200. The Utility of a Rapid Multiplex PCR Assay in the Management of Staphylococcus Aureus Bacteremia at a Tertiary Care Center

Background

Staphylococcus aureus bacteremia (SAB) is a major cause of community and healthcare-acquired bacteremia and is associated with a high burden of morbidity and mortality. Appropriately tailoring management based on methicillin sensitivity can help minimize unnecessary administration of broad-spectrum antibiotics and ensure adequate treatment of MSSA/MRSA. The Verigene® (Luminex Corporation) is a multiplex PCR assay that provides rapid identification of bloodstream pathogens. We performed a QI project to determine the utility of this assay in managing patients with SAB.

Methods

We performed a single-center retrospective cohort study of positive SAB cultures from May 2020 to May 2021. Electronic health record review was conducted to abstract patient demographics, clinical characteristics, outcomes, blood culture data, and antibiotic management. Statistical analysis was done with the unpaired t-test and fishers exact test to identify associations of statistical significance.

Results

We identified 97 cases of SAB: 66% MSSA (n = 64), 34% MRSA (n = 33). Patient characteristics included: mean age 61 years, 58.8% male, 42% immunocompromised, 83.5% with ID consult, 38.1% with ICU admission, mean length of stay 20.3d, and 24.7% mortality. Using the Verigene® assay, we noted 2.6% discordance with standard microbiological technique (n = 2). The timing of Verigene® results and provider response were as follows:

The mean duration of SAB was 3.1d (MSSA = 2.8d, MRSA = 3.6d, p = 0.2477). There was a statistically significant difference in patient mortality with respect to methicillin sensitivity status: MSSA 15.6%, MRSA 42.4%, p = 0.0075, as well as mortality with ID consult 19.8% versus no ID consult 50%, p = 0.0223.

Conclusion

Despite the incorporation of a rapid multiplex PCR assay to detect bloodstream infections, the time to de-escalation for MSSA was sub-optimal (2.7 days). ID consultation continues to be an important component of SAB management as it improves patient outcomes and contributes to education of healthcare providers.

Disclosures

Lan Duong, PharmD, Johnson & Johnson: Stocks/Bonds|Lilly USA: Stocks/Bonds|Novavax: Stocks/Bonds Princy N. Kumar, MD, American Gene Technologies: Grant/Research Support|BioHaven: Grant/Research Support|Eli Lilly: Grant/Research Support|Gilead: Advisor/Consultant|Gilead: Grant/Research Support|Gilead: Stocks/Bonds|GSK: Grant/Research Support|GSK: Stocks/Bonds|Johnson&Johnson: Advisor/Consultant|Johnson&Johnson: Stocks/Bonds|Merck: Advisor/Consultant|Merck: Grant/Research Support|Merck: Stocks/Bonds|Moderna: Stocks/Bonds|Pfizer: Stocks/Bonds|Regeneron: Grant/Research Support|TheraTechnologies: Grant/Research Support|ViiV: Advisor/Consultant Joseph G. Timpone, Jr., MD, Gilead: Stocks/Bonds|Merck: Stocks/Bonds.

Evaluation of cytomegalovirus "Blips" in high risk kidney/kidney-pancreas transplant recipients

BACKGROUND

Cytomegalovirus (CMV) is a significant cause of morbidity and mortality after solid organ transplantation. While guidelines suggest using highly sensitive QNAT assays for CMV detection, there is no defined viral load to guide initiation of preemptive therapy.^1,2 This study evaluates the progression to quantifiable CMV (DNAemia) following a CMV "blip" in high risk (D+/R) kidney/kidney-pancreas (KP) transplant recipients.

METHODS

This is a single center, retrospective study. A CMV "blip" was defined as the first positive QNAT assay below the level of quantification (< 1.37×10² IU/mL or < 200 viral copies). Subsequent CMV QNAT assays were followed to assess the progression from blip to CMV DNAemia for 1 year following transplant.

RESULTS

134 patients were included in the study. Fifty-three (39.6%) patients had their first positive CMV QNAT value below the level of quantification, a "CMV blip". Of these 53 patients, 69.8% (n = 37) progressed to DNAemia while 30.2% (n = 16) did not. The median time from transplant to the first CMV blip was 68 (46-97) days and most patients with viral blips (71.1%) were on prophylaxis. No differences in patient characteristics were found among those who progressed from blip to DNAemia and those who only had a blip.

CONCLUSIONS

In CMV high risk kidney/KP transplant recipients, CMV blips progressed to CMV DNAemia in the majority of cases. This progression typically occurred 2-3 weeks following the initial blip. CMV blips are common early post-transplant despite prophylaxis and likely represent an early marker of CMV infection. This article is protected by copyright. All rights reserved.

297. Infectious Complications Associated with Tocilizumab Use in Patients Infected with SARS-CoV-2 at a Mid-Atlantic Hospital Consortium

Background

The IL-6 inhibitor Tocilizumab (TOCI) has been associated with infections in 5-8% of patients with Rheumatoid Arthritis. TOCI has now been recommended as a treatment option for select patients with COVID-19; however, the risk of infection in this patient population is yet to be determined.

Methods

We performed a retrospective chart review of patients diagnosed with COVID-19 and admitted to MedStar hospitals within the D.C./Baltimore corridor from 03/01/2020 to 12/31/2020. We identified patients who had positive culture data within 30 days of administration of TOCI-based regimens and analyzed clinical characteristics and outcomes. Univariate analyses (Wilcoxon, T-test, Chi-Square, Fisher’s Exact) were used to compare these outcome variables between patients who had post-treatment infections and those who did not.

Results

A total of 220 patients received TOCI-based regimens; 16% (N=36) of patients developed positive cultures within 30 days of treatment. Of the 99 cultures, 50% were gram positive (N=49), 38% were gram negative (N=38), 10% were Candida spp. (N=10), and 2% were anaerobic organisms (N=2). Only 9% (8/87) of the gram positive and gram negative organisms were MDROs. Bloodstream infections were the most common and accounted for 58.4% of all infections. Length of stay (LOS) was approximately twice as long in those with post-treatment infections (26 days) compared to those without infections (14 days, p< 0.001). Although the mortality rate was higher in patients with infections after TOCI-based treatment compared to patients with no post-treatment infection (47% vs 31% respectively), this did not reach statistical significance (p=0.09). Moreover, there was no significant difference in the infection rate of patients treated with TOCI alone compared to TOCI and Dexamethasone (16.6% vs. 13.3%, p=0.99). No cases of invasive Aspergillosis were observed.

Conclusion

Tocilizumab treatment in patients with COVID-19 may predispose patients to an increased risk of infection which is associated with a prolonged LOS and possibly higher mortality. We observed a two-fold increase in infections in COVID-19 patients compared to other patient groups receiving this treatment.

Disclosures

Princy N. Kumar, MD, AMGEN (Other Financial or Material Support, Honoraria)Eli Lilly (Grant/Research Support)Gilead (Grant/Research Support, Shareholder, Other Financial or Material Support, Honoraria)GSK (Grant/Research Support, Shareholder, Other Financial or Material Support, Honoraria)Merck & Co., Inc. (Grant/Research Support, Shareholder, Other Financial or Material Support, Honoraria)

509. Clinical Characteristics and Outcomes in Patients Infected with SARS-CoV-2 Treated with Remdesivir, Tocilizumab, and/or Dexamethasone at a Mid-Atlantic Hospital Consortium

Background

Treatment strategies for COVID-19 have evolved based on clinical trials. We performed a retrospective analysis to determine treatment outcomes for Remdesivir (RDV), Tocilizumab (TOCI), and/or Dexamethasone (DEX) in a representative population from the Mid-Atlantic region.

Methods

A retrospective chart review was performed for patients admitted to MedStar hospitals within the D.C./Baltimore corridor from 03/01/2020 to 12/31/2020, and diagnosed with COVID-19 using a NP SARS-CoV-2 RT PCR assay. The MedStar Pharmacy Database was utilized to stratify based on any combination of RDV, TOCI, DEX treatment. Our primary endpoints included O2 delivery device, length of stay (LOS), and mortality.

Results

A total of 2488 patients were included. Overall, the average age of patients was 62yrs, 53% male, and the majority of patients were of Black (54%) or White (27%) race. The average length of stay was 11 days (SD = 12) with a mortality of 14%. Using univariate analyses, all combinations of RDV, TOCI, and DEX treatment regimens were evaluated. Patients who received DEX required the most ventilatory support on Day 1 (5%, p&lt; 0.001) compared to all other groups. These same patients, however, did not go on to have higher ventilatory needs (17%, p&lt; 0.001) compared to the group which ultimately required the most ventilatory support, TOCI plus DEX (94%, p&lt; 0.001) at Day 28 of treatment. TOCI use alone was associated with a 4% to 63% (p&lt; 0.001) increase in need for ventilatory support over the course of 28 days (Figure 1). The shortest LOS was seen in those treated with DEX alone (9.5 days, p&lt; 0.001). Longer LOS outcomes were associated with all treatment groups which included TOCI use (19 to 22 days, p&lt; 0.001, Figure 2). Mortality was similarly higher among all treatment groups which contained TOCI (30% to 62.5%, p&lt; 0.001, Figure 3) when compared to those with RDV and/or DEX use alone (10% to 14%, p&lt; 0.001).

Barplot of Oxygen Delivery Device at Admission and within 28 Days among Treatments

Conclusion

Our study demonstrates that “real-world” clinical outcomes for patients with COVID-19 treated with Remdesivir, Tocilizumab, and Dexamethasone are consistent with what has been reported in clinical trials. The higher mortality associated with Tocilizumab treatment may reflect the use of this agent in critically ill patients with COVID-19.

Disclosures

Princy N. Kumar, MD, AMGEN (Other Financial or Material Support, Honoraria)Eli Lilly (Grant/Research Support)Gilead (Grant/Research Support, Shareholder, Other Financial or Material Support, Honoraria)GSK (Grant/Research Support, Shareholder, Other Financial or Material Support, Honoraria)Merck & Co., Inc. (Grant/Research Support, Shareholder, Other Financial or Material Support, Honoraria)

286. Infectious Complications and Antimicrobial Utilization in Hospitalized Patients with COVID-19

Background

Hospitalized patients with COVID-19 have created increased demands on health care infrastructure and resources. Bacterial and fungal infections have been reported and have increased the need for antimicrobial utilization. We performed a retrospective chart review to characterize bacterial infections and antibiotic utilization during the COVID-19 surge at our tertiary care center.

Methods

All patients diagnosed with COVID-19 using SARS-CoV-2 PCR admitted to MedStar Georgetown University Hospital from 01Mar2020 through 31Aug2020 were included in the analysis. Data was collected on hospital-wide antimicrobial utilization [mean days of therapy per 1000-patient-days (DOT)] during the 6-month surge and was compared to antimicrobial utilization during a 6-month period that preceded the COVID-19 surge. Clinical and microbiological data and patient outcomes were also collected and analyzed.

Results

A total of 238 patients met eligibility criteria during the observation period, of which 25.6% (n = 61) developed a bacterial, fungal, or viral co-infection. Culture-positive bacterial complications were seen in 21.8% (n = 52) with 32.8% (n = 20) having a multidrug resistant organism (MDRO). There was a statistically significant difference between COVID-19 patients with co-infection and those without for intubation (p &lt; 0.001), vasopressor use (p &lt; 0.001), and renal replacement therapy (p = 0.001). COVID-19 patients with co-infections had a longer mean length of stay (21.9 days vs 13.5 days, p &lt; 0.001) and greater mortality (32.8% vs 20.6%, p = 0.006) compared to those without a co-infection, respectively.

Mean antimicrobial utilization for the entire hospital population was 790.6 DOT during the COVID surge compared to 928.7 DOT during a 6-month period preceding the COVID surge (p &lt; 0.001). For all COVID-19 patients, antimicrobial utilization was 846.9 DOT; however, this increased to 1236.4 DOT for COVID-19 patients with co-infections.

Table 1. Demographics

Conclusion

Although hospital-wide antimicrobial utilization had decreased during the COVID surge, COVID-19 patients with co-infections demonstrated a disproportionate use of antimicrobial agents as well as ICU resources. As MDRO infections were relatively common, antimicrobial stewardship should be prioritized in the COVID-19 population.

Disclosures

Lan Duong, Pharm.D., Astra Zeneca (Shareholder)Eli Lilly & Co. (Shareholder)Gilead Sciences, Inc. (Shareholder)Merck & Co. (Speaker’s Bureau)Moderna, Inc. (Shareholder)Novavax, Inc. (Shareholder)Sarepta Therapeutics (Shareholder)Thermo Fisher Scientific (Shareholder) Princy N. Kumar, MD, AMGEN (Other Financial or Material Support, Honoraria)Eli Lilly (Grant/Research Support)Gilead (Grant/Research Support, Shareholder, Other Financial or Material Support, Honoraria)GSK (Grant/Research Support, Shareholder, Other Financial or Material Support, Honoraria)Merck & Co., Inc. (Grant/Research Support, Shareholder, Other Financial or Material Support, Honoraria)

Bartonella Endocarditis and Pauci-Immune Glomerulonephritis: A Case Report and Review of the Literature

Among culture-negative endocarditis in the United States, Bartonella species are the most common cause, with Bartonella henselae and Bartonella quintana comprising the majority of cases. Kidney manifestations, particularly glomerulonephritis, are common sequelae of infectious endocarditis, with nearly half of all Bartonella patients demonstrating renal involvement. Although a pauci-immune pattern is a frequent finding in infectious endocarditis-associated glomerulonephritis, it is rarely reported in Bartonella endocarditis. Anti-neutrophil cytoplasmic antibody (ANCA) positivity can be seen with many pathogens causing endocarditis and has been previously reported with Bartonella species. In addition, ANCA-associated vasculitis can also present with renal and cardiac involvement, including noninfectious valvular vegetations and pauci-immune glomerulonephritis. Given the overlap in their clinical presentation, it is difficult to differentiate between Bartonella endocarditis and ANCA-associated vasculitis but imperative to do so to guide management decisions. We present a case of ANCA-positive Bartonella endocarditis with associated pauci-immune glomerulonephritis that was successfully treated with medical management alone.

Tracking colistin-treated patients to monitor the incidence and outcome of carbapenem-resistant Gram-negative infections

BACKGROUND

Existing surveillance mechanisms may underestimate the incidence of carbapenem-resistant gram-negative infections (CRGNIs). Although carbapenem resistance increases the risk of death, the trend in mortality over time is unknown.

METHODS

A retrospective cohort study was conducted at 40 academic medical centers using a discharge database to identify adult hospital admissions without cystic fibrosis in 2006-2012 and received intravenous colistin for >3 consecutive days or died during therapy (termed colistin cases). The primary outcomes were the number of colistin cases per 100,000 admissions per year and change in the hospital mortality rate over time compared with the rate of discharges to home. Secondary outcomes included median overall and intensive care unit lengths of stay.

RESULTS

From 2006 to 2012, a total of 5011 unique patients were identified as colistin cases. The number per 100,000 admissions per year increased from 35.56 to 92.98 during the 7-year study (P < .001). The odds of in-hospital death among colistin cases (compared with discharge to home) decreased by a mean of 5.2%/y (P = .04), whereas discharge to an institution (P = .24) or hospice (P = .89) remained steady over time. The median overall and intensive care unit lengths of stay decreased by 7.5 and 6 days, respectively (P < .001). In a 4-hospital chart review, 81.6% of colistin cases were found to have culture-positive CRGNIs. Conversely, 53% of extensively drug-resistant bloodstream CRGNIs at 2 of these hospitals met colistin case criteria.

CONCLUSIONS

Colistin cases represent a severely ill population with a high probability of having culture-confirmed CRGNIs. Colistin tracking is a novel strategy for monitoring the incidence and mortality of CRGNIs, particularly those caused by extensively drug-resistant bacteria. Although the incidence of colistin cases nearly tripled within 7 years, more of these patients are surviving hospitalization and going home.

Infection among adult small bowel and multivisceral transplant recipients in the 30-day postoperative period

BACKGROUND

Intestinal transplantation is a potential option for patients with short gut syndrome (SGS), and infection is common in the postoperative period. The aim of our study was to identify the incidence and characteristics of bacterial and fungal infections of adult small bowel or multivisceral (SB/MV) transplantation recipients in the 30-day postoperative period.

METHODS

This retrospective chart review assessed the incidence and characteristics of bacterial and fungal infections in patients who underwent SB/MV transplant at our center between April 2004 and November 2008. Patient data were retrieved from computerized databases, flow-charts, and medical records.

RESULTS

A total of 40 adult patients with a mean age of 38.7 ± 13.4 years received transplants during this period: 27 patients received isolated SB, 12 received MV, and 1 received SB and kidney. Our immunosuppressive regimen included basiliximab for induction, and tacrolimus, sirolimus, and methylprednisolone for maintenance therapy. The most common indications for transplant were SGS, intestinal ischemia, Crohn's disease, trauma, motility disorders, and Gardner's syndrome. We report a 30-day postoperative infection rate of 57.5% and mean time to first infection of 10.78 ± 8.99 days. A total of 36 infections were documented in 23 patients. Of patients who developed infections, 56.5% developed 1 infection, 30.4% developed 2 infections, and 13% developed 3 infections. The most common site of infection was the abdomen, followed by blood, urine, lung, and wound infection. The isolates were gram-negative bacteria in 49.3%, gram-positive bacteria in 39.4%, and 11.3% were fungi. The most common organisms were Pseudomonas (19%), Enterococcus (15%), and Escherichia coli (13%). Overall, 47% of infections were due to drug-resistant pathogens; 31% of E. coli and Klebsiella species were extended-spectrum beta-lactamase-producing organisms, 36% of Pseudomonas was multidrug resistant (MDR), 75% of Enterococcus was vancomycin resistant, and 100% of Staphylococcus aureus was methicillin resistant.

CONCLUSION

These findings demonstrate that bacterial and fungal infections remain an important complication in SB/MV transplant recipients within the early postoperative period. Infections due to MDR organisms have emerged as an important clinical problem in this patient population.

Occupational transmission of Acinetobacter baumannii from a United States serviceman wounded in Iraq to a health care worker

BACKGROUND

Acinetobacter baumannii is increasingly recognized as being a significant pathogen associated with nosocomial outbreaks in both civilian and military treatment facilities. Current analyses of these outbreaks frequently describe patient-to-patient transmission. To date, occupational transmission of A. baumannii from a patient to a health care worker (HCW) has not been reported. We initiated an investigation of an HCW with a complicated case of A. baumannii pneumonia to determine whether a link existed between her illness and A. baumannii-infected patients in a military treatment facility who had been entrusted to her care.

METHODS

Pulsed-field gel electrophoresis and polymerase chain reaction/electrospray ionization mass spectrometry, a form of multilocus sequencing typing, were done to determine clonality. To further characterize the isolates, we performed a genetic analysis of resistance determinants.

RESULTS AND CONCLUSIONS

A "look-back" analysis revealed that the multidrug resistant A. baumannii recovered from the HCW and from a patient in her care were indistinguishable by pulsed-field gel electrophoresis. In addition, polymerase chain reaction/electrospray ionization mass spectrometry indicated that the isolates were similar to strains of A. baumannii derived from European clone type II (Walter Reed Army Medical Center strain type 11). The exposure of the HCW to the index patient lasted for only 30 min and involved endotracheal suctioning without use of an HCW mask. An examination of 90 A. baumannii isolates collected during this investigation showed that 2 major and multiple minor clone types were present and that the isolates from the HCW and from the index patient were the most prevalent clone type. Occupational transmission likely occurred in the hospital; HCWs caring for patients infected with A. baumannii should be aware of this potential mode of infection spread.

Serious infection from Staphylococcus aureus in 2 HIV-infected patients receiving fusion inhibitor therapy

Fusion inhibitors are novel antiretroviral agents, administered as subcutaneous injections, approved for use in treatment-experienced HIV-infected patients. HIV-infected patients are at increased risk for Staphylococcus aureus colonization, specifically with methicillin-resistant S aureus (MRSA), and subsequent systemic infection. We present the cases of 2 patients without a history of MRSA infection in whom a series of severe S aureus infections developed after fusion inhibitor therapy.

Ocular syphilis in HIV-positive patients receiving highly active antiretroviral therapy

BACKGROUND

From October 2001 to October 2002, we have observed a surprisingly high incidence of ocular syphilis in human immunodeficiency virus-positive (HIV+) patients receiving highly active antiretroviral therapy at our clinic.

METHODS

We conducted a retrospective chart and patient database review.

RESULTS

From 1997 to 2002, 455 patients in our clinic were screened for syphilis; 320 were screened from 2001 to 2002; 7.3% of patients (33/455) were diagnosed with syphilis. During the past year, syphilis was diagnosed in 7.5% of patients (24/320), of whom 13% (3/24) had ocular syphilis. We estimate the prevalence of ocular syphilis in HIV+ patients on highly active antiretroviral therapy screened for syphilis to be 9% (3/33). Presenting symptoms included blurred vision, loss of vision, central scotomas, and bilateral ocular involvement. The most common ocular manifestation of syphilis was posterior chamber uveitis; one patient also had a retinal detachment. All patients demonstrated reactive rapid plasma reagin and fluorescent treponemal antibody absorption test results, cerebrospinal fluid pleocytosis, and elevated total protein. Each patient received a 21-day course of intravenous penicillin G (24 million units daily) with improvement of visual symptoms.

CONCLUSION

Our data demonstrate an unexpectedly high incidence of ocular syphilis in our HIV+ patients receiving highly active antiretroviral therapy during the past year. A diagnosis of ocular syphilis should be considered in any HIV+ patient who presents with visual symptoms, irrespective of the patient's CD4 count.

The safety and pharmacokinetics of single-agent and combination therapy with megestrol acetate and dronabinol for the treatment of HIV wasting syndrome. The DATRI 004 Study Group. Division of AIDS Treatment Research Initiative

This randomized, open-labeled, multicenter study was designed to assess safety and pharmacokinetics of dronabinol (Marinol) tablets and megestrol acetate (Megace) micronized tablets, alone and in combination, for treatment of HIV wasting syndrome. Weight and quality of life data were also collected. Fifty-two patients (mean CD4+ count, 59 cells/microliter) were randomized to one of four treatment arms: dronabinol 2.5 mg twice/day (D); megestrol acetate 750 mg/day (M750); megestrol acetate 750 mg/day+dronabinol 2.5 mg twice/day (M750+D); or megestrol acetate 250 mg/day+dronabinol 2.5 mg twice/day (M250+D). After therapy initiation, 47 patients returned for at least one visit, and 39 completed the planned 12 weeks of study visits. Occurrence of adverse events, drug discontinuation, new AIDS-defining conditions, or CD4+ T lymphocyte changes were not statistically significantly different among arms. Serious adverse events assessed as related to dronabinol included CNS events (e.g., confusion, anxiety, emotional lability, euphoria, hallucinations) and those assessed as related to megestrol acetate included dyspnea, liver enzyme changes, and hyperglycemia. The mean weight change +/- SE over 12 weeks was as follows: D, -2.0 +/- 1.3 kg; M750, +6.5 +/- 1.1 kg; M750+D, +6.0 +/- 1.0 kg; and M250+D, -0.3 +/- 1.0 kg (difference among treatment arms, p = 0.0001). Pharmacokinetic parameters measured after 2 weeks of therapy for M750 were Cmax = 985 ng/ml and AUC = 22,487 ng x hr/ml, and for dronabinol and its active metabolite (HO-THC), respectively, were Cmax = 2.01; 4.61 ng/ml and AUC = 5.3; 23.7 ng x hr/ml. For megestrol acetate, but not dronabinol, there was a positive correlation at week 2 between both Cmax and AUC with each of the following: (1) weight change, (2) breakfast visual analog scale for hunger (VASH) score, and (3) dinner VASH score.

Changing Patterns of Resistance to Ampicillin/Sulbactam

Objective:

To report on methods to halt the increasing resistance of gram-negative organisms to ampicillin/sulbactam.

Design:

A before-after observational design was used to evaluate susceptibility of organisms to ampicillin/sulbactam.

Setting:

A university teaching hospital.

Interventions:

An educational program regarding appropriate prescribing of ampicillin/sulbactam and restriction of the use of ampicillin/sulbactam.

Main Outcome Measures:

Antimicrobial susceptibility to ampicillin/sulbactam.

Results:

The trend in increasing resistance was halted for Escherichia coli and Enterobacter. Emerging resistance of other organisms was not observed.

Conclusions:

The trend in increasing resistance was halted by restrictions on prescribing and by providing education regarding rational prescribing of ampicillin/sulbactam. We recommend that this combination not be used empirically to treat nosocomial infections or for bacteria against which ampicillin alone is effective.

Immune-based therapeutics: scientific rationale and the promising approaches to the treatment of the human immunodeficiency virus-infected individual

The primary approach to therapy for infection with human immunodeficiency virus (HIV) continues to be centered around antiretroviral agents that have conferred significant clinical benefits. The considerable degree of immunologic dysfunction in HIV infection, however, has led to intense interest in methods of immune stimulation and reconstitution. Immunomodulatory intervention in HIV infection is highly controversial. Over the years a number of immunomodulatory agents--many with only a poor rationale for their clinical use--have been evaluated. In this review we concentrate on immunomodulatory approaches that are currently being investigated. We group these interventions, reviewing the rationale and clinical data for each category: passive immunity (administration of immunoglobulins and use of apheresis), thymic hormone treatment, cytokine treatment (administration of interleukins, tumor necrosis factor, and interferons), adoptive cellular immunity, and therapeutic vaccination. At present, the only interventions supported by data from well-controlled studies are the parenteral administration of interferon alpha to patients with HIV-associated Kaposi's sarcoma and the administration of pooled immunoglobulin (to decrease the rate of bacterial infections) to children who cannot take trimethoprim-sulfamethoxazole. However, several other approaches under development show promise in reversing some of the immune deficits of HIV infection. Clinical evaluation of these approaches should yield valuable insights into the immunopathogenesis of HIV infection, and these insights should facilitate the formulation of new modalities of treatment.

Emergence of unusual opportunistic pathogens in AIDS: a review

Opportunistic infections are a major cause of morbidity and death among patients infected with the human immunodeficiency virus (HIV), particularly late in the disease, when immunosuppression is severe. Some pathogens, such as Pneumocystis carinii and Toxoplasma gondii, are extremely common in this population and are readily recognized by clinicians caring for these patients. However, many other organisms occasionally cause conditions that clinically mimic the more commonly encountered pathogens. Clinicians must be alert to the threat posed by these less frequently occurring organisms and of the broader differential diagnosis that must be considered for infections in patients with HIV infection.