Practice guidelines for the treatment of candidiasis. Infectious Diseases Society of America

Infections due to Candida species are the most common of the fungal infections. Candida species produce a broad range of infections, ranging from nonlife-threatening mucocutaneous illnesses to invasive process that may involve virtually any organ. Such a broad range of infections requires an equally broad range of diagnostic and therapeutic strategies. This document summarizes current knowledge about treatment of multiple forms of candidiasis and is the guideline of the Infectious Diseases Society of America (IDSA) for the treatment of candidiasis. Throughout this document, treatment recommendations are scored according to the standard scoring scheme used in other IDSA guidelines to illustrate the strength of the underlying data. The document covers 4 major topical areas. The role of the microbiology laboratory. To a greater extent than for other fungi, treatment of candidiasis can now be guided by in vitro susceptibility testing. The guidelines review the available information supporting current testing procedures and interpretive breakpoints and place these data into clinical context. Susceptibility testing is most helpful in dealing with infection due to non-albicans species of Candida. In this setting, especially if the patient has been treated previously with an azole antifungal agent, the possibility of microbiological resistance must be considered. Treatment of invasive candidiasis. In addition to acute hematogenous candidiasis, the guidelines review strategies for treatment of 15 other forms of invasive candidiasis. Extensive data from randomized trials are really available only for therapy of acute hematogenous candidiasis in the nonneutropenic adult. Choice of therapy for other forms of candidiasis is based on case series and anecdotal reports. In general, both amphotericin B and the azoles have a role to play in treatment. Choice of therapy is guided by weighing the greater activity of amphotericin B for some non-albicans species (e.g., Candida krusei) against the lesser toxicity and ease of administration of the azole antifungal agents. Flucytosine has activity against many isolates of Candida but is not often used. Treatment of mucocutaneous candidiasis. Therapy for mucosal infections is dominated by the azole antifungal agents. These drugs may be used topically or systemically and have been proven safe and efficacious. A significant problem with mucosal disease is the propensity for a small proportion of patients to suffer repeated relapses. In some situations, the explanation for such a relapse is obvious (e.g., relapsing oropharyngeal candidiasis in an individual with advanced and uncontrolled HIV infection), but in other patients the cause is cryptic (e.g., relapsing vaginitis in a healthy woman). Rational strategies for these situations are discussed in the guidelines and must consider the possibility of induction of resistance over time. Prevention of invasive candidiasis. Prophylactic strategies are useful if the risk of a target disease is sharply elevated in a readily identified group of patients. Selected patient groups undergoing therapy that produces prolonged neutropenia (e.g., some bone-marrow transplant recipients) or who receive a solid-organ transplant (e.g., some liver transplant recipients) have a sufficient risk of invasive candidiasis to warrant prophylaxis.

Nosocomial candidemia: risk factors and attributable mortality

Over the past decade, the incidence of hospital-acquired bloodstream infections caused by Candida species has risen and the species associated with such infections have changed. The incidence of candidemia is dramatically higher in high-risk, critical-care units than in other parts of the hospital. Certain underlying physical conditions including acute leukemia, leukopenia, burns, gastrointestinal disease, and premature birth predispose patients to nosocomial candidemia. Independent risk factors include prior treatment with multiple antibiotics, prior Hickman catheterization, isolation of Candida species from sites other than the blood, and prior hemodialysis. In this article some of the challenges posed by the management of nosocomial candidemia are presented in three case studies. In addition, the results of several investigations of nosocomial candidemia at the University of Iowa Hospitals and Clinics are reviewed.

A Candida auris Outbreak and Its Control in an Intensive Care Setting

BACKGROUND

Candida auris is an emerging and multidrug-resistant pathogen. Here we report the epidemiology of a hospital outbreak of C. auris colonization and infection.

METHODS

After identification of a cluster of C. auris infections in the neurosciences intensive care unit (ICU) of the Oxford University Hospitals, United Kingdom, we instituted an intensive patient and environmental screening program and package of interventions. Multivariable logistic regression was used to identify predictors of C. auris colonization and infection. Isolates from patients and from the environment were analyzed by whole-genome sequencing.

RESULTS

A total of 70 patients were identified as being colonized or infected with C. auris between February 2, 2015, and August 31, 2017; of these patients, 66 (94%) had been admitted to the neurosciences ICU before diagnosis. Invasive C. auris infections developed in 7 patients. When length of stay in the neurosciences ICU and patient vital signs and laboratory results were controlled for, the predictors of C. auris colonization or infection included the use of reusable skin-surface axillary temperature probes (multivariable odds ratio, 6.80; 95% confidence interval [CI], 2.96 to 15.63; P<0.001) and systemic fluconazole exposure (multivariable odds ratio, 10.34; 95% CI, 1.64 to 65.18; P=0.01). C. auris was rarely detected in the general environment. However, it was detected in isolates from reusable equipment, including multiple axillary skin-surface temperature probes. Despite a bundle of infection-control interventions, the incidence of new cases was reduced only after removal of the temperature probes. All outbreak sequences formed a single genetic cluster within the C. auris South African clade. The sequenced isolates from reusable equipment were genetically related to isolates from the patients.

CONCLUSIONS

The transmission of C. auris in this hospital outbreak was found to be linked to reusable axillary temperature probes, indicating that this emerging pathogen can persist in the environment and be transmitted in health care settings. (Funded by the National Institute for Health Research Health Protection Research Unit in Healthcare Associated Infections and Antimicrobial Resistance at Oxford University and others.).

Predominant pathogens in hospital infections

To determine the distribution of pathogens causing nosocomial infections in United States hospitals, we analysed data from the National Nosocomial Infections Surveillance (NNIS) System. From October 1986 to December 1990, amongst hospitals conducting hospital-wide surveillance, the five most commonly reported pathogens were Escherichia coli (13.7%), Staphylococcus aureus (11.2%), enterococci (10.7%), Pseudomonas aeruginosa (10.1%), and coagulase-negative staphylococci (9.7%). The commonest pathogens reported by site included, bloodstream: coagulase-negative staphylococci, S. aureus, enterococci, E. coli, and Candida spp.; lower respiratory tract infection: S. aureus, P. aeruginosa and Enterobacter spp.; surgical wound infection: S. aureus, enterococci and coagulase-negative staphylococci; and urinary tract infection: E. coli, enterococci, and P. aeruginosa. Among hospitals conducting intensive care unit (ICU) surveillance, the commonest pathogens were P. aeruginosa (12.4%), S. aureus (12.3%), coagulase-negative staphylococci (10.2%), Candida spp. (10.1%), Enterobacter spp. and enterococci (8.6% each). In the ICUs, the commonest pathogens found in the bloodstream were coagulase-negative staphylococci, S. aureus, and enterococci; in lower respiratory tract infections P. aeruginosa, S. aureus, and enterococci; in surgical wound infections enterococci, coagulase-negative staphylococci, and Enterobacter spp. and in urinary tract infections Candida spp., E. coli, enterococci, P. aeruginosa, and Enterobacter spp. These data show that S. aureus, E. coli and P. aeruginosa remain important nosocomial pathogens, that coagulase-negative staphylococci, enterococci and C. albicans are pathogens of increasing importance, and that the distribution of pathogens differs by site and hospital location.

Nosocomial candidiasis: emerging species, reservoirs, and modes of transmission

During the 1980s, the frequency of nosocomial candidiasis increased dramatically. This trend has continued into the 1990s, and Candida species remain a major cause of nosocomial infections. Although Candida albicans remains the most frequent cause of fungemia and hematogenously disseminated candidiasis, a number of reports have documented infections caused by other Candida species: C. tropicalis, C. glabrata, C. parapsilosis, C. krusei, and C. lusitaniae. Many of these infections arise from an endogenous source, and their frequency is influenced by the patient population, the various treatment regimens, and the antibiotics or other supportive care measures employed at specific institutions. Additional infections may be accounted for by exogenous acquisition via the hands of health care workers, contaminated infusates and biomaterials, and the inanimate environment. Ongoing investigation should help improve our understanding of the epidemiology of candidiasis and facilitate the development of rational preventive measures.

National epidemiology of mycoses survey (NEMIS): variations in rates of bloodstream infections due to Candida species in seven surgical intensive care units and six neonatal intensive care units

Candida species are the fourth most frequent cause of nosocomial bloodstream infections, and 25%-50% occur in critical care units. During an 18-month prospective study period, all patients admitted for > or = 72 hours to the surgical (SICUs) or neonatal intensive care units (NICUs) at each of the participant institutions were followed daily. Among 4,276 patients admitted to the seven SICUs in six centers, there were 42 nosocomial bloodstream infections due to Candida species (9.8/1,000 admissions; 0.99/1,000 patient-days). Of 2,847 babies admitted to the six NICUs, 35 acquired a nosocomial bloodstream infection due to Candida species (12.3/1,000 admissions; 0.64/1,000 patient-days). The following were the most commonly isolated Candida species causing bloodstream infections in the SICU: Candida albicans, 48%; Candida glabrata, 24%; Candida tropicalis, 19%; Candida parapsilosis, 7%; Candida species not otherwise specified, 2%. In the NICU the distribution was as follows: C. albicans, 63%; C. glabrata, 6%; C. parapsilosis, 29%; other, 3%. Of the patients, 30%-50% developed incidental stool colonization, 23% of SICU patients developed incidental urine colonization, and one-third of SICU health care workers' hands were positive for Candida species.

Risk factors for Candida species colonization of neonatal intensive care unit patients

BACKGROUND

Candida spp. are increasingly important pathogens in neonatal intensive care units (NICU). Prior colonization is a major risk factor for candidemia, but few studies have focused on risk factors for colonization, particularly in NICU patients.

METHODS

A prospective, multicenter cohort study was performed in six NICUs to determine risk factors for Candida colonization. Infant gastrointestinal tracts were cultured on admission and weekly until NICU discharge and health care worker hands were cultured monthly for Candida spp.

RESULTS

The prevalence of Candida spp. colonization was 23% (486 of 2157 infants); 299 (14%), 151 (7%) and 74 (3%) were colonized with Candida albicans, Candida parapsilosis and other Candida spp., respectively. Multiple logistic regression analysis adjusting for length of stay, birth weight < or = 1000 g and gestational age < 32 weeks revealed that use of third generation cephalosporins was associated with either C. albicans (155 incident cases) or C. parapsilosis (104 incident cases) colonization. Use of central venous catheters or intravenous lipids were risk factors for C. albicans, whereas delivery by cesarean section was protective. Use of H2 blockers was an independent risk factor for C. parapsilosis. Of 2989 cultures from health care workers' hands, 150 (5%) were positive for C. albicans and 575 (19%) for C. parapsilosis, but carriage rates did not correlate with NICU site-specific rates for infant colonization.

CONCLUSIONS

We speculate that NICU patients acquire Candida spp., particularly C. parapsilosis, from the hands of health care workers. H2 blockers, third generation cephalosporins and delayed enteral feedings alter gastrointestinal tract ecology, thereby facilitating colonization.

Effects of nosocomial candidemia on outcomes of critically ill patients

PURPOSE

To determine whether nosocomial candidemia is associated with increased mortality in intensive care unit (ICU) patients.

SUBJECTS AND METHODS

We performed a retrospective (1992 to 2000) cohort study of 73 ICU patients with candidemia and 146 matched controls. Controls were matched based on disease severity as measured by the Acute Physiology and Chronic Health Evaluation (APACHE) II score (+/- 1 point), diagnostic category, and length of ICU stay before onset of candidemia.

RESULTS

In comparison with the control group, patients with candidemia developed more acute respiratory failure (97% [n = 71] vs. 88% [n = 129], P = 0.03) during their ICU stay. They were mechanically ventilated for a longer period (29 +/- 26 days vs. 19 +/- 19 days, P<0.01) and had a longer stay in the ICU (36 +/- 33 days vs. 25 +/- 23 days, P = 0.02) as well as in the hospital (77 +/- 81 days vs. 64 +/- 69 days, P = 0.04). There was no difference in in-hospital mortality between the groups (48% [n = 35] vs. 43% [n = 62], P = 0.44), a difference of 5% (95% confidence interval [CI]: -8% to 19%). In a multivariate analysis, older age (hazard ratio [HR] = 1.13 per 10 years; 95% CI: 1.04 to 1.23; P = 0.004), acute renal failure (HR = 1.4; 95% CI: 1.1 to 2.0; P = 0.02), and unfavorable APACHE II scores (HR = 1.10 per 5 points; 95% CI: 1.00 to 1.20; P = 0.05) were independent predictors of mortality. Candidemia was not associated with mortality in a model that adjusted for these factors (HR = 0.9; 95% CI: 0.7 to 1.2; P = 0.53).

CONCLUSION

Nosocomial candidemia does not adversely affect the outcome in ICU patients in whom mortality is attributable to age, the severity of underlying disease, and acute illness.

Behavioral reduction of infection risk

Evolutionary biologists have long postulated that there should be fitness advantages to animals that are able to recognize and avoid conspecifics infected with contact-transmitted disease. This avoidance hypothesis is in direct conflict with much of epidemiological theory, which is founded on the assumptions that the likelihood of infection is equal among members of a population and constant over space. The inconsistency between epidemiological theory and the avoidance hypothesis has received relatively little attention because, to date, there has been no evidence that animals can recognize and reduce infection risk from conspecifics. We investigated the effects of Candida humicola, a pathogen that reduces growth rates and can cause death of tadpoles, on associations between infected and uninfected individuals. Here we demonstrate that bullfrog (Rana catesbeiana) tadpoles avoid infected conspecifics because proximity influences infection. This avoidance behavior is stimulated by chemical cues from infected individuals and thus does not require direct contact between individuals. Such facultative modulations of disease infection risk may have critical consequences for the population dynamics of disease organisms and their impact on host populations.

Pharmacodynamics of amphotericin B in a neutropenic-mouse disseminated-candidiasis model

In vivo pharmacodynamic parameters have been described for a variety of antibacterials. These parameters have been studied in correlation with in vivo outcomes in order to determine which dosing parameter is predictive of outcome and the magnitude of that parameter associated with efficacy. Very little is known about pharmacodynamics for antifungal agents. We utilized a neutropenic mouse model of disseminated candidiasis to correlate pharmacodynamic parameters (percent time above MIC [T > MIC], area under the concentration time curve [AUC]/MIC ratio, and peak serum level/MIC ratio) for amphotericin B in vivo with efficacy, as measured by organism number in homogenized kidney cultures after 72 h of therapy. Amphotericin B was administered by the intraperitoneal route. Drug kinetics for amphotericin B in infected mice were nonlinear. Serum half-lives ranged from 13 to 27 h. Infection was achieved by intravenous inoculation with 10(6) CFU of yeast cells per ml via the lateral tail vein of neutropenic mice. Groups of mice were treated with fourfold escalating total doses of amphotericin B ranging from 0.08 to 20 mg/kg of body weight divided into 1, 3, or 6 doses over 72 h. Increasing doses produced concentration-dependent killing, ranging from 0 to 2 log(10) CFU/kidney compared to the organism number at the start of therapy. Amphotericin B also produced prolonged dose-dependent suppression of growth after serum levels had fallen below the MIC. Nonlinear regression analysis was used to determine which pharmacodynamic parameter best correlated with efficacy. Peak serum level in relation to the MIC (peak serum level/MIC ratio) was the parameter best predictive of outcome, while the AUC/MIC ratio and T > MIC were only slightly less predictive (peak serum level/MIC ratio, coefficient of determination [R(2)] = 90 to 93%; AUC/MIC ratio, R(2) = 49 to 69%; T > MIC, R(2) = 67 to 85%). The total amount of drug necessary to achieve various microbiological outcomes over the treatment period was 4.8- to 7.6-fold smaller when the dosing schedule called for large single doses than when the same amount of total drug was administered in 2 to 6 doses. Given the narrow therapeutic window of amphotericin B and frequent treatment failures, these results suggest the need for a reevaluation of current dosing regimens.

Candida vaginitis

The pathogenesis incidence and epidemiology of Candida vaginitis is considered.

Efficacy of the echinocandin caspofungin against disseminated aspergillosis and candidiasis in cyclophosphamide-induced immunosuppressed mice

The in vivo efficacy of the echinocandin antifungal caspofungin acetate (caspofungin; MK-0991) was evaluated in models of disseminated aspergillosis and candidiasis in mice with cyclophosphamide (CY)-induced immunosuppression. Caspofungin is a 1, 3-beta-D-glucan synthesis inhibitor efficacious against a number of clinically relevant fungi including Aspergillus and Candida species. Models of CY-induced transient or chronic leukopenia were used with once daily administration of therapy initiated 24 h after microbial challenge. Caspofungin was effective in treating disseminated aspergillosis in mice that were transiently leukopenic (significant prolongation of survival at doses of > or =0.125 mg/kg of body weight and a 50% protective dose [PD(50)] of 0.245 mg/kg/day at 28 days after challenge) or chronically leukopenic (50 to 100% survival at doses of > or =0.5 mg/kg and PD(50)s ranging from 0.173 to 0.400 mg/kg/day). Caspofungin was effective in the treatment and sterilization of Candida infections in mice with transient leukopenia with a 99% effective dose based on reduction in log(10) CFU of Candida albicans/gram of kidneys of 0.119 mg/kg and 80 to 100% of the caspofungin-treated mice having sterile kidneys at caspofungin doses from 0.25 to 2.0 mg/kg. In Candida-infected mice with chronic leukopenia, caspofungin was effective at all dose levels tested (0.25 to 1.0 mg/kg), with the log(10) CFU of C. albicans/gram of kidneys of caspofungin-treated mice being significantly lower (>99% reduction) than that of sham-treated mice from day 4 to day 28 after challenge. Also, 70 to 100% of the caspofungin-treated, chronic leukopenic mice had sterile kidneys at caspofungin doses of 0.5 to 1.0 mg/kg from day 8 to 28 after challenge. Sterilization of Candida infections by caspofungin in the absence of host leukocytes provides compelling in vivo evidence for fungicidal activity against C. albicans. Further human clinical trials with caspofungin against serious fungal infections are in progress.

Multilocus sequence typing reveals intrafamilial transmission and microevolutions of Candida albicans isolates from the human digestive tract

Candida albicans is a human commensal that is also responsible for superficial and systemic infections. Little is known about the carriage of C. albicans in the digestive tract and the genome dynamics that occur during commensalisms of this diploid species. The aim of this study was to evaluate the prevalence, diversity, and genetic relationships among C. albicans isolates recovered during natural colonization of the digestive tract of humans, with emphasis on Crohn's disease patients who produce anti-yeast antibodies and may have altered Candida sp. carriage. Candida sp. isolates were recovered from 234 subjects within 25 families with multiple cases of Crohn's disease and 10 control families, sampled at the oral and fecal sites. Prevalences of Candida sp. and C. albicans carriage were 53.4% and 46.5%, respectively, indicating frequent commensal carriage. No differences in prevalence of carriage could be observed between Crohn's disease patients and healthy subjects. Multilocus sequence typing (MLST) of C. albicans isolates revealed frequent colonization of a subject or several members of the same family by genetically indistinguishable or genetically close isolates. These latter isolates differed by loss-of-heterozygosity events at one or several of the MLST loci. These loss-of-heterozygosity events could be due to either chromosome loss followed by duplication or large mitotic recombination events between complementary chromosomes. This study was the first to jointly assess commensal carriage of C. albicans, intrafamilial transmission, and microevolution. The high frequency of each of these events suggests that the digestive tract provides an important and natural niche for microevolutions of diploid C. albicans through the loss of heterozygosity.

Vertical and horizontal transmission of unique Candida species to premature newborns

The number of nosocomial bloodstream infections due to Candida species in critically ill newborns is increasing. This pathogen may be vertically transmitted from the mother or nosocomially acquired in the nursery. The goal of this study was to identify the route of transmission of unique Candida species and strains from mothers to their preterm offspring. Specimens from mothers for fungal cultures were obtained before delivery, and specimens from infants for sequential fungal cultures were obtained at defined intervals. Candida species were identified by standard methods and were typed by electrophoretic karyotyping (EK) and restriction endonuclease analysis of genomic DNA (REAG) with pulsed-field gel electrophoresis. Antifungal susceptibility testing was performed on all isolates. Fungal cultures were positive for Candida species in 12 (63%) of 19 mothers' specimens and in seven (33%) of 21 infants' specimens. EK and REAG revealed that both the mother and the infant in three (14%) of 21 mother-infant pairs were colonized with the identical strain of Candida albicans. C. albicans was most commonly transmitted vertically. Candida parapsilosis colonized other infants and could not be accounted for by a maternal reservoir.

Horizontal transmission of Candida parapsilosis candidemia in a neonatal intensive care unit

This report describes the nosocomial acquisition of Candida parapsilosis candidemia by one of the six premature newborns housed in the same room of a neonatal intensive care unit at the Ospedale Santa Chiara, Pisa, Italy. The infant had progeria, a disorder characterized by retarded physical development and progressive senile degeneration. The infant, who was not found to harbor C. parapsilosis at the time of his admission to the intensive care unit, had exhibited symptomatic conjunctivitis before the onset of a severe bloodstream infection. In order to evaluate the source of infection and the route of transmission, two independent molecular typing methods were used to determine the genetic relatedness among the isolates recovered from the newborn, the inanimate hospital environment, hospital personnel, topically and intravenously administered medicaments, and indwelling catheters. Among the isolates collected, only those recovered from the hands of two nurses attending the newborns and from both the conjunctiva and the blood of the infected infant were genetically indistinguishable. Since C. parapsilosis was never recovered from indwelling catheters or from any of the drugs administered to the newborn, we concluded that (i) horizontal transmission of C. parapsilosis occurred through direct interaction between nurses and the newborn and (ii) the conjunctiva was the site through which C. parapsilosis entered the bloodstream. This finding highlights the possibility that a previous C. parapsilosis colonization and/or infection of other body sites may be a predisposing condition for subsequent C. parapsilosis hematogenous dissemination in severely ill newborns.

Epidemiology of candidiasis

The increase in infections due to Candida over the past decade is significant. This is particularly true for hospitalized patients where the rate of blood-stream infection due to Candida spp. has increased by almost 500% over the decade of the 1980s. This increase is accompanied by a significant excess mortality and a prolonged length of stay in the hospital. This trend continues into the 1990s where in the US Candida spp. remains the fourth most common blood-stream pathogen, accounting for 8% of all hospital-acquired blood-stream infections. Notably, more than one-third of candidal blood-stream infections are caused by species other than C. albicans. The majority of these infections arise from an endogenous focus of colonization; however, the documentation of nosocomial transmission or 'cross-infection' and the recognition of resistance to antifungal agents pose new and significant problems. Recent studies indicate that Candida may be isolated from the hands of 15-54% of health care workers in the intensive care unit setting and that the strain of Candida carried on the hands may be shared by infected patients. These studies are facilitated by molecular typing and careful epidemiological investigation and suggest that cross-infection is an important and preventable feature of candidal blood-stream infection. Both endogenous and exogenous sources of infection are now well-documented and such information should help direct measures to prevent infections in high risk individuals.

Efficacy of oral cochleate-amphotericin B in a mouse model of systemic candidiasis

Amphotericin B (AMB) remains the principal therapeutic choice for deep mycoses. However, its application is limited by toxicity and a route of administration requiring slow intravenous injection. An oral formulation of this drug is desirable to treat acute infections and provide prophylactic therapy for high-risk patients. Cochleates are a novel lipid-based delivery system that have the potential for oral administration of hydrophobic drugs. They are stable phospholipid-cation crystalline structures consisting of a spiral lipid bilayer sheet with no internal aqueous space. Cochleates containing AMB (CAMB) inhibit the growth of Candida albicans, and the in vivo therapeutic efficacy of CAMB administered orally was evaluated in a mouse model of systemic candidiasis. The results indicate that 100% of the mice treated at all CAMB doses, including a low dosage of 0.5 mg/kg of body weight/day, survived the experimental period (16 days). In contrast, 100% mortality was observed with untreated mice by day 12. The fungal tissue burden in kidneys and lungs was assessed in parallel, and a dose-dependent reduction in C. albicans from the kidneys was observed, with a maximum 3.5-log reduction in total cell counts at 2.5 mg/kg/day. However, complete clearance of the organism from the lungs, resulting in more than a 4-log reduction, was observed at the same dose. These results were comparable to a deoxycholate AMB formulation administered intraperitoneally at 2 mg/kg/day (P < 0.05). Overall, these data demonstrate that cochleates are an effective oral delivery system for AMB in a model of systemic candidiasis.

High frequency of yeast carriage on hands of hospital personnel

The hands of 36 nurses and 21 nonnursing hospital employees were tested by culture with a modification of the broth wash technique. Seventy-five percent of the nurses and 81% of the nonnurses were found to harbor yeasts on their hands; 58% of nurses and 38% of nonnurses were carrying Candida spp.

The Incidence of Fungal Keratitis and Endophthalmitis Following Penetrating Keratoplasty

PURPOSE

To determine the incidence of postkeratoplasty fungal endophthalmitis and keratitis at the New York Eye and Ear Infirmary. To determine whether there is a relationship between culture-positive corneoscleral donor material and postoperative infection.

METHODS

The microbiologic records of corneoscleral donor rims submitted for culture following penetrating keratoplasty at the New York Eye and Ear Infirmary between January 1998 and January 2003 were reviewed. The incidence of rim cultures positive for fungi was tabulated. Clinical outcome measures were recorded for each patient receiving corneal donor tissue.

RESULTS

Of 2466 donor corneoscleral rims cultured during the study period, 344 were positive for microbial growth (13%). Of those rims with positive cultures, 28 (8.6%) were positive for fungus. All fungi cultured were Candida species. Four of the 28 recipient eyes (14%) who received contaminated donor material went on to develop postkeratoplasty fungal infections. There were no cases of fungal infection in any postkeratoplasty patients in the absence of contaminated donor rims during the study period. Overall, there was a 0.16% incidence of fungal infection (4/2466) following penetrating keratoplasty. There were 18 positive donor rims identified in the first 4 years of the study, but there were 10 cases in the last 10 months of the study.

CONCLUSIONS

The overall incidence of fungal infection following penetrating keratoplasty is low, but all cases in our study were associated with positive rim cultures. Whether prophylactic antifungal therapy would be of any benefit in the presence of a positive corneoscleral rim culture has not yet been determined.

Nosocomial acquisition of Candida parapsilosis: an epidemiologic study

OBJECTIVE

The purpose of this study was to determine aspects of the epidemiology of nosocomial infection due to Candida parapsilosis. Candida species are important nosocomial pathogens; however, little epidemiologic information is available.

PATIENTS AND METHODS

We prospectively cultured specimens from 98 patients admitted to the bone marrow transplant unit and a medicine intensive care unit (ICU) of a tertiary care hospital. Specimens from hands of personnel and environmental surfaces were also cultured. Environmental cultures were done before patients were admitted to a studied unit. Restriction enzyme analysis (REA) of chromosomal DNA was used as a typing system to determine the relatedness of strains.

RESULTS

C. parapsilosis was identified from five patients, six hand cultures from four hospital staff, and two environmental surfaces. All five patients had negative initial cultures and acquired C. parapsilosis after admission to the study unit. There were no significant differences between patients and control subjects in age, underlying disease, immunosuppressive therapy, and instrumentation. The duration of antibiotic therapy (median: 32.8 versus 11.8 days, p = 0.05) and the duration in the unit (means: 30.1 versus 16.1 days, p = 0.048) was longer in patients than in controls. No common source was identified. REA revealed three strain types; however, one strain type was identical in four patients, three staff members, and two environmental surfaces.

CONCLUSION

These results suggest exogenous acquisition of C. parapsilosis. Based upon isolation of identical patient strains of C. parapsilosis from inanimate surfaces before patients were admitted to a study unit, there is evidence that the organism may have been acquired from the hospital environment. The principal mechanism of transmission was probably indirect contact via the hands of hospital personnel.

Circumcision and sexually transmissible disease

The relationship between circumcision and sexually transmissible disease was studied in 1350 men who attended the Public Health Department Special Treatment Clinic in Perth, Western Australia. Evidence of circumcision was obtained by examination. More than 98% of the men studied gave a verbal report of their circumcision status which was consistent with the examination findings. Eight hundred and forty-eight men had STD; 471 men, who presented to the clinic for diagnosis and treatment but who were found not to have STD, constituted the control group. The results of the study show significant associations between the state of being uncircumcised and four major sexually transmissible diseases--herpes genitalis, candidiasis, gonorrhoea and syphilis. Estimates of the relative risk suggest that uncircumcised men are twice as likely as circumcised men to develop herpes genitalis or gonorrhoea, and five times as likely to develop candidiasis or syphilis. However, the data for syphilis should be interpreted with caution because of the small number of cases. No significant increase in risk was found for any of the other sexually transmissible diseases diagnosed at the clinic.

Candida parapsilosis fungemia in neonates: genotyping results suggest healthcare workers hands as source, and review of published studies

An outbreak of Candida parapsilosis fungemia involving 17 neonatal intensive care unit (NICU) patients was studied. There were 14 blood culture and nine colonizing isolates from other sites available. The hands of NICU healthcare workers (HCW) yielded eight isolates. Screening of the isolates by random amplified polymorphic DNA (RAPD) method showed only three profiles. Typing by restriction fragment length polymorphism (RFLP) revealed all blood isolates were RFLP subtype VII-1. Among the nine infant colonizing isolates, there were four different RFLP subtypes; four of the isolates were subtype VII-1. Seven of the eight isolates from HCW were RFLP subtype VII-1. The majority of infant colonizers were not found in the blood, suggesting a possible direct spread of the epidemic subtype VII-1 strain from HCW hands to infant blood. The source of the infant colonizing strains is unclear, but non-VII-1 strains may be largely of maternal origin and VII-1 strains from HCW. These findings reinforce prior studies that have implicated HCW hands as the source of nosocomial, including neonatal, fungemia.