Mortality difference from Klebsiella aerogenes vs Enterobacter cloacae bloodstream infections

Members of the order Enterobacterales, including Escherichia coli , Klebsiella species and Enterobacter species, are important pathogens in healthcare-associated infections. Higher mortality has been reported from infections due to Klebsiella pneumoniae than from E. coli , but prior studies comparing Enterobacter aerogenes (recently renamed Klebsiella aerogenes ) bacteraemia and Enterobacter cloacae complex bacteraemia have yielded conflicting results regarding whether clinical outcomes differ. We found bacteraemia with K. aerogenes was independently associated with greater risk of 30-day mortality than bacteraemia with Enterobacter cloacae complex.

Glycemic Control and Infections Among US Hemodialysis Patients With Diabetes Mellitus

Introduction

Patients with diabetes mellitus (DM) on hemodialysis (HD) may be particularly vulnerable to infections.

Methods

We used merged data from the United States Renal Data System and electronic health records data from a large US dialysis provider to retrospectively examine the association between glycemic control and infections in these patients. Adult patients with DM aged ≥18 years who initiated in-center maintenance HD treatment from 2006 to 2011 and survived >90 days were included. Quarterly mean time-averaged hemoglobin A1c (HbA1c) values were categorized into <5.5%, 5.5 to <6.5%, 6.5 to <7.5%, 7.5 to <8.5%, and ≥8.5%. We used Medicare claims to ascertain infection-related outcomes and the ESRD Death Notification to identify death from infectious cause. We used Cox proportional hazards models to estimate multivariable-adjusted hazard ratios and 95% confidence intervals (CIs) for the associations between time-averaged HbA1c categories and infectious events.

Results

In a cohort of 33,753 eligible patients, those with higher HbA1c levels had higher rates of diabetic foot infections and skin and soft tissue infections, with patients with HbA1c ≥8.5% having 23% (95% CI, 5%, 45%) and 22% (95% CI, 5%, 42%) higher rates, respectively, compared with HbA1c 5.5 to <6.5%. Patients in the lower HbA1c categories had higher rates of infection-related and all-cause mortality (P-for-trend <0.001).

Conclusion

This study highlights the need for greater attention to foot evaluation and skin and soft tissue infections among patients on HD with less than optimal diabetes control.

Ordering Patterns and Costs of Specialized Laboratory Testing by Hospitalists and House Staff in Hospitalized Patients With HIV at a County Hospital: An Opportunity for Diagnostic Stewardship

Background

Inpatient HIV care often requires specialized laboratory testing with which practitioners may not be familiar. In addition, computerized physician order entry allows for ordering tests without understanding test indications, but it can also provide a venue for education and diagnostic stewardship.

Methods

All charts of HIV-positive patients hospitalized at a tertiary care public safety net hospital in Houston, Texas, between January 1, 2014, and June 30, 2014, were reviewed for a set list of laboratory tests. Appropriateness of test ordering was assessed by 2 providers. Cost estimates for each test were obtained from Medicaid and a national nonprofit health care charge database.

Results

A total of 274 HIV-positive patients were admitted 429 times in the 6-month study period. During the study period, 45% of the study laboratory tests ordered were not indicated. A total of 532 hepatitis serologies were ordered, only 52% of which were indicated. Overall, 71 serum qualitative cytomegalovirus (CMV) polymerase chain reactions (PCRs) and eight CMV quantitative PCRs were ordered, with most (85%) qualitative PCRs ordered for nonspecific signs of infection (eg, fever). Other tests ordered without clear indications included Aspergillus IgE (7), serum Epstein-Barr virus (EBV) PCR (5), parvovirus serology (7), and Toxoplasma IgM (18). Overall, the estimated laboratory cost of inappropriate testing over the study period was between $14 000 and $92 000, depending on which cost database was used.

Conclusions

Many tests ordered in HIV-positive inpatients do not have indications, representing a substantial source of health care waste and cost and potentially leading to inappropriate treatment. Opportunities exist to decrease waste through education of trainees and hospitalists and through implementation of diagnostic stewardship via the electronic medical record.

1329. Beyond Reporting: Using an Accreditation Council for Graduate Medical Education (ACGME) Milestone-Linked Evaluation System to Improve Clinical Infectious Diseases Rotations for Baylor College of Medicine Internal Medicine (BCM IM) Residents

Background

ACGME requires reporting of trainee performance on specialty-specific “milestones.” Online evaluation platforms facilitate reporting by linking evaluation questions to these milestones. Whether a milestone-linked evaluation system can be used to identify educational strengths and weaknesses within a training program has not been reported.

Methods

In 2016, the BCM IM residency program implemented a milestone-linked evaluation system to increase transparency to residents regarding educational goals and streamline milestone reporting. Residents are evaluated on rotation-specific educational objectives; scores range from 1 to 5 (Figure 1), or “not observed” if the skill was not observed during the rotation. Evaluation data from residents on infectious diseases (ID) rotations between 2016 and 2018 were analyzed to compare performance by post-graduate year (PGY) and to assess curricular strengths and deficiencies.

Results

Two hundred five inpatient and 43 ambulatory ID rotation evaluations were analyzed. In the inpatient setting, mean scores for PGY-1, -2, and -3 trainees were 2.62, 3.06, and 3.88. Residents scored highly on communicating consult recommendations and collecting data from the health record. Residents received lower scores on identifying infections associated with immune deficiencies and in knowledge of antimicrobial spectrum/indications. In the ambulatory setting, mean scores for PGY-2 and -3 trainees were 3.44 and 3.61. Relative to the inpatient setting, more objectives on ambulatory rotations were rated as “not observed.” Objectives with high rates of “not observed” ratings included managing infections in returning travelers (70%); testing/treating latent tuberculosis (63%); interpreting viral hepatitis studies (31%); and managing sexually transmitted infections (25%).

Conclusion

Data from a milestone-linked evaluation system identified educational strengths and weaknesses of clinical ID experiences for internal medicine residents. Objectives with consistently low or “not observed” ratings may be judged as educational deficiencies, and should prompt modifications to the curriculum to provide increased clinical exposure and/or dedicated didactics to help residents develop these important skills.

Disclosures

All authors: No reported disclosures.

Adherence to clinical practice guidelines for the treatment of candidemia at a Veterans Affairs Medical Center

OBJECTIVES

The primary objective of this study was to examine the appropriateness of candidemia management at a Veterans Affairs Medical Center as recommended by the 2009 Infectious Diseases Society of America (IDSA) guidelines for treatment of Candida infections.

METHODS

A retrospective analysis of 94 adult patients with blood cultures positive for Candida spp. was performed. Patients were stratified by severity of disease into two groups: non-neutropenic, mild-moderate disease (Group 1, n = 54, 56%) and non-neutropenic, moderate-severe disease (Group 2, n = 40, 42%).

RESULTS

Adherence to the IDSA recommendations for recommended antifungal drug, dose, and duration of therapy was low in both groups (16.7% in Group 1 and 17.5% in Group 2). Although adherence was not associated with higher clinical resolution of infection (P = 0.111), it was associated with a significantly lower mortality rate (P = 0.001) when compared to variance from the guidelines at 6 weeks.

CONCLUSION

Although adherence to published guidelines for treating patients with candidemia was suboptimal at our institution, patients that were managed based on the guidelines had a statistically lower mortality rate.

Therapeutics targeting inflammation in the immune reconstitution inflammatory syndrome

Immune reconstitution inflammatory syndrome (IRIS) is characterized by improvement in a previously incompetent human immune system manifesting as worsening of clinical symptoms secondary to the ability of the immune system to now mount a vigorous inflammatory response. IRIS was first recognized in the setting of human immunodeficiency virus, and this clinical setting continues to be where it is most frequently encountered. Hallmarks of the pathogenesis of IRIS, independent of the clinical presentation and the underlying pathogen, include excessive activation of the immune system, with increased circulating effector memory T cells, and elevated levels of serum cytokines and inflammatory markers. Patients with undiagnosed opportunistic infections remain at risk for unmasking IRIS at the time of active antiretroviral therapy (ART) initiation. Systematic screening for opportunistic infections before starting ART is a key element to prevent this phenomenon. Appropriate management of IRIS requires prompt recognition of the syndrome and exclusion of alternative diagnoses, particularly underlying infections and drug resistance. Controlled studies supporting the use of pharmacologic interventions in IRIS are scare, and recommendations are based on case series and expert opinions. The only controlled trial published to date, showed reduction in morbidity in patients with paradoxical tuberculosis-related IRIS with the use of oral corticosteroids. There are currently limited data to recommend other anti-inflammatory or immunomodulatory therapies that are discussed in this review, and further research is needed. Ongoing research regarding the immune pathogenesis of IRIS will likely direct future rational therapeutic approaches and clinical trials.

Amphotericin B formulations: a comparative review of efficacy and toxicity

Because of the increasing prevalence and changing microbiological spectrum of invasive fungal infections, some form of amphotericin B still provides the most reliable and broad spectrum therapeutic alternative. However, the use of amphotericin B deoxycholate is accompanied by dose-limited toxicities, most importantly, infusion-related reactions and nephrotoxicity. In an attempt to improve the therapeutic index of amphotericin B, three lipid-associated formulations were developed, including amphotericin B lipid complex (ABLC), liposomal amphotericin B (L-AmB), and amphotericin B colloidal dispersion (ABCD). The lipid composition of all three of these preparations differs considerably and contributes to substantially different pharmacokinetic parameters. ABLC is the largest of the lipid preparations. Because of its size, it is taken up rapidly by macrophages and becomes sequestered in tissues of the mononuclear phagocyte system such as the liver and spleen. Consequently, compared with the conventional formulation, it has lower circulating amphotericin B serum concentrations, reflected in a marked increase in volume of distribution and clearance. Lung levels are considerably higher than those achieved with other lipid-associated preparations. The recommended therapeutic dose of ABLC is 5 mg/kg/day. Because of its small size and negative charge, L-AmB avoids substantial recognition and uptake by the mononuclear phagocyte system. Therefore, a single dose of L-AmB results in a much higher peak plasma level (Cmax) than conventional amphotericin B deoxycholate and a much larger area under the concentration-time curve. Tissue concentrations in patients receiving L-AmB tend to be highest in the liver and spleen and much lower in kidneys and lung. Recommended therapeutic dosages are 3-6 mg/kg/day. After intravenous infusion, ABCD complexes remain largely intact and are rapidly removed from the circulation by cells of the macrophage phagocyte system. On a milligram-to-milligram basis, the Cmax achieved is lower than that attained by conventional amphotericin B, although the larger doses of ABCD that are administered produce an absolute level that is similar to amphotericin B. ABCD exhibits dose-limiting, infusion-related toxicities; consequently, the administered dosages should not exceed 3-4 mg/kg/day. The few comparative clinical trials that have been completed with the lipid-associated formulations have not demonstrated important clinical differences among these agents and amphotericin B for efficacy, although there are significant safety benefits of the lipid products. Furthermore, only one published trial has ever compared one lipid product against another for any indication. The results of these trials are particularly difficult to interpret because of major heterogeneities in study design, disease definitions, drug dosages, differences in clinical and microbiological endpoints as well as specific outcomes examined. Nevertheless, it is possible to derive some general conclusions given the available data. The most commonly studied syndrome has been empiric therapy for febrile neutropenic patients, where the lipid-associated preparations did not appear to provide a survival benefit over conventional amphotericin B deoxycholate, but did offer a significant advantage for the prevention of various breakthrough invasive fungal infections. For treatment of documented invasive fungal infections that usually involved hematological malignancy patients, no individual randomized trial has demonstrated a mortality benefit due to therapy with one of the lipid formulations. Results from meta-analyses have been contradictory, with one demonstrating a mortality benefit from all-cause mortality and one that did not demonstrate a mortality benefit. In the only published study to examine HIV-infected patients with disseminated histoplasmosis, clinical success and mortality were significantly better with L-AmB compared with amphotericin B deoxycholate; there were no differences in microbiological outcomes between treatment groups. The lipid-associated preparations were not significantly better than amphotericin B deoxycholate for treatment of AIDS-associated acute cryptococcal meningitis for either clinical or microbiological outcomes that were studied. In all of the trials that specifically examined renal toxicity, the lipid-associated formulations were significantly less nephrotoxic than amphotericin B deoxycholate. Infusion-related reactions occurred less frequently with L-AmB when compared with amphotericin B deoxycholate; however, ABCD had equivalent or more frequent infusion-related reactions than conventional amphotericin B, and this resulted in the cessation of at least one clinical trial. At the present time, this particular lipid formulation is no longer commercially available. For the treatment of most invasive fungal infections, an amphotericin B lipid formulation provides a safer alternative than conventional amphotericin B, with at least equivalent efficacy. As the cost of therapy with these agents continues to decline, these drugs will likely maintain their important role in the antifungal drug armamentarium because of their efficacy and improved safety profile.

A polymorphic, mucocutaneous eruption in a patient with end-stage renal disease

An 81-year-old man is presented who developed cryptococcal infection after treatment for Clostridium difficile infection.

Toward repurposing ciclopirox as an antibiotic against drug-resistant Acinetobacter baumannii, Escherichia coli, and Klebsiella pneumoniae

Antibiotic-resistant infections caused by gram-negative bacteria are a major healthcare concern. Repurposing drugs circumvents the time and money limitations associated with developing new antimicrobial agents needed to combat these antibiotic-resistant infections. Here we identified the off-patent antifungal agent, ciclopirox, as a candidate to repurpose for antibiotic use. To test the efficacy of ciclopirox against antibiotic-resistant pathogens, we used a curated collection of Acinetobacter baumannii, Escherichia coli, and Klebsiella pneumoniae clinical isolates that are representative of known antibiotic resistance phenotypes. We found that ciclopirox, at 5–15 µg/ml concentrations, inhibited bacterial growth regardless of the antibiotic resistance status. At these same concentrations, ciclopirox reduced growth of Pseudomonas aeruginosa clinical isolates, but some of these pathogens required higher ciclopirox concentrations to completely block growth. To determine how ciclopirox inhibits bacterial growth, we performed an overexpression screen in E. coli. This screen revealed that galE, which encodes UDP-glucose 4-epimerase, rescued bacterial growth at otherwise restrictive ciclopirox concentrations. We found that ciclopirox does not inhibit epimerization of UDP-galactose by purified E. coli GalE; however, ΔgalU, ΔgalE, ΔrfaI, or ΔrfaB mutant strains all have lower ciclopirox minimum inhibitory concentrations than the parent strain. The galU, galE, rfaI, and rfaB genes all encode enzymes that use UDP-galactose or UDP-glucose for galactose metabolism and lipopolysaccharide (LPS) biosynthesis. Indeed, we found that ciclopirox altered LPS composition of an E. coli clinical isolate. Taken together, our data demonstrate that ciclopirox affects galactose metabolism and LPS biosynthesis, two pathways important for bacterial growth and virulence. The lack of any reported fungal resistance to ciclopirox in over twenty years of use in the clinic, its excellent safety profiles, novel target(s), and efficacy, make ciclopirox a promising potential antimicrobial agent to use against multidrug-resistant problematic gram-negative pathogens.

Novel Conserved Genotypes Correspond to Antibiotic Resistance Phenotypes of E. coli Clinical Isolates

Current efforts to understand antibiotic resistance on the whole genome scale tend to focus on known genes even as high throughput sequencing strategies uncover novel mechanisms. To identify genomic variations associated with antibiotic resistance, we employed a modified genome-wide association study; we sequenced genomic DNA from pools of E. coli clinical isolates with similar antibiotic resistance phenotypes using SOLiD technology to uncover single nucleotide polymorphisms (SNPs) unanimously conserved in each pool. The multidrug-resistant pools were genotypically similar to SMS-3-5, a previously sequenced multidrug-resistant isolate from a polluted environment. The similarity was evenly spread across the entire genome and not limited to plasmid or pathogenicity island loci. Among the pools of clinical isolates, genomic variation was concentrated adjacent to previously reported inversion and duplication differences between the SMS-3-5 isolate and the drug-susceptible laboratory strain, DH10B. SNPs that result in non-synonymous changes in gyrA (encoding the well-known S83L allele associated with fluoroquinolone resistance), mutM, ligB, and recG were unanimously conserved in every fluoroquinolone-resistant pool. Alleles of the latter three genes are tightly linked among most sequenced E. coli genomes, and had not been implicated in antibiotic resistance previously. The changes in these genes map to amino acid positions in alpha helices that are involved in DNA binding. Plasmid-encoded complementation of null strains with either allelic variant of mutM or ligB resulted in variable responses to ultraviolet light or hydrogen peroxide treatment as markers of induced DNA damage, indicating their importance in DNA metabolism and revealing a potential mechanism for fluoroquinolone resistance. Our approach uncovered evidence that additional DNA binding enzymes may contribute to fluoroquinolone resistance and further implicate environmental bacteria as a reservoir for antibiotic resistance.

Etiology of thrombocytosis in a general medicine population: analysis of 801 cases with emphasis on infectious causes

BACKGROUND

The clinical importance of an elevated platelet count is often overlooked, particularly as a diagnostic clue to the presence of an underlying infection. We sought to better describe the relationship between thrombocytosis and inflammatory conditions, with a focus on infectious causes.

METHODS

We retrospectively reviewed 801 sequential cases of thrombocytosis (platelet count > 500 × 10(9)/L) at a tertiary care hospital.

RESULTS

Essential thrombocythemia was the most common cause of primary thrombocytosis, and these patients were more likely to have extreme (> 800 × 10(9)/L) and prolonged (> 1 month) thrombocytosis. Secondary thrombocytosis was more common than primary, with infectious causes accounting for nearly half the cases. Demographic factors associated with an infectious etiology included inpatient status, quadriplegia/paraplegia, an indwelling prosthesis, dementia and diabetes. Clinical and laboratory characteristics associated with an infectious cause of thrombocytosis included fever, tachycardia, weight loss, hypoalbuminemia, neutrophilia, leukocytosis and anemia. Patients with thrombocytosis secondary to infection had a more rapid normalization of platelet count, but higher risk of dying, than those with secondary, non-infectious causes.

CONCLUSIONS

Infection is a common cause of thrombocytosis and should be considered in patients with comorbidities that increase risk of infection and when clinical and/or laboratory data support an infectious etiology. Thrombocytosis may have prognostic implications as a clinical parameter.

Comparison of 2 doses of liposomal amphotericin B and conventional amphotericin B deoxycholate for treatment of AIDS-associated acute cryptococcal meningitis: a randomized, double-blind clinical trial of efficacy and safety

BACKGROUND. It is generally acknowledged that amphotericin B is the most effective treatment for cryptococcal meningitis. However, administration of this drug is accompanied by substantial adverse effects. This double-blind study, performed before the routine availability of highly active antiretroviral therapy, was designed to compare the efficacy and safety of liposomal amphotericin B to conventional amphotericin deoxycholate in patients with acquired immunodeficiency syndrome (AIDS) and acute cryptococcal meningitis. METHODS. Patients were randomized (ratio, 1:1:1) from multiple sites in the United States and Canada to receive either amphotericin B at 0.7 mg/kg/day (n = 87), liposomal amphotericin B at 3 mg/kg/day (n = 86), or liposomal amphotericin B at 6 mg/kg/day (n = 94). RESULTS. Efficacy was similar among all 3 treatment groups. The overall incidence of infusion-related reactions was significantly lower for both the 3 mg/kg/day and 6 mg/kg/day dosages of liposomal amphotericin B, compared with conventional amphotericin B (P < .001). Significantly fewer patients who received the 3 mg/kg/day dosage of liposomal amphotericin B developed nephrotoxicity, indicated by a doubling of the serum creatinine value, compared with recipients of conventional amphotericin B (P = .004). Overall mortality at 10 weeks was 11.6%, with no significant differences among the treatment groups. CONCLUSIONS. Liposomal amphotericin B provides an equally efficacious alternative to conventional amphotericin B deoxycholate in patients with AIDS and acute cryptococcal meningitis. Liposomal amphotericin B at a dosage of 3 mg/kg/day is accompanied by significantly fewer adverse effects.

Clinical practice guidelines for the management of cryptococcal disease: 2010 update by the infectious diseases society of america

Cryptococcosis is a global invasive mycosis associated with significant morbidity and mortality. These guidelines for its management have been built on the previous Infectious Diseases Society of America guidelines from 2000 and include new sections. There is a discussion of the management of cryptococcal meningoencephalitis in 3 risk groups: (1) human immunodeficiency virus (HIV)-infected individuals, (2) organ transplant recipients, and (3) non-HIV-infected and nontransplant hosts. There are specific recommendations for other unique risk populations, such as children, pregnant women, persons in resource-limited environments, and those with Cryptococcus gattii infection. Recommendations for management also include other sites of infection, including strategies for pulmonary cryptococcosis. Emphasis has been placed on potential complications in management of cryptococcal infection, including increased intracranial pressure, immune reconstitution inflammatory syndrome (IRIS), drug resistance, and cryptococcomas. Three key management principles have been articulated: (1) induction therapy for meningoencephalitis using fungicidal regimens, such as a polyene and flucytosine, followed by suppressive regimens using fluconazole; (2) importance of early recognition and treatment of increased intracranial pressure and/or IRIS; and (3) the use of lipid formulations of amphotericin B regimens in patients with renal impairment. Cryptococcosis remains a challenging management issue, with little new drug development or recent definitive studies. However, if the diagnosis is made early, if clinicians adhere to the basic principles of these guidelines, and if the underlying disease is controlled, then cryptococcosis can be managed successfully in the vast majority of patients.

Clinical Evidence of Interaction Between Itraconazole and Nonnucleoside Reverse Transcriptase Inhibitors in HIV-Infected Patients with Disseminated Histoplasmosis

Background

Itraconazole is the preferred drug for chronic maintenance therapy in HIV-infected patients with disseminated histoplasmosis. Unfortunately, few clinical data exist confirming a presumed interaction between itraconazole and nonnucleoside reverse transcriptase inhibitors (NNRTIs).

Objective

To determine whether serum itraconazole concentrations are affected by the type of antiretroviral therapy (NNRTI or protease inhibitor [PI]) being taken concomitantly.

Methods

This retrospective cohort identified patients on antiretroviral therapy and itraconazole for disseminated histoplasmosis between January 2003 and December 2006 at a large HIV clinic in Houston, TX. Available laboratory values were abstracted from medical records.

Results

Thirteen itraconazole concentrations from 10 patients were avaitable for analysis: 7 patients were on concomitant Pls, 4 on concomitant NNRTIs, and 2 on antiretroviral regimens containing both Pls and NNRTIs. Six of the itraconazole concentrations during concomitant PI treatment were therapeutic (>1.0 μg/mL). in contrast with none in patients taking an NNRTI. All patients taking concomitant NNRTIs had undetectable serum itraconazole concentrations (<0.05 μg/mL). Two patients switched from NNRTI-based to PI-based antiretroviral regimens and subsequently reached therapeutic itraconazole concentrations. Although limited by small sample size, this study provides the largest clinical data among HIV-infected patients demonstrating that coadministration of an NNRTI and itraconazole results in significant decreases in itraconazole blood concentrations, likely by inducing the CYP3A4 enzyme system.

Conclusions

Itraconazole concentrations should be monitored in patients taking concomitant NNRTIs. PI-based highly active antiretroviral therapy (HAART) may be preferred over NNRTI-based HAART when itraconazole is used to treat HIV-infected patients with disseminated histoplasmosis.

Increased fluoroquinolone resistance with time in Escherichia coli from >17,000 patients at a large county hospital as a function of culture site, age, sex, and location

Background

Escherichia coli infections are common and often treated with fluoroquinolones. Fluoroquinolone resistance is of worldwide importance and is monitored by national and international surveillance networks. In this study, we analyzed the effects of time, culture site, and patient age, sex, and location on fluoroquinolone resistance in E. coli clinical isolates.

Methods

To understand how patient factors and time influenced fluoroquinolone resistance and to determine how well data from surveillance networks predict trends at Ben Taub General Hospital in Houston, TX, we used Perl to parse and MySQL to house data from antibiograms (n ≅ 21,000) for E. coli isolated between 1999 to 2004 using Chi Square, Bonferroni, and Multiple Linear Regression methods.

Results

Fluoroquinolone resistance (i) increased with time; (ii) exceeded national averages by 2- to 4-fold; (iii) was higher in males than females, largely because of urinary isolates from male outpatients; (iv) increased with patient age; (v) was 3% in pediatric patients; (vi) was higher in hospitalized patients than outpatients; (vii) was higher in sputum samples, particularly from inpatients, than all other culture sites, including blood and urine, regardless of patient location; and (viii) was lowest in genital isolates than all other culture sites. Additionally, the data suggest that, with regard to susceptibility or resistance by the Dade Behring MicroScan system, a single fluoroquinolone suffices as a "surrogate marker" for all of the fluoroquinolone tested.

Conclusion

Large surveillance programs often did not predict E. coli fluoroquinolone resistance trends at a large, urban hospital with a largely indigent, ethnically diverse patient population or its affiliated community clinics.

Drug-drug interaction between itraconazole and efavirenz in a patient with AIDS and disseminated histoplasmosis

Although there is a presumed drug-drug interaction between itraconazole and nonnucleoside reverse-transcriptase inhibitors, the medical literature lacks such documentation. We describe a drug-drug interaction between itraconazole and efavirenz in a patient with disseminated histoplasmosis and acquired immunodeficiency syndrome (AIDS). The drug combination resulted in persistently elevated urinary Histoplasma antigen levels and subtherapeutic plasma itraconazole concentrations. Changing treatment from efavirenz to a protease inhibitor was accompanied by improvements in the desired urinary Histoplasma antigen level and plasma itraconazole concentration.

Clostridium difficile colitis that fails conventional metronidazole therapy: response to nitazoxanide

OBJECTIVES

Clostridium difficile-associated disease has increased in incidence and severity. Recommended treatments include metronidazole and vancomycin. Recent investigations, however, document the failure of metronidazole to cure a substantial proportion of patients with Clostridium difficile colitis, but oral administration of vancomycin raises concerns over selection of antibiotic-resistant organisms in the hospital environment. We have recently shown that nitazoxanide is as effective as metronidazole in initial therapy for C. difficile colitis. We hypothesized that this drug might be effective in treating patients who fail therapy with metronidazole.

METHODS

In the present study, we identified 35 patients who failed treatment with metronidazole for C. difficile colitis; failure was defined as either no improvement in symptoms or signs of disease (28 patients) after >or= 14 days of treatment with metronidazole or prompt recurrence on at least two occasions after initially responding to such treatment (seven patients). These patients were ill with numerous co-morbidities. Nitazoxanide, 500 mg twice daily, was given for 10 days; results from all patients are included.

RESULTS

Twenty-six (74%) of 35 patients responded to nitazoxanide, of whom seven later had recurrent disease, yielding a cure rate of 19 of 35 (54%) from initial therapy. Three who initially failed and one who had recurrent disease were re-treated with, and responded to, nitazoxanide. Thus, the aggregate cure with nitazoxanide in this difficult-to-treat population was 23 of 35 (66%).

CONCLUSIONS

Nitazoxanide appears to provide effective therapy for patients with C. difficile colitis who fail treatment with metronidazole.

Study of common functional genetic polymorphisms ofFCGR2A,3Aand3Bgenes and the risk for cryptococcosis in HIV-uninfected patients

A pilot candidate gene association study was conducted to investigate the role of three common functional genetic polymorphisms of the low-affinity Fc gamma receptors, FCGR2A (131H/R), FCGR3A (158F/V) and FCGR3B (NA1/NA2) in Cryptococcus neoformans infections in individuals not infected with HIV. The FCGR2A 131RR and FCGR3A 158VV genotypes were over-represented [OR: 1.67 (1.05-2.63) and 2.04 (1.06-4.00), respectively] whereas the FCGR3B NA2NA2 was under-represented in patients with cryptococcosis (28% vs. 40% in controls). An analysis of haplotypes showed a significant difference in distribution between cases and controls overall and in Caucasians.

Community-associated strains of methicillin-resistant Staphylococccus aureus as the cause of healthcare-associated infection

OBJECTIVE

Methicillin-resistant Staphylococcus aureus (MRSA) isolates from patients with community-associated infection have been described as strains genetically distinct from the strains isolated from patients with healthcare-associated infection. This study examines the hypothesis that community-associated MRSA (CA-MRSA) strains now cause serious infections in hospitalized patients.

METHODS

Thirty-seven clinical MRSA isolates were randomly selected from blood isolates obtained from July 2003 through June 2004. Strains were tested for staphylococcal chromosomal cassette mec (SCCmec) type, pulsed-field gel electrophoresis (PFGE) type, and presence of Panton-Valentine leukocidin (PVL) genes. Medical records review and epidemiologic classification was performed by an investigator blinded to the results of the bacterial strain analysis. Episodes of bloodstream infection were independently classified as either community-associated or healthcare-associated infections, and bacterial isolates were independently classified as either CA-MRSA strains or healthcare-associated MRSA (HA-MRSA) strains, according to established definitions.

SETTING

A tertiary care Veterans Affairs Medical Center.

RESULTS

Twenty-four (65%) of 37 MRSA isolates were SCCmec type IV, a genetic type characteristic of CA-MRSA strains; 22 of these 24 isolates belonged to the CA-MRSA clone USA300 and carried PVL genes. Thirteen (35%) of the 37 strains were SCCmec type II, of which 12 were USA100-ST5 and 12 lacked PVL genes. Thirty patients (81%) had healthcare-associated infections; 18 (60%) of these 30 were infected with isolates carrying markers of CA-MRSA strains. Of 7 patients with CA-MRSA infections, 6 were infected with isolates belonging to the USA300 clone. Patients with healthcare-associated bloodstream infections were as likely to be infected with a CA-MRSA strain as patients with a community-associated infection (P = .38).

CONCLUSIONS

MRSA strains with molecular characteristics of CA-MRSA strains have emerged as an important cause of serious healthcare-associated infection in our hospital.

Nitazoxanide for the treatment of Clostridium difficile colitis

BACKGROUND

Clostridium difficile colitis has increased in incidence and severity, and treatment failure with metronidazole therapy has increasingly been documented. It is uncertain whether treatment with vancomycin is more effective than treatment with metronidazole, but concern over the emergence of vancomycin resistance has motivated the search for alternative therapy. Nitazoxanide, a nitrothiazolide, blocks anaerobic metabolism of eukaryocyes and effectively treats intestinal infestation due to Cryptosporidium or Giardia species. At low concentrations, this compound inhibits C. difficile in vitro.

METHODS

We designed a prospective, randomized, double-blind study to compare nitazoxanide to metronidazole in treating hospitalized patients with C. difficile colitis.

RESULTS

Thirty-four patients received metronidazole at a dosage of 250 mg 4 times per day for 10 days, 40 patients received nitazoxanide at a dosage of 500 mg 2 times per day for 7 days, and 36 patients received nitazoxanide at a dosage of 500 mg 2 times per day for 10 days. After 7 days of treatment, 28 (82.4%) of 34 patients had responded to metronidazole therapy, compared with 68 (89.5%) of 76 who had received nitazoxanide therapy (difference, 7.1%; 95% confidence interval, -7.1% to 25.5%). Thirty-one days after beginning treatment, sustained responses were observed in 19 (57.6%) of 33 patients who had received metronidazole therapy for 10 days, compared with 25 (65.8%) of 38 who had received nitazoxanide for 7 days and 26 (74.3%) of 35 who had received nitazoxanide for 10 days (P = .34).

CONCLUSION

Nitazoxanide is at least as effective as metronidazole in treating C. difficile colitis.

Clostridium difficilelacks detectable superantigen activity

Clostridium difficile colitis causes striking leukocytosis. We examined the possibility that toxins A or B, or other nontoxin products of C. difficile, act as superantigens, thereby stimulating leukocytosis. Our results failed to show major histocompatibility complex class II-dependent T lymphocyte proliferation, the hallmark of superantigen activity. Elevated white blood cell counts in C. difficile colitis are probably due to increased generation of cytokines such as interleukin-6 (IL-6) or IL-8.

Bactericidal activity of orally available agents against methicillin-resistant Staphylococcus aureus

BACKGROUND

The recent proliferation of community-acquired (CA) methicillin-resistant Staphylococcus aureus (MRSA) has led to a marked increase in the need for outpatient treatment of MRSA infections. Many oral agents active against MRSA have been available for years, and a paucity of literature compares them, leaving physicians with little guidance for choosing among them. The purpose of the present study was to compare the bactericidal effects of orally available antibiotics against MRSA and to determine whether there were differences in antimicrobial killing activity against CA-MRSA and hospital-acquired (HA) MRSA isolates.

METHODS

A total of 12 unique patient MRSA isolates were studied. Six strains were CA, carrying the staphylococcal chromosomal cassette (SCCmec) type IVa, while six were HA and carried SCCmec type II. Time-kill methods were used to study the bactericidal activity of the orally available antimicrobials linezolid, rifampicin, trimethoprim/sulfamethoxazole, clindamycin, minocycline, and moxifloxacin alone and in combination in vitro.

RESULTS

Trimethoprim/sulfamethoxazole was rapidly bactericidal resulting in >2 log(10) cfu/mL decrease at 8 h and >3 log(10) cfu/mL decrease at 24 h in vitro. No antibiotic combination exhibited better killing than trimethoprim/sulfamethoxazole alone. Adding rifampicin to trimethoprim/sulfamethoxazole showed a trend towards antagonism in vitro. There were no differences in the bactericidal activity of any antimicrobial or antimicrobial combination against MRSA isolates carrying SCCmec type IVa versus those carrying SCCmec type II.

CONCLUSION

Trimethoprim/sulfamethoxazole is rapidly bactericidal against MRSA in vitro when compared with most other orally available antimicrobials. No differences in bactericidal activity were detected when activities against CA-MRSA and HA-MRSA were compared.

Immune reconstitution inflammatory syndrome: more answers, more questions

The institution of highly active antiretroviral therapy (HAART) in HIV-infected patients restores protective immune responses against a wide variety of pathogens and dramatically decreases mortality. In a subset of patients receiving HAART, immune reconstitution is associated with a pathological inflammatory response leading to substantial short-term morbidity and even mortality. The past several years have seen marked advances in our clinical understanding of the immune reconstitution inflammatory syndrome (IRIS), but many questions remain. This article summarizes recent data on clinical risk factors for the development of IRIS. A consistent finding from multiple groups is that IRIS develops in a substantial percentage of HIV-infected patients who have an underlying opportunistic infection and receive HAART. As the use of HAART stands to markedly increase over the next several years, optimal care of patients receiving HAART will need to incorporate monitoring for and treating complications of IRIS.

Treatment of Clostridium difficile-associated disease: old therapies and new strategies

Clostridium difficile-associated disease (CDAD) causes substantial morbidity and mortality. The pathogenesis is multifactorial, involving altered bowel flora, production of toxins, and impaired host immunity, often in a nosocomial setting. Current guidelines recommend treatment with metronidazole; vancomycin is a second-line agent because of its potential effect on the hospital environment. We present the data that led to these recommendations and explore other therapeutic options, including antimicrobials, antibody to toxin A, probiotics, and vaccines. Treatment of CDAD has increasingly been associated with failure and recurrence. Recurrent disease may reflect relapse of infection due to the original infecting organism or infection by a new strain. Poor antibody responses to C difficile toxins have a permissive role in recurrent infection. Hospital infection control and pertinent use of antibiotics can limit the spread of CDAD. A vaccine directed against C difficile toxin may eventually offer a solution to the CDAD problem.

Relatively poor outcome after treatment of Clostridium difficile colitis with metronidazole

BACKGROUND

Clostridium difficile is a frequent cause of serious nosocomial infection. Earlier reports have suggested that treatment with metronidazole cured nearly 90% of patients, with only a modest rate of recurrence of infection. In recent years, the rate of response to treatment with this drug has appeared to be much lower.

METHODS

We undertook a prospective, observational study of 207 patients who were treated with metronidazole for C. difficile colitis.

RESULTS

A total of 103 patients (50%) were cured by the initial course of therapy and had no recurrence of disease. Forty-six patients (22%) continued to have symptoms of colitis for > or = 10 days despite treatment, and 58 (28%) responded initially but had a recurrence within the ensuing 90 days. The mortality rate among patients who developed C. difficile colitis was 27%, and it was higher among patients who did not respond fully to an initial course of therapy, compared with those who did (33% vs. 21%; P < .05).

CONCLUSIONS

Because of the relatively poor response to therapy, additional approaches to prevention and/or treatment of C. difficile colitis appear to be warranted.

The Role of Immune Reconstitution Inflammatory Syndrome in AIDS‐RelatedCryptococcus neoformansDisease in the Era of Highly Active Antiretroviral Therapy

This study of human immunodeficiency virus (HIV)-infected patients coinfected with Cryptococcus neoformans found that 30% of patients who initiated highly active antiretroviral therapy developed immune reconstitution inflammatory syndrome (IRIS). Patients with C. neoformans-related IRIS had higher cerebrospinal fluid opening pressures, glucose levels, and white blood cell counts, compared with patients with typical HIV-associated C. neoformans meningitis.

Incidence and risk factors for immune reconstitution inflammatory syndrome during highly active antiretroviral therapy

BACKGROUND

There is little systematic information regarding the immune reconstitution inflammatory syndrome (IRIS).

OBJECTIVE

To determine the incidence, risk factors, and long-term outcome of IRIS in HIV-infected patients receiving highly active antiretroviral therapy (HAART) who were coinfected with one of three common opportunistic pathogens.

DESIGN

A retrospective cohort identified through a city-wide prospective surveillance program.

METHODS

A retrospective chart review was performed for 180 HIV-infected patients who received HAART and were coinfected with Mycobacterium tuberculosis, Mycobacterium avium complex, or Cryptococcus neoformans between 1997 and 2000. Medical records were reviewed for baseline demographics, receipt and type of HAART, response to antiretroviral therapy, development of IRIS, and long-term outcome.

RESULTS

In this cohort, 31.7% of patients who received HAART developed IRIS. Patients with IRIS were more likely to have initiated HAART nearer to the time of diagnosis of their opportunistic infection (P < 0.001), to have been antiretroviral naive at time of diagnosis of their opportunistic infection (P < 0.001), and to have a more rapid initial fall in HIV-1 RNA level in response to HAART (P < 0.001).

CONCLUSIONS

IRIS is common among HIV-infected persons coinfected with M. tuberculosis, M. avium complex, or C. neoformans. Antiretroviral drug-naive patients who start HAART in close proximity to the diagnosis of an opportunistic infection and have a rapid decline in HIV-1 RNA level should be monitored for development of this disorder.

In vitro killing of community-associated methicillin-resistant Staphylococcus aureus with drug combinations

This study employs time-kill techniques to examine the most common drug combinations used in the therapy of methicillin-resistant Staphylococcus aureus (MRSA) infections, vancomycin plus either gentamicin or rifampin. Community-associated MRSA were more likely to be synergistically inhibited by combinations of vancomycin and gentamicin versus vancomycin alone compared to inhibition associated with hospital-acquired strains.

Reactive hemophagocytosis associated with the initiation of highly active antiretroviral therapy (HAART) in a patient with AIDS

Reactive hemophagocytosis has been associated with neoplasia, bacteria, parasitic, and viral infections including human immunodeficiency virus (HIV). Here we present a case of reactive hemophagocytosis associated with the initiation of highly active antiretroviral therapy (HAART), probably representing a syndrome termed the immune reconstitution inflammatory syndrome (IRIS) or immune reconstitution syndrome.

Benefits and harms of doxycycline treatment for Gulf War veterans' illnesses: a randomized, double-blind, placebo-controlled trial

BACKGROUND

It has been hypothesized that certain Mycoplasma species may cause Gulf War veterans' illnesses (GWVIs), chronic diseases characterized by pain, fatigue, and cognitive symptoms, and that affected patients may benefit from doxycycline treatment.

OBJECTIVE

To determine whether a 12-month course of doxycycline improves functional status in Gulf War veterans with GWVIs.

DESIGN

A randomized, double-blind, placebo-controlled clinical trial with 12 months of treatment and 6 additional months of follow-up.

SETTING

26 U.S. Department of Veterans Affairs and 2 U.S. Department of Defense medical centers.

PARTICIPANTS

491 deployed Gulf War veterans with GWVIs and detectable Mycoplasma DNA in the blood.

INTERVENTION

Doxycycline, 200 mg, or matching placebo daily for 12 months.

MEASUREMENTS

The primary outcome was the proportion of participants who improved more than 7 units on the Physical Component Summary score of the Veterans Short Form-36 General Health Survey 12 months after randomization. Secondary outcomes were measures of pain, fatigue, and cognitive function and change in positivity for Mycoplasma species at 6, 12, and 18 months after randomization.

RESULTS

No statistically significant differences were found between the doxycycline and placebo groups for the primary outcome measure (43 of 238 participants [18.1%] vs. 42 of 243 participants [17.3%]; difference, 0.8 percentage point [95% CI, -6.5 to 8.0 percentage points]; P > 0.2) or for secondary outcome measures at 1 year. In addition, possible differences in outcomes at 3 and 6 months were not apparent at 9 or 18 months. Participants in the doxycycline group had a higher incidence of nausea and photosensitivity.

LIMITATIONS

Adherence to treatment after 6 months was poor.

CONCLUSION

Long-term treatment with doxycycline did not improve outcomes of GWVIs at 1 year.

Recombinant Interferon‐γ1b as Adjunctive Therapy for AIDS‐Related Acute Cryptococcal Meningitis

We conducted a phase 2, double-blind, placebo-controlled study to evaluate the safety and antifungal activity of adjuvant recombinant interferon (rIFN)- gamma 1b in patients with acquired immunodeficiency syndrome and acute cryptococcal meningitis. Patients received 100 or 200 microg of rIFN- gamma 1b or placebo, thrice weekly for 10 weeks, plus standard therapy with intravenous amphotericin B, with or without flucytosine, followed by therapy with fluconazole. End points included conversion of cerebrospinal fluid fungal cultures from positive to negative at 2 weeks, resolution of symptoms, and survival. Among 75 patients, 2-week culture conversion occurred in 13% of placebo recipients, 36% of rIFN- gamma 1b (100 microg) recipients, and 32% of rIFN- gamma 1b (200 microg) recipients. There was a trend toward improved combined mycologic and clinical success in rIFN- gamma 1b recipients (26% vs. 8%; P=.078). Therapy with rIFN- gamma 1b was well tolerated, and there was no apparent influence on serial CD4 cell counts and human immunodeficiency virus load measurements. Adjunctive therapy with rIFN- gamma 1b holds promise for patients with acute cryptococcal meningitis and warrants further study.

Antifungal susceptibility survey of 2,000 bloodstream Candida isolates in the United States

Candida bloodstream isolates (n = 2,000) from two multicenter clinical trials carried out by the National Institute of Allergy and Infectious Diseases Mycoses Study Group between 1995 and 1999 were tested against amphotericin B (AMB), flucytosine (5FC), fluconazole (FLU), itraconazole (ITR), voriconazole (VOR), posaconazole (POS), caspofungin (CFG), micafungin (MFG), and anidulafungin (AFG) using the NCCLS M27-A2 microdilution method. All drugs were tested in the NCCLS-specified RPMI 1640 medium except for AMB, which was tested in antibiotic medium 3. A sample of isolates was also tested in RPMI 1640 supplemented to 2% glucose and by using the diluent polyethylene glycol (PEG) in lieu of dimethyl sulfoxide for those drugs insoluble in water. Glucose supplementation tended to elevate the MIC, whereas using PEG tended to decrease the MIC. Trailing growth occurred frequently with azoles. Isolates were generally susceptible to AMB, 5FC, and FLU. Rates of resistance to ITR approached 20%. Although no established interpretative breakpoints are available for the candins (CFG, MFG, and AFG) and the new azoles (VOR and POS), they all exhibited excellent antifungal activity, even for those strains resistant to the other aforementioned agents.

A prospective observational study of candidemia: epidemiology, therapy, and influences on mortality in hospitalized adult and pediatric patients

We conducted a prospective, multicenter observational study of adults (n=1447) and children (n=144) with candidemia at tertiary care centers in the United States in parallel with a candidemia treatment trial that included nonneutropenic adults. Candida albicans was the most common bloodstream isolate recovered from adults and children (45% vs. 49%) and was associated with high mortality (47% among adults vs. 29% among children). Three-month survival was better among children than among adults (76% vs. 54%; P<.001). Most children received amphotericin B as initial therapy, whereas most adults received fluconazole. In adults, Candida parapsilosis fungemia was associated with lower mortality than was non-parapsilosis candidemia (24% vs. 46%; P<.001). Mortality was similar among subjects with Candida glabrata or non-glabrata candidemia; mortality was also similar among subjects with C. glabrata candidemia who received fluconazole rather than other antifungal therapy. Subjects in the observational cohort had higher Acute Physiology and Chronic Health Evaluation II scores than did participants in the clinical trial (18.6 vs. 16.1), which suggests that the former subjects are more often excluded from therapeutic trials.

The immune reconstitution inflammatory syndrome

The use of highly active antiretroviral therapy (HAART) has led to a substantial decrease in the frequency of opportunistic infections among HIV-infected individuals, along with a significant reduction in their mortality rate. However, a subgroup of HAART-treated patients will exhibit paradoxical deterioration in their clinical status, despite satisfactory control of viral replication and improvements in CD4 lymphocyte counts. This clinical deterioration, known as the immune restoration syndrome or immune reconstitution inflammatory syndrome (IRIS), is a result of an exuberant inflammatory response towards previously diagnosed or incubating opportunistic pathogens, as well as responses towards other as yet undefined antigens. A variety of manifestations of IRIS have been described, most prominently including Mycobacterium avium complex lymphadenitis, paradoxical exacerbations of pulmonary and CNS Mycobacterium tuberculosis infection, paradoxical exacerbations of Cryptococcus neoformans meningitis and cytomegalovirus uveitis. Treatment for this disorder includes continuation of primary therapy against the offending pathogen in order to decrease the antigenic load, continuation of effective HAART, and judicious use of anti-inflammatory agents. Although the clinical manifestations of IRIS are sometimes dramatic, and result in substantial morbidity, the fact that these patients are capable of generating an inflammatory response allows many of them to ultimately discontinue secondary prophylaxis for the offending pathogen.

Spectrum of bacille Calmette-Guérin (BCG) infection after intravesical BCG immunotherapy

Intravesical instillation of bacille Calmette-Guérin (BCG) effectively treats transitional cell carcinoma of the bladder. Occasionally, BCG infection complicates such treatment. In some patients, infection appears early (within 3 months after instillation) and is characterized by generalized symptoms, with pneumonitis and hepatitis. Late-presentation disease occurs >1 year after the first BCG treatment and usually involves focal infection of the genitourinary tract (the site at which bacteria were introduced) and/or other sites that are typical for reactivation of mycobacterial disease, such as the vertebral spine or the retroperitoneal tissues. Noncaseating granulomas are found in the majority of cases, whether early or late. Most patients respond to treatment with antituberculous drugs; in early-presentation disease, when features of hypersensitivity predominate, glucocorticosteroids are sometimes added. Late localized infection often requires surgical resection.

Management of Increased Intracranial Pressure in Cryptococcal Meningitis

Therapy of cryptococcal meningitis has been focused primarily on optimizing the antifungal regimen to improve the previously high treatment failure rates. Until recently, relatively little attention has been paid to the impact of increased intracranial pressure, which is a frequent problem that complicates management of patients with cryptococcal meningitis. Patients with elevated baseline opening pressures have higher titers of cerebrospinal fluid cryptococcal capsular polysaccharide antigen, more frequent headaches, meningismus, papilledema, hearing loss, and pathologic reflexes, as well as increased morbidity and mortality compared with those patients with normal opening pressures. Optimal therapy has not yet been firmly established, but the diagnostic evaluation and available treatment options are reviewed here, including frequent high volume lumbar punctures, lumbar drains, ventriculoperitoneal shunting, and corticosteroids.

Trends in antifungal drug susceptibility of Cryptococcus neoformans isolates in the United States: 1992 to 1994 and 1996 to 1998

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 (>or=2 microg/ml) for 2 isolates, and the MICs of flucytosine were elevated (>or=32 microg/ml) for 14 isolates. Among the azoles, the fluconazole MIC was elevated (>or=64 microg/ml) for 8 isolates and the itraconazole MIC (>or=1 microg/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.

Cryptococcosis in human immunodeficiency virus-negative patients in the era of effective azole therapy

We conducted a case study of human immunodeficiency virus (HIV)-negative patients with cryptococcosis at 15 United States medical centers from 1990 through 1996 to understand the demographics, therapeutic approach, and factors associated with poor prognosis in this population. Of 306 patients with cryptococcosis, there were 109 with pulmonary involvement, 157 with central nervous system (CNS) involvement, and 40 with involvement at other sites. Seventy-nine percent had a significant underlying condition. Patients with pulmonary disease were usually treated initially with fluconazole (63%); patients with CNS disease generally received amphotericin B (92%). Fluconazole was administered to approximately two-thirds of patients with CNS disease for consolidation therapy. Therapy was successful for 74% of patients. Significant predictors of mortality in multivariate analysis included age > or =60 years, hematologic malignancy, and organ failure. Overall mortality was 30%, and mortality attributable to cryptococcosis was 12%. Cryptococcosis continues to be an important infection in HIV-negative patients and is associated with substantial overall and cause-specific mortality.

Coccidioidomycosis Pulmonary Infection

Disease caused by Coccidioides immitis has increased in frequency in recent years because of marked population shifts into highly endemic areas, as well as perturbations of the environment caused by construction, agricultural, and natural activities. Because disease may occur in persons in locations outside of the endemic regions, practitioners must be aware of the possibility of infection in those who may have traveled or resided in areas of risk. Recently, advances in laboratory methods have facilitated diagnosis of coccidioidomycosis, and information about therapies that are easier to administer has become available. Challenges in the management of this infection still remain, particularly with regard to more reliable antifungal drugs and protective vaccines.

Clinical prediction model for differentiation of disseminated Histoplasma capsulatum and Mycobacterium avium complex infections in febrile patients with AIDS

BACKGROUND

Disseminated infection with Histoplasma capsulatum and Mycobacterium avium complex (MAC) in patients with AIDS are frequently difficult to distinguish clinically.

METHODS

We retrospectively compared demographic information, other opportunistic infections, medications, symptoms, physical examination findings and laboratory parameters at the time of hospital presentation for 32 patients with culture documented disseminated histoplasmosis and 58 patients with disseminated MAC infection.

RESULTS

Positive predictors of histoplasma infection by univariate analysis included lactate dehydrogenase level, white blood cell (WBC) count, platelet count, alkaline phosphatase level, and CD4 cell count. By multivariate logistic regression analysis, those characteristics that remained significant included a lactate dehydrogenase value > or =500 U/L (risk ratio [RR], 42; 95% confidence interval [CI], 18.53-97.5; p < .001), alkaline phosphatase < or =300 U/L (RR, 9.35; 95% CI, 2.61-33.48; p = .008), WBC < or =4.5 x 10(6)/L (RR, 21.29; 95% CI, 6.79-66.75; p = .008), and CD4 cell count (RR, 0.958; 95% CI, 0.946-0.971; p = .001).

CONCLUSIONS

A predictive model for distinguishing disseminated histoplasmosis from MAC infection was developed using lactate dehydrogenase and alkaline phosphatase levels as well as WBC count. This model had a sensitivity of 83%, a specificity of 91%, and a misclassification rate of 13%.

Acute respiratory failure associated with cryptococcosis in patients with AIDS: analysis of predictive factors

The incidence of acute respiratory failure (ARF) associated with cryptococcal disease in patients with AIDS is underestimated in the literature. We performed a retrospective, case-control (referent) study to determine the prevalence of ARF associated with cryptococcal disease and analyzed associated factors. Potential cases of ARF were identified at four university-affiliated teaching hospitals from a cohort of 210 patients with AIDS who had positive cryptococcal antigen tests and/or Cryptococcus neoformans isolated from any body site. Twenty-nine of the 210 (13.8%) had ARF associated with cryptococcal disease. Nineteen were thought to have respiratory failure due solely to C. neoformans. The demographic, clinical, laboratory, treatment, and outcome data of 19 cases of respiratory failure were compared with data for 20 patients without respiratory failure. In-hospital mortality was 100% and median survival was 2 days for cases, vs. 25% and > 365 days, respectively, for referents. The clinical presentation was identical to that of Pneumocystis carinii pneumonia. In multivariate analysis, variables independently predictive of ARF in patients with cryptococcal disease were black race, a lactate dehydrogenase level of > or = 500 IU/L, the presence of interstitial infiltrates, and the presence of cutaneous lesions. ARF with cryptococcosis in patients with AIDS is associated with disseminated disease and high mortality. The diagnosis frequently is not considered before death. Serum cryptococcal antigen testing is a sensitive and rapid screening method.

Ventilator-associated pneumonia

Mechanically ventilated patients are at a substantially higher risk for developing nosocomial pneumonia. Overall, there is a relatively constant 1&!TN!150;3% risk per day of developing pneumonia while receiving mechanical ventilation. The sensitivity and specificity of clinical criteria alone for diagnosis of ventilator-associated pneumonias (VAP) is low. Several techniques have been developed to sample and quantitate the lower respiratory tract to improve the diagnostic yield. Gram-negative bacillary pneumonias account for the majority of the VAP. Strategies for prevention of VAP such as use of sucralfate for stress ulcer prophylaxis and selective decontamination of the digestive tract have been the focus of many clinical studies. Cost-effective preventive measures are needed to combat the increasing antimicrobial resistance, growing population of immunocompromised patients and increasing number of mechanically ventilated patients.