Randomized trial of the addition of gram-positive prophylaxis to standard antimicrobial prophylaxis for patients undergoing autologous bone marrow transplantation

Early versus Late Fluconazole Prophylaxis in Autologous Hematopoietic Cell Transplantation

Candidemia is a major complication in hematopoietic cell transplantation (HCT), and antifungal prophylaxis with fluconazole decreases the incidence of this complication. We compared 2 strategies for fluconazole prophylaxis in patients with hematologic malignancy undergoing autologous HCT between 1997 and 2017. From 1997 to 2003, fluconazole prophylaxis (400 mg/d) was given to all HCTs, started with the conditioning regimen (early prophylaxis), and given until neutrophil engraftment or the need of non-prophylactic antifungal therapy. From 2004 on, fluconazole (400mg daily) was started only if (and when) the patient developed oral mucositis (late prophylaxis). Among 571 HCT, 270 received early prophylaxis, 112 received late prophylaxis, and 189 did not receive fluconazole because they did not develop oral mucositis. The incidence of candidemia was 1.8% in the early prophylaxis group, 0% in the late prophylaxis group, and 1.1% in the no prophylaxis group (P = .31). Among patients receiving fluconazole, the median duration of prophylaxis was 17 days (range, 6-36 days) in the early prophylaxis group and 6 days (range, 2-16 days) in the late prophylaxis group (P < .001). The initiation of fluconazole prophylaxis guided by the occurrence of oral mucositis (late prophylaxis) was as good as early fluconazole prophylaxis.

Prevention of Infections in Patients with Hematological Malignancies

Infection is a major complication of patients with hematological malignancies. Prophylaxis is a key element in the management of these patients, and is composed by two main components: infection control measures and antimicrobial chemoprophylaxis. Infection control measures are safe, but not always effective. Antimicrobial prophylaxis is usually effective but may increase resistance rates, toxicity, and cost. Therefore, a careful evaluation of the actual risk for infection, the pathogens that predominate in a particular setting, and the periods at risk are important in order to define the most appropriate strategy. In this chapter we review the most important parameters to assess the risk on an individual basis, and the evidences and recommendations supporting infection control measures and antimicrobial prophylaxis against bacteria, fungi, viruses, and parasites.

Antibiotic prophylaxis in hematopoietic stem cell transplantation. A meta-analysis of randomized controlled trials

OBJECTIVES

We performed a meta-analysis to evaluate the impact of systemic antibiotic prophylaxis in hematopoietic stem cell transplantation (HSCT) recipients.

METHODS

We collected reports from PubMed, the Cochrane Library, EMBASE, CINAHL, and Web of Science, along with references cited therein. We included prospective, randomized studies on systemic antibiotic prophylaxis in HSCT recipients.

RESULTS

Seventeen trials with 1453 autologous and allogeneic HSCT recipients were included. Systemic antibiotic prophylaxis was compared with placebo or no prophylaxis in 10 trials and with non-absorbable antibiotics in two trials. Systemic antibiotics other than fluoroquinolones were evaluated in five of these 12 trials. Four trials evaluated the effect of the addition of antibiotics for gram-positive bacteria to fluoroquinolones. One trial compared two different systemic antibiotic regimens: fluoroquinolones versus trimethoprim-sulfamethoxazole. As a result, systemic antibiotic prophylaxis reduced the incidence of febrile episodes (OR 0.16; 95%CI 0.09-0.30), clinically or microbiologically documented infection (OR 0.38; 95%CI 0.22-0.63) and bacteremia (OR 0.31; 95%CI 0.16-0.59) without significantly affecting all-cause mortality or infection-related mortality.

CONCLUSIONS

Systemic antibiotic prophylaxis successfully reduced the incidence of infection. However, there was no significant impact on mortality. The clinical benefits of prophylaxis with fluoroquinolones were inconclusive because of the small number of clinical trials evaluated.

Prevention of Infections in Patients with Hematological Malignancies

Infection is a frequent complication and a leading cause of morbidity and mortality in patients with hematological malignancies. Problems associated with the management of infections in these patients include difficulties in early diagnosis because the clinical signs of infection are subtle, the low performance of diagnostic tests, and suboptimal response to treatment because recovery of host defenses is a key factor for resolution of infection. Preventing these infections relies on infection control measures and antimicrobial chemoprophylaxis. While infection control measures are safe (but not always effective), the use of antimicrobial agents for prophylaxis of infection is not devoid of problems. Its wide use may increase the possibility of the development of resistance, select for resistant organisms, and increase toxicity and cost. Therefore, any attempt to administer an antimicrobial agent should be accompanied by a reflection of the potential benefits and risks of prophylaxis.

Antibiotic prophylaxis for bacterial infections in afebrile neutropenic patients following chemotherapy

BACKGROUND

Bacterial infections are a major cause of morbidity and mortality in patients who are neutropenic following chemotherapy for malignancy. Trials have shown the efficacy of antibiotic prophylaxis in reducing the incidence of bacterial infections but not in reducing mortality rates. Our systematic review from 2006 also showed a reduction in mortality.

OBJECTIVES

This updated review aimed to evaluate whether there is still a benefit of reduction in mortality when compared to placebo or no intervention.

SEARCH METHODS

We searched the Cochrane Cancer Network Register of Trials (2011), Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 2, 2011), MEDLINE (1966 to March 2011), EMBASE (1980 to March 2011), abstracts of conference proceedings and the references of identified studies.

SELECTION CRITERIA

Randomised controlled trials (RCTs) or quasi-RCTs comparing different types of antibiotic prophylaxis with placebo or no intervention, or another antibiotic, to prevent bacterial infections in afebrile neutropenic patients.

DATA COLLECTION AND ANALYSIS

Two authors independently appraised the quality of each trial and extracted data from the included trials. Analyses were performed using RevMan 5.1 software.

MAIN RESULTS

One-hundred and nine trials (involving 13,579 patients) that were conducted between the years 1973 to 2010 met the inclusion criteria. When compared with placebo or no intervention, antibiotic prophylaxis significantly reduced the risk of death from all causes (46 trials, 5635 participants; risk ratio (RR) 0.66, 95% CI 0.55 to 0.79) and the risk of infection-related death (43 trials, 5777 participants; RR 0.61, 95% CI 0.48 to 0.77). The estimated number needed to treat (NNT) to prevent one death was 34 (all-cause mortality) and 48 (infection-related mortality).Prophylaxis also significantly reduced the occurrence of fever (54 trials, 6658 participants; RR 0.80, 95% CI 0.74 to 0.87), clinically documented infection (48 trials, 5758 participants; RR 0.65, 95% CI 0.56 to 0.76), microbiologically documented infection (53 trials, 6383 participants; RR 0.51, 95% CI 0.42 to 0.62) and other indicators of infection.There were no significant differences between quinolone prophylaxis and TMP-SMZ prophylaxis with regard to death from all causes or infection, however, quinolone prophylaxis was associated with fewer side effects leading to discontinuation (seven trials, 850 participants; RR 0.37, 95% CI 0.16 to 0.87) and less resistance to the drugs thereafter (six trials, 366 participants; RR 0.45, 95% CI 0.27 to 0.74).

AUTHORS' CONCLUSIONS

Antibiotic prophylaxis in afebrile neutropenic patients significantly reduced all-cause mortality. In our review, the most significant reduction in mortality was observed in trials assessing prophylaxis with quinolones. The benefits of antibiotic prophylaxis outweighed the harm such as adverse effects and the development of resistance since all-cause mortality was reduced. As most trials in our review were of patients with haematologic cancer, we strongly recommend antibiotic prophylaxis for these patients, preferably with a quinolone. Prophylaxis may also be considered for patients with solid tumours or lymphoma.

Levofloxacin vs. ciprofloxacin plus phenethicillin for the prevention of bacterial infections in patients with haematological malignancies

An open-label randomised clinical trial was designed to compare the efficacy and tolerance of levofloxacin and ciprofloxacin plus phenethicillin for the prevention of bacterial infections in patients with high-risk neutropenia, and to monitor the emergence of antimicrobial resistance. Adult patients (n = 242) scheduled to receive intensive treatment for haematological malignancies were assigned randomly to receive oral prophylaxis with either levofloxacin 500 mg once-daily (n = 122), or ciprofloxacin 500 mg twice-daily plus phenethicillin 250 mg four-times-daily (n = 120). The primary endpoint was failure of prophylaxis, defined as the first occurrence of either the need to change the prophylactic regimen or the initiation of intravenous broad-spectrum antibiotics. This endpoint was observed in 89 (73.0%) of 122 levofloxacin recipients and in 85 (70.8%) of 120 ciprofloxacin plus phenethicillin recipients (RR 1.03, 95% CI 0.88-1.21, p 0.71). No differences were noted between the two groups with respect to secondary outcome measures, including time to endpoint, occurrence of fever, type and number of microbiologically documented infections, and administration of intravenous antibiotics. A questionnaire revealed that levofloxacin was tolerated significantly better than ciprofloxacin plus phenethicillin. Surveillance cultures indicated the emergence of viridans group (VG) streptococci resistant to levofloxacin in 17 (14%) of 122 levofloxacin recipients; in these cases, the prophylactic regimen was adjusted. No bacteraemia with VG streptococci occurred. It was concluded that levofloxacin and ciprofloxacin plus phenethicillin are equally effective in the prevention of bacterial infections in neutropenic patients, but that levofloxacin is tolerated better. Emergence of levofloxacin-resistant VG streptococci is of concern, but appears to be a manageable problem.

Emergence of quinolone resistance among viridans group streptococci isolated from the oropharynx of neutropenic peripheral blood stem cell transplant patients receiving quinolone antimicrobial prophylaxis

In neutropenic patients receiving quinolone prophylaxis, bacteremia with viridans group streptococci resistant to quinolones is a known complication. The frequency of occurrence of quinolone-resistant organisms colonizing the oropharynx during antibacterial prophylaxis with a quinolone is not well defined. In 48 patients undergoing hematopoietic stem cell transplantation, the prevalence of quinolone resistance in viridans group streptococci colonizing the oropharynx before and during antibacterial prophylaxis with gatifloxacin or moxifloxacin (most with concomitant penicillin) was determined. For quinolone-resistant isolates, mutations in the genes gyrA and parC, which confer resistance to quinolones, were analyzed. Seventy-four isolates before and 27 isolates during quinolone use were recovered from patients' oropharynxes. The numbers of susceptible isolates recovered before versus during quinolone use were as follows: 52 (70%) versus three (11%) for ciprofloxacin, 66 (89%) versus eight (30%) for levofloxacin, 66 (89%) versus ten (37%) for gatifloxacin, and 67 (91%) versus 11 (41%) for moxifloxacin (p<0.0001). Mutations in gyrA and/or parC were detected in quinolone-resistant isolates. Quinolone-resistant viridans group streptococci are frequently found in the oropharynx of neutropenic patients after a brief (median, 8 days) exposure to gatifloxacin or moxifloxacin.

Antibiotic prophylaxis for bacterial infections in afebrile neutropenic patients following chemotherapy

BACKGROUND

Bacterial infections are a major cause of morbidity and mortality in neutropenic patients following chemotherapy for malignancy. Trials have shown the efficacy of antibiotic prophylaxis in decreasing the incidence of bacterial infections, but not in reducing mortality rates.

OBJECTIVES

This review aimed to evaluate whether antibiotic prophylaxis in afebrile neutropenic patients reduced mortality when compared to placebo or no intervention.

SEARCH STRATEGY

Electronic searches on The Cochrane Cancer Network Register of Trials (2004), Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 4, 2004), MEDLINE (1966 to 2004) and EMBASE (1980 to 2004) and abstracts of conference proceedings; references of identified studies; the first author of each included trial was contacted.

SELECTION CRITERIA

RCTs or quasi-RCTs comparing different types of antibiotic prophylaxis with placebo or no intervention, or another antibiotic to prevent bacterial infections in afebrile neutropenic patients.

DATA COLLECTION AND ANALYSIS

Two authors independently appraised the quality of each trial and extracted data from the included trials. Relative risks (RR) or average differences, with their 95% confidence intervals (CI) were estimated.

MAIN RESULTS

One hundred trials (10,274 patients) performed between the years 1973 to 2004 met inclusion criteria. Antibiotic prophylaxis significantly decreased the risk for death when compared with placebo or no intervention (RR, 0.66 [95% CI 0.54 to 0.81]). The authors estimated the number needed to treat (NNT) in order to prevent 1 death from all causes as 60 (95% CI 34 to 268). Prophylaxis resulted in a significant decrease in the risk of infection-related death, RR 0.58 (95% CI 0.45 to 0.74) and in the occurrence of fever, RR 0.78 (95% CI 0.75 to 0.82). A reduction in mortality was also evident when the more recently conducted quinolone trials were analysed separately. Quinolone prophylaxis reduced the risk for all-cause mortality, RR 0.52 (95% CI, 0.37 to 0.84).

AUTHORS' CONCLUSIONS

Our review demonstrated that prophylaxis significantly reduced all-cause mortality. The most significant reduction in mortality was observed in trials assessing prophylaxis with quinolones. The benefit demonstrated in our review outweighs harm, such as adverse effects, and development of resistance, since all-cause mortality is reduced. Since most trials in our review were of patients with haematologic cancer, prophylaxis, preferably with a quinolone, should be considered for these patients.

New agents for the prevention of opportunistic infections in haematopoietic stem cell transplant recipients

Over the past three decades, autologous and allogeneic haematopoietic stem cell transplants (HSCTs) have become effective treatments for a variety of malignant and nonmalignant conditions. Patients who undergo HSCT receive high doses of chemotherapy and/or radiation that induce a prolonged period of profound immunodeficiency, placing them at high risk for infection from a panoply of opportunistic organisms. Although supportive treatment for these patients has markedly improved, 10-20% of allogeneic HSCT recipients will ultimately succumb to infection. Joint guidelines to prevent opportunistic infection were released in 2000 by the Centers for Disease Control, the Infectious Diseases Society of America, and the American Society of Blood and Marrow Transplantation; however, treatment decisions for these patients are often based on limited studies or depend on institution-specific transplant protocols and antibiotic resistance patterns. This paper will discuss new agents for preventing bacterial, fungal and viral infections in HSCT recipients.

Early bacteremia in pediatric hematopoietic stem cell transplant patients on oral antibiotic prophylaxis

BACKGROUND

Bacteremia occurs during hematopoietic stem cell transplant (HSCT) in 20%-25% of patients and the use of gut decontamination (GD) to decrease this risk is controversial. Our purpose was to determine the incidence of bacteremia and antimicrobial resistance post-HSCT in pediatric patients receiving GD, and to identify risk factors associated with infection.

PROCEDURES

This was a retrospective cohort study of 182 pediatric patients undergoing first HSCT for malignant disease at The Children's Hospital of Philadelphia from January, 1999 to December, 2002. We examined the impact of age, sex, race, diagnosis, disease status, conditioning regimen, recent bacteremia, stem cell source, donor, graft versus host disease prophylaxis agents, and mucositis severity using Cox proportional hazard models. GD consisted of amoxicillin (azithromycin, if penicillin allergic) and oral gentamicin. Outcome was first episode of bacteremia prior to absolute neutrophil count (ANC) 500/mm(3). Antibiotic susceptibilities were performed on all isolates.

RESULTS

Seventy-four patients (41%) developed bacteremia. The majority were Gram-positive cocci, with Staphylococcal (50%) and Streptococcal species (28%) the most common. Gram-negative organisms were identified in 22% with Pseudomonas (5.7%) and Klebsiella species (3.4%) the most common. Of the Streptococcal infections, 72% were resistant to ampicillin; only 25% of the Gram-negative bacteria were resistant to gentamicin. Race was the only factor associated with early bacteremia (hazard ratio 2.3 for non-Caucasian, non-African-American patients, CI 1.3-4.3, P = 0.007).

CONCLUSIONS

Early bacteremia is common after HSCT, despite the use of GD. Resistant Gram-positive organisms predominate, consistent with recent trends in immunocompromised patients. Although used in practice, there is no clear evidence for the efficacy of GD and this study provides the basis upon which to develop a randomized clinical trial evaluating the current GD regimen with placebo.

Antimicrobial susceptibility patterns among viridans group streptococcal isolates from infective endocarditis patients from 1971 to 1986 and 1994 to 2002

To determine whether changes in antimicrobial resistance have occurred among viridans group streptococci, we retrospectively examined 50 viridans group streptococcal isolates recovered from patients with infective endocarditis over 3 decades. Resistance rates (percent resistant isolates 1971 to 1986 and 1994 to 2002) were as follows: levofloxacin, 0 and 9; penicillin and clindamycin, 0 and 4; and erythromycin and azithromycin, 11 and 26, respectively.

Prevention of peritransplantation viridans streptococcal bacteremia with early vancomycin administration: a single-center observational cohort study

BACKGROUND

Viridans streptococcal bacteremia (VSB) after allogeneic hematopoietic stem cell transplantation (HSCT) is associated with substantial mortality. Prevention of this serious complication is therefore a high priority. The objective of this study was to evaluate the effect of early vancomycin administration on rates and outcomes of VSB.

METHODS

We analyzed the effect of early vancomycin on the incidence of VSB in a cohort of 430 consecutive HSCTs performed during the period of 1 January 1998 to 30 September 2002. The primary end point was time to diagnosis of VSB. Early vancomycin was defined as >or=2 doses of vancomycin between days -7 through +7 after HSCT or diagnosis of VSB, whichever occurred first. Risk factors for VSB were identified in univariate and multivariate Cox proportional hazard models.

RESULTS

The incidence of VSB in the cohort was 7.4%. The incidence of VSB in patients who did not receive early vancomycin was 24.8%, compared with 0.3% in patients who did (P<.001). Additional risk factors were female sex, conditioning with total body irradiation, and diagnosis of chronic myelogenous leukemia.

CONCLUSIONS

The attributable mortality rate for VSB in our cohort was 21%. Early vancomycin was associated with decreased VSB (hazard ratio, 0.02; 95% confidence interval, 0.003-0.19) after controlling for age, sex, underlying disease, and transplantation variables. The benefits of vancomycin prophylaxis for the prevention of VSB and associated mortality need to be evaluated in a prospective clinical trial.

Pharmacokinetics and effects on bowel and throat microflora of oral levofloxacin as antibacterial prophylaxis in neutropenic patients with haematological malignancies

Gram-positive breakthrough infections pose a major drawback to the use of quinolones for antibacterial prophylaxis in neutropenic patients. Levofloxacin offers the advantage of an augmented Gram-positive spectrum and may potentially overcome this problem. In an open-label, clinical pilot study, we investigated the effects on throat and bowel microflora and pharmacokinetics of a once-daily oral dose of 500 mg levofloxacin, during neutropenia in 20 patients with haematological malignancies. Gram-negative bowel flora and Staphylococcus aureus were successfully eradicated. No Gram-negative infections occurred. Minimal inhibitory concentration values for viridans group (VG) streptococci tended to increase, in four patients over 8 mg/l, indicating resistance to levofloxacin. Four patients developed blood-stream infections with levofloxacin-resistant Gram-positive cocci. No significant changes in numbers of anaerobic microorganisms were observed. Pharmacokinetic parameters of levofloxacin, including the maximum serum concentration (C(max)), time to C(max) (T(max)), area under the concentration-time curve (AUC), volume of distribution at steady state (V(ss)/F) and clearance (CL/F) were not statistically different at first dose and during neutropenia. In conclusion, levofloxacin eradicates Gram-negative microorganisms and S. aureus and spares the anaerobic flora. Its pharmacokinetic profile is unaltered during neutropenia. However, prolonged administration of levofloxacin as antibacterial prophylaxis may be hampered by the emergence of levofloxacin-resistant VG streptococci.

Antibiotic prophylaxis with meropenem after allogeneic stem cell transplantation

In the present study, we analyze the efficacy of prophylaxis with meropenem in patients receiving a matched related donor allogeneic transplant. In total, 38 patients were sequentially treated with meropenem starting on the day of the first febrile episode (n=17, group A) vs prophylactic meropenem starting on the first day with <500/mm(3) granulocytes (n=21, group B), and maintained until resolution of fever or after granulocyte count >500/mm(3). Of these, 16 (94%) patients in group A developed fever as compared to 16 (76%) in group B (P=0.02). While only one patient in group A did not require first-line antibiotherapy, there were seven (33%) in group B who did not require it (P=0.01) since fever lasted less than 72 h. In addition, 52% patients in group B did not require second-line antibiotics as compared to 11% among patients in group A (P=0.04). In multivariate analysis prophylaxis with meropenem (HR=2.83, 95% CI (1-8.02); P=0.04) and disease status at transplant (HR for early stage=0.15, 95% CI (0.04-0.62); P=0.04) significantly influenced the development of fever. In conclusion, the current pilot study suggests that the use of prophylaxis with meropenem during the period of neutropenia in patients undergoing allogeneic transplantation favorably affects the morbidity of the procedure by reducing febrile episodes.

Reappraisal With Meta-Analysis of the Addition of Gram-Positive Prophylaxis to Fluoroquinolone in Neutropenic Patients

Purpose: Past reports and meta-analyses indicate that fluoroquinolones are highly effective in preventing Gram-negative infections in neutropenic cancer patients, but offer inadequate coverage for Gram-positive infections. We evaluated by meta-analysis the efficacy of the addition of antimicrobial agents with enhanced Gram-positive activity to prophylaxis with quinolones.

Materials and Methods: Randomized trials comparing fluoroquinolones alone (ciprofloxacin, ofloxacin, pefloxacin, or norfloxacin) with fluoroquinolone in combination with Gram-positive prophylaxis (rifampin, vancomycin, amoxicillin, roxithromycin, or penicillin) were retrieved. We pooled relative risks (RRs) using a fixed-effects model.

Results: Nine trials (1,202 patients) published between 1993 and 2000 meet inclusion criteria. Compared with fluoroquinolone alone, Gram-positive prophylaxis reduced total bacteremic episodes (RR, 1.54; 95% CI, 1.26 to 1.88), streptococcal infections (RR, 2.20; 95% CI, 1.44 to 3.37), coagulase-negative staphylococcal infections (RR, 1.46; 95% CI, 1.04 to 2.04), and rate of febrile patients (RR 1.08; 95% CI, 1.00 to 1.16). Occurrence of clinically documented infections, unexplained fever, and infectious mortality was similar in the two groups. The addition of Gram-positive prophylaxis, however, significantly increased side effects (RR, 0.46; 95% CI, 0.28 to 0.76). Rifampin use resulted in a higher incidence of undesirable effects.

Conclusion: Considering the lack of cut-clear benefit on some parameters of morbidity and mortality, routine use of Gram-positive prophylaxis is not advisable. This strategy, however, should be particularly valuable in subgroups of patients at high risk of streptococcal infection (eg, those with severe and prolonged neutropenia or mucositis, and those receiving cytarabine). Problems of tolerability and the potential for the emergence of resistant microorganisms should be considered when prescribing prophylaxis with enhanced Gram-positive activity to neutropenic patients.

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.

Alpha hemolytic streptococcal infection during intensive treatment for acute myeloid leukemia: a report from the Children's cancer group study CCG-2891

PURPOSE

Past reports indicate that alpha hemolytic streptococcal (AHS) organisms are a common cause of infection among acute myeloid leukemia (AML) patients. This study was intended to ascertain the population incidence and rate (infections per 100 patient-days of treatment) of AHS and to identify associated risk factors.

PATIENTS AND METHODS

Patients (n = 874 with 151,350 days of risk) enrolled on the Children's Cancer Group (CCG) protocol for newly diagnosed AML, CCG-2891, which randomly assigned intensity of induction and intensification, were prospectively evaluated for infectious complications.

RESULTS

AHS occurred in 21% of patients, was primarily blood borne (86%), made up 21% of bacteremic infections, and had a recurrent incidence of 31% during subsequent therapy. AHS was more often life-threatening (59%) than other infections (41%) (P = .001). AHS rates increased with age less than 10 years (odds ratio [OR], 2.0; P = .007), intensively timed induction (OR, 1.8 to 1.9; P = .02), and high-dose cytarabine intensification (OR, 3.7; P<.0001). Among all courses, the greatest incidence (19%) and rate (0.41) were associated with the use of high-dose cytarabine. Gastrointestinal toxicity correlated significantly with AHS bacteremia (P<.01). Infection with AHS resulted in increased hospital days (P =.0001). Only among bone marrow transplant patients were overall survival (OR, 2.8; P = .0001) and disease-free survival (OR, 2.1; P = .008) decreased after AHS bacteremia.

CONCLUSION

This study, the first to prospectively examine AHS incidence among uniformly treated patients in multiple institutions, established that as the intensity of AML therapy has increased, so has the rate of AHS. Young children, those with previous AHS bacteremias, and those receiving high-dose cytarabine are at particularly high risk of AHS bacteremia.

Infections in adults undergoing unrelated donor bone marrow transplantation

This study retrospectively reviews infections over a 7-year period in 60 consecutive adults (median age 25 years) undergoing their first unrelated donor bone marrow transplant (UD-BMT). T-cell depletion was employed in 93%. More than half the patients had one or more severe, potentially life-threatening, infections. There was a high incidence of invasive fungal infections (Aspergillus 17, Candida four), despite the use of itraconazole or amphotericin prophylaxis. Ten Aspergillus infections occurred beyond 100 d. Two patients (11%) with invasive aspergillosis survived. Clustering of infections was noted, with invasive fungal infections significantly associated with bacteraemias (OR 3.73, P=0.06) and multiple viral infections (OR 4.25, P=0.05). There were 21 severe viral infections in 16 patients, with CMV disease occurring in four patients only; viral pneumonitis was predominantly due to 'community respiratory' viruses. Most early bacteraemias (68%) were due to Gram-positive organisms. The majority of episodes of Gram-negative sepsis were caused by non-fastidious non-fermentative bacteria, such as Pseudomonas spp. and Acinetobacter spp., historically regarded as organisms of low pathogenicity. In patients with successful engraftment and minimal graft-versus-host disease, late infections suggestive of continued immune dysfunction (shingles, recurrent lower respiratory infections, Salmonella enteritis and extensive warts) were common.

Oral antimicrobial prophylaxis in bone marrow transplant recipients: randomized trial of ciprofloxacin versus ciprofloxacin-vancomycin

The optimal oral antimicrobial prophylactic regimen for bone marrow transplant recipients remains to be elucidated. We randomized 84 patients to receive either oral ciprofloxacin or ciprofloxacin plus vancomycin at hospital admission. Patients were monitored for bacteremias and clinical parameters, and stool and throat swab surveillance cultures were performed. The addition of vancomycin resulted in a significant decrease in the frequency of patients with surveillance cultures positive for coagulase-negative staphylococci (stool cultures, 44 versus 23%; throat swab cultures, 37 versus 19%) and alpha-hemolytic streptococci (throat swab cultures, 90 versus 60%). The frequencies of positivity for Candida spp. and gram-negative organisms on surveillance cultures were comparable. Despite these results, no differences in the incidences of bacteremias (12 of 41 versus 12 of 43 patients) or clinical parameters such as number of days to first fever, total number of febrile days, length of stay, and number of transfusions could be demonstrated. Because of a lack of efficacy of vancomycin and emerging problems with vancomycin-resistant isolates, vancomycin should not be used in oral antimicrobial prophylaxis regimens.

Prophylactic antibiotics eliminate bacteremia and allow safe outpatient management following high-dose chemotherapy and autologous stem cell rescue

This study examines the effectiveness of prophylactic ciprofloxacin and rifampin following high-dose chemotherapy and autologous stem cell rescue (HDC/ ASCR). Specific endpoints included the incidence of fever, clinically documented infection, bacteremia, and readmission rates from an outpatient bone marrow transplant setting following infection or fever. A group of 97 patients receiving 134 cycles of HDC/ASCR were studied. Patients were given ciprofloxacin 750 mg p.o. twice daily and rifampin 300 mg p.o. twice daily beginning on the day of stem cell reinfusion (24-48 h after completion of high-dose chemotherapy). Most patients were either discharged to an outpatient setting following completion of their chemotherapy or received all of their chemotherapy in an outpatient setting. Febrile neutropenia was treated with empirical antibiotics in an outpatient setting unless it was complicated by hypotension, renal failure, severe mucositis or other problems. The median duration of neutropenia (absolute neutrophil count below 500/mm3) was 7 days. Neutropenic fever occurred in 62% of patients but clinically documented bacterial infection occurred in only 2 (1.5%) patients during their neutropenic period. No bacteremia was noted. Readmission to the hospital following fever or infection occurred in 26% of patients maintained in the outpatient setting. There were no deaths from a bacterial infection in this study although 1 patient (0.7%) died from aspergillosis. Prophylactic ciprofloxacin and rifampin is a well-tolerated and highly effective combination that effectively decreases the risk of both gram-positive and gram-negative bacterial infection following HDC/ASCR. It facilitates outpatient management of myelosuppressed patients receiving autologous stem cell rescue.