[Incidence of bacteremia among histologic groups of hematologic malignancies]

INTRODUCTION

Subgroups having dissimilar prognoses are being identified among cancer patients with infection. Previous studies have suggested that these differences may be related to the histologic diagnosis, but this issue has not as yet been demonstrated.

METHODS

We reviewed the medical records of all patients admitted with acute leukemia (AL) or lymphoma (ML) from 1988 to 1998. Incidence of bacteremia was calculated for the following subgroups: acute lymphocytic leukemia (ALL), acute myelocytic leukemia (AML), AML following refractory anaemia with excess blasts (AML-RAEB), high-grade ML (HGML), intermediate-grade ML (IGML), low-grade ML (LGML) and indeterminate ML (IML). Kaplan-Meier curves of time to the first positive blood culture were constructed and compared by means of log-rank test.

RESULTS

In the period covered there were 244 new diagnoses of AL or ML: 62 AML, 32 ALL, 20 AML-RAEB, 78 HGML, 7 IGML, 37 LGML and 6 IML. At the end of the study period, 44 patients were alive, 147 were known to have died at a certain date and 53 had been formally lost to follow-up (most of them, transferred for hospice care). Among 684 blood cultures, there were 51 contaminations and 155 significant isolates. Among the latter, gram-positive bacteria were isolated in 74 and gram-negative bacteria in 47; in 27 cases more than 1 bacterial species were recovered. Fungi were isolated in 7 cases. The incidence of bacteremia expressed as cases per 1000 patient-days was 5.80 for AML, 5.03 for AML-RAEB, 1.56 for ALL, 0.21 for HGML and 0.40 for the remaining ML. Time to the first positive blood culture was significantly shorter for AML than for any other group, and was shorted for ALL and AML-RAEB than for ML.

CONCLUSION

Differences in the incidence of bacteremia were observed among histologically-defined groups of unselected patients with hematologic malignancies.

Nontuberculous mycobacterial infections in pediatric acute leukemia

We report on 3 children undergoing treatment for acute lymphoblastic leukemia (ALL), who developed systemic nontuberculous mycobacterial (NTM) infections. All 3 patients were treated successfully with 5 months or less of antimicrobial therapy and completed their chemotherapy with no further recurrence of their NTM infection. NTM infections in some children with ALL may be successfully treated with antimicrobial agents without necessarily compromising the ALL treatment. The optimal duration of therapy for NTM remains unclear, but may be shorter than previously reported.

Rhinocerebral mucormycosis in a boy with recurrent acute lymphoblastic leukemia: long-term survival with systemic antifungal treatment

Rhinocerebral mucormycosis is rare in hematologic malignancies and usually leads to death within weeks. In contrast, chronic rhinocerebral mucormycosis takes a slowly progressive course and has not been reported in hematologic malignancies in children so far. The authors report the long-term survival of a boy with rhinocerebral mucormycosis in a relapse of acute lymphoblastic leukemia after allogeneic cord blood transplantation. The disease started acutely but took a chronic course thereafter. No surgical debridement was performed because of extensive involvement of the sinuses, orbits, and cerebrum. His long-term survival of 15 months is attributed to the long-range administration of liposomal amphotericin B, early neutrophil recovery, and slow progression of the relapsing acute lymphoblastic leukemia.

Pneumocystis carinii pneumonia in patients with malignant haematological diseases: 10 years' experience of infection in GIMEMA centres

A retrospective survey was conducted over a 10-year period (1990-99) among 52 haematology divisions in order to evaluate the clinical and laboratory characteristics and outcome of patients with proven Pneumocystis carinii pneumonia (PCP) complicating haematological diseases. The study included 55 patients (18 with non-Hodgkin's lymphoma, 10 with acute lymphoblastic leukaemia, eight with acute myeloid leukaemia, five with chronic myeloid leukaemia, four with chronic lymphocytic leukaemia, four with multiple myeloma, three with myelodysplastic syndrome, two with myelofibrosis and one with thalassemia) who developed PCP. Among these, 18 (33%) underwent stem cell transplantation; only two received an oral prophylaxis with trimethroprim/sulphamethoxazole. Twelve patients (22%) developed PCP despite protective isolation in a laminar airflow room. The most frequent symptoms were: fever (86%), dyspnoea (78%), non-productive cough (71%), thoracic pain (14%) and chills (5%); a severe hypoxaemia was present in 39 patients (71%). Chest radiography or computerized tomography showed interstitial infiltrates in 34 patients (62%), alveolar infiltrates in 12 patients (22%), and alveolar-interstitial infiltrates in nine patients (16%). Bronchoalveolar lavage was diagnostic in 47/48 patients, induced sputum in 9/18 patients and lung biopsy in 3/8 patients. The diagnosis was made in two patients at autopsy. All patients except one started a specific treatment (52 patients trimethroprim/sulphamethoxazole, one pentamidine and one dapsone). Sixteen patients (29%) died of PCP within 30 d of diagnosis. Multivariate analysis showed that prolonged steroid treatment (P < 0.006) and a radiological picture of diffuse lung involvement (P < 0.003) were negative diagnostic factors.

Characterization of Klebsiella pneumoniae and Escherichia coli strains that produce CTX-M-2-type broad spectrum beta-lactamase isolated from a child with leukemia

An 8-year-old girl with acute leukemia had bacteremia caused by Klebsiella pneumoniae producing CTX-M-2-type broad spectrum beta-lactamase. K. pneumoniae and Escherichia coli strains producing the same enzyme and harboring identical conjugative plasmids were recovered from stoor culture. Patients with frequent episodes of neutropenia and prophylactic administration of beta-lactams are at risk of harboring colonizing strains that produce broad spectrum beta-lactamases.

Evidence on the infectious etiology of childhood leukemia: the role of low herd immunity (Greece)

OBJECTIVE

Acute lymphoblastic leukemia (ALL) among children may be a rare outcome of a delayed non-specific infection in situations of overall low herd immunity. We evaluated the hypothesis as to whether newly diagnosed ALL cases, compared to their controls, are characterized by lower herd immunity, as reflected in a more seronegative spectrum to several agents, with the exception of a strongly positive response to a single infectious agent, assumed to trigger ALL.

METHODS

The study included 94 incident cases of ALL, from all pediatric hematology-oncology units of Greece, and 94, matched for age and gender, controls hospitalized with minor non-infectious conditions. The past exposure to common infections was assessed using 10 serological markers.

RESULTS

There was little evidence for an association of ALL with the serology of any of the studied infectious agents among the very young children. In contrast, among children aged 5 years or older, leukemia was inversely associated with seropositivity to Epstein-Barr virus, human herpes virus-6, Mycoplasma pneumoniae and parvovirus B19.

CONCLUSIONS

Among children aged 5 years or older the risk of leukemia may be higher when the low herd immunity for several agents is challenged by late infection from an agent that, as a rule, would attack children at a younger age.

Surgical implications of pseudomonas aeruginosa necrotizing fasciitis in a child with acute lymphoblastic leukemia

Necrotizing fasciitis caused by Pseudomonas aeruginosa is extremely rare. Only 4 cases were reported in the literature. The authors report the occurrence of P aeruginosa necrotizing fasciitis starting out as a vulval abscess in a girl before induction chemotherapy for acute lymphoblastic leukemia. To our knowledge, this is the second case described in association with leukemia. In this case, the outcome was favorable because of early surgical intervention, confirming the diagnosis. J Pediatr Surg 36:948-950.

Acrophialophora fusispora brain abscess in a child with acute lymphoblastic leukemia: review of cases and taxonomy

A 12-year-old girl with acute lymphoblastic leukemia was referred to King Faisal Specialist Hospital and Research Center. The diagnosis without central nervous system (CNS) involvement was confirmed on admission, and chemotherapy was initiated according to the Children Cancer Group (CCG) 1882 protocol for high-risk-group leukemia. During neutropenia amphotericin B (AMB) (1 mg/kg of body weight/day) was initiated for presumed fungal infection when a computed tomography (CT) scan of the chest revealed multiple nodular densities. After 3 weeks of AMB therapy, a follow-up chest CT revealed progression of the pulmonary nodules. The patient subsequently suffered a seizure, and a CT scan of the brain was consistent with infarction or hemorrhage. Because of progression of pulmonary lesions while receiving AMB, antifungal therapy was changed to liposomal AMB (LAMB) (6 mg/kg/day). Despite 26 days of LAMB, the patient continued to have intermittent fever, and CT and magnetic resonance imaging of the brain demonstrated findings consistent with a brain abscess. Aspiration of brain abscess was performed and the Gomori methenamine silver stain was positive for hyphal elements. Culture of this material grew Acrophialophora fusispora. Lung biopsy showed necrotizing fungal pneumonia with negative culture. The dosage of LAMB was increased, and itraconazole (ITRA) was added; subsequently LAMB was discontinued and therapy was continued with ITRA alone. The patient demonstrated clinical and radiological improvement. In vitro, the isolate was susceptible to low concentrations of AMB and ITRA. A. fusispora is a thermotolerant, fast-growing fungus with neurotropic potential. We report the first case of human infection involving the CNS. Acrophialophora resembles Paecilomyces but differs in having colonies that become dark and in the development of phialides along the sides or at the tips of echinulate brown conidiophores. Conidia are borne in long chains and are smooth or ornamented with fine-to-coarse echinulations, sometimes in spiral bands. The taxonomy of the genus Acrophialophora is reviewed, and Acrophialophora nainiana and Acrophialophora levis are considered as synonyms of A. fusispora.

Fungal discitis due to Aspergillus terreus in a patient with acute lymphoblastic leukemia

We report a case of Aspergillus terreus discitis which developed in a patient with acute lymphoblastic leukemia following induction chemotherapy. A. terreus was isolated from sputum, one month earlier, but the physician did not consider it significant at the time. Magnetic resonance imaging study showed the involvement of L3-4, L4-5 and L5-S1 intervertebral discs. Etiology was established by means of histology and culturing a surgical specimen of disc materials. Our patient survived after a surgical debridement and amphotericin B administration with a total dose of 2.0 g. Discitis caused by Aspergillus terreus is a very rare event. A. terreus is one of the invasive Aspergillus species. The pathogenetic mechanism is discussed and the literature is reviewed.

Trimethoprim-sulfamethoxazole salvage for refractory listeriosis during maintenance chemotherapy for acute lymphoblastic leukemia

A 5-year-old boy with acute lymphoblastic leukemia (ALL) and intolerance to oral trimethoprim-sulfamethoxazole (TMP/SMX) had Listeria monocytogenes bacteremia and meningitis develop during maintenance chemotherapy. Despite prompt administration of IV amoxicillin/gentamicin and microbiologic clearance of the bloodstream, the patient had no response to therapy after a course of 7 days. Intravenous TMP/SMX (10 mg/kg per day of TMP) was added to the antibiotic regimen after desensitization. Fever and meningeal signs rapidly resolved, and the patient was ultimately cured. Amoxicillin and gentamicin, although highly active and synergistic in vitro against L. monocytogenes, have limited intracellular penetration and activity. In contrast, TMP/SMX has bactericidal extracellular and intracellular activity against Listeria and excellent central nervous system penetration, and thus may be effective for the treatment of refractory listeriosis.

Surveillance of the serum Candida antigen titer for initiation of antifungal therapy after post-remission chemotherapy in patients with acute leukemia

The early diagnostic efficacy of serial Candida antigen detection by the assay kit CAND-TEC (a latex particle agglutination test) was evaluated in 12 episodes in 10 patients with acute leukemia after post-remission chemotherapy. To determine the timing to initiate antifungal chemotherapy, we performed the CAND-TEC assay serially in each patient. When the patients revealed febrile neutropenia after antileukemic chemotherapy and the Candida antigen titer was increased compared to that measured before the antileukemic chemotherapy (even if the increased titer was at a lower level, e.g., from negative to 1:1 positive or from 1:1 to 1:2), azole antifungal agents (fluconazole or miconazole) were administered intravenously. In 9 (81.8%) of the 11 evaluable cases, the antifungal chemotherapy was effective and the titers decreased to less than or equal to the previous titers in all cases. In 2 cases, the antifungal chemotherapy was not effective, and the titers did not decrease. These results suggest that serial Candida antigen detection provides a useful method in the early diagnosis of invasive candidiasis in febrile neutropenia and in determining the timing of the initiation of early antifungal chemotherapy. This method might also be useful in preventing the excess use of antifungal agents; thus preventing the proliferation of azole-resistant Candida infection.

Hepatosplenic candidiasis in patients with acute leukaemia

A retrospective study of 23 patients with acute leukaemia and hepatosplenic candidiasis (HSC) was conducted to evaluate clinical treatment characteristics in terms of amount and duration of antifungal agents and to assess treatment outcome. Patients were admitted to two major tertiary care centres between 1990 and 1998. The diagnosis of HSC was based on clinical, blood cultures, histologic and imaging studies. Patients were treated with amphotericin B without interruption of the planned chemotherapy regimens. Serial magnetic resonance imaging (MRI) studies were the main tool for following patients' response and activity of the fungal lesions in conjunction with clinical and laboratory parameters. Treatment with amphotericin B was continued until resolution of all clinical symptoms and signs attributable to HSC, obtaining negative blood cultures and the appearance of at least healed lesions on MRI. Amphotericin B was discontinued in four patients because of severe nephrotoxicity (two patients), or continuous fever and persistent fungal lesions on MRI (two patients). Amphotericin B lipid complex (ABELCET) was successfully used as salvage therapy for these refractory patients. Four patients died with evidence of HSC despite treatment and supportive measures. The response rate for treatment of HSC was 82%. The mean total dose of amphotericin B including empirical treatment was 4 g and the median duration of treatment for responding patients was 112 d. The median number of days of anti- fungal treatment before the disappearance of fever was 19 d. Our results confirmed the need for protracted courses of antifungal agents for the successful eradication of HSC. Chemotherapy for the underlying disorder should not be interrupted or delayed in order to treat HSC.

Fungal colonization and infection in children with acute leukemia and lymphoma during induction therapy

BACKGROUND

Fungal infection represents a growing problem in children with hematologic malignancies. During chemotherapy induced neutropenia, colonization with fungi is considered a major risk factor for subsequent fungal infection. The rates and risk factors for mycotic infections in pediatric oncology patients is undetermined, particularly for centers in developing countries. The aim of this study was to evaluate the rates and risk factors of fungal colonization in children with acute leukemia and lymphoma at one of the major pediatric hematology/oncology centers in Turkey.

PROCEDURE

Fifty-two consecutive children newly diagnosed with acute leukemia and lymphoma during intensive remission induction therapy were evaluated for the occurrence of fungal colonization (defined as at least one positive surveillance culture) and infection.

RESULTS

Thirty-six of the 52 patients (69.2%) were colonized by Candida albicans which was the only fungus isolated from surveillance cultures. There were three (5.8%) proven systemic fungal infections: two cases of candidemia and one case of brain abscess with Aspergillus spp. isolated from tissue. All patients with fungal colonization were receiving prophylactic or curative antibiotics. No significant association was found between type of disease and fungal colonization, but there was a significant association with neutropenia.

CONCLUSIONS

Our findings suggest that there is a high rate of fungal colonization in children receiving remission induction therapy for acute leukemia and lymphoma. Limiting the use of antibiotics and instituting antifungal chemoprophylaxis may decrease the rate, while the early initiation of empiric antifungal therapy in patients with fever and suspected mycotic colonization may increase survival in these patients.

[Bacteremia with granulocytopenia--microbiology and empiric antibiotic treatment]

This article sums up a retrospective analysis of 84 episodes of bacteraemia in acute leukaemia patients with severe neutropenia in a Norwegian teaching hospital during the period 1990-95. Gram negative bacteria represented 54% of the blood culture isolates, all of which were susceptible to aminoglycosides, and nearly all to ceftazidime and imipenem. Penicillin/aminoglycoside was used as initial therapy in 43% of the episodes. Initial empiric therapy was modified in 52% of the events. Only 15% of patients receiving the penicillin/aminoglycoside combination actually had infections with organisms susceptible to penicillin. Only 2% of patients with gram negative infections received initial synergistic treatment with two effective drugs. Mortality from infections was 8% in acute leukaemia patients with documented bacteraemia. Deaths mainly occurred in patients with terminal leukaemia disease. Late breakthrough bacteraemias with Stenotrophomonas maltophilia and Pseudomonas aeruginosa caused 50% of all fatal infections. The analysis suggests that no patients died during initial bacteraemia with penicillin-resistant organisms treated with penicillin/aminoglycoside. The antibiotic susceptibility of the isolated bacteria was favourable compared to what has been found in other countries. For the time being, we believe that the ecological advantages of using penicillin/aminoglycoside as initial empiric treatment of febrile neutropenia are greater than the disadvantages.

[Bacteremia in children with acute lymphoblastic leukemia]

The purpose of this study was to describe the pattern of bacterial infections in children with acute lymphoblastic leukemia. Forty-six children with ALL were treated for 119 febrile episodes. Antibiotic therapy was initiated with ampicillin and gentamicin, +/- dicloxacillin and lasted for 5-8 days. Bacterial cultures were positive in 36 of 119 febrile events. At the beginning of the febrile disease there was no difference in CRP and neutrophil count between children with positive and negative blood cultures. The maximum CRP was, however, significantly higher in children with positive blood cultures. In 75% there was no need to change the initial antibiotic treatment with ampicillin and gentamicin +/- dicloxacillin. If the temperature has been normal for 2-3 days and the neutrophil count is increasing it appears safe to discontinue the antibiotic therapy after five days when blood cultures are negative and after 7-8 days when cultures are positive.

Bacteremia caused by CDC group IV c-2 in a patient with acute leukemia

Human infection due to CDC group IV c-2, a gram negative bacillous, are rare. We describe a case of nosocomial bacteremia caused by this organism in a neutropenic patient with acute lymphoblastic leukemia and include a literature review of CDC group IV c-2 infection in patients with hematologic malignancies.

Stomatococcus mucilaginosus septicemia in a patient with acute lymphoblastic leukaemia

A 16-year-old patient with acute lymphoblastic leukaemia which had relapsed for the third time developed clinical signs and symptoms of septicemia during a period of neutropenia. The patient had signs of oral mucositis, and Stomatococcus mucilaginosus was isolated from blood cultures. The patient responded well to antibiotic therapy. The biochemical characteristics and antimicrobial susceptibility patterns of 68 other pharyngeal isolates of Stomatococcus mucilaginosus from immunocompromised patients are presented.

The correlation between the numbers of some bacteria in human oral cavity and blood neutrophil count

The correlation between the number of blood polymorphonuclear granulocytes (PMNs) and the counts of oral bacteria in 92 children (33 girls and 59 boys), aged 4-15 was investigated. The groups of children comprised 44 healthy individuals and 48 children suffering from acute lymphoblastic leukaemia who were given intensive antileukaemic chemotherapy. It was found that while the number of PMNs in blood decreased, the counts of Streptococcus spp., Staphylococcus spp., mutans streptococci, Lactobacillus spp., and Actinomyces spp. in the saliva tended to increase. The similar reciprocal correlation between the number of blood PMNs and the counts of these bacteria in the saliva was found in the group of healthy children. We concluded that the blood PMNs, by influencing the number of oral PMNs which control bacteria in this habitat, influence also the number of some groups of bacteria there.

Amphotericin B treatment of fungemia due to unusual pathogens in neutropenic patients: report of two cases

Invasive fungal infections occur frequently in neutropenic patients although only in recent years has the role of emerging fungi been clearly established. We describe two cases of fungemia caused by Trichosporon beigelii and Rhodotorula glutinis respectively in two neutropenic patients with hematological malignancies who were treated with amphotericin B. The first patient, with refractory multiple myeloma, died following massive pneumonia despite therapy with amphotericin B and granulocyte-colony stimulating factor (G-CSF); the second patient, with relapsed acute lymphatic leukemia and persistent fever without any other clinical evidence, finally recovered. Amphotericin B continues to be considered the "gold standard" in the treatment of invasive mycoses although other approaches need to be tested for refractory infections.