Karin Nielsen

Invasive fungal infections in pediatric oncology patients: 11-year experience at a single institution.

The purpose of this study was to determine the incidence of fungal infections in pediatric hematology and oncology (PHO) patients and to describe variations regarding site of infection, organisms, and mortality. The records of 1,052 patients presenting to the UCLA PHO service with various malignancies from 1991 to 2001 were retrospectively reviewed. No patient received invasive antifungal prophylaxis. Transplant patients were excluded. The 11-year incidence of fungal infections in this pediatric oncology cohort was 4.9%. There was a linear increase in the incidence of fungal infections from 2.9% to 7.8% between 1996 and 2001 (P = 0.001). Patients with acute leukemia represented 36% of the population but had a disproportionate incidence (67%) of fungal infections. Adolescents had twice the expected incidence of infection (P < 0.0001). Overall, Candida sp. was the major pathogen. Over time, a trend of fewer infections caused by Candida and more due to Aspergillus was noted. Blood-borne infections decreased over time, while those in the urinary and respiratory tracts increased (P = 0.04). Sixty-two percent of infections occurred in neutropenic patients. PHO patients had an overall mortality of 21%, but those with fungal infections experienced a 2.6-fold higher mortality that was not attributable to infections alone. Empiric antifungal therapy had no effect on mortality rates. Concurrent nonfungal infections did not increase mortality rates. The incidence of fungal infections increased over time, possibly as a result of advances in antibacterial and chemotherapeutic regimens. Adolescents and patients with leukemia were especially at risk. Fungal infections are a poor prognostic factor, independent of fungal-related mortality. New diagnostic methods allowing for early detection and treatment as well as more effective therapies are needed.

Treatment of Human Immunodeficiency Virus 1-Infected Infants and Children with the Protease Inhibitor Nelfinavir Mesylate

An open-label study was conducted of nelfinavir mesylate, given with reverse transcriptase inhibitors to human immunodeficiency virus 1 (HIV-1)-infected infants and children 3 months to 13 years of age. Doses of nelfinavir mesylate of 20-30 mg/kg yielded drug exposures comparable to those seen in adults. The drug was well tolerated; mild diarrhea was the primary toxic effect observed. Seventy-one percent (39) of the 55 evaluable subjects had an initial decrease in plasma HIV-1 RNA, of at least 0.7 log10 copies/mL; suppression of plasma HIV-1 RNA levels to < 400 copies/mL was observed in 15. Children who began taking at least one new reverse transcriptase inhibitor near the time when nelfinavir mesylate was started, and those with a > or = 24% proportion of CD4 lymphocytes, had a greater chance of achieving and maintaining a decline in plasma HIV-1 RNA to < 400 copies/mL. Suppression of viremia was achieved in children as young as 3 months of age.

Distributed medical image analysis and diagnosis through crowd-sourced games: a malaria case study.

In this work we investigate whether the innate visual recognition and learning capabilities of untrained humans can be used in conducting reliable microscopic analysis of biomedical samples toward diagnosis. For this purpose, we designed entertaining digital games that are interfaced with artificial learning and processing back-ends to demonstrate that in the case of binary medical diagnostics decisions (e.g., infected vs. uninfected), with the use of crowd-sourced games it is possible to approach the accuracy of medical experts in making such diagnoses. Specifically, using non-expert gamers we report diagnosis of malaria infected red blood cells with an accuracy that is within 1.25% of the diagnostics decisions made by a trained medical professional.

Frequency of fungemia in hospitalized pediatric inpatients over 11 years at a tertiary care institution.

Objectives. To determine the frequency of bloodstream fungal infections in children who were admitted to our tertiary institution over an 11-year period. Methods. We conducted a retrospective cohort study of patients who were aged 0 to 21 years, had bloodstream fungal infections, and were admitted to the University of California, Los Angeles from 1991 through 2001. Patients were identified through the microbiology laboratory database. All positive fungal cultures for pediatric inpatients were reviewed. For each fungemic patient, a review of clinical course, cause, and outcome was performed. Results. Over 11 years, 1124 pediatric inpatients with 3633 positive cultures had evidence of fungal colonization or infection. The mean incidence of positive fungal cultures increased from 105 between 1991 and 1996 to 129 patients per year between 1997 and 2001. Fungal isolates were mainly Candida species (85%) obtained primarily from respiratory (41%) and urine (27%) cultures. Only 7.5% of positive fungal cultures were from blood, although 24490 pediatric admissions prompted 72960 bacterial and fungal blood cultures, at charges of

DIAGNOSIS OF HIV INFECTION IN CHILDREN

2.52 million. Of 14592 fungal blood cultures, <2% (n = 272) were positive, involving <1% (n = 97) of patients. The mean rise in number of children with fungemia was significant, from 6.8 between 1991 and 1996 to 13.0 patients per year between 1997 and 2001. Fungemia was associated with a high all-cause mortality rate (46%), particularly in immunocompromised patients (57%). Organisms recovered were primarily Candida species (91%). There was a decline in C albicans and C glabrata fungemia and an increase in C parapsilosis organisms. In 84% of patients, fungal organisms were isolated from both bacterial and fungal blood cultures, and in 74%, the same organism was isolated from additional body sites. Conclusions. Episodes of fungemia increased significantly over 11 years as compared with a moderate increase in positive fungal cultures and were associated with high all-cause mortality rates. More sensitive assays for early identification of fungal bloodstream infections are warranted.

Clearance of Cellulosimicrobium cellulans bacteremia in a child without central venous catheter removal.

Many advances have been made in the area of HIV diagnostics. Commercially available virologic assays are sensitive and specific for the early detection of HIV in perinatal infection. The timing of the transmission of HIV from mother to child (in utero, at the time of birth, or postnatally by breast-feeding) is a critical consideration in the appropriate diagnosis of infants. Several algorithms can be used to define early infection and the potential timing of acquisition of infection that combine different assays and timing of specimens. The use of virologic assays, including HIV DNA PCR and HIV RNA detection methods and culture, can define and rule out infection in infants less than 18 months of age. Serologic diagnostic methods, including HIV ELISA, immunofluorescence, and western blot assays, can be used to diagnose infants more than 18 months of age, when transplacental antibody has disappeared in uninfected HIV-exposed infants. The challenge of the early and accurate diagnosis of perinatally HIV-exposed infants is the use of new assays to detect different HIV subtype infections that are prevalent in developing countries. Rapid, simple, and inexpensive serologic and virologic assays are being developed for worldwide use.

Thymic volume, T-cell populations, and parameters of thymopoiesis in adolescent and adult survivors of HIV infection acquired in infancy.

ABSTRACT Cellulosimicrobium cellulans (formerly known as Oerskovia xanthineolytica) rarely causes human infection. Infections have been reported in immunocompromised hosts or in patients with foreign bodies, such as catheters, where treatment has generally involved removal of the foreign body. We report on a case in which the organism was isolated in multiple blood cultures from a 13-year-old male. After initial therapy failed, treatment with vancomycin and rifampin resulted in infection clearance without removal of the central venous catheter.

Psychiatric symptoms and antiretroviral nonadherence in US youth with perinatal HIV: a longitudinal study.

Objectives:Antiretroviral therapy has significantly prolonged the lifespan of children who acquire HIV infection in infancy, but the impact of HIV on thymus-mediated maintenance of T lymphocytes has not been studied. To examine the long-term effects of HIV infection in childhood on thymopoiesis, thymic volume and parameters of thymic function from clinically stable adolescents and young adults with HIV infection acquired in infancy were compared with those from uninfected controls. Methods:Thymic volume was determined using three-dimensional reconstruction and volumetric analysis of non-contrast enhanced computed tomography images of the upper chest. The degree of fat involution was assessed using a semiquantitive scoring system. CD4 and CD8 T cell populations and T cell receptor recombination excision circles (TREC) concentrations in peripheral blood lymphocytes were measured in all subjects. Results:Twenty youths (aged 17.6 ± 2.5 years) with HIV infection acquired perinatally (n = 18) or by neonatal transfusion (n = 2) were enrolled whose HIV plasma viral load had been undetectable for a median of 3.1 years, along with 18 seronegative healthy young adults (aged 20.6 ± 1.3 years). HIV infected subjects and controls had indistinguishable CD4 T cell counts, thymus volumes (20.5 versus 15.8 cm3), thymic index scores, and TREC values. Thymic volume correlated with the number and percentage of CD4 T lymphocytes in the control group and with the number of TREC in CD4 lymphocytes in the HIV infected group. Conclusions:Long term survivors of pediatric HIV infection appear to have retained or recovered thymic volume and thymic activity approximating uninfected youths.

Nocardia asteroides brain abscesses and meningitis in an immunocompromized 10-year-old child

Objectives:The relationship of specific psychiatric conditions to adherence has not been examined in longitudinal studies of youth with perinatal HIV infection (PHIV). We examined associations between psychiatric conditions and antiretroviral nonadherence over 2 years. Design:Longitudinal study in 294 PHIV youth, 6–17 years old, in the United States and Puerto Rico. Methods:We annually assessed three nonadherence outcomes: missed above 5% of doses in the past 3 days, missed a dose within the past month, and unsuppressed viral load (>400 copies/ml). We fit multivariable logistic models for nonadherence using Generalized Estimating Equations, and evaluated associations of psychiatric conditions (attention deficit hyperactivity disorder, disruptive behavior, depression, anxiety) at entry with incident nonadherence using multivariable logistic regression. Results:Nonadherence prevalence at study entry was 14% (3-day recall), 32% (past month nonadherence), and 38% (unsuppressed viral load), remaining similar over time. At entry, 38% met symptom cut-off criteria for at least one psychiatric condition. Greater odds of 3-day recall nonadherence were observed at week 96 for those with depression [adjusted odds ratio (aOR) 4.14, 95% confidence interval (CI) 1.11–15.42] or disruptive behavior (aOR 3.36, 95% CI 1.02–11.10], but not at entry. Those with vs. without attention deficit hyperactivity disorder had elevated odds of unsuppressed viral load at weeks 48 (aOR 2.46, 95% CI 1.27–4.78) and 96 (aOR 2.35, 95% CI 1.01–5.45), but not at entry. Among 232 youth adherent at entry, 16% reported incident 3-day recall nonadherence. Disruptive behavior conditions at entry were associated with incident 3-day recall nonadherence (aOR 3.01, 95% CI 1.24–7.31). Conclusion:In PHIV youth, comprehensive adherence interventions that address psychiatric conditions throughout the transition to adult care are needed.

The In Vitro Growth and Serial Passage of RA 27/3 Rubella Vaccine Virus in Cord Blood Mononuclear Leukocytes from Normal Babies

Nocardiosis is an uncommon pediatric infection. We describe the successful treatment of Nocardia brain abscesses and meningitis in an immunocompromized boy with a history of both liver and bone marrow transplants.