Shey-Ying Chen

Comparison of Both Clinical Features and Mortality Risk Associated with Bacteremia due to Community-Acquired Methicillin-Resistant Staphylococcus aureus and Methicillin-Susceptible S. aureus

BACKGROUND The majority of research about community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) infection has focused on skin and soft-tissue infections. No literature has been published on the clinical features and outcomes of adult patients with CA-MRSA bacteremia in comparison with patients with community-acquired methicillin-susceptible S. aureus (CA-MSSA) bacteremia. METHODS From 1 January 2001 through 31 December 2006, the demographic data and outcome of 215 consecutive adult patients admitted to a tertiary care center in Taiwan with S. aureus bacteremia (age, >16 years) who fulfilled the criteria for community-acquired S. aureus bacteremia were collected for analysis. RESULTS The mean age (+/-SD) was 56.8+/-20.5 years. There were 30 patients (14%) with CA-MRSA bacteremia and 185 (86%) patients with CA-MSSA bacteremia. Cutaneous abscess (odds ratio, 5.46; 95% confidence interval, 1.66-17.94) and necrotizing pneumonia (odds ratio, 24.81; 95% confidence interval, 2.63-234.03) were the independent predictors of CA-MRSA bacteremia; endovascular infection was the only independent predictor of CA-MSSA bacteremia. After Cox regression analysis, the independent significant risk factors for 30-day mortality included increased age, shock, and thrombocytopenia (<100,000 cells/microL). After adjustment, the day 30 mortality of patients with CA-MRSA bacteremia was not significantly higher than that of patients with CA-MSSA bacteremia (adjusted hazard ratio, 1.01; 95% confidence interval, 0.30-3.39; P = .986). Most (92%) of 25 available CA-MRSA isolates were multilocus sequence typing 59. CONCLUSIONS The number of adult patients with CA-MRSA bacteremia increased with time, and the disease was associated with more necrotizing pneumonia and cutaneous abscess but less endovascular infection than was CA-MSSA bacteremia. Patients with CA-MRSA bacteremia did not have higher mortality than did patients with CA-MSSA, even though most of the patients with CA-MRSA bacteremia did not receive empirical glycopeptide therapy.

Consensus review of the epidemiology and appropriate antimicrobial therapy of complicated urinary tract infections in Asia-Pacific region

Urinary tract infections (UTIs) are among the most prevalent infectious diseases in the general population. They cause a substantial financial burden in the community and are associated with significant morbidity and mortality, particularly in hospitals. With increased rates of antimicrobial resistance, especially in the Asia-Pacific region, treatment of complicated UTIs (cUTIs) can be challenging for clinicians. Consideration of an optimal antimicrobial agent should be based on local resistance patterns, patient-specific factors, pharmacokinetic and pharmacodynamic principles, and cost. In the Asia-Pacific region, nearly half of Escherichia coli urinary isolates were resistant (including intermediate and resistant) to levofloxacin or ciprofloxacin and ≥30% were resistant to third-generation cephalosporins (cefotaxime, ceftriaxone, and ceftazidime) and cefepime. Overall, 33% of urinary E. coli isolates exhibited extended-spectrum β-lactamase (ESBL)-producing phenotypes. Prevalence of ESBL-producing urinary E. coli was highest in India (60%), followed by Hong Kong (48%) and Singapore (33%). All urinary isolates of E. coli were susceptible to both ertapenem and imipenem. All urinary isolates of Klebsiella pneumoniae were susceptible to imipenem and 4% of them were resistant to ertapenem. Care should be exercised when using trimethoprim-sulfamethoxazole (TMP-SMX), fluoroquinolones, and cephalosporins for the empirical treatment of UTIs, particularly cUTI among moderately to severely ill patients. Empiric antimicrobial treatment for serious cUTIs in which risk factors for resistant organisms exist should include broad-spectrum antibiotics such as carbapenems (ertapenem, imipenem, meropenem, and doripenem) and piperacillin-tazobactam. Aminoglycosides, tigecycline, and polymyxins (colistin or polymyxin B) can be used for the treatment of multidrug-resistant organisms or serious cUTIs when first-line options are deemed inappropriate or patients fail therapy. Because of considerable variability in different countries, local epidemiological data is critical in the effective management of UTIs in the Asia-Pacific region.

Epidemiology and prognostic determinants of patients with bacteremic cholecystitis or cholangitis.

OBJECTIVES:To compare mortalities in patients with sepsis due to biliary tract infections (BTIs) and due to infections from other sources, and to identify independent predictors of mortality in these patients.METHODS:This study was part of a community-acquired bloodstream infection (BSI) study that prospectively collected comprehensive clinical, laboratory, and outcome data from 937 consecutive patients with microbiologically documented BSI in the emergency department. BTI was the confirmed source of 145 of the 937 BSIs. We determined the independent prognostic factors by evaluating the correlation between 30-day mortality and various factors, for example, comorbidity, clinical severity, related hepatobiliary complication, and decompressive procedures.RESULTS:Patients with biliary sepsis had a high percentage of Gram-negative (88.3%), polymicrobial (26.9%), and anaerobic infections (6.9%). The 30-day overall mortality was 11.7%. Cox proportional hazard regression analysis disclosed five significant independent predictors: acute renal failure (hazard ratio, 95% confidence interval: 6.86, 6.02–25.5), septic shock (5.83, 4.36–15.64), malignant obstruction (4.35, 1.89–12.96), direct type hyperbilirubinemia (1.26, 1.1–1.42), and Charlson score ≥6 (1.57, 1.12–2.22). Compared with the remaining 792 patients in the source population, patients with bacteremic BTI had significantly better prognosis (log-rank test, P = 0.007). Adjusting for age, comorbidity, and clinical severity, BTI was still independently associated with better 30-day survival (0.25–0.76).CONCLUSIONS:Though the mortality rate in patients with bacteremic BTI is substantial, survival is better than in those with bacteremia from other sources. The main prognostic factors identified in this study may help clinicians recognize patients at high risk for early mortality so that they can give prompt, appropriate treatment.

Detection of SARS-associated Coronavirus in Throat Wash and Saliva in Early Diagnosis

Early detection of SARS-CoV in throat wash and saliva suggests that these specimens are ideal for SARS diagnosis.

Diagnostic value of procalcitonin for bacterial infection in elderly patients in the emergency department.

OBJECTIVES: To evaluate the diagnostic performance of procalcitonin (PCT) in elderly patients with bacterial infection in the emergency department (ED).

Impact of Adding Video Communication to Dispatch Instructions on the Quality of Rescue Breathing in Simulated Cardiac Arrests- a Randomized Controlled Study

OBJECTIVE Both ventilations and compressions are important for victims of prolonged cardiopulmonary resuscitation (CPR) and asphyxial arrest. Dispatch assistance increases bystander CPR, but the quality of dispatcher-assisted CPR (DA-CPR), especially rescue breathing, remains unsatisfactory. This study was conducted to assess the impact of adding interactive video communication to dispatch instructions on the quality of rescue breathing in simulated cardiac arrests. METHODS In this simulation-based study, adults without CPR training within 5 years were recruited between April and July 2007 and randomized to receive dispatch assistance with either voice instruction alone (voice group, n=53) or interactive voice and video instruction (video group, n=43) via a video cell phone. The quality of rescue breathing was evaluated by reviewing the videos and mannequin reports. RESULTS Subjects in the video group were more likely to open the airway correctly (95.3% vs. 58.5%, P<0.01) and to lift the chin properly (95.3% vs. 62.3%, P<0.01), but had similar rates of head-tilt (95.3% vs. 84.9%, P=0.10). Volunteers in the video group had larger volume of ventilation (median volume 540 ml vs. 0 ml, P<0.01), greater possibility to sustain an open airway (88.4% vs. 60.4%, P<0.01) and a tendency towards better nose-pinch (97.7% vs. 86.8%, P=0.06). The video group spent longer time to open the airway (59 s vs. 56 s, P<0.05) and to give the first rescue breathing (139 s vs. 102 s, P<0.01). CONCLUSION Adding video communication to dispatch instructions improved the quality of bystander rescue breathing, including higher proportion of airway opened, and larger volume of ventilation delivered, in simulated cardiac arrests.

Distribution of Staphylococcal Cassette Chromosome mec Types and Correlation with Comorbidity and Infection Type in Patients with MRSA Bacteremia

Background Molecular epidemiological definitions that are based on staphylococcal cassette chromosome mec (SCCmec) typing and phylogenetic analysis of methicillin-resistant Staphylococcus aureus (MRSA) isolates are considered a reliable way to distinguish between healthcare-associated MRSA (HA-MRSA) and community-associated MRSA (CA-MRSA). However, there is little information regarding the clinical features and outcomes of bacteremia patients with MRSA carrying different SCCmec types. Methods From January 1 through December 31, 2006, we recorded the demographic data and outcomes of 159 consecutive adult MRSA bacteremia patients from whom isolates for SCCmec analysis were collected. All participants were patients at a tertiary care center in Taiwan. Principal Findings The following SCCmec types were identified in MRSA isolates: 30 SCCmec II (18.9%), 87 SCCmec III (54.7%), 22 SCCmec IV (13.8%), and 20 SCCmec V (12.6%). The time from admission to the first MRSA-positive blood culture for patients infected with isolates with the SCCmec III element (mean/median, 50.7/26 days) was significantly longer than for patients infected with isolates carrying SCCmec IV or V (mean/median, 6.7/3 days for SCCmec IV; 11.1/10.5 days for SCCmec V) (P<0.05). In univariate analysis, community onset, soft tissue infection, and deep-seated infection were predictors for SCCmec IV/V. In multivariate analysis, length of stay before index culture, diabetes mellitus, and being bedridden were independent risk factors associated with SCCmec II/III. Conclusions These findings are in agreement with previous studies of the genetic characteristics of CA-MRSA. MRSA bacteremia with SCCmec II/III isolates occurred more among patients with serious comorbidities and prolonged hospitalization. Community onset, skin and soft tissue infection, and deep-seated infection best predicted SCCmec IV/V MRSA bacteremia.

Temporal Relationship of Viral Load, Ribavirin, Interleukin (IL)—6, IL-8, and Clinical Progression in Patients with Severe Acute Respiratory Syndrome

Abstract Although viral replication and overwhelming immune responses are believed to contribute to the progression of severe acute respiratory syndrome (SARS), little is known about the temporal relationship between viral load, ribavirin, proinflammatory cytokines, and clinical progression. We report that ribavirin was not effective in reducing the SARS coronavirus load in 3 of 8 probable cases studied and that elevated levels of interleukin (IL)—6 and IL-8 subsequent to the peak viral load were found in 8 and 6 cases, respectively. The nadir lymphocyte count during lymphopenia, the peak level of lactate dehydrogenase, and the peak density of pulmonary infiltrates lag further behind the peak viral load by a median of 4, 5, and 3.5 days, respectively. These findings provide important information for therapeutic strategies to treat SARS.

Methicillin-Resistant Staphylococcus aureus (MRSA) Staphylococcal Cassette Chromosome mec Genotype Effects Outcomes of Patients With Healthcare-Associated MRSA Bacteremia Independently of Vancomycin Minimum Inhibitory Concentration

BACKGROUND Recent evidence has shown that community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) is less virulent than traditional hospital-associated MRSA. We explored whether the antimicrobial susceptibilities of the different strains account for their disparity in clinical virulence. METHODS This 10-year retrospective cohort study enrolled 291 patients with community-onset, healthcare-associated MRSA bacteremia. The vancomycin minimum inhibitory concentration (MIC) and staphylococcal cassette chromosome mec (SCCmec) type were determined for all isolates. CA-MRSA was defined as an isolate possessing the SCCmec type IV or V genes, and hospital-associated MRSA (HA-MRSA) was defined as an isolate possessing SCCmec type I, II, or III genes. Low and high vancomycin MICs were defined as MICs of ≤1 and ≥2 μg/mL, respectively. Patients with bacteremia due to CA-MRSA with a low vancomycin MIC (n = 111), due to HA-MRSA with a low vancomycin MIC (n = 127), or due to HA-MRSA with a high vancomycin MIC (n = 47) entered the outcome analysis. The outcomes of the 2 HA-MRSA bacteremia groups were compared to those of the CA-MRSA bacteremia group. RESULTS Treatment failure was observed in 35 (31.5%), 59 (46.5%), and 27 (57.4%) of patients with low-vancomycin-MIC CA-MRSA, low-vancomycin-MIC HA-MRSA, and high-vancomycin-MIC HA-MRSA bacteremia, respectively. After adjustment for potential confounding factors, the risk of treatment failure was significantly higher among patients with low-vancomycin-MIC HA-MRSA (adjusted odds ratio [aOR], 1.853; 95% confidence interval [CI], 1.006-3.413) and high-vancomycin-MIC HA-MRSA (aOR, 2.393; 95% CI, 1.079-5.309), compared with patients with low-vancomycin-MIC CA-MRSA. CONCLUSIONS The higher risk for treatment failure among patients with traditional hospital-associated MRSA infections, compared with patients with CA-MRSA infections, is independent of the vancomycin MIC, suggesting a potential intrinsic strain-specific virulence effect.

Predictive model of diagnosing probable cases of severe acute respiratory syndrome in febrile patients with exposure risk

Abstract Study objective Since the World Health Organization issued a global alert about severe acute respiratory syndrome (SARS) on March 12, 2003, the illness has become a major public health challenge worldwide. The objective of this study is to identify the clinical risk factors of SARS and to develop a scoring system for early diagnosis. Methods The detailed clinical data of all patients presenting to the emergency department (ED) with a temperature higher than 38.0°C (100.3°F), documented at home or at the ED, and risks of exposure to SARS within 14 days were assessed. The diagnosis of probable SARS was made according to the definition of the Centers for Disease Control and Prevention. Items with significant differences among symptoms, signs, and laboratory tests on presentation between SARS and non-SARS groups were determined and used to develop the scoring system. Results Seventy patients were enrolled and 8 were diagnosed as probably having SARS. None of the initially discharged patients or their relatives developed SARS. Compared with the non-SARS group, the SARS group was younger (33.9±15.9 years versus 44±9.8 years; P=.02), had a higher percentage of fever prolonged more than 5 days (87.5% versus 6.5%; P<.01), myalgia (75% versus 27.4%; P=.01), and diarrhea (50% versus 9.7%; P=.02); had less occurrence of cough before or during fever (0% versus 64.5%; P=.01); and had lower absolute lymphocyte (0.9±0.3×109/L versus 1.5±1.1×109/L; P<.01) and platelet counts (144.1±36.3×109/L versus 211.6±78.8×109/L; P=.02). A 4-item symptom score based on the presence of cough before or concomitant with fever, myalgia, diarrhea, and rhinorrhea or sore throat detects SARS with 100% sensitivity and 75.9% specificity; a 6-item clinical score based on lymphopenia (<1.0×109/L), thrombocytopenia (<150×109/L) and the 4 symptom items detects SARS with 100% sensitivity and 86.3% specificity. Conclusion Certain symptoms and laboratory tests indicate higher risk of febrile probable SARS. In nonendemic areas, the febrile patients with recent contact with SARS or travel history to endemic areas could be screened for the probability of SARS by the use of clinical and symptom scores.