Clinical predictors for laboratory-confirmed influenza infections: exploring case definitions for influenza-like illness.

OBJECTIVE: To identify clinical signs and symptoms (ie, "terms") that accurately predict laboratory-confirmed influenza cases and thereafter generate and evaluate various influenza-like illness (ILI) case definitions for detecting influenza. A secondary objective explored whether surveillance of data beyond the chief complaint improves the accuracy of predicting influenza. DESIGN: Retrospective, cross-sectional study. SETTING: Large urban academic medical center hospital. PARTICIPANTS: A total of 1,581 emergency department (ED) patients who received a nasopharyngeal swab followed by rRT-PCR testing between August 30, 2009, and January 2, 2010, and between November 28, 2010, and March 26, 2011. METHODS: An electronic surveillance system (GUARDIAN) scanned the entire electronic medical record (EMR) and identified cases containing 29 clinical terms relevant to influenza. Analyses were conducted using logistic regressions, diagnostic odds ratio (DOR), sensitivity, and specificity. RESULTS: The best predictive model for identifying influenza for all ages consisted of cough (DOR=5.87), fever (DOR=4.49), rhinorrhea (DOR=1.98), and myalgias (DOR=1.44). The 3 best case definitions that included combinations of some or all of these 4 symptoms had comparable performance (ie, sensitivity=89%-92% and specificity=38%-44%). For children <5 years of age, the addition of rhinorrhea to the fever and cough case definition achieved a better balance between sensitivity (85%) and specificity (47%). For the fever and cough ILI case definition, using the entire EMR, GUARDIAN identified 37.1% more influenza cases than it did using only the chief complaint data. CONCLUSIONS: A simplified case definition of fever and cough may be suitable for implementation for all ages, while inclusion of rhinorrhea may further improve influenza detection for the 0-4-year-old age group. Finally, ILI surveillance based on the entire EMR is recommended.

Pseudo-outbreak of Mycobacterium gordonae Following the Opening of a newly constructed hospital at a Chicago Medical Center.

OBJECTIVE To identify the source of a pseudo-outbreak of Mycobacterium gordonae DESIGN Outbreak investigation. SETTING University Hospital in Chicago, Ilinois. PATIENTS Hospital patients with M. gordonae-positive clinical cultures. METHODS An increase in isolation of M. gordonae from clinical cultures was noted immediately following the opening of a newly constructed hospital in January 2012. We reviewed medical records of patients with M. gordonae-positive cultures collected between January and December 2012 and cultured potable water specimens in new and old hospitals quantitatively for mycobacteria. RESULTS Of 30 patients with M. gordonae-positive clinical cultures, 25 (83.3%) were housed in the new hospital; of 35 positive specimens (sputum, bronchoalveolar lavage, gastric aspirate), 32 (91.4%) had potential for water contamination. M. gordonae was more common in water collected from the new vs. the old hospital [147 of 157 (93.6%) vs. 91 of 113 (80.5%), P=.001]. Median concentration of M. gordonae was higher in the samples from the new vs. the old hospital (208 vs. 48 colony-forming units (CFU)/mL; P<.001). Prevalence and concentration of M. gordonae were lower in water samples from ice and water dispensers [13 of 28 (46.4%) and 0 CFU/mL] compared with water samples from patient rooms and common areas [225 of 242 (93%) and 146 CFU/mL, P<.001]. CONCLUSIONS M. gordonae was common in potable water. The pseudo-outbreak of M. gordonae was likely due to increased concentrations of M. gordonae in the potable water supply of the new hospital. A silver ion-impregnated 0.5-µm filter may have been responsible for lower concentrations of M. gordonae identified in ice/water dispenser samples. Hospitals should anticipate that construction activities may amplify the presence of waterborne nontuberculous mycobacterial contaminants.

Identification, management, and clinical characteristics of hospitalized patients with influenza-like illness during the 2009 H1N1 influenza pandemic, Cook County, Illinois.

OBJECTIVE: To describe the identification, management, and clinical characteristics of hospitalized patients with influenza-like illness (ILI) during the peak period of activity of the 2009 pandemic strain of influenza A virus subtype H1N1 (2009 H1N1). DESIGN: Retrospective review of electronic medical records. PATIENTS AND SETTING: Hospitalized patients who presented to the emergency department during the period October 18 through November 14, 2009, at 4 hospitals in Cook County, Illinois, with the capacity to perform real-time reverse-transcriptase polymerase chain reaction testing for influenza. METHODS: Vital signs and notes recorded within 1 calendar day after emergency department arrival were reviewed for signs and symptoms consistent with ILI. Cases of ILI were classified as recognized by healthcare providers if an influenza test was performed or if influenza was mentioned as a possible diagnosis in the physician notes. Logistic regression was used to determine the patient attributes and symptoms that were associated with ILI recognition and with influenza infection. RESULTS: We identified 460 ILI case patients, of whom 412 (90%) had ILI recognized by healthcare providers, 389 (85%) were placed under airborne or droplet isolation precautions, and 243 (53%) were treated with antiviral medication. Of 401 ILI case patients tested for influenza, 91 (23%) had a positive result. Fourteen (3%) ILI case patients and none of the case patients who tested positive for influenza had sore throat in the absence of cough. CONCLUSIONS: Healthcare providers identified a high proportion of hospitalized ILI case patients. Further improvements in disease detection can be made through the use of advanced electronic health records and efficient diagnostic tests. Future studies should evaluate the inclusion of sore throat in the ILI case definition.

Microbiologic and clinical epidemiologic characteristics of the Chicago subset of a multistate outbreak of Serratia marcescens bacteremia.

We describe 22 patients from a multistate outbreak of Serratia marcescens bacteremia that was linked to contaminated prefilled syringes of heparin and saline supplied by 1 manufacturer. Contents of unused syringes were cultured in pools; samples from 25 (5.3%) of 472 syringes grew S. marcescens. Despite good clinical outcomes overall, patients had substantial morbidity.

Predicting need for hospitalization of patients with pandemic (H1N1) 2009, Chicago, Illinois, USA.

In the absence of established guidelines for hospitalization of patients with pandemic (H1N1) 2009, we studied emergency department patients to identify clinical parameters that predict need for hospitalization. Independent predictors of hospitalization include multiple high-risk medical conditions, dyspnea, and hypoxia. These findings are easily applicable, with a 79% positive predictive value for hospitalization.

Multistate outbreak of Serratia marcescens bloodstream infections caused by contamination of prefilled heparin and isotonic sodium chloride solution syringes.

BACKGROUND: To investigate clusters of Serratia marcescens (SM) bloodstream infections (BSIs) at health care facilities in several states and determine whether contaminated prefilled heparin and isotonic sodium chloride solution (hereinafter, saline) syringes from a single manufacturer (company X) were the likely cause, we performed an outbreak investigation of inpatient and outpatient health care facilities from October 2007 through February 2008. METHODS: Active case finding for clusters of SM BSIs. Information on SM BSIs was obtained, and SM blood isolates were sent to the Centers for Disease Control and Prevention (CDC). Culture specimens were taken from various lots of prefilled heparin and saline syringes by health care facilities and the CDC to test for the presence of SM. The SM isolates from syringes and blood were compared by pulsed-field gel electrophoresis. RESULTS: A total of 162 SM BSIs in 9 states were reported among patients at facilities using prefilled heparin and/or saline syringes made by company X. Cultures of unopened prefilled heparin and saline syringes manufactured by company X grew SM. Of 83 SM blood isolates submitted to the CDC from 7 states, 70 (84%) were genetically related to the SM strain isolated from prefilled syringes. A US Food and Drug Administration inspection revealed that company X was not in compliance with quality system regulations. CONCLUSIONS: A multistate outbreak of SM BSIs was associated with intrinsic contamination of prefilled syringes. Our investigation highlights important issues in medication safety, including (1) the importance of pursuing possible product-associated outbreaks suggested by strong epidemiologic data even when initial cultures of the suspected product show no contamination and (2) the challenges of medical product recalls when production has been outsourced from one company to another.

Learning by doing: developing fellows' academic skills through collaborative research.

Physicians in postgraduate training are expected to learn research methods but how best to achieve that curricular goal is unclear. This article describes a novel educational approach to develop research skills among infectious disease fellows. Five infectious disease fellows and two faculty members participated in a collaborative research project as a vehicle for active, problem-based learning. During the learning experience several tasks with specific learning objectives were achieved. The authors evaluated the weaknesses and strengths of the collaborative research project as an educational program. This problem-based approach for learning research methods seems more effective than traditional methods and may be applicable to a broad range of training programs.

The duration of hypotension before the initiation of antibiotic treatment is a critical determinant of survival in a murine model of Escherichia coli septic shock: association with serum lactate and inflammatory cytokine levels.

BACKGROUND: This study was designed to examine the relationship between the timing of antibiotic treatment and both survival rates and hemodynamic/inflammatory correlates of survival in a murine model of Escherichia coli septic shock. METHODS: Surgical implantation of an E. coli (O18:K1:H7)-laced, gelatin capsule-encased fibrinogen clot was used to generate a bacteremic model of murine septic shock. Survival duration, hemodynamic responses, and circulating serum tumor necrosis factor (TNF)-alpha , interleukin (IL)-6, and lactate levels were assessed in relation to increasing delays in or absence of antibiotic treatment. RESULTS: A critical inflection point with respect to survival occurred between 12 and 15 h after implantation. When initiated at or before 12 h, antibiotic treatment resulted in < or = 20% mortality, but, when initiated at or after 15 h, it resulted in >85% mortality. Physiologically relevant hypotension developed in untreated septic mice by 12 h after implantation. Values for heart rate differed between untreated septic mice and sham-infected control mice by 6 h after implantation, whereas values for cardiac output and stroke volume did not differ until at least 18-24 h after implantation. Antibiotic treatment initiated > or = 12 h after implantation was associated with persistence of increased circulating serum lactate, TNF- alpha , and IL-6 levels. CONCLUSIONS: The timing of antibiotic treatment relative to hypotension is closely associated with survival in this murine model of septic shock. Delay in antibiotic treatment results in the persistence of inflammatory/stress markers even after antibiotic treatment is initiated.

Left ventricular assist device-related infection: treatment and outcome.

BACKGROUND: Left ventricular assist device (LVAD) implantation has become an effective treatment option for patients with severe heart failure awaiting transplantation. Significant infection rates have been reported among LVAD recipients. However, few reports have focused specifically on device infection, its treatment, and the impact of LVAD-related infection on clinical outcome. METHODS: Forty-six LVAD-related infections were diagnosed in 38 (50%) of 76 patients who underwent LVAD implantation as a bridge to transplantation. Twenty-nine episodes of LVAD-related bloodstream infection (BSI) (including 5 that were cases of LVAD endocarditis) and 17 episodes of local LVAD infection were identified. RESULTS: Diabetes mellitus appeared to increase the risk of BSI among patients with LVAD infection. LVAD-related infection delayed transplantation, as reflected by longer device-support times (a mean duration +/- SEM of 182.8+/-31.1 days, compared with 66.3+/-8.8 days; P

Evolution of vaccinia virus-specific CD8+ cytotoxic T-lymphocyte responses in primary vaccinees and revaccinees.

Determination of successful vaccination with vaccinia virus is based on visual confirmation of a dermal response (take). Some revaccinees do not manifest a take, which may be due to a preexisting immunity rather than to poor technique or inadequate virus. Cytotoxic T-lymphocyte (CTL) response appears to be the most important immune defense in limiting response to vaccination. We evaluated vaccinia virus-specific CTL responses in revaccinees. Subjects with and without takes displayed comparable CTL responses. Vaccinia virus-specific CD8+ CTL responses may be useful in interpreting the response to vaccination, particularly in individuals who are revaccinated and have difficult-to-interpret visual takes.

Antibiotic therapy for Klebsiella pneumoniae bacteremia: implications of production of extended-spectrum beta-lactamases.

The prevalence of extended-spectrum beta -lactamase (ESBL) production by Klebsiella pneumonia approaches 50% in some countries, with particularly high rates in eastern Europe and Latin America. No randomized trials have ever been performed on treatment of bacteremia due to ESBL-producing organisms; existing data comes only from retrospective, single-institution studies. In a prospective study of 455 consecutive episodes of Klebsiella pneumoniae bacteremia in 12 hospitals in 7 countries, 85 episodes were due to an ESBL-producing organism. Failure to use an antibiotic active against ESBL-producing K. pneumoniae was associated with extremely high mortality. Use of a carbapenem (primarily imipenem) was associated with a significantly lower 14-day mortality than was use of other antibiotics active in vitro. Multivariate analysis including other predictors of mortality showed that use of a carbapenem during the 5-day period after onset of bacteremia due to an ESBL-producing organism was independently associated with lower mortality. Antibiotic choice is particularly important in seriously ill patients with infections due to ESBL-producing K. pneumoniae.

Why don't they listen? Adherence to recommendations of infectious disease consultations.

The effectiveness of an infectious diseases (ID) consultation is dependent on adherence to the recommendations. To delineate the factors that affect adherence, we conducted a prospective cohort study of 465 consultations at 2 academic institutions in which we evaluated the consultation process, patient and consultant characteristics, types of recommendations, and compliance with recommendations. The overall compliance rate was 80%, with 85% adherence to crucial recommendations. Multivariate analysis revealed that adherence to ID recommendations was higher when the recommendations were therapeutic instead of diagnostic, when they related to a specific clinical question, when recommendations were deemed crucial by the ID service, if the primary service was medicine, and if the consultation note was legible and organized. Whether modification of consultant practice will lead to improved recommendation compliance and patient outcomes warrants further study.

International prospective study of Klebsiella pneumoniae bacteremia: implications of extended-spectrum beta-lactamase production in nosocomial Infections.

BACKGROUND: Commonly encountered nosocomially acquired gram-negative bacteria, especially Klebsiella pneumoniae, produce extended-spectrum beta-lactamases (ESBLs) as an antibiotic resistance mechanism. OBJECTIVE: To determine whether microbiology laboratories should report the presence of ESBLs and to establish the infection-control implications of ESBL-producing organisms. DESIGN: Prospective observational study. SETTING: 12 hospitals in South Africa, Taiwan, Australia, Argentina, the United States, Belgium, and Turkey. PATIENTS: 440 patients with 455 consecutive episodes of K. pneumoniae bacteremia between 1 January 1996 and 31 December 1997; of these, 253 episodes were nosocomially acquired. MEASUREMENTS: The K. pneumoniae isolates were examined for the presence of ESBLs. Pulsed-field gel electrophoresis was used to analyze the molecular epidemiology of nosocomial bacteremia with ESBL-producing K. pneumoniae. RESULTS: Overall, 30.8% (78 of 253) episodes of nosocomial bacteremia and 43.5% (30 of 69) episodes acquired in intensive care units were due to ESBL-producing organisms. After adjustment for potentially confounding variables, previous administration of beta-lactam antibiotics containing an oxyimino group (cefuroxime, cefotaxime, ceftriaxone, ceftazidime, or aztreonam) was associated with bacteremia due to ESBL-producing strains (risk ratio, 3.9 [95% CI, 1.1 to 13.8]). In 7 of 10 hospitals with more than 1 ESBL-producing isolate, multiple strains with the same genotypic pattern were observed, indicating patient-to-patient spread of the organism. CONCLUSIONS: Production of ESBLs by Klebsiella pneumoniae is a widespread nosocomial problem. Appropriate infection control and antibiotic management strategies are needed to stem the spread of this emerging form of resistance.

Q fever: a biological weapon in your backyard.

Coxiella burnetii, which causes Q fever, is a highly infectious agent that is widespread among livestock around the world. Although the culture process for coxiella is laborious, large amounts of infectious material can be produced. If used as an aerosolised biological weapon, coxiella may not cause high mortality, but could provoke acute disabling disease. In its late course, Q fever can be complicated by fatal (eg, endocarditis) or debilitating (eg, chronic fatigue syndrome) disorders. The diagnosis of Q fever might be delayed because of non-specific and protean presentations. Effective antibiotic treatment is available for the acute form of disease but not for the chronic complications. Vaccination and chemoprophylaxis in selected individuals may be used in the event of bioterrorism.

Problems in the therapy for imported malaria in the United States.

BACKGROUND: Errors in the diagnosis of imported malaria are increasingly recognized. However, there are few data on the treatment of malaria in the United States. METHODS: Medical records were reviewed for 83 patients with microscopically confirmed malaria at Cook County Hospital, Chicago, Ill, between 1991 and 1999. RESULTS: Errors in drug treatment occurred in 25% of patients in this study. The most common error in therapy was the failure to prescribe primaquine to eradicate the liver forms of Plasmodium vivax. Another 5 patients with P vivax received an inappropriate drug regimen. Errors in Plasmodium falciparum therapy occurred in 5 patients. All patients received an inappropriate drug regimen. While the clinical symptoms and signs do not help distinguish the infecting Plasmodium species, the travel history is extremely helpful in guiding drug selection. Non-infectious diseases specialists are more likely to make errors in therapy than are infectious diseases specialists. CONCLUSIONS: Despite widely published guidelines on the treatment of malaria, there are frequent errors in the therapy for malaria. A detailed travel history emphasizing the duration and country of travel should be sought. Primaquine should be included in the primary prescription for the treatment of P vivax infection. Improvements in the therapy for malaria can be made with the aid of an infectious diseases specialist and/or a tropical medicine specialist.

Protein-free phospholipid emulsion treatment improved cardiopulmonary function and survival in porcine sepsis.

Lipoprotein phospholipid (PL) plays a major role in neutralization of endotoxin. This study tested the hypothesis that prophylactic administration of a PL-enriched emulsion (PRE), which augments PL content of serum lipoproteins and neutralizes endotoxin in vitro, would preserve cardiovascular function and improve survival in porcine septic peritonitis. A control group was compared with low-, mid-, and high-dose treatment groups that received PRE by primed continuous infusion for 48 h. A fibrin clot containing live Escherichia coli 0111.B4 was implanted intraperitoneally 30 min after the priming dose. Survival increased in a dose-dependent manner and was correlated with serum PL. Infused PL was associated with high-density lipoprotein in the low-dose group and all serum lipoproteins at higher doses. Treatment significantly lowered serum endotoxin and tumor necrosis factor (TNF)-alpha, preserved cardiac output and ejection fraction, and attenuated increases in systemic and pulmonary vascular resistances. This study demonstrated that augmentation of lipoprotein PL via administration of PRE improved survival and offered a novel therapeutic approach to sepsis.