Song Mi Moon

Viral Infection in Patients with Severe Pneumonia Requiring Intensive Care Unit Admission

RATIONALE The role of viruses in pneumonia in adults and the impact of viral infection on mortality have not been elucidated. Previous studies have significant limitations in that they relied predominantly on upper respiratory specimens. OBJECTIVES To investigate the role of viral infection in adult patients with pneumonia requiring intensive care unit (ICU) admission. METHODS A retrospective analysis of a prospective cohort was conducted in a 28-bed medical ICU. Patients with severe community-acquired pneumonia (CAP) or healthcare-associated pneumonia (HCAP) were included in the study. MEASUREMENTS AND MAIN RESULTS A total of 198 patients (64 with CAP, 134 with HCAP) were included for analysis. Of these, 115 patients (58.1%) underwent bronchoscopic bronchoalveolar lavage (BAL), 104 of whom were tested for respiratory viruses by BAL fluid reverse-transcription polymerase chain reaction (RT-PCR). Nasopharyngeal specimen RT-PCR was performed in 159 patients (84.1%). Seventy-one patients (35.9%) had a bacterial infection, and 72 patients (36.4%) had a viral infection. Rhinovirus was the most common identified virus (23.6%), followed by parainfluenza virus (20.8%), human metapneumovirus (18.1%), influenza virus (16.7%), and respiratory syncytial virus (13.9%). Respiratory syncytial virus was significantly more common in the CAP group (CAP, 10.9%; HCAP, 2.2%; P = 0.01). The mortalities of patients with bacterial infections, viral infections, and bacterial-viral coinfections were not significantly different (25.5, 26.5, and 33.3%, respectively; P = 0.82). CONCLUSIONS Viruses are frequently found in the airway of patients with pneumonia requiring ICU admission and may cause severe forms of pneumonia. Patients with viral infection and bacterial infection had comparable mortality rates.

Outcomes of Moderate-to-Severe Pneumocystis Pneumonia Treated with Adjunctive Steroid in Non-HIV-Infected Patients

ABSTRACT While it is well-known that adjunctive corticosteroid use improves the outcome of moderate-to-severe Pneumocystis jirovecii pneumonia (PcP) in patients with human immunodeficiency virus (HIV), there are limited data on its efficacy in non-HIV-infected patients with PcP. Patients undergoing fiber-optic bronchoscopy with bronchoalveolar lavage for suspected PcP from January 2007 through December 2010 were reviewed retrospectively. We compared demographics, clinical characteristics, and outcomes in 88 non-HIV-infected patients with moderate-to-severe PcP with (n = 59) and without (n = 29) adjunctive corticosteroid use. Outcomes of PcP were assessed by respiratory failure and 30-day and 90-day all-cause mortality. Survival curves were analyzed by the Kaplan-Meier method and estimated by the log rank test. All-cause mortality of moderate-to-severe PcP at 90 days was lower in the solid-organ transplant recipients than in all other patients (6/26 [23%] versus 34/62 [55%], respectively; P = 0.006), and mortality at 30 days was lower in patients with hematologic malignancies than in all other patients (4/26 [15%] versus 24/62 [39%], respectively; P = 0.03). The outcomes of PcP were not significantly different in moderate-to-severe PcP patients with and without adjunctive corticosteroid use, regardless of recent corticosteroid use. Survival analysis of PcP patients with and without corticosteroid use by the Kaplan-Meier method also did not reveal any difference (log rank test; P = 0.81). There again was no difference within the subgroup of PcP patients with solid-organ transplants. Adjunctive corticosteroid use may not improve the outcome of moderate-to-severe PcP in non-HIV-infected patients.

Treatment Duration for Uncomplicated Staphylococcus aureus Bacteremia To Prevent Relapse: Analysis of a Prospective Observational Cohort Study

ABSTRACT Practice guidelines recommend at least 14 days of antibiotic therapy for uncomplicated Staphylococcus aureus bacteremia (SAB). However, these recommendations have not been formally evaluated in clinical studies. To evaluate the duration of therapy for uncomplicated SAB, we analyzed data from our prospective cohort of patients with SAB. A prospective observational cohort study was performed in patients with SAB at a tertiary-care hospital in Korea between August 2008 and September 2010. All adult patients with SAB were prospectively enrolled and observed over a 12-week period. Uncomplicated SAB was defined as follows: negative results of follow-up blood cultures at 2 to 4 days, defervescence within 72 h of therapy, no evidence of metastatic infection, and catheter-related bloodstream infection or primary bacteremia without evidence of endocarditis on echocardiography. Of 483 patients with SAB, 111 met the study criteria for uncomplicated SAB. Fifty-three (47.7%) had methicillin-resistant SAB. When short-course therapy (<14 days) and intermediate-course therapy (≥14 days) were compared, the treatment failure rates (10/38 [26.3%] versus 16/73 [21.9%]) and crude mortality (7/38 [18.4%] versus 16/73 [21.9%]) did not differ significantly between the two groups. However, short-course therapy was significantly associated with relapse (3/38 [7.9%] versus 0/73; P = 0.036). In multivariate analysis, primary bacteremia was associated with a trend toward increased treatment failure (P = 0.06). Therefore, in the treatment of uncomplicated SAB, it seems reasonable to consider at least 14 days of antibiotic therapy to prevent relapse, as practice guidelines recommend. Because of its poor prognosis, primary bacteremia, even with a low risk of complication, should not be treated with short-course therapy.

Comparison of the clinical features, bacterial genotypes and outcomes of patients with bacteraemia due to heteroresistant vancomycin-intermediate Staphylococcus aureus and vancomycin-susceptible S. aureus

OBJECTIVES We compared the clinical characteristics and outcomes of, and the bacterial genotypes in, patients with bacteraemia due to heteroresistant vancomycin-intermediate Staphylococcus aureus (hVISA) and vancomycin-susceptible S. aureus (VSSA). METHODS A total of 268 consecutive patients with methicillin-resistant S. aureus (MRSA) bacteraemia were prospectively enrolled. All isolates were selected on the first day of bacteraemia and subjected to population analysis profiling for identification of hVISA phenotype and PCR analysis for 41 virulence factors. RESULTS Of 268 MRSA isolates, 101 (37.7%) were identified as hVISA. Overall mortality was similar in hVISA- and VSSA-infected patients (45/101 versus 65/167; P = 0.36). The following factors were independently associated with the presence of hVISA: a vancomycin MIC ≥2 mg/L by Etest [adjusted OR (aOR), 9.98; 95% CI, 4.22-23.59], rifampicin resistance (aOR, 5.74; 95% CI, 1.35-24.37), prior vancomycin therapy (aOR, 3.04; 95% CI, 1.49-6.17) and use of immunosuppressive therapy (aOR, 2.41; 95% CI, 1.12-5.17). Among patients with hVISA, bacteraemia was more likely to persist for ≥7 days in patients with an initial vancomycin trough <15 mg/L than in those with an initial trough ≥15 mg/L (13/34 versus 5/35; P = 0.02). The hVISA and VSSA isolates were genotypically similar. CONCLUSIONS The hVISA phenotype was present in more than one-third of MRSA isolates and was independently associated with several baseline factors. Although this phenotype did not affect patient outcomes, our results indicate that targeting an initial vancomycin trough of 15-20 mg/L may be beneficial in patients with hVISA bacteraemia.

Clinical significance of Propionibacterium acnes recovered from blood cultures : Analysis of 524 episodes

ABSTRACT Of 522 patients with Propionibacterium acnes bacteremia (PAB), 18 (3.5%) had clinically significant PAB. Of these 18 patients, 10 (55.6%) had hospital-acquired bacteremia and 6 (33.3%) had undergone invasive procedures before development of PAB. One patient with a ventricular septal defect presented with infective endocarditis. After the exclusion of 1 patient whose outcome was not available, the overall mortality rate was 5.9% (1/17).

Impact of adequate empirical combination therapy on mortality from bacteremic Pseudomonas aeruginosa pneumonia

BackgroundPseudomonas aeruginosa has gained an increasing amount of attention in the treatment of patients with pneumonia. However, the benefit of empirical combination therapy for pneumonia remains unclear. We evaluated the effects of adequate empirical combination therapy and multidrug-resistance in bacteremic Pseudomonas pneumonia on the mortality.MethodsA retrospective cohort study was performed at the 2,700-bed tertiary care university hospital. We reviewed the medical records of patients with bacteremic pneumonia between January 1997 and February 2011. Patients who received either inappropriate or appropriate empirical therapy were compared by using marginal structural model. Furthermore, we investigated the direct impact of combination therapy on clinical outcomes in patients with monomicrobial bacteremic pneumonia.ResultsAmong 100 consecutive patients with bacteremic Pseudomonas pneumonia, 65 patients were classified in the adequate empirical therapy group, 32 of whom received monotherapy and 33 combination therapy. In the marginal structural model, only inadequate therapy was significantly associated with 28-day mortality (p = 0.02), and multidrug-resistance was not a significant risk factor.To examine further the direct impact of combination therapy, we performed a subgroup analysis of the 65 patients who received adequate therapy. Multivariate logistic regression analysis identified absence of septic shock at the time of bacteremia (OR, 0.07; 95% CI, 0.01-0.49; p = 0.008), and adequate combination therapy (OR, 0.05; 95% CI, 0.01-0.34; p = 0.002) as variables independently associated with decreased all-cause 28-day mortality.ConclusionsOur study suggests that adequate empirical combination therapy can decrease mortality in patients with bacteremic Pseudomonas pneumonia.

Outcomes of non-HIV-infected patients with Pneumocystis pneumonia and concomitant pulmonary cytomegalovirus infection.

Abstract Background: The pathogenic effect of concomitant pulmonary cytomegalovirus (CMV) infection on morbidity and mortality of Pneumocystis jirovecii pneumonia (PCP) has been questioned in the case of non-HIV-infected patients. Methods: We conducted a retrospective cross-sectional study of patients who were diagnosed with PCP by bronchoalveolar lavage. We compared demographics, clinical characteristics, morbidity, and mortality in non-HIV-infected PCP patients with (n = 31) and without (n = 75) pulmonary CMV infection. Morbidity was assessed by length of hospital stay, admission to the intensive care unit, and use of mechanical ventilation. Mortality was defined as 30-day and 90-day all-cause mortality. Results: Morbidity and mortality did not differ between PCP patients with and without pulmonary CMV infection. In multivariate analysis using the Cox proportional hazard model, haematological malignancy (relative risk (RR) 0.20, 95% confidence interval (95% CI) 0.06–0.71), PCP treatment duration (RR 0.81, 95% CI 0.75–0.88), changing to a second-line regimen due to treatment failure (RR 4.51, 95% CI 1.61–12.64), and mechanical ventilation (RR 17.99, 95% CI 4.83–67.04) were independently associated with 30-day all-cause mortality. Being a solid organ transplant recipient (RR 0.17, 95% CI 0.05–0.56) and the use of mechanical ventilation (RR 6.49, 95% CI 2.84–14.83) were independently associated with 90-day all-cause mortality. However, concomitant pulmonary CMV infection was not associated with either 30-day or 90-day mortality. Conclusions: Our results suggest that concomitant pulmonary CMV infection does not significantly affect the prognosis of PCP, as indicated by morbidity and mortality in non-HIV-infected patients with PCP. Based on this result, we propose that it is not essential to administer an anti-CMV regimen when CMV is co-isolated from the bronchoalveolar lavage in patients with PCP.

Rapid diagnosis of tuberculous peritonitis by T cell-based assays on peripheral blood and peritoneal fluid mononuclear cells.

OBJECTIVES The utility of a newly-developed Mycobacterium tuberculosis-specific enzyme-linked immunosorbent spot (ELISPOT) assay for diagnosis of tuberculous peritonitis (TBP) has not been fully assessed. METHODS All patients with suspected TBP in a tertiary care hospital in an intermediate TB burden country were prospectively enrolled over a 30-month period. ELISPOT assays were performed on peripheral mononuclear cells (PBMC) and mononuclear cells from peritoneal fluid (PF-MC). RESULTS Sixty-four patients with suspected TBP were enrolled. Of these, 30 (47%) were classified as having TBP (27 confirmed and 3 probable cases), and 25 (39%) were classified as not having active tuberculosis. The remaining 9 (14%) with possible TBP were excluded from the final analysis. Five (8%) of the total 64 patients gave indeterminate PBMC ELISPOT results and 7 (18%) of 39 patients who underwent PF-MC ELISPOT assay revealed indeterminate PF-MC ELISPOT results. The sensitivity and specificity, respectively, of the tested methods for diagnosing TBP were as follows: PBMC ELISPOT (≥ 6 spots), 86% and 67%; PF-MC ELISPOT (≥ 14 spots), 92% and 86%; PF-MC ELISPOT/PBMC ELISPOT ratio (≥ 2), 75% and 93%; and PF ADA levels (≥ 38 IU/L), 95% and 100%. The areas under the receiver operating characteristics curves were as follows: PF-MC ELISPOT, 0.96; PF ADA, 0.96; PBMC ELISPOT, 0.88; and PF-MC ELISPOT/PBMC ELISPOT ratio, 0.87, respectively. CONCLUSIONS Although the ELISPOT assay does not outperform PF ADA, the ELISPOT assay using PBMC and PF-MC is a useful adjunct for diagnosing TBP, especially for a rule-in test when PF/MC/PBMC ELISPOT ratio (≥ 2) is used. However, the relatively high proportion of indeterminate results limits test utility, so further studies are needed to develop an optimized assay prototype.

Comparison of clinical manifestations, outcomes and cerebrospinal fluid findings between herpes simplex type 1 and type 2 central nervous system infections in adults.

In previous reports on the viral causes of central nervous system (CNS) infections, it has been generally recognized that HSV‐1 is a major cause of encephalitis, while HSV‐2 is the predominant cause of aseptic meningitis in adults. To examine this matter, the clinical characteristics in the two types of HSV CNS infections were investigated. In a retrospective cohort study which included all adult patients (≥16 years) between January 1999 and December 2013 in a 2,700‐bed tertiary care hospital, all the patients in whom PCR of the CSF for HSV was positive were identified. Ninety‐five patients with positive CSF PCR results for HSV were included, 21 with HSV‐1 and 74 with HSV‐2. Many patients with HSV‐1 had encephalitis (13/21, 61.9%), whereas most patients with HSV‐2 had meningitis (62/74, 83.8%). However, HSV‐1 and HSV‐2 accounted for similar proportion of patients with HSV encephalitis (13/25, 52.0% vs. 12/25, 48.0%). Neurological sequelae were more frequent among patients with HSV‐1 (9/21, 42.9% vs. 6/74, 8.1%; P = 0.001). The present study suggests that HSV‐2 is not only a major cause of aseptic meningitis, but also it may cause serious manifestation as HSV‐1 encephalitis in adults. J. Med. Virol. 86: 1766–1771, 2014.

Therapeutic Outcomes of Hematogenous Vertebral Osteomyelitis With Instrumented Surgery

BACKGROUND Patients with hematogenous vertebral osteomyelitis (HVO) occasionally require instrumentation for spinal stabilization. However, placing instrumentation in the setting of spinal infection raises concerns about recurrent infection due to bacteria adhering to the foreign material. In this study, we evaluated the therapeutic outcomes of patients with HVO who underwent instrumented surgery. METHODS We conducted a retrospective chart review of adult patients with microbiologically diagnosed HVO who underwent surgical intervention in 5 tertiary care hospitals over an 8-year period. RESULTS A total of 153 patients with HVO underwent surgical management for their infections. Of these 153 patients, 94 (61.4%) underwent surgical debridement alone (noninstrumented surgery) and 59 (38.6%) underwent surgical debridement and instrumentation (instrumented surgery). The median durations of antibiotic therapy were 66 and 80 days for the noninstrumentation and instrumentation groups, respectively (P = .22). Clinical outcomes were similar between the groups, including rates of infection-related death (2.1% vs 0%; P = .52), primary failure (1.1% vs 5.1%; P = .30), and recurrence (4.8% vs 6.8%; P = .72). Among the instrumentation group, there was a significant decreasing trend for recurrence according to total duration of antibiotic therapy: 22.2% (4-6 weeks), 9.1% (6-8 weeks), and 2.6% (≥ 8 weeks; P = .04). Duration of pre-instrumentation antibiotic therapy and single-stage operation (vs 2-stage operation) were not risk factors for recurrence. CONCLUSIONS Spinal instrumentation in patients with HVO may be safe with pathogen-directed prolonged antibiotic therapy and should not be abandoned or delayed solely because of the risk of recurrence.