Vancomycin-resistant enterococcus (VRE) in pediatric oncology patients: An analysis of potential consequences of colonization and infection

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Background: VRE colonization and infection have emerged as an issue for pediatric oncology patients, but little is known about the long-term risks following initial VRE positivity in this population. The purpose of this study was to determine the risk of subsequent VRE infection in colonized or infected pediatric oncology patients and to try to identify risk factors. Methods: A retrospective analysis was performed of the 57 pediatric oncology patients who had a positive VRE culture at MSKCC from 1996–2000 and subsequently received chemotherapy and/or radiation therapy. Patients whose only subsequent treatment was allogeneic stem cell transplantation were excluded. The incidence of subsequent VRE infection was calculated using a competing risk analysis accounting for death from non-VRE causes as a competing risk. Data regarding hypothesized risk factors for subsequent VRE infections were collected. Results: Ten of the 57 patients had subsequent VRE infection, but none was the primary cause of death. The cumulative incidence of subsequent infection was 14% (7–27%, 95% confidence interval) at 1 year and 16% (9–29%, 95% confidence interval) at 2 years. Eight developed their subsequent infection within 3 months; the other 2 occurred at 15 and 30 months. A formal analysis of risk factors was not attempted due to the small number of events; however, none of the hypothesized risk factors (initial VRE colonization versus infection, number of chemotherapy or radiation therapy regimens, number of neutropenic or mucositis episodes, number of hospitalizations, number of abdominal surgeries or stem cell transplantations) appeared to differ between those who developed a subsequent infection and those who did not. Conclusions: Pediatric oncology patients with VRE colonization or initial infection are at risk for subsequent VRE infection, particularly within the first 3 months of initial diagnosis of VRE positivity.

No significant financial relationships to disclose.

Preemptive diagnosis and treatment of Epstein-Barr virus-associated post transplant lymphoproliferative disorder after hematopoietic stem cell transplant: an approach in development

Hematopoietic stem cell transplant (HSCT) recipients are at risk for Epstein-Barr virus (EBV)-associated, post transplant lymphoproliferative disorder (PTLD). Studies have suggested that early treatment may improve the outcome of patients with PTLD. Thus, significant attention has been focused on PCR-based approaches for preemptive (i.e., prior to clinical presentation) diagnosis. Reports from several transplant centers have demonstrated that HSCT recipients with PTLD generally have higher concentrations of EBV DNA in the peripheral blood than patients without PTLD. However, the PCR values of patients with PTLD typically span multiple orders of magnitude and overlap significantly with values from patients without PTLD. Thus, questions remain about the sensitivity and predictive value of these assays. Preemptive strategies using rituximab and/or EBV-specific cytotoxic T lymphocytes have been evaluated in patients with elevated EBV viral loads. We review the current literature, discuss our institutional experience and identify several areas of future research that could improve the diagnosis and treatment of this life-threatening disorder in HSCT recipients.

Pre- and post-engraftment bloodstream infection rates and associated mortality in allogeneic hematopoietic stem cell transplant recipients

We report on bloodstream infection (BSI) rates, risk factors, and outcome in a cohort of 298 adult and pediatric hematopoietic stem cell transplantation (HSCT) recipients at Memorial Sloan-Kettering Hospital from September 1999 through June 2003. Methods. Prospective surveillance study. BSI rates are reported per 10,000 HSCT days. Date of engraftment is defined as the first of at least 3 consecutive dates of absolute neutrophil count >500/mm(3) after stem cell infusion. BSI severity grades: severe (intravenous antibiotics), life threatening (sepsis), or fatal (caused or contributed to death). Results. The incidence of pre- and post-engraftment BSI was 22% and 19.5%, respectively. Pre-engraftment highest rates were observed for viridans streptococci (58), Enterobacteriaceae (39), and Enterococcus faecium (34). Post-engraftment rates ranged from 0.2 to 2.9 without any predominant pathogen. In multivariate analyses, pre-engraftment BSI was associated with diagnosis of chronic myelogenous leukemia, age >18 years and peripheral blood stem cell graft; post-engraftment BSI was associated with acute graft-versus-host disease, neutropenia, and liver or kidney dysfunction. Attributable mortality was 12.5% and 1.7% for pre- and post-engraftment BSI, respectively. BSI fatality rates were 24% for viridans streptococci, 8% for E. faecium, 11% for Staphylococcus aureus, and 67% for Candida. Conclusions. Pre-engraftment BSI, especially by viridans streptococci and E. faecium, was associated with substantial attributable mortality. Post-engraftment BSI was a marker of post-transplant complications and rarely the primary cause of death.

Respiratory syncytial virus infection following hematopoietic stem cell transplantation

Respiratory syncytial virus, one of the most common causes of respiratory infections in immunocompetent individuals, is frequently spread to recipients of HSCT by family members, other patients, and health care workers. In immunosuppressed individuals, progression from upper respiratory tract disease to pneumonia is common, and usually fatal if left untreated. We performed a retrospective analysis of RSV infections in recipients of autologous or allogeneic transplants. The incidence of RSV following allogeneic or autologous HSCT was 5.7% and 1.5%, respectively. Of the 58 patients with an RSV infection, 16 of 21 patients identified within the first post-transplant month, developed pneumonia. Seventy-two percent of patients received aerosolized ribavirin and/or RSV-IGIV, including 23 of 25 patients diagnosed with RSV pneumonia. In this aggressively treated patient population, three patients died of RSV disease, each following an unrelated HSCT.

Cytomegalovirus ventriculoencephalitis in a bone marrow transplant recipient receiving antiviral maintenance: clinical and molecular evidence of drug resistance

We describe a case of CMV ventriculoencephalitis in a severely immunocompromised bone marrow transplant recipient who was receiving combination therapy with ganciclovir and foscarnet for treatment of viremia and retinitis. Analysis of sequential viral isolates recovered from the patient's cerebrospinal fluid suggested that disease developed because of the presence of viral resistance and, possibly, low tissue penetration of antiviral agents.

Mycobacterium haemophilum in immunocompromised patients

Mycobacterium haemophilum, a recently described pathogen, can cause an array of symptoms in immunocompromised patients. To date, 90 patients with this infection have been described worldwide. We report our institution's experience with 23 patients who were treated from 1990 through 2000. Fourteen patients had undergone bone marrow transplantation, 5 were infected with human immunodeficiency virus, 3 had hematologic malignancies, and 1 had no known underlying immunosuppression. Clinical syndromes on presentation included skin lesions alone in 13 patients, arthritis or osteomyelitis in 4 patients, and lung disease in 6 patients. Although patients with skin or joint involvement had favorable outcomes, 5 of 7 patients with lung infection died. Prolonged courses of multidrug therapy are required for treatment. A diagnosis of M. haemophilum infection must be considered for any immunocompromised patient for whom acid-fast bacilli are identified in a cutaneous, synovial fluid or respiratory sample or for whom granulomas are identified in any pathological specimen.

Candida dubliniensis at a cancer center

Candida dubliniensis, a germ tube-positive yeast first described and identified as a cause of oral candidiasis in patients with acquired immunodeficiency syndrome in Europe in 1995, has an expanding clinical and geographic distribution that appears to be similar to that of the other germ tube-positive yeast, Candida albicans. This study determined the frequency, clinical spectrum, drug susceptibility profile, and suitable methods for identification of this emerging pathogen at a cancer center in 1998 and 1999. Twenty-two isolates were recovered from 16 patients with solid-organ or hematologic malignancies or acquired immunodeficiency syndrome. Two patients with cancer had invasive infection, and 14 were colonized with fungus or had superficial fungal infection. All isolates produced germ tubes and chlamydospores at 37 degrees C, did not grow at 45 degrees C, and gave negative reactions with d-xylose and alpha-methyl-d-glucoside in the API 20 C AUX and ID 32 C yeast identification systems. Phenotypic identification was confirmed by molecular beacon probe technology. All isolates were susceptible to the antifungal drugs amphotericin B, 5-fluorocytosine, fluconazole, itraconazole, and ketoconazole.

Application of the Sherlock Mycobacteria Identification System using high-performance liquid chromatography in a clinical laboratory

There is a growing need for a more accurate, rapid, and cost-effective alternative to conventional tests for identification of clinical isolates of Mycobacterium species. Therefore, the ability of the Sherlock Mycobacteria Identification System (SMIS; MIDI, Inc.) using computerized software and a Hewlett-Packard series 1100 high-performance liquid chromatograph to identify mycobacteria was compared to identification using phenotypic characteristics, biochemical tests, probes (Gen-Probe, Inc.), gas-liquid chromatography, and, when necessary, PCR-restriction enzyme analysis of the 65-kDa heat shock protein gene and 16S rRNA gene sequencing. Culture, harvesting, saponification, extraction, derivatization, and chromatography were performed following MIDI's instructions. Of 370 isolates and stock cultures tested, 327 (88%) were given species names by the SMIS. SMIS software correctly identified 279 of the isolates (75% of the total number of isolates and 85% of the named isolates). The overall predictive value of accuracy (correct calls divided by total calls of a species) for SMIS species identification was 85%, ranging from only 27% (3 of 11) for M. asiaticum to 100% for species or groups including M. malmoense (8 of 8), M. nonchromogenicum (11 of 11), and the M. chelonae-abscessus complex (21 of 21). By determining relative peak height ratios (RPHRs) and relative retention times (RRTs) of selected mycolic acid peaks, as well as phenotypic properties, all 48 SMIS-misidentified isolates and 39 (91%) of the 43 unidentified isolates could be correctly identified. Material and labor costs per isolate were $10.94 for SMIS, $26.58 for probes, and $42.31 for biochemical identification. The SMIS, combined with knowledge of RPHRs, RRTs, and phenotypic characteristics, offers a rapid, reasonably accurate, cost-effective alternative to more traditional methods of mycobacterial species identification.

Control of influenza A on a bone marrow transplant unit

In January 1998, an outbreak of influenza A occurred on our adult bone marrow transplant unit. Aggressive infection control measures were instituted to halt further nosocomial spread. A new, more rigorous approach was implemented for the 1998/99 influenza season and was extremely effective in preventing nosocomial influenza at our institution.

Rapid identification of Candida dubliniensis using a species-specific molecular beacon

Candida dubliniensis is an opportunistic fungal pathogen that has been linked to oral candidiasis in AIDS patients, although it has recently been isolated from other body sites. DNA sequence analysis of the internal transcribed spacer 2 (ITS2) region of rRNA genes from reference Candida strains was used to develop molecular beacon probes for rapid, high-fidelity identification of C. dubliniensis as well as C. albicans. Molecular beacons are small nucleic acid hairpin probes that brightly fluoresce when they are bound to their targets and have a significant advantage over conventional nucleic acid probes because they exhibit a higher degree of specificity with better signal-to-noise ratios. When applied to an unknown collection of 23 strains that largely contained C. albicans and a smaller amount of C. dubliniensis, the species-specific probes were 100% accurate in identifying both species following PCR amplification of the ITS2 region. The results obtained with the molecular beacons were independently verified by random amplified polymorphic DNA analysis-based genotyping and by restriction enzyme analysis with enzymes BsmAI and NspBII, which cleave recognition sequences within the ITS2 regions of C. dubliniensis and C. albicans, respectively. Molecular beacons are promising new probes for the rapid detection of Candida species.

Disseminated toxoplasmosis following T cell-depleted related and unrelated bone marrow transplantation

More than 95% of reported cases of disseminated toxoplasmosis following BMT have occurred following an unmodified transplant. Most have been fatal, diagnosed at autopsy and without antemortem institution of specific therapy. From 1989 to 1999, we identified 10 cases of disseminated toxoplasmosis, in 463 consecutive recipients of a T cell-depleted (TCD) BMT. Transplants were from an unrelated donor (n = 5), an HLA-matched sibling (n = 4) or an HLA-mismatched father (n = 1). In 40%, both the donor and recipient had positive IgG titers against T. gondii pre-transplant; in 30%, only the recipient was sero-positive. Three recipients of an unrelated TCD BMT developed toxoplasmosis despite both donor and host testing negative pretransplant. All 10 patients presented with high grade fever. CNS involvement ultimately occurred in seven patients, with refractory respiratory failure and hypotension developing in nine. Eight of 10 cases were found only at autopsy, involving the lungs (n = 7), heart (n = 5), GI tract (n = 5), brain (n = 8), liver and/or spleen (n = 5). The only survivor, treated on the day of presentation with fever and headache, was diagnosed by detection of T. gondii DNA by polymerase chain reaction (PCR) performed on the blood and spinal fluid. This study demonstrates the similar incidence of toxoplasmosis following TCD BMT and that reported post T cell-replete BMT, and underscores the need for rapid diagnostic tests in an effort to improve outcome.

Histologic reactions to cutaneous infections by Mycobacterium haemophilum

Mycobacterium haemophilum is an emerging pathogen in immunocompromised patients. We report the clinical and histologic findings of 16 skin biopsies from 11 patients with culture-proven infections by M. haemophilum. The patients had leukemia or non-Hodgkin's lymphoma. Ten of them had undergone bone marrow transplantation. When the skin biopsy specimens were taken, a portion of the skin was simultaneously submitted to a microbiology laboratory for cultures. The remaining skin was processed routinely. Acid-fast bacilli were found in 11 of 16 lesions. The number of histologically detectable organisms was typically low: nine biopsies had fewer than three bacilli per 50 oil immersion fields. The most common histologic pattern was a mixed suppurative and granulomatous reaction (7 of 16 biopsies). Four biopsies showed well-formed epithelioid granulomas. Two showed necrosis, one of which was ulcerated. One lesion was a subcutaneous abscess. Two biopsies showed a mixed lichenoid and granulomatous dermatitis. In one of them, the granulomatous reaction was focal and small. One biopsy lacked a granulomatous tissue reaction altogether; it showed an interface dermatitis, a perivascular and periadnexal lymphocytic infiltrate, and necrotizing lymphocytic small vessel vasculitis. A subsequent biopsy from the same patient additionally showed a focal granulomatous reaction. Our observation that infections by M. haemophilum can present with nongranulomatous or pauci-granulomatous reactions without necrosis is of note. Failure to suspect mycobacterial infection in such reactions contributes to probable underreporting of M. haemophilum and to misdiagnoses. Furthermore, our findings emphasize the importance of simultaneous biopsies for culture and histology in immunocompromised patients.

Pulmonary nodule due to Mycobacterium haemophilum in an immunocompetent host

We present a case of a pulmonary nodular lesion in an immunocompetent patient documented at open lung biopsy to be due to Mycobacterium haemophilum. This organism has recently been recognized as a cause of disease in immunocompromised patients, presenting predominantly as skin lesions, arthritis, and rarely pneumonia. Because this mycobacterium is fastidious and difficult to grow without the use of special media and conditions, our case raises the possibility that M. haemophilum could be an underrecognized cause of granulomatous pulmonary lesions and should be considered particularly in cases where smears for acid-fast bacteria are positive but cultures are negative.

Mycobacterium tuberculosis infection in a green-winged macaw (Ara chloroptera): report with public health implications

Mycobacterium tuberculosis was isolated from the eyelid, skin, tongue, and lungs of a green-winged macaw (Ara chloroptera). Two persons living in the same household were culture positive for pulmonary tuberculosis 3 to 4 years before tuberculosis was diagnosed in the bird. Although humans have not been shown to acquire tuberculosis from birds, an infected bird may be a sentinel for human infection.

Mycobacterium haemophilum: microbiology and expanding clinical and geographic spectra of disease in humans

Reports of the association of Mycobacterium haemophilum with disease in humans have greatly increased. At least 64 cases have now been reported, with symptoms ranging from focal lesions to widespread, systemic disease. The organism is now known to cause primarily cutaneous and subcutaneous infection, septic arthritis, osteomyelitis, and pneumonitis in patients who are immunologically compromised and lymphadenitis in apparently immunocompetent children. Underlying conditions in the compromised patients have included AIDS; renal, bone marrow, and cardiac transplantation; lymphoma; rheumatoid arthritis; marrow hypoplasia; and Crohn's disease. Reports have originated from diverse geographic areas worldwide. The epidemiology of M. haemophilum remains poorly defined; there appears to be a genetic diversity between strains isolated from different regions. The organism is probably present in the environment, but recovery by sampling has not been successful. M. haemophilum has several unique traits, including predilection for lower temperatures (30 to 32 degrees C) and requirement for iron supplementation (ferric ammonium citrate or hemin). These may in the past have compromised recovery in the laboratory. Therapy has not been well elucidated, and the outcome appears to be influenced by the patient's underlying immunosuppression. The organisms are most susceptible to ciprofloxacin, clarithromycin, rifabutin, and rifampin. Timely diagnosis and therapy require communication between clinician and the laboratory.

Mycobacterium genavense infections in pet animals

Mycobacterium genavense, a recently reported cause of a wasting illness in patients with AIDS, was isolated from a cervical lymph mode from a dog with severe hind limb weakness and from trachael tissue from a parrot with acute onset respiratory distress. Physicians caring for immunocompromised patients should consider birds and dogs potential sources of M. genavense infection and submit appropriate specimens for culture.

Mycobacterium haemophilum infections in bone marrow transplant recipients

The purpose of this study was to describe the clinical presentation, treatment, and outcome of Mycobacterium haemophilum infection in patients undergoing bone marrow transplantation at a cancer center. Bone marrow transplant recipients with M haemophilum infection were identified upon culture of the organism by implementing the organism's unique requirements for growth. This report of the patients' clinical and immunologic course is based on a retrospective chart review. Two distinctly different presentations of M haemophilum infection were observed. Three patients presented with cutaneous lesions, typical of those seen in previous reports of the infection. Two others developed pulmonary disease only. All patients received directed therapy against M haemophilum, but respiratory failure developed in the patients with pneumonia and they died. The remaining 3 patients survived and are free of infection. These are the only reported cases of M haemophilum infection in bone marrow transplant recipients. Early diagnosis obtained through biopsy and special request for culture conditions conducive to the growth of the organism may decrease morbidity and mortality, particularly in patients with pulmonary disease.

Direct observations of surgical wound infections at a comprehensive cancer center

OBJECTIVES

To identify the rate of surgical site infection and risk factors for surgical site infection in patients with cancer and to evaluate antibiotic use patterns on surgical oncology services.

DESIGN

Criterion standard.

SETTING

Memorial Sloan-Kettering Cancer Center, a comprehensive cancer center at a university hospital.

PATIENTS

Over a 15-month period, 1226 patients undergoing 1283 surgical procedures performed by the Breast, Colorectal, and Gastric-Mixed Tumor surgical services.

MAIN OUTCOME MEASURE

Direct observation of surgical sites was performed by a single, surgeon-trained member of the hospital's Infection Control Section, adhering to an established protocol for grading of the surgical site.

RESULTS

Operative procedures accounted for the following traditional wound class distributions: class I (clean), 630 cases; class II (clean-contaminated), 577 cases; class III (contaminated), 29 cases; and class IV (dirty-infected), 47 cases. Surgical site infection rates were 3.8% in class I; 8.8% in class II; 20.7% in class III; and 46.9% in class IV procedures. The mean (+/- SD) age was 57.7 +/- 14.3 years and the Anesthesiology Society of America physical assessment score, 2.3 +/- 0.7. The mean (+/- SD) operation time was 145 +/- 104.9 minutes. Logistic regression analysis demonstrated several risk factors for surgical site infection: obesity (P < .0001); a contaminated or dirty-infected surgical procedure category (P < .0001); operation time greater than 4 hours (P = .0004); Anesthesiology Society of America physical assessment score of 3 or greater (P < .01); and preoperative length of stay of 3 or more days (P = .03).

CONCLUSIONS

Risk factors for surgical site infection in patients with cancer are similar to those found in the National Nosocomial Infections Surveillance System. However, as an individual risk factor among our patient population, obesity contributed as strongly as the surgical procedure category to a patient's likelihood of acquiring a surgical site infection. In addition to Anesthesiology Society of America status, length of the surgical procedure, and surgical procedure category, obesity should warrant consideration as an individual risk factor for surgical site infection.

Tuberculosis in the AIDS era

A resurgence of tuberculosis has occurred in recent years in the United States and abroad. Deteriorating public health services, increasing numbers of immigrants from countries of endemicity, and coinfection with the human immunodeficiency virus (HIV) have contributed to the rise in the number of cases diagnosed in the United States. Outbreaks of resistant tuberculosis, which responds poorly to therapy, have occurred in hospitals and other settings, affecting patients and health care workers. This review covers the pathogenesis, epidemiology, clinical presentation, laboratory diagnosis, and treatment of Mycobacterium tuberculosis infection and disease. In addition, public health and hospital infection control strategies are detailed. Newer approaches to epidemiologic investigation, including use of restriction fragment length polymorphism analysis, are discussed. Detailed consideration of the interaction between HIV infection and tuberculosis is given. We also review the latest techniques in laboratory evaluation, including the radiometric culture system, DNA probes, and PCR. Current recommendations for therapy of tuberculosis, including multidrug-resistant tuberculosis, are given. Finally, the special problem of prophylaxis of persons exposed to multidrug-resistant tuberculosis is considered.

Mycobacterium haemophilum: an emerging pathogen

Mycobacterium haemophilum is emerging as a pathogen of immunocompromised patients particularly those with AIDS and organ transplants. Infection has also occurred in healthy children. Adults usually present with cutaneous manifestations, septic arthritis or occasionally pneumonia. Children have perihilar, cervical or submandibular adenitis. The organism grows on mycobacterial media supplemented with ferric ammonium citrate or hemin, incubated at 30 degrees C to 32 degrees C, two to three weeks after inoculation. The most active antimicrobial agents in vitro are amikacin, ciprofloxacin, clarithromycin, rifabutin and rifampin. Development of resistance to the rifamycins has been demonstrated after patients were treated for several months with several antimycobacterial agents, including the rifamycins. Treatment for several months with at least two agents demonstrated to have low MICs for the organism has been shown to be effective.

Restriction fragment length polymorphism analysis of clinical isolates of Mycobacterium haemophilum

Mycobacterium haemophilum is an emerging opportunistic pathogen, and since 1989, infections caused by this organism have been identified more frequently in the New York City area than in any other region of the United States. A DNA fingerprinting method, based on restriction fragment length polymorphisms (RFLPs) was developed. A genomic library of M. haemophilum isolate 1A was constructed; screening the library yielded a recombinant strain that incorporated a genetic element present in multiple copies in the M. haemophilum genome. This clone was used to produce a probe for RFLP analyses of PvuII digests of genomic DNA. We used this probe to determine the RFLP patterns of 43 clinical isolates of M. haemophilum from 28 patients. A total of six distinct patterns were observed. Two patterns, designated types 1 and 2, accounted for 91% of the infections in patients from the New York City area. Two isolates from Arizona had identical patterns but were distinct from those of New York isolates, and an isolate from Israel, the type strain, had another distinct pattern (type 6). The type 6 pattern was also seen in a recent isolate from Norway. All of the type 1 isolates and 60% of the type 2 isolates were recovered from patients with AIDS in the New York City area. This molecular subtyping method should provide a useful tool for epidemiological studies and may help identify the associated risk factors, vehicles, and possible reservoirs of this newly emerging pathogen.

Sepsis caused by Flavimonas oryzihabitans

Previous reports of F. oryzihabitans sepsis involving central venous access devices reveal a relatively high rate of complications, including device removal, despite a course of broad-spectrum anti-microbials with compatible in vitro susceptibility results. In the present report of 22 cases of F. oryzihabitans sepsis treated at Memorial Sloan-Kettering Cancer Center from February 1986 through September 1993, the majority of CVAD-related infections with F. oryzihabitans were successfully treated with a 14-day course of antimicrobials with antipseudomonal activity, and removal of the device was usually not required. Factors that may complicate successful treatment of CVAD-related sepsis caused by F. oryzihabitans include polymicrobial infections and premature discontinuation of antibiotic therapy.

Clinical and epidemiologic characteristics of Mycobacterium haemophilum, an emerging pathogen in immunocompromised patients

OBJECTIVE

To describe 13 infections caused by Mycobacterium haemophilum.

DESIGN

Identification of patients by microbiologic record review, followed by medical record review and a case-control study.

SETTING

Seven metropolitan hospitals in New York.

PATIENTS

All patients with M. haemophilum infections diagnosed between January 1989 and September 1991 and followed through September 1992. Surviving patients were enrolled in the case-control study.

RESULTS

Infection with M. haemophilum causes disseminated cutaneous lesions, bacteremia, and diseases of the bones, joints, lymphatics, and the lungs. Improper culture techniques may delay laboratory diagnosis, and isolates may be identified incorrectly as other mycobacterial species. Persons with profound deficits in cell-mediated immunity have an increased risk for infection. These include persons with human immunodeficiency virus infection or lymphoma and those receiving medication to treat immunosuppression after organ transplant. Various antimycobacterial regimens have been used with apparent success to treat M. haemophilum infection. However, standards for defining antimicrobial susceptibility to the organism do not exist.

CONCLUSIONS

Clinicians should consider this pathogen when evaluating an immunocompromised patient with cutaneous ulcerating lesions, joint effusions, or osteomyelitis. Microbiologists must be familiar with the fastidious growth requirements of this organism and screen appropriate specimens for mycobacteria using an acid-fast stain. If acid-fast bacilli are seen, M. haemophilum should be considered as the infecting organism as well as other mycobacteria, and appropriate media and incubation conditions should be used.

Infectious morbidity associated with long-term use of venous access devices in patients with cancer

OBJECTIVE

To evaluate infectious morbidity associated with long-term use of venous access devices.

DESIGN

Prospective, observational study.

SETTING

Comprehensive cancer center at a university hospital.

PARTICIPANTS

1431 consecutive patients with cancer requiring 1630 venous access devices for long-term use inserted between 1 June 1987 and 31 May 1989.

MEASUREMENTS

Quantitative microbiologic tests to identify device-related bacteremia and fungemia, catheter tunnel infection, pocket infection in implantable port devices, and site infections; number of days the device remained in situ and time until infectious morbidity; vessel or device thrombosis and device breakage.

RESULTS

At least one device-related infection occurred with 341 of 788 (43% [95% CI, 39% to 47%]) catheters compared with 57 of 680 (8% [CI, 6% to 10%]) completely implanted ports (P < or = 0.001). Device-related bacteremia or fungemia is the predominant infection occurring with catheters, whereas ports have a more equal distribution of pocket, site, and device-related bacteremia. The predominant organisms isolated in catheter-related bacteremia were gram-negative bacilli (55%) compared with gram-positive cocci (65.5%) in port-related bacteremia. The number of infections per 1000 device days was 2.77 (95% CI, 2.48 to 3.06) for catheters compared with 0.21 (CI, 0.16 to 0.27) for ports (P < or = 0.001). Based on a parametric model of time to first infection, devices lasted longer in patients with solid tumors than in those with hematopoietic tumors. Ports lasted longer than catheters across all patient groups.

CONCLUSIONS

The incidence of infections per device-day was 12 times greater with catheters than with ports. Patients with solid tumors were the least likely to have device-related infectious morbidity compared with those with hematologic cancers. The reasons for the difference in infectious complications is uncertain but may be attributable to type of disease, intensity of therapy, frequency with which devices are accessed, or duration of neutropenia.

The diagnostic mycobacteriology laboratory of the 1990s

The diagnostic mycobacterial laboratory of the 1990s must respond to a change in the clinical spectrum of mycobacterial infections brought about by an increase in the number of patients who are immunocompromised, are indigent, or have temporary or permanent implanted devices. Emerging pathogens such as Mycobacterium haemophilum and Mycobacterium genavense, multidrug-resistant strains of Mycobacterium tuberculosis, and catheter infections with rapidly growing mycobacteria are examples of new issues. Fortunately, new methods for detection and identification of microbes have been or are being developed. Procedures that, when applied directly to clinical specimens or actively growing cultures, dramatically reduce the time to diagnosis of mycobacterial infections include radiometric broth, lysis-centrifugation, and biphasic systems for specimen culture, and DNA probes, high-performance liquid chromatography, DNA hybridization, restriction fragment length polymorphism, and gene amplification for organism detection and identification. At present, in vitro antimicrobial susceptibility tests are most helpful in guiding treatment of infections caused by M. tuberculosis and rapidly growing mycobacteria.

Activities of antimicrobial agents against clinical isolates of Mycobacterium haemophilum

Mycobacterium haemophilum, first described in 1978, can cause severe infections of skin, respiratory tract, bone, and other organs of immunocompromised patients. There is no standardized antimicrobial susceptibility test, and for the 27 reported cases, a variety of test methods have been used. This paper reports the in vitro test results for 17 isolates of M. haemophilum recovered from 12 patients in the New York City area. MICs of 16 antimicrobial agents were determined in microtiter trays containing Middlebrook 7H9 broth plus 60 microM hemin, inoculated with 10(6) CFU of the organism per ml and incubated at 30 degrees C for 10 days. Ethambutol, ethionamide, tetracycline, cefoxitin, and trimethoprim-sulfamethoxazole were inactive against initial isolates from the 12 patients. Isoniazid was weakly active with a MIC for 50% of strains tested (MIC50) of 8 micrograms/ml and a MIC90 of > 32 micrograms/ml. Three quinolones, ciprofloxacin, ofloxacin, and sparfloxacin, were moderately active with MIC50s of 2 to 4 micrograms/ml and MIC90s of 4 to 8 micrograms/ml. Amikacin and clofazamine were active with MIC90s of 4 and 2 micrograms/ml, respectively. Clarithromycin was the most active macrolide with a MIC90 of < or = 0.25 microgram/ml. The MIC90 of azithromycin was 8 micrograms/ml, and the MIC90 of erythromycin was 4 micrograms/ml. The rifamycins were active with a MIC90 of 1 microgram/ml for rifampin and one of < or = 0.03 micrograms/ml for rifabutin. For a second isolate from the skin of one patient and a isolate from an autopsy culture of the spleen of a second patient, MICs of rifampin and rifabutin were > 16 microgram/ml, whereas initial isolates were inactivated by low concentrations of the rifamycins. Both patients had been treated for several months with several antimicrobial agents, including a rifamycin.

Catheter-related Malassezia furfur fungemia in immunocompromised patients

PURPOSE, PATIENTS, AND METHODS

Malassezia furfur has usually been described as a cause of catheter-related sepsis in neonates receiving intravenous lipid emulsion. We report seven cases of catheter-related M. furfur fungemia that occurred in seven immunocompromised patients including four adults and three children who were not neonates. Only two of these patients were receiving concurrent intravenous lipid emulsion.

RESULTS

All positive blood cultures were obtained from a central venous access device, one of which was a port device. Quantitative M. furfur colony counts ranged from 50 cfu/mL to greater than 1,000 cfu/mL. All seven patients were treated with amphotericin B. Blood drawn through the central lines of three patients yielded additional organisms. One central venous access device required removal due to persistently positive M. furfur blood cultures despite treatment with amphotericin B.

CONCLUSION

We conclude that catheter-related M. furfur fungemia occurs in immunocompromised patients with central venous access devices whether or not they are receiving intravenous lipids. Prompt, aggressive treatment with amphotericin B (1 mg/kg/d) may spare patients removal of their central venous access device. Further studies are needed to determine the role of endogenous lipids in the development of catheter-related M. furfur fungemia and to determine if there is a seasonal incidence in populations other than neonates, since all of our cases occurred between late March and July.

A cluster of four cases of Mycobacterium haemophilum infection

Four cases of infection with Mycobacterium haemophilum occurred at a single hospital in a seven-month period. Only 22 cases have been reported since 1976. All four patients were immunocompromised; two had AIDS and two were the first known recipients of allogeneic bone marrow transplants (BMT) to develop the infection. One BMT recipient died of Mycobacterium haemophilum pneumonia. The organism requires hemin or ferric ammonium citrate and incubation of media at 30 degrees C for optimum growth. Clinicians and microbiologists should consider infection with Mycobacterium haemophilum, particularly when specimens are from immunocompromised patients with unexplained illness and/or when acid-fast bacilli are seen on smear.

Disseminated Nocardia brasiliensis infection with septic arthritis

An unusual case of disseminated Nocardia brasiliensis infection is presented. The patient, who had been receiving chronic dexamethasone therapy for 4 years, had pneumonia and septic arthritis of the left knee due to N. brasiliensis. To our knowledge, this is the first report from the United States of a synovial joint infection with this organism. Disseminated disease due to N. brasiliensis is infrequently reported; it is most often seen in the immunocompromised patient and is often unresponsive to therapy.

Sepsis due to Rhodotorula related to use of indwelling central venous catheters

With increased use of surgically implanted silastic central venous catheters, there has been an increase in the recovery from blood cultures at Memorial Sloan-Kettering Cancer Center (New York) of environmental and skin organisms including the red yeast Rhodotorula. From 1985 through 1989, 23 patients had catheter-related Rhodotorula sepsis. All 23 patients had indwelling central venous catheters that had been in place from 1 to 22 months (average, 9.3 months) prior to the detection of fungemia. All patients had blood drawn both through the catheter and from a peripheral source, and only one patient had a peripheral blood culture positive for Rhodotorula. Colony counts of yeast from the catheter cultures often exceeded 100 (15 patients) and even 1,000 (seven patients) cfu/mL of blood. Thirteen of the patients were treated with antifungal therapy and had the catheter removed, and five patients received antifungal therapy without catheter removal (suggesting that compulsory removal of the catheter may not always be required). Five patients had the catheter removed without antifungal therapy. All patients survived the fungemic episode and experienced no recurrence of the infection.

Meningitis due to beta-hemolytic non-A, non-D streptococci among adults at a cancer hospital: report of four cases and review

Four cases of meningitis due to beta-hemolytic non-A, non-D streptococci among adult patients with neoplastic disease are reported. All four patients had head or neck tumors for greater than or equal to 4 years, and all had undergone surgery for these tumors. Three of four patients had received local radiation therapy. None of the patients were neutropenic. One patient died. A review of the literature revealed that most patients with non-A, non-D streptococcal meningitis had disruption of the normal barrier protecting the CNS due to trauma, surgery, or the presence of a tumor, or had extensive exposure to animals or an underlying medical disease. Infection with non-A, non-D streptococci should be considered in any patient with meningitis who has a tumor of the head or neck and who has undergone surgery and/or radiation therapy.

Changes in the spectrum of organisms causing bacteremia and fungemia in immunocompromised patients due to venous access devices

A significant increase in the use of vascular access devices has changed the spectrum of organisms causing bacteremia and fungemia at Memorial Sloan-Kettering Cancer Center. This paper documents the 1988 laboratory experience with bacteremia and fungemia and contrasts some of that data with information obtained in 1984. In 1988, 439 tunnelled-catheters and 355 ports were inserted in patients; 2,778 organisms were subsequently recovered from 933 episodes of bacteremia and fungemia. Fifty-percent of the episodes of bacteremia and fungemia were vascular access device-related. Compared to 1984, the relative incidence of bacteremia due to gram-positive organisms increased from 33 to 43%, polymicrobic cultures increased from 24 to 27%, and the number of organisms with colony counts greater than 100 cfu/ml increased from 24 to 44%. In 1988, device-related sepsis was often caused by Acinetobacter spp., Bacillus spp., Corynebacterium spp., pseudomonads other than Pseudomonas aeruginosa, and coagulase-negative staphylococci. Infection was also caused by species of flavobacteria, Micrococcus, and Rhodotorula. Efforts required for identification of many of the newer pathogens have escalated material and personnel costs.

Nocardia infection in the acquired immunodeficiency syndrome

A case of Nocardia asteroides pneumonia in a patient with the acquired immunodeficiency syndrome who was intolerant of sulfadiazine is described. On cefuroxime, the patient had a complete resolution of his Nocardia pneumonia. Disk-diffusion and broth microdilution antibiotic susceptibility testing (MIC less than or equal to 2 micrograms/ml) strongly supported the use of cefuroxime as treatment in this patient. Susceptibility testing with newer cephalosporins should be considered for all significant Nocardia isolates.

Role of the microbiology laboratory in care of the immunosuppressed patient

In the immunosuppressed patient the usual hallmarks of infection, such as leukocytosis and antibody response, may be absent; thus the microbiology laboratory plays a fundamental role in the diagnosis of infection. Methods used to demonstrate microorganisms in a specimen submitted to the laboratory include visualization techniques, culture, and non-cultural methods involving immunologic, immunochemical, and nucleic acid probe methodologies. Because infections in the immunosuppressed patient may be caused by unusual organisms whose identification requires special techniques, close communication between the physician and the laboratory is important. New technologies allow the clinical microbiology laboratory to gather important diagnostic information more readily. When these results are delivered rapidly to physicians via computerized information systems, care of the immunosuppressed patient is significantly enhanced.

Bacteremia and fungemia in the immunocompromised patient

Considerable changes have occurred during the 1980s in the clinical nature and diagnosis of bacteremia and fungemia in the immunocompromised patient. Cancer patients with prolonged neutropenia, many with indwelling catheters, and AIDS patients with both T-cell and B-cell deficiencies have changed the spectrum of organisms causing septicemia. There has been a shift to infection with gram-positive bacteria, including mycobacteria, and water-borne organisms, including Acinetobacter spp. and Pseudomonas spp. New blood culture systems, including a lysis-centrifugation system and radiometric methods utilizing resin broth media, remove antagonistic antimicrobial agents, and the lysis-centrifugation system routinely provides quantitation of organisms from the blood. Quantitation has been used to identify sources of infection, to differentiate contamination from true infection, and to monitor the course of antibiotic treatment.

Prospective study of infections in indwelling central venous catheters using quantitative blood cultures

PURPOSE

Surgically implanted central venous catheters are widely used in cancer patients in whom there is a need for prolonged venous access for chemotherapy, parenteral nutrition, antibiotics, and blood sampling. This study evaluated catheter infectious complications, including catheter-related sepsis, exit site infection, and tunnel infection. Specifically, an evaluation of the incidence, type, and response to treatment of indwelling catheter infections was performed, and conditions under which the catheter should be removed were delineated.

PATIENTS AND METHODS

During the year of this study, 488 central venous catheters were implanted. Records were maintained on demographic variables, date of catheter implantation, surgeon, white blood cell count, absolute neutrophil count, and underlying diagnosis. Blood for both aerobic and anaerobic culture was collected from each patient. For patients in whom infection developed, clinical features, white blood cell count, absolute neutrophil count, and microbiologic data were noted, as were the clinical course and response to treatment.

RESULTS

A total of 142 episodes of infectious complications were documented. There were 88 episodes of catheter-related sepsis, and 33 of 54 evaluable episodes (61 percent) were successfully treated with antibiotics. There were 34 episodes of exit site infection, and 20 of the 29 evaluable episodes (69 percent) were successfully treated with antibiotics and local care. Of the 20 tunnel infections, only five (25 percent) were successfully treated with antibiotics, and the other 15 required catheter removal for cure. Twelve of the 15 cases requiring catheter removal were caused by Pseudomonas species.

CONCLUSION

On the basis of these results, compulsory removal of the catheter is not required in cases of catheter-related sepsis. Similarly, exit site infections can often be cured by means of antibiotics and local care. However, catheter removal is required to achieve cure in most tunnel infections, particularly if Pseudomonas species are cultured from the exit sites of patients with tunnel infection.

Rapid detection and identification of pathogenic mycobacteria by combining radiometric and nucleic acid probe methods

The combination of radiometric methodology (BACTEC 12B) and probe technology for recovery and identification of mycobacteria was studied in two large hospital laboratories. The sediment from vials with positive growth indices was tested with DNA probes specific for Mycobacterium tuberculosis, Mycobacterium avium, and Mycobacterium intracellulare. The sensitivity of the radiometric method and the specificity of the probes resulted in a marked reduction in the time to the final report. Biochemical testing could be eliminated on isolates giving a positive reaction with one of the probes. Some 176 isolates of M. tuberculosis, 110 of M. avium, and 5 of M. intracellulare were recovered. Two-thirds of these isolates were detected and identified within 2 weeks of inoculation and the remainder was detected by 4 weeks, a reduction of 5 to 7 weeks to the final report.

Comparative recoveries of Mycobacterium avium-M. intracellulare from isolator lysis-centrifugation and BACTEC 13A blood culture systems

Blood cultures processed with a lysis-centrifugation (Isolator) system and a radiometric (BACTEC 13A) broth system were compared for the recovery of Mycobacterium avium-M. intracellulare from patients with acquired immunodeficiency syndrome. Forty-nine isolates of M. avium-M. intracellulare were recovered by both systems, 9 were recovered by the Isolator system only, and 12 were recovered by the BACTEC system only. Average times to detection were 16 and 14 days for the Isolator and BACTEC systems, respectively. There was no significant difference between the two blood culture systems in sensitivity or time to detection.

Liver infection caused by Coniothyrium fuckelii in a patient with acute myelogenous leukemia

A case of liver infection caused by Coniothyrium fuckelii is described in a patient with acute myelogenous leukemia. This fungus is found in the soil and can be a pathogen of plants. Coniothyrium spp. are members of the order Sphaeropsidales, an order composed of fungi whose conidiomata are usually pycnidia with the conidiogenous hymenium lining the walls of the locule. Coniothyrium spp. must be differentiated from Phoma spp. and Hendersonula spp., the two most commonly isolated members of the Sphaeropsidales.

Rapid identification using a specific DNA probe of Mycobacterium avium complex from patients with acquired immunodeficiency syndrome

Specific DNA probes (Gen-Probe Corp., San Diego, Calif.) for Mycobacterium avium, Mycobacterium intracellulare, and Mycobacterium tuberculosis were compared with conventional methods for the identification of isolates of the Mycobacterium avium complex. A total of 56 isolates of M. avium complex were recovered from 34 respiratory, 13 blood, 6 stool, and 3 urine samples from 23 patients. A total of 33 isolates were tested directly from Middlebrook 7H11 agar plates, and 23 isolates were tested directly from BACTEC radiometric 12B bottles (Johnston Laboratories, Inc., Towson, Md.). Of the 56 M. avium complex isolates, 41 tested positive with the M. avium probe, 4 were positive with the M. intracellulare probe, and 7 were positive with both probes. Four direct tests from BACTEC bottles were initially negative but were subsequently M. avium probe positive when subcultures from Lowenstein-Jensen agar were tested. All 56 strains were negative when tested with the M. tuberculosis probe.

Bacteremia and fungemia in patients with neoplastic disease

This study reviewed 431 episodes of septicemia occurring in 356 patients with cancer at Memorial Sloan-Kettering Cancer Center during 1982. The most frequent organisms causing 273 episodes in 239 non-neutropenic patients were Escherichia coli (20 percent), Staphylococcus aureus (13 percent), polymicrobic (12 percent), Pseudomonas species (8 percent), Klebsiella species (7 percent), Candida species (7 percent), Bacteroides species (6 percent), Enterobacter species (4 percent), and Clostridium species (4 percent). The overall mortality was 31 percent (21 percent with adequate therapy; 50 percent with inadequate therapy). The most frequent organisms causing 158 episodes in 117 neutropenic patients were polymicrobic (21 percent), E. coli (16 percent), Klebsiella species (15 percent), Pseudomonas species (8 percent), Candida species (6 percent), S. aureus (6 percent), Streptococcus faecalis (5 percent), S. epidermidis (4 percent), and Corynebacterium CDC-JK (3 percent). The overall mortality was 52 percent (36 percent with adequate therapy; 88 percent with inadequate therapy). Since a review a decade ago, the spectrum of organisms changed in that the gram-positive organisms, S. faecalis, S. epidermidis, and C. CDC-JK, emerged as important pathogens. Neutropenic patients had a high incidence (42 percent) of septicemia due to multiple organisms, occurring concurrently or sequentially. The overall mortality of these patients was exceptionally high (80 percent). In contrast, the overall mortality of neutropenic patients with single-organism septicemia was comparable to that of non-neutropenic patients with single-organism septicemia (37 percent versus 29 percent).

Laboratory diagnosis of mycobacterial infections in patients with acquired immunodeficiency syndrome

Disseminated mycobacterial infections are commonly seen in acquired immunodeficiency syndrome (AIDS) patients, and laboratory culture is the best method for diagnosing these infections. In addition to conventional agar media, we used BACTEC 12A (Johnston Laboratories, Inc., Towson, Md.) broth medium for culture. More isolates of Mycobacterium avium complex and Mycobacterium tuberculosis were recovered from 12A broth than from Lowenstein-Jensen or Middlebrook 7H11 agar. Also, the average detection time of these mycobacteria was the earliest with 12A broth. Stool examination has been helpful in diagnosing mycobacterial disease in AIDS patients, and in this study both acid-fast stain and culture of fecal material was necessary for efficient detection of mycobacteria. Another sensitive and practical method for detecting mycobacterial infections in patients with AIDS is the Isolator lysis-centrifugation system (Du Pont Co., Wilmington, Del.) which offers the advantage of quantitating the degree of mycobacteremia. Laboratories should be alerted to the possibility of mixed mycobacterial infection in patients with AIDS, and positive cultures should be repeatedly examined to detect coinfection with a slower-growing mycobacterium such as M. tuberculosis as well as M. avium complex.

Clinical comparison of lysis-centrifugation and radiometric resin systems for blood culture

The Isolator 10 lysis-centrifugation blood culture system (E. I. du Pont de Nemours & Co., Inc., Wilmington, Del.) and the BACTEC 16B-17D radiometric resin system (Johnston Laboratories, Inc., Towson, Md.) both remove antimicrobial agents from the blood for culture. We compared these two systems for recovery of aerobic bacteria, facultatively anaerobic bacteria, and yeasts. A total of 5,000 blood cultures yielded 467 clinically significant isolates. Both systems recovered 350 (75%) organisms, 56 (12%) were detected by Isolator only, and 61 (13%) were detected by BACTEC resin bottles only. No group of organisms was isolated significantly more often from either system.

Mycobacterium avium complex infections in patients with the acquired immunodeficiency syndrome

Disseminated infection with Mycobacterium avium complex developed in 67 patients with the acquired immunodeficiency syndrome (AIDS) who were followed at Memorial Sloan-Kettering Cancer Center. Twenty-nine patients were treated with two or more antimycobacterial drugs for a mean of 6 weeks, and 7 patients received therapy for less than 1 month. Most patients received ansamycin, clofazimine, and ethionamide or ethambutol. Clinical improvement did not occur in treated patients, and microbiologic cure was never obtained. Mycobacterial bacteremia persisted in 24 of 26 treated patients. Colony counts of M. avium complex in sequential blood cultures decreased in 3 patients. Every autopsied patient with M. avium complex infection diagnosed before death, whether treated or not, had disseminated M. avium complex infection at autopsy.

Bacteremia and fungemia in patients with the acquired immunodeficiency syndrome

Forty-nine episodes of bacteremia and fungemia occurred in 38 of 336 patients with the acquired immunodeficiency syndrome seen at our institution since 1980. There were five types of infections. Infections commonly associated with a T-cell immunodeficiency disorder comprised 16 episodes and included those with Salmonella species, Listeria monocytogenes, Cryptococcus neoformans, and Histoplasma capsulatum. Infections commonly associated with a B-cell immunodeficiency disorder included those with Streptococcus pneumoniae and Haemophilus influenzae. Infections occurring with neutropenia were caused by Pseudomonas aeruginosa, Staphylococcus epidermidis, and Streptococcus faecalis. Other infections occurring in the hospital were caused by Candida albicans, Staphylococcus epidermidis, enteric gram-negative rods, Staphylococcus aureus, and mixed S. aureus and group G streptococcus. Other infections occurring out of the hospital included those with S. aureus, Clostridium perfringens, Shigella sonnei, Pseudomonas aeruginosa, and group B streptococcus. Because two thirds of the septicemias were caused by organisms other than T-cell opportunists, these pathogens should be anticipated during diagnostic evaluation and when formulating empiric therapy.