This is a cohort study of pediatric outpatients receiving total parenteral nutrition ( TPN) and follow-up care in a Tennessee hospital between January and June 1999. The study was conducted following an increase in the incidence of candidemia. Of 13 children receiving home TPN, five had candidemia; three were due to Candida parapsilosis. Case patients were more likely to have an underlying hematologic disease ( P = 0.02) as well as previous history of fungemia ( P = 0.02). Two case patients had successive candidemia episodes 3 months apart; karyotypes and RAPD profiles of each patient's successive C. parapsilosis isolates were similar. Candida spp. were frequently detected in hand cultures from cohort members ( four of 10) and family member caregivers ( nine of 11); C. parapsilosis was isolated from five caregivers. Our findings underscore the challenges of maintaining stringent infection control practices in the home health care setting and suggest the need for more intensive follow-up and coordination of home TPN therapy among pediatric patients.

We describe a case in which the Histoplasma capsulatum AccuProbe test displayed cross-reactivity with a respiratory isolate thought to be Histoplasma but not morphologically consistent with H. capsulatum. The isolate was later identified as the Chrysosporium anamorph of Nannizziopsis vriesii by sequence analysis and phenotypic data.

Zygoascus hellenicus (Candida hellenica) was isolated from a blood culture from a patient who had received an allogeneic stem cell transplant. The isolate displayed an antifungal susceptibility pattern of decreased susceptibility to fluconazole and itraconazole, high susceptibility to voriconazole, and low susceptibility to caspofungin. The organism was misidentified by a commercial yeast identification system. This is the first reported case of human infection with this rare ascomycetous yeast.

Candida parapsilosis is an important cause of bloodstream infections in the health care setting. We investigated a large C. parapsilosis outbreak occurring in a community hospital and conducted a case-control study to determine the risk factors for infection. We identified 22 cases of bloodstream infection with C. parapsilosis: 15 confirmed and 7 possible. The factors associated with an increased risk of infection included hospitalization in the intensive care unit (adjusted odds ratio, 16.4; 95% confidence interval, 1.8 to 148.1) and receipt of total parenteral nutrition (adjusted odds ratio, 9.2; 95% confidence interval, 0.9 to 98.1). Samples for surveillance cultures were obtained from health care worker hands, central venous catheter insertion sites, and medical devices. Twenty-six percent of the health care workers surveyed demonstrated hand colonization with C. parapsilosis, and one hand isolate was highly related to all case-patient isolates by tests with the DNA probe Cp3-13. Outbreak strain isolates also demonstrated reduced susceptibilities to fluconazole and voriconazole. This largest known reported outbreak of C. parapsilosis bloodstream infections in adults resulted from an interplay of host, environment, and pathogen factors. Recommendations for control measures focused on improving hand hygiene compliance.

Background: A histoplasmosis outbreak occurred in an Indiana high school in November–December 2001. Methods: To describe the risk factors for this outbreak, we conducted a cohort study of all available students and staff (N = 682) and an environmental investigation. Results: Of the 523 (77%) persons who displayed serologic evidence of recent Histoplasma capsulatum infection, 355 (68%) developed symptoms consistent with acute pulmonary histoplasmosis. Rototilling of soil in a school courtyard known to be a bird roosting site had been performed during school hours on November 12, 2001, 14 days before both the peak of the onset of illness and a rise in student absenteeism. Being a student (odds ratio, 3.3; 95% confidence interval, 2.2–5.0) and being a student in a classroom near the courtyard during the rototilling (odds ratio, 3.1; 95% confidence interval, 1.8–5.2) were independently associated with infection and symptomatic illness. H. capsulatum was isolated from environmental samples, including soil from the courtyard and dust collected from a filter of a heating, ventilating and air-conditioning system. Conclusions: Soil-disrupting activities within a school courtyard caused the largest outbreak to date of histoplasmosis among adolescents. Improved efforts are needed to educate the community in endemic areas about histoplasmosis to prevent the occurrence of such outbreaks in the future. In addition, increased awareness among health care providers of this disease would facilitate appropriate diagnosis and treatment.

ABSTRACT Candida species bloodstream isolates were collected from institutions participating in an active, population-based surveillance for candidemia. Species identifications were performed locally and then confirmed at the Centers for Disease Control and Prevention (CDC) by phenotype-based methods. Discrepancies in species identification between the referring institution and the CDC were noted for 43 of 935 isolates (4.6%). A DNA probe-based species identification system (PCR-enzyme immunoassay [EIA]) was then used to resolve these discrepancies. The PCR-EIA result was identical to the CDC phenotypic identification method for 98% of the isolates tested. The most frequently misidentified species was Candida glabrata (37% of all discrepant identifications). Such misidentifications could lead to the administration of inappropriate therapy given the propensity of C. glabrata to develop resistance to azole antifungal drugs.

ABSTRACT To determine the incidence of Candida bloodstream infections (BSI) and antifungal drug resistance, population-based active laboratory surveillance was conducted from October 1998 through September 2000 in two areas of the United States (Baltimore, Md., and the state of Connecticut; combined population, 4.7 million). A total of 1,143 cases were detected, for an average adjusted annual incidence of 10 per 100,000 population or 1.5 per 10,000 hospital days. In 28% of patients, Candida BSI developed prior to or on the day of admission; only 36% of patients were in an intensive care unit at the time of diagnosis. No fewer than 78% of patients had a central catheter in place at the time of diagnosis, and 50% had undergone surgery within the previous 3 months. Candida albicans comprised 45% of the isolates, followed by C. glabrata (24%), C. parapsilosis (13%), and C. tropicalis (12%). Only 1.2% of C. albicans isolates were resistant to fluconazole (MIC, ≥64 μg/ml), compared to 7% of C. glabrata isolates and 6% of C. tropicalis isolates. Only 0.9% of C. albicans isolates were resistant to itraconazole (MIC, ≥1 μg/ml), compared to 19.5% of C. glabrata isolates and 6% of C. tropicalis isolates. Only 4.3% of C. albicans isolates were resistant to flucytosine (MIC, ≥32 μg/ml), compared to <1% of C. parapsilosis and C. tropicalis isolates and no C. glabrata isolates. As determined by E-test, the MICs of amphotericin B were ≥0.38 μg/ml for 10% of Candida isolates, ≥1 μg/ml for 1.7% of isolates, and ≥2 μg/ml for 0.4% of isolates. Our findings highlight changes in the epidemiology of Candida BSI in the 1990s and provide a basis upon which to conduct further studies of selected high-risk subpopulations.

Candida versatilitis was isolated from 10 blood cultures that had been supplemented with olive oil to promote the growth of Malassezia spp., and from the stock olive oil bottle in the laboratory. This unusual non-pathogenic yeast isolate was readily identified by DNA sequencing methodology. This report also points out that care must be taken to ensure the sterility of supplements added to blood culture media.

Allelic distributions and frequencies of five Candida albicans microsatellite loci have been determined for strains isolated from the bloodstream and obtained through active population-based surveillance in two U.S. metropolitan areas between 1998 and 2000. These data were compared to data for isolates obtained from two other U.S. regions in 1992 to 1993. In a majority of pairwise combinations between sites, no evidence was seen for shifts in microsatellite allelic frequencies. One to three alleles were highly predominant and correlated with major genotypes. These data both support the concepts of allelic stability and genetic equilibria and suggest that, in the United States, strains of C. albicans isolated from the bloodstream may form a defined, genetically homogeneous population across geographical distance and time.

During spring 2001, college students from Pennsylvania reported an acute febrile respiratory illness after returning from spring break vacation in Acapulco, Mexico. Acute pulmonary histoplasmosis was presumptively diagnosed and the cluster of illness was reported to the Centers of Disease Control and Prevention. A large investigation then ensued, which included finding student-travelers for interviews and requesting sera for histoplasmosis testing. We defined a clinical case by fever and at least one of the following: cough, shortness of breath, chest pain, or headache, in an Acapulco traveler during March-May 2001. A laboratory-confirmed case had positive serology. An initial study determined that the likely site of histoplasmosis exposure was Hotel H; we therefore performed a large cohort study among travelers who stayed at Hotel H. Of 757 contacted, 262 (36%) met the clinical case definition. Of 273 serum specimens tested, 148 (54%) were positive. Frequent use of Hotel H's stairwells, where construction was ongoing, was associated with increased risk of illness (relative risk = 10.5, 95% confidence interval = 3.7-30.5; P < 0.001). This is the first histoplasmosis outbreak associated with a hotel undergoing construction. Hotels in endemic areas should consider construction precaution measures to prevent histoplasmosis among their guests.

Invasive aspergillosis (IA) is rare among renal transplant recipients (RTRs). We investigated a cluster of IA among RTRs at a California hospital from January to February 2001, when construction was ongoing. We conducted a cohort study among RTRs who were hospitalized between January 1 and February 5, 2001, to determine risk factors for IA. IA was defined using established guidelines. Four IA cases occurred among 40 RTRs hospitalized during the study period. Factors associated with an increased risk of IA included prolonged hemodialysis, lengthy corticosteroid treatment posttransplant, and use of sirolimus alone or with mycophenolate (P<0.05). After the study period, three additional RTRs developed IA; two Aspergillus isolates recovered from these patients had indistinguishable profiles by DNA fingerprinting, suggesting common-source exposure. This study suggests that immunosuppressed RTRs can be at an increased risk for IA. Measures to prevent IA in these patients should be taken during hospital construction.

Population-based surveillance and a case-control study were conducted in Abancay, Peru, to estimate the burden of disease and to determine risk factors for sporadic lymphocutaneous sporotrichosis (LS). Laboratory records from local hospitals were reviewed for the years of 1997 and 1998, and prospective surveillance was conducted for the period of September 1998 through September 1999. A case-control study was conducted with 2 matched control subjects per case patient. The mean annual incidence was 98 cases per 100,000 persons. Children had an incidence 3 times higher than that for adults and were more likely to have LS lesions on the face and neck. Identified risk factors included owning a cat, playing in crop fields, having a dirt floor in the house, working mainly outdoors, and having a ceiling made of raw wood or conditions associated with a lower socioeconomic status. Decreased environmental exposure, such wearing protective clothing during construction activities for adults or limiting contact with cats and soil for children, and improvements in living spaces may decrease the incidence of LS.

To examine trends in the incidence and epidemiology of cryptococcosis, active, population-based surveillance was conducted during 1992-2000 in 2 areas of the United States (the Atlanta, Georgia, and Houston, Texas, metropolitan areas; combined population, 7.4 million). A total of 1491 incident cases were detected, of which 1322 (89%) occurred in HIV-infected persons. The annual incidence of cryptococcosis per 1000 persons with AIDS decreased significantly during the study period, from 66 in 1992 to 7 in 2000 in the Atlanta area, and from 24 in 1993 to 2 in 1994 in the Houston area. Poisson regression analysis revealed that African American persons with AIDS were more likely than white persons with AIDS to develop disease. Less than one-third of all HIV-infected persons with cryptococcosis were receiving antiretroviral therapy before diagnosis. Our findings suggest that HIV-infected persons who continue to develop cryptococcosis in the era of highly active antiretroviral therapy (HAART) in the United States are those with limited access to health care. More efforts are needed to expand the availability of HAART and routine HIV care services to these persons.

The dematiaceous (brown-pigmented) fungi are a large and heterogenous group of moulds that cause a wide range of diseases including phaeohyphomycosis, chromoblastomycosis, and eumycotic mycetoma. Among the more important human pathogens are Alternaria species, Bipolaris species, Cladophialophora bantiana, Curvularia species, Exophiala species, Fonsecaea pedrosoi, Madurella species, Phialophora species, Scedosporium prolificans, Scytalidium dimidiatum, and Wangiella dermatitidis. These organisms are widespread in the environment, being found in soil, wood, and decomposing plant debris. Cutaneous, subcutaneous, and corneal infections with dematiaceous fungi occur worldwide, but are more common in tropical and subtropical climates. Infection results from traumatic implantation. Most cases occur in immunocompetent individuals. Dematiaceous moulds are also important causes of invasive sinusitis and allergic fungal sinusitis. Infection is thought to follow inhalation. Although cerebral infection is the commonest form of systemic phaeohyphomycosis, other localized deep forms of the disease, such as arthritis, and endocarditis, have been reported. Disseminated infection is uncommon, but its incidence is increasing, particularly among immunocompromised individuals. Scedosporium prolificans is the most frequent cause. A number of dematiaceous fungi are neurotropic, including Cladophialophora bantiana, Ramichloridium mackenziei, and Wangiella dermatitidis. Although cases have occurred in immunocompromised persons, cerebral phaeohyphomycosis is most common in immunocompetent individuals with no obvious risk factors. Most forms of disease caused by dematiaceous fungi require both surgical and medical treatment. Itraconazole is currently the most effective antifungal agent for chromoblastomycosis and subcutaneous phaeohyphomycosis, while ketoconazole remains useful for mycetoma. Extensive surgical debridement combined with amphotericin B treatment is recommended for chronic invasive sinusitis. Long-term treatment with itraconazole has led to improvement or remission in some patients that had failed to respond to amphotericin B. Allergic fungal sinusitis requires surgical removal of impacted mucin combined with postoperative oral corticosteroids. Antifungal treatment is not usually of benefit, but post-operative itraconazole may reduce the need for reoperation. The clinical outcome of cerebral and other deep-seated forms of phaeohyphomycosis is dismal, with long-term survival being reported only when complete surgical resection of discrete lesions is possible. The development of new antifungal agents and combination treatment may help to improve the management of these infections.

ABSTRACT Visual determination of MIC end points for azole antifungal agents can be complicated by the trailing growth phenomenon. To determine the incidence of trailing growth, we performed testing of in vitro susceptibility to fluconazole and itraconazole using the National Committee for Clinical Laboratory Standards broth microdilution M27-A reference procedure and 944 bloodstream isolates of seven Candida spp., obtained through active population-based surveillance between 1998 and 2000. Of 429 C. albicans isolates, 78 (18.2%) showed trailing growth at 48 h in tests with fluconazole, and 70 (16.3%) showed trailing in tests with itraconazole. Of 118 C. tropicalis isolates, 70 (59.3%) showed trailing growth in tests with fluconazole, and 35 (29.7%) showed trailing in tests with itraconazole. Trailing growth was not observed with any of the other five Candida spp. tested (C. dubliniensis, C. glabrata, C. krusei, C. lusitaniae, and C. parapsilosis). To confirm whether or not isolates that showed trailing growth in fluconazole and/or itraconazole were resistant in vitro to these agents, all isolates that showed trailing growth were retested by the sterol quantitation method, which measures cellular ergosterol content rather than growth inhibition after exposure to azoles. By this method, none of the trailing isolates was resistant in vitro to fluconazole or itraconazole. For both agents, a 24-h visual end point or a spectrophotometric end point of 50% reduction in growth relative to the growth control after 24 or 48 h of incubation correlated most closely with the result of sterol quantitation. Our results indicate that MIC results determined by either of these end point rules may be more predictive of in vivo outcome for isolates that give unclear visual end points at 48 h due to trailing growth.

Cryptococcus neoformans is a major pathogen of humans throughout the world. Using commercial mAbs to capsular epitopes, strains of C. neoformans manifest five distinct serotypes--A, B, C, D and AD. Previous studies demonstrated significant divergence among serotypes A, B, C and D, which are thought to be haploid. In this study the origins and evolution of strains of serotype AD were investigated. A portion (537 bp) of the laccase gene was cloned and sequenced from 14 strains of serotype AD. Each strain contained two different alleles and sequences for both alleles were obtained. These sequences were compared to those from serotypes A, B, C and D. This analysis indicated that each of the 14 serotype AD strains contained two phylogenetically distinct haplotypes: one haplotype was highly similar to the serotype A group and the other to the serotype D group. To explain the origins of these serotype AD strains, genealogical analysis is consistent with at least three recent and independent hybridization events. The results demonstrate that the evolution of C. neoformans is continuing and dynamic.

ABSTRACT The antifungal drug susceptibilities of two collections of Cryptococcus neoformans isolates obtained through active laboratory-based surveillance from 1992 to 1994 (368 isolates) and 1996 to 1998 (364 isolates) were determined. The MICs of fluconazole, itraconazole, and flucytosine were determined by the National Committee for Clinical Laboratory Standards broth microdilution method; amphotericin B MICs were determined by the E-test. Our results showed that the MIC ranges, the MICs at which 50% of isolates are inhibited (MIC 50 s), and the MIC 90 s of these four antifungal agents did not change from 1992 to 1998. In addition, very small numbers of isolates showed elevated MICs suggestive of in vitro resistance. The MICs of amphotericin B were elevated (≥2 μg/ml) for 2 isolates, and the MICs of flucytosine were elevated (≥32 μg/ml) for 14 isolates. Among the azoles, the fluconazole MIC was elevated (≥64 μg/ml) for 8 isolates and the itraconazole MIC (≥1 μg/ml) was elevated for 45 isolates. Analysis of 172 serial isolates from 71 patients showed little change in the fluconazole MIC over time. For isolates from 58 patients (82% of serial cases) there was either no change or a twofold change in the fluconazole MIC. In contrast, for isolates from seven patients (12% of serial cases) the increase in the MIC was at least fourfold. For isolates from another patient there was a 32-fold decrease in the fluconazole MIC over a 1-month period. We conclude that in vitro resistance to antifungal agents remains uncommon in C. neoformans and has not significantly changed with time during the past decade.

We report the first four North American cases of Candida dubliniensis fungemia, including the first isolation of this organism from the bloodstream of an HIV-infected person. All isolates were susceptible in vitro to commonly used antifungal drugs. This report demonstrates that C. dubliniensis can cause bloodstream infection; however, the incidence of disease is not known.

National surveillance of blood stream infections (BSI) attributable to Candida spp. has been limited to date. Recent studies have suggested an increase in the proportion of BSI attributable to non-Candida albicans species and have also raised concerns regarding the emergence of antifungal resistance among Candida spp. The increased utilization of broad-spectrum antifungal agents and the recognition of Candida spp. as prominent pathogens with the potential for developing antifungal resistance, emphasize the need for ongoing surveillance of antifungal susceptibility patterns. In this investigation trends in species distribution and susceptibility to fluconazole among BSI isolates of Candida spp. referred to our laboratory by United States hospitals were evaluated over the 7-year period from 1992 to 1998. A total of 1579 BSI isolates from more than 50 medical centers were processed. Overall, C. albicans accounted for 52% of isolates followed by C. glabrata (18%), C. parapsilosis (15%), C. tropicalis (11%), and C. krusei (2%). The proportion of BSI isolates that were C. albicans ranged from 45% in 1992 to 60% in 1998. Among the non-C. albicans isolates, C. glabrata succeeded C. parapsilosis as the most common species beginning in 1995. Overall, the susceptibility of all Candida species (C. albicans plus all other species) to fluconazole remained stable (MIC90, 16 μg/mL). The fluconazole MIC90 for C. albicans was 0.5–2.0 μg/ml for all years studied except 1995 (8.0 μg/mL) and was 1.0 μg/mL overall. The present study suggests a continued prominent role of C. albicans as a cause of BSI, and a constant level of susceptibility of Candida BSI isolates to fluconazole over 7 years. These data should serve as a baseline for future surveillance efforts for anti-fungal agents tested against yeast BSI isolates.