BACKGROUND AND OBJECTIVE

Over the last years, we registered an increase in the number of listeriosis cases. The aim of this study was to analyze the co-morbidity, clinical presentation and prognosis of Listeria monocytogenes bacteremia episodes diagnosed over 15 years.

PATIENTS AND METHOD

From January 1991 to April 2005, we prospectively recorded the medical records of 110 patients in whom L. monocytogenes was isolated from one or more blood cultures. In all patients, demographic, clinical presentation, antimicrobial treatment and outcome data were recorded.

RESULTS

Twenty cases (18.2%) were recorded from 1991 to 1995; 27 (24.6%) from 1996 to 2000 and 63 (57.3%) from 2001 to April 2005 (p < 0.05). One hundred patients (90.9%) had one or more underlying diseases or immunosuppressive conditions, and 54 (49.9%) were under steroid therapy. In 63 patients, primary bacteremia developed, in 35 there was a central nervous system infection and 6 patients developed a spontaneous peritonitis (all patients with liver cirrhosis). Thirteen patients (11.8%) developed septic shock, and 18 (16.3%) died. The mortality rate of patients with meningitis who were treated empirically with a third generation cephalosporin was 50% (5 out of 10) whereas the mortality rate of those patients who received initially an antimicrobial agent active against L. monocytogenes was 12% (3 out of 25) (p = 0.05).

CONCLUSIONS

The rate of systemic infection due to L. monocytogenes increased over the last years. Immunosuppressed patients should have a better knowledge of the guidelines needed to avoid eating potentially contaminated food. When empiric treatment is to be selected in immunosuppressed patients with unexplained fever and/or meningitis, a lack of activity against L. monocytogenes by cephalosporins should be considered.

A rare case of brainstem encephalitis by Listeria monocytogenes with isolated mesencephalic localization. Case report and review

We describe a case of brainstem infection by Listeria monocytogenes with right oculomotor palsy and lip drop, facial hypoesthesia, left arm paresthesia, positive blood culture, and sterile liquor in a 63-year-old man. Magnetic resonance imaging revealed an isolated mesencephalic lesion. Localization of this kind accounted for 3% of 111 cases reviewed.

Listeria monocytogenes skin infection with cerebritis and haemophagocytosis syndrome in a bone marrow transplant recipient

In this report, we describe unusual and unreported manifestations of Listeria monocytogenes infection in a bone marrow transplant recipient, including cutaneous infection with an hamophagocytosis syndrome and cerebritis. L. monocytogenes occurred despite a broad spectrum antibiotherapy. L. monocytogenes was isolated from a skin biopsy. Outcome was favorable with amoxicillin and gentamicin therapy. L. monocytogenes infection should be suspected in patients with cerebritis despite large spectrum antibiotherapy and this report underscores the usefulness of skin biopsies in febrile immunocompromised patients.

Listeria Meningitis Associated with Infliximab

OBJECTIVE:

To report a case of Listeria monocytogenes meningitis in a 73-year-old man receiving infliximab for rheumatoid arthritis.

CASE SUMMARY:

A 73-year-old white man taking infliximab for rheumatoid arthritis developed listeria meningitis following his second dose. He was receiving other immunosuppressants; however, these remained constant immediately prior to the infection. Diagnosis was confirmed with L. monocytogenes isolated in the cerebrospinal fluid. The patient received 21 days of antibiotic therapy and recovered without any complications.

DISCUSSION:

L. monocytogenes is a gram-positive, non—spore-forming rod that has been associated with the ingestion of undercooked foods. This organism can cause sepsis or meningitis; however, immunocompromised patients, elderly patients, pregnant women, and neonates appear to be at greater risk for this type of infection. Tumor-necrosis factor-α (TNF-α) plays an important role in resistance to this type of infection, and listeria infections have been reported in 26 patients receiving TNF-α inhibitors. In our patient, the listeria infection occurred following his second course of infliximab, which provides a temporal relationship between the listeria infection and infliximab. However, his underlying rheumatoid arthritis and chronic steroid therapy would also increase his risk for a listeria infection.

CONCLUSIONS:

The listeria infection in our patient was a possible adverse event of infliximab according to the Naranjo probability scale. Because the majority of listeria infections occur in patients who are immunosuppressed, it would be reasonable to provide education for healthcare professionals on preventing these infections in all patients receiving immunosuppressants, including anti—TNF-α therapy. Those at risk due to their underlying health conditions should also be monitored closely.

Infection with Listeria monocytogenes following orthotopic liver transplantation: case report and review of the literature

Infection with Listeria monocytogenes is rare with a reported annual incidence of 4.4 cases/million individuals. Epidemiological data have identified certain groups to be higher risk of developing listeriosis, including neonates, pregnant women, adults older than 60 years of age, individuals afflicted with hematologic malignancies, acquired immunodeficicency syndrome, cirrhosis, and those receiving corticosteroid therapy and organ transplants. Within this last group, multiple cases have been described following bone marrow and renal transplantation, but only a few following liver transplantation. We report a case of a 66-year-old woman presenting with Listeria monocytogenes bacteremia at 32 months following orthotopic liver transplantation.

Infectious complications in patients undergoing unrelated donor bone marrow transplantation: experience from a single institution

OBJECTIVE

To analyze the incidence and characteristics of documented infections in patients with hematologic malignancies undergoing unrelated donor bone marrow transplantation (UD-BMT).

METHODS

We studied the occurrence of infections in 22 patients with hematologic malignancies or severe aplastic anemia who underwent UD-BMT from April 1990 to December 2000. The median age was 26 years (range 13-46). Acyclovir-ganciclovir, co-trimoxazole, fluconazole-nystatin and ciprofloxacin were administered for anti-infectious prophylaxis.

RESULTS

We registered 61 infectious episodes. During the early post-transplant period, there were eight clinically documented infections (CDIs), four cases of fever of unknown origin (FUO), seven cases of bacteremia, two cases of cytomegalovirus (CMV) antigenemia, and one case of CMV disease. In the intermediate period (days 30-100 after BMT), there were nine cases of CMV antigenemia, three bacterial infections, two fungal infections, one case of disseminated toxoplasmosis, and one case of FUO. In the late period (day 100 and later), we documented 13 viral infections, eight bacterial infections, one CDI, and one case of invasive aspergillosis. Infections contributed to death in 10 of 17 patients. Citrobacter bacteremia and sepsis of unknown origin were the main causes of infectious mortality in the early period. Infection was the main cause of death in six of seven patients in the late period.

CONCLUSION

A high incidence of life-threatening infections and infection-related mortality was observed. A high rate of CMV infection in the early period, and death caused by multiresistant Gram-negative microorganisms in the late period, were the main findings in this series.

Listeriosis in recipients of allogeneic blood and marrow transplantation: thirteen year review of disease characteristics, treatment outcomes and a new association with human cytomegalovirus infection

Listeriosis is uncommon in recipients of allogeneic blood, marrow and organ transplantation. Six patients with systemic Listeria monocytogenes infection during 1985-1997 at Bone Marrow Transplantation Service, Memorial Sloan-Kettering Cancer Center are described. In two male and four female patients, the median duration from transplantation to isolation of L. monocytogenes was 62.5 (range 29 to 821) days. Among five allogeneic marrow transplant recipients, four (80%) received HLA antigen matched, T cell-depleted grafts from three unrelated and a single related donor. One patient underwent mismatched-related marrow graft transplant. Cord stem cell transplantation was performed in a single patient. Two required therapy for graft-versus-host disease (GVHD). The 13 year incidence of systemic Listeria infections was 0.47 percent. All six presented with fever (>39 degrees C), and L. monocytogenes bloodstream invasion. Mental status changes and meningioencephalitis were observed in two (33.3%). A concurrent primary opportunistic infection was present in five individuals (83.3%), and four (80%) were being treated for acute human cytomegalovirus (HCMV) viremia. Sixty-six percent responded to therapy and two died from unrelated, non-listeric causes. Systemic listeriosis was uncommon in our high-risk allogeneic blood and marrow transplantation population, and response to therapy with parenteral ampicillin and gentamicin was excellent. The association between primary HCMV reactivation and subsequent listeric infection emphasizes the significance of HCMV-related dysfunction in hosts' cellular immune responses, especially in the setting of allogeneic transplantation.

Gastrointestinal infections in the immunocompromised host

Gastrointestinal disease is a significant cause of morbidity and mortality in the immunocompromised patient. This article focuses on the infectious gastrointestinal complications associated with the treatment of malignant disease and with solid organ transplantation but not HIV. Gastrointestinal defenses and the various mechanisms by which they are impaired are reviewed. The major pathogens and malignancies of this patient population and an approach to their diagnosis, treatment, and prevention are discussed.

Infections following hematopoietic stem cell transplantation

Numerous advances have been made in the management of infection in HSCT recipients. With increasing knowledge the authors are able to prevent several serious infections from occurring, and reduce the severity of infections once they occur. Despite these advances, several previously unrecognized pathogens have emerged and pose risks to this population. Ongoing surveillance and reporting of atypical infections are warranted. Transplant and infectious disease clinicians alike must be vigilant to the shifts in infectious syndromes as a consequence of various prophylaxis and preemptive strategies, and be ready to modify empiric strategies to meet the changing microbiologic milieu. As we increase our understanding of the HSCT process, and use the immune system rather than relying on high-dose chemotherapy, the authors are likely to reduce toxicities and improve patient outcomes.

Acute bacterial meningitis in adults. A 12-year review

One hundred three episodes of acute bacterial meningitis in adults hospitalized in Edmonton's 2 largest hospitals from 1985 to 1996 were reviewed. Cases complicating neurosurgery were excluded. Most cases were community-acquired (87%). Twenty-three cases remained culture-negative, and there was no statistical relation between culture negativity and antibiotic pretreatment. Streptococcus pneumoniae was the predominant pathogen (52.5%), but Listeria monocytogenes was the second most common isolate, accounting for 12.5% of culture-positive cases. Compared to non-listerial meningitis, those with listeriosis were more likely to have negative cerebrospinal fluid (CSF) Gram stains (p = 0.07), CSF leukocyte counts < 1,000 cells/mm3 (p < 0.003), and normal CSF glucose (p = 0.006). Bacterial antigen detection was found to be of low sensitivity: 33% in all patients, but only 9% in cases with negative CSF Gram stains. The overall mortality was 18%, with 15 deaths directly attributable to acute meningitis; the case-fatality rates for S. pneumoniae and L. monocytogenes were 24% and 40%, respectively. Mortality was significantly higher among those with seizures (34% versus 7%, respectively; p < 0.001; OR = 17.6). Despite the urgency of acute bacterial meningitis, there were considerable delays in the institution of empiric antibiotics; mortality rates were slightly higher in those who experienced such a delay (16% versus 7% respectively; p = 0.18).

Monotherapy versus combination therapy for bacterial infections

The authors discuss the latest findings regarding the use of one or more antimicrobial drugs for a variety of infections. They offer suggestions for treatment based on a host of considerations, including the synergy and antagonism of specific drugs, type of infection, potential toxicities, and cost.

Reconstitution of gammadelta T cell repertoire diversity after human allogeneic hematopoietic cell transplantation and the role of peripheral expansion of mature T cell population in the graft

We have examined the reconstitution of gammadelta T cell repertoire diversity after human allogeneic hematopoietic cell transplantation using a polymerase chain reaction (PCR)-based complementarity-determining region (CDR) 3 size spectratyping and DNA sequencing. The CDR3 complexity in the variable region of the T cell receptor (TCR)-delta chain was different amongst the individuals studied. Furthermore, CDR3 size distribution patterns of allogeneic hematopoietic cell transplant recipients were almost completely recovered by a few months after transplantation. In some patients, clonal predominance of the TCRDV1+ T cells became evident during the period after transplantation. In one particular donor/recipient pair, clonal predominance of TCRDV1+ T cells was already present in blood lymphocytes of the donor, and was also observed in the recipient after transplantation. Using this donor/recipient pair, we have questioned whether gammadelta T cell regeneration occurs via the peripheral expansion of mature T cells in the graft. In the donor lymphocytes, two expanding gammadelta T cell clones, which were demonstrated by CDR3 sequences of the TCR-delta chain, were recognized. These two clones were identified in the T cells from the recipient post transplant, but not before transplantation. One of the two clones was still detectable 1(1/2) years after the transplant procedure. These results strongly suggest that peripheral expansion of mature T cells in the graft is the principal pathway of gammadelta T cell regeneration after allogeneic hematopoietic cell transplantation in adults.

Infections in recipients of blood and marrow transplantation

The approach to infections in blood and marrow transplant (BMT) recipients involves an understanding of clinical infection syndromes and the natural history of individual infections, taken in the context of patterns of immunosuppression after transplantation and mechanisms underlying immune system reconstitution over time. The conditioning regimen used to prepare the host is a major determinant of host tissue injury and may lead to mucositis or diarrhea, facilitating transmucosal origin of bloodstream infections. Infectious risk also differs between autologous and allogeneic grafts as a consequence of ongoing immunosuppression from graft-versus-host disease and its therapy. Post-transplant complications may mimic infectious processes, and multiple infections may occur in one patient at the same time. Thus, the BMT patient with suspected infection should be evaluated in the context of pretransplant exposure history (infectious disease serologies), conditioning regimen, available culture data from nonsterile mucosal surfaces, previous and recent infections, contemporary transplant complications, and the current degree and duration of neutropenia, cellular immunodeficiency, and hypogammaglobulinemia.

Listeria infection after liver transplantation: report of a case and review of the literature

Listeria monocytogenes is a well-recognized cause of bacteremia and meningitis in immunocompromised individuals, including recipients of solid organ transplants, but has only rarely been reported following orthotopic liver transplantation (OLT). Most previously reported cases of listeriosis occurred months to years following liver transplantation; we describe a case of listeriosis that occurred within 1 wk of liver transplantation, shortly after discontinuation of trimethoprim-sulfamethoxazole prophylaxis, and review the English literature on Listeria infection after OLT. The patient developed abdominal pain and fever that suggested a bile leak, but was definitively diagnosed with Listeria infection by blood culture. The infection was successfully treated with 3 wk of intravenous ampicillin. We conclude that serious systemic infection with Listeria monocytogenes is uncommon following OLT, may occur early in the postoperative period, and responds well to treatment with high dose ampicillin.

Central nervous system infection with Listeria monocytogenes. 33 years' experience at a general hospital and review of 776 episodes from the literature

We reviewed 776 previously reported and 44 new cases of CNS listeriosis outside of pregnancy and the neonatal period, and evaluated the epidemiologic, diagnostic, and therapeutic characteristics of this infection. Among patients with Listeria meningitis/meningoencephalitis, hematologic malignancy and kidney transplantation were the leading predisposing factors, but 36% of patients had no underlying diseases recognized. The infection occurred throughout life, with a higher incidence before the age of 3 and after the age of 45-50 years. Fever, altered sensorium, and headache were the most common symptoms, but 42% of patients had no meningeal signs on admission. Compared with patients with acute meningitis due to other bacterial pathogens, patients with Listeria infection had a significantly lower incidence of meningeal signs, and the CSF profile was significantly less likely to have a high WBC count or a high protein concentration. Gram stain of CSF was negative in two-thirds of cases of CNS listeriosis. One-third of patients had focal neurologic findings, and approximately one-fourth developed seizures over their course. Mortality was 26% overall, and was higher among patients with seizures and those older than 65 years of age. Relapse occurred in 7% of episodes. Ampicillin for a minimum of 15-21 days (with an aminoglycoside for at least the first 7-10 days) remains the treatment of choice. Cerebritis/abscess due to L. monocytogenes, without meningeal involvement, is less common but may be diagnosed by blood cultures and CNS imaging, or by stereotactic biopsy. Longer antibiotic therapy (at least 5-6 weeks) is needed in the presence of localized CNS involvement.

Listeriosis in pediatric oncology patients

BACKGROUND

Adult cancer patients are considered to be at an increased risk for Listeria monocytogenes infections, but, to the authors' knowledge, little information regarding this infection in the pediatric oncology population has been published.

METHODS

The Memorial Sloan-Kettering Cancer Center microbiology laboratory's database was searched for cases of Listeria monocytogenes infection during the period from January 1981 to December 1996, and thorough chart reviews of the cases identified in patients age < 21 years were performed.

RESULTS

Listerial infections occurred in 5 children (3 with leukemia, 1 with lymphoma, and 1 with a brain tumor) among 20,612 admissions to the pediatric department during this period. All five children were actively receiving therapy for their malignancy, and two also were receiving other potentially immunosuppressive therapies. None was receiving co-trimoxazole prophylaxis. All were treated successfully for the Listeria monocytogenes infection with ampicillin and gentamicin (four patients) or ampicillin alone (one patient). At last follow-up two patients were long term, event-free survivors, two had died of their underlying malignancy, and one patient had died of cytomegalovirus pneumonitis.

CONCLUSIONS

Listeria monocytogenes infections in pediatric oncology patients can be treated successfully with ampicillin-containing antibiotic regimens.

Antimicrobial prophylaxis to prevent opportunistic infections in patients with chronic lymphocytic leukemia after allogeneic blood or marrow transplantation

Opportunistic infections have been a problem after BMT in CLL. We have allografted seven patients with B-CLL (n = 6) or B-prolymphocytic leukemia (n = 1) from matched siblings (n = 6) or a mismatched unrelated donor (n = 1). Amongst the first six, we saw two cases of recurrent or prolonged cytomegaloviremia and CMV disease, one listeria meningitis, and one fatal toxoplasma encephalitis. The latter two developed in the setting of steroid therapy of GVHD with extensive prior fludarabine therapy. Prophylaxis for opportunistic infections was developed on an ongoing basis as new infectious complications were seen. The current drug prophylaxis, which has been successful for eight months in the last patient despite pretreatment with fludarabine and steroid therapy for GVHD, is directed against pneumocystis, toxoplasma, fungi, and pneumococci. It includes immunoglobulin (for 3 1/2 months), pyrimethamine-sulfadiazine (for 4 months and during steroids), fluconazole (for 2 1/2 months), cotrimoxazole or pentamidine (for 2 years) and penicillin (lifelong). Dietary precautions are followed for 4 months and during steroids to prevent listeriosis. Four patients are alive in remission with no active infectious problems 8-44 months (median 29) after BMT. We recommend adoption of these or similar prophylactic measures for BMT in CLL as a baseline which can be modified if new infections are identified and according to individual needs.

Infection in the bone marrow transplant recipient and role of the microbiology laboratory in clinical transplantation

Over the past quarter century, tremendous technological advances have been made in bone marrow and solid organ transplantation. Despite these advances, an enduring problem for the transplant recipient is infection. As immunosuppressive regimens have become more systematic, it is apparent that different pathogens affect the transplant recipient at different time points in the posttransplantation course, since they are influenced by multiple intrinsic and extrinsic factors. An understanding of this evolving risk for infection is essential to the management of the patient following transplantation and is a key to the early diagnosis and treatment of infection. Likewise, diagnosis of infection is dependent upon the quality of laboratory support, and services provided by the clinical microbiology laboratory play an important role in all phases of clinical transplantation. These include the prescreening of donors and recipients for evidence of active or latent infection, the timely and accurate microbiologic evaluation of the transplant patient with suspected infection, and the surveillance of asymptomatic allograft recipients for infection. Expert services in bacteriology, mycology, parasitology, virology, and serology are needed and communication between the laboratory and the transplantation team is paramount for providing clinically relevant, cost-effective diagnostic testing.