Shue Ren Wann

Catheter-associated urinary tract infections in intensive care units can be reduced by prompting physicians to remove unnecessary catheters.

OBJECTIVE Indwelling urinary catheters are the most common source of infections in intensive care units (ICUs). The aim of this study was to evaluate the efficacy of nurse-generated daily reminders to physicians to remove unnecessary urinary catheters 5 days after insertion. DESIGN A time-sequence nonrandomized intervention study. SETTING Adult ICUs (medical, surgical, cardiovascular surgical, neurosurgical, and coronary care) of a tertiary-care university medical center. PATIENTS All patients admitted to the adult ICUs during a 2-year period. The study consisted of a 12-month observational phase (15,960 patient-days) followed by a 12-month intervention phase (15,525 patient-days). INTERVENTION Daily reminders to physicians from the nursing staff to remove unnecessary urinary catheters 5 days after insertion. RESULTS The duration of urinary catheterization was significantly reduced during the intervention phase (from 7.0 + 1.1 days to 4.6 +/- 0.7 days; P < .001). The rate of catheter-associated urinary tract infection (CAUTI) was also significantly reduced (from 11.5 +/- 3.1 to 8.3 +/- 2.5 patients with CAUTI per 1,000 catheter-days; P = .009). There was a linear relationship between the monthly average duration of catheterization and the rate of CAUTI (r = 0.50; P = .01). The excess monthly cost of antibiotics for CAUTI was reduced by 69% (from 4021 dollars +/- 1800 dollars to 1220 dollars +/- 941 dollars; P = .004). CONCLUSION This study demonstrated that a simple measure instituted as part of a continuous quality improvement program significantly reduced the duration of urinary catheterization, rate of CAUTI, and additional costs of antibiotics to manage CAUTI.

Predictors of Septic Metastatic Infection and Mortality among Patients with Klebsiella pneumoniae Liver Abscess

BACKGROUND Primary liver abscess caused by Klebsiella pneumoniae is an infection that is emerging worldwide and that is associated with severe morbidity and considerable mortality. METHODS A retrospective analysis of 110 episodes of primary liver abscess caused by K. pneumoniae that required hospitalization during 2001-2002 was conducted to identify predictors of metastatic infection, mortality, and the efficacy of first-generation cephalosporins and percutaneous drainage. The potential role of Klebsiella rmpA and magA genes was also evaluated. RESULTS The study included 59 men and 51 women, with a mean age of 61.8 years. Diabetes was noted in 67 patients (60.9%). Metastatic infection occurred in 17 patients (15.5%), with meningitis accounting for 11 patients (64.7%) and endophthalmitis accounting for 4 patients (23.5%). The overall mortality rate was 10.0% (11 patients). Most of the severe complications occurred within the first 3 days after hospital admission. Ninety-two patients (83.6%) received treatment with cefazolin for >3 days. Four patients (4.3%) of the group who received cefazolin had metastatic infection, 1 patient (1.1%) experienced septic shock, and 3 (3.3%) experienced acute respiratory failure. Five (5.4%) of those 92 patients died. Multivariable analysis revealed that rmpA (odds ratio [OR], 28.85), Acute Physiologic and Chronic Health Evaluation (APACHE) II score >or=20 (OR, 8.08), and septic shock (OR, 4.33) were statistically significant predictors of metastatic infection. Metastatic infection (OR, 6.73), severity of disease (APACHE II score >or=16; OR, 11.82), septic shock (OR, 8.30), acute respiratory failure (OR, 69.92), and gas formation revealed on imaging (OR, 13.26) predicted mortality. Pigtail drainage protected against both metastatic infection (OR, 0.25) and mortality (OR, 0.14). CONCLUSION Management of primary liver abscess caused by K. pneumoniae with use of first-generation cephalosporins and percutaneous drainage was associated with low rates of mortality, metastatic infection, and complications. These rates are comparable to those reported for third-generation cephalosporins.

Skin and soft-tissue manifestations of Shewanella putrefaciens infection.

Shewanella putrefaciens, a saprophytic gram-negative rod, is infrequently recovered from clinical specimens. Although a number of clinical syndromes have been attributed to S. putrefaciens, the pathogenic role of this agent remains largely undefined. We report 16 cases of S. putrefaciens infection that occurred at the Veterans General Hospital-Kaohsiung in Taiwan between 1990 and 1995. S. putrefaciens infection was associated with a wide clinical spectrum including bacteremia/septicemia, skin and soft-tissue infection, biliary tract infection, peritonitis, and empyema. Five of our patients had skin and soft-tissue manifestations, including fulminant periorbitofacial cellulitis, dacryocystitis, perineal abscess, finger abscess, and postcholecystectomy wound infection. These clinical features deviated from the chronic ulcers or infected burns of the lower extremities that have been described in previous reports. Seven (44%) of our 16 patients had bacteremia/septicemia, and all seven had underlying hepatobiliary diseases. S. putrefaciens was isolated in mixed cultures of specimens from 14 patients; Escherichia coli was the most common coisolate. Hepatobiliary diseases and malignancy were the major predisposing factors for S. putrefaciens infection of the biliary tract and S. putrefaciens bacteremia/septicemia.

Role of Benzathine Penicillin G in Prophylaxis for Recurrent Streptococcal Cellulitis of the Lower Legs

Cellulitis of the lower leg is an infection caused by streptococci or, less commonly, Staphylococcus aureus and other gram-negative rods. Recurrence of cellulitis is a common problem. In the present study, we evaluated the use of monthly intramuscular injections of benzathine penicillin G to prevent recurrences of cellulitis. A total of 115 patients with definite or presumptive cases of streptococcal cellulitis were enrolled in this study. Eighty-four of these patients who declined follow-up or received incomplete prophylaxis were considered controls. Recurrence occurred in four (12.9%) of 31 cases who received prophylaxis and 16 (19%) of the 84 cases who did not receive prophylaxis. The difference was not statistically significant. Predisposing factors for cellulitis were found in 57 (49.6%) of the 115 enrolled cases and were mostly related to the impairment of local circulation. Administration of prophylaxis successfully reduced the recurrence rate to zero among patients without predisposing factors but failed to prevent recurrence in those with predisposing factors (20%). We conclude that monthly benzathine penicillin G prophylaxis benefits only patients without predisposing factors for cellulitis.

Comparison of the interferon- gamma release assay and the tuberculin skin test for contact investigation of tuberculosis in BCG-vaccinated health care workers.

Health care workers are at increased risk of Mycobacterium tuberculosis infection. The tuberculin skin test (TST) is frequently false positive in BCG-vaccinated health care workers. QuantiFERON-TB GOLD (QFT-G) is a sensitive and specific interferon-γ release assay unaffected by BCG vaccination. This study compared TST and QFT-G in the diagnosis of latent TB infection in BCG-vaccinated health care workers. 39 health care workers exposed to a smear-positive TB patient were enrolled. Initial TST was positive in 33 (84.6%) cases, but only 4 (10.2%) cases using QFT-G. TST conversion occurred in 2/6 (33.3%), compared to 4/32(12.5%), cases using QFT-G. A higher proportion of QFT converters was associated with intimate contact, although not reaching statistical significance. Face-to-face contact >1 h was significantly associated with QFT-G conversion ≥0.7 IU/ml (OR 8.63, 95%CI 1.08–69.07, p=0.04). Agreement between TST and QFT-G was 18.0%, (κ: −0.03). Concordance between TST and QFT (≥0.35 IU/ml) conversion was 40.0%(κ=−0.40), and 60.0%(κ=0.00) if QFT ≥0.7 IU/ml was used. Agreement increased with increasing TST cut-offs. TST is not useful in contact investigation among BCG-vaccinated health care workers, in an area with intermediate burden of TB. QFT may provide additional information for the diagnosis and strategic management of preventive treatment of LTBI in BCG-vaccinated health care workers in a country with intermediate burden of TB.

A prospective etiologic study of community-acquired pneumonia in Taiwan

BACKGROUND AND PURPOSE The treatment of community-acquired pneumonia (CAP) is complicated by the growing threat of antimicrobial resistance and the tendency to rely on empirical therapy. This study investigated the etiologic agents of adult CAP in Taiwan and the susceptibility of Streptococcus pneumoniae isolates from these patients. METHODS A collaborative group was established in the emergency department to conduct a prospective study of the etiology of adult CAP. The etiologic agent was determined by a combination of microscopic, culture, serologic and antigen detection methods. Pneumococcal susceptibility testing was performed to determine the extent of penicillin resistance. RESULTS A total of 100 consecutive cases of mild to moderate adult CAP prior to the severe acute respiratory syndrome epidemic were enrolled. The etiologic agent was determined in 72% of cases. The 5 most common causative pathogens were S. pneumoniae (26%), Mycoplasma pneumoniae (20%), Chlamydia pneumoniae (13%), Haemophilus influenzae (9%), and Klebsiella pneumoniae (5%). Atypical pathogens accounted for 40% of CAP. Bacteremic pneumonia was diagnosed in 6.2% of cases. Co-infections with 2 or more pathogens were found in 16% of the cases. Among the 20 isolates of S. pneumoniae, 85% (17/20) were susceptible to penicillin, 3 (15%) were intermediate, and none were resistant to penicillin. CONCLUSION S. pneumoniae, M. pneumoniae and C. pneumoniae were the 3 leading causes of mild to moderate CAP in Taiwan. This study indicates that penicillin-resistant S. pneumoniae play a very limited role in this condition in adults.

Antimicrobial Resistance of Rapidly Growing Mycobacteria in Western Taiwan: SMART Program 2002

BACKGROUND/PURPOSE To understand the resistance patterns of rapidly growing mycobacteria (RGM) in Taiwan, antimicrobial resistance of clinical isolates was determined as part of the SMART (Surveillance from Multicenter Antimicrobial Resistance in Taiwan) program. METHODS During the period from January 2002 to December 2003, clinical isolates were collected from eight hospitals located on the west side of Taiwan and one reference laboratory. Broth microdilution minimum inhibitory concentrations of 11 antimicrobial agents were determined for 312 clinical isolates of RGM, including the Mycobacterium fortuitum group (110 isolates), Mycobacterium abscessus group (168 isolates), and Mycobacterium chelonae group (34 isolates). RESULTS Nearly all of the RGM were susceptible to amikacin and ofloxacin (= 90%) and resistant to doxycycline (less than 3% susceptible). Tobramycin showed similar in vitro activity against the M. fortuitum and M. chelonae (77%) groups, but was less active against the M. abscessus group (58%). Ciprofloxacin was active mainly against M. fortuitum (95%). Nearly all RGM were resistant to erythromycin and doxycycline. However, around half of the RGM isolates remained susceptible to minocycline (50-54%). Clarithromycin was active against the M. abscessus group (53% susceptible), with a high rate of resistance in the M. chelonae (38% susceptible) and M. fortuitum (15% susceptible) group. Cefoxitin was more active against the M. fortuitum group (65%) than the other two RGM (40-44%), and les than 40% of the RGM isolates remained susceptible to imipenem (21-38%). CONCLUSION The resistance of RGM in Taiwan is not as high as previously reported (notably for tobramycin, ciprofloxacin and cefoxitin), but reduction in the susceptibility rates of clarithromycin and imipenem for the M. fortuitum and M. abscessus groups demonstrates the importance of in vitro susceptibility testing of clinically important isolates, as susceptibility may differ in different geographical areas, even regionally, and over time.

Streptococcus Suis Meningitis with Ventriculoperitoneal Shunt Infection and Spondylodiscitis

Streptococcus suis is a zoonotic pathogen which causes meningitis, bacteremia, and endocarditis in pigs. Human infection is rare and often presents as meningitis with the sequela of permanent deafness and endocarditis. Previous cases were reported from pig-rearing countries such as Holland and Hong Kong. We report a 55-year-old bedridden man with S. suis meningitis complicated with ventriculoperitoneal shunt infection and lumbar spine spondylodiscitis. He presented with fever, delirium, neck stiffness, lower leg weakness and sudden onset hearing loss for several days. He was successfully treated with intravenous antibiotics, ventriculoperitoneal shunt replacement, lumbar spinal laminotomy and discectomy. Cerebrospinal fluid culture initially misidentified the organism as Streptococcus acidominimus, and S. suis was later identified by 16S rRNA sequencing. Misidentification of the microbiological findings may lead to a failure to correctly diagnose this disease. S. suis meningitis should be included in the differential diagnosis of patients with meningitis and sudden hearing loss.

Isolated pathogens and clinical outcomes of adult bacteremia in the emergency department: A retrospective study in a tertiary Referral Center

BACKGROUND Approximately two-thirds of the patients with severe sepsis or septic shock are first encountered in the emergency departments (EDs) of western countries, in which bacteremia is present in about 50% of patients with severe sepsis. The situation of bacteremia presenting to the EDs in Taiwan is not well documented. The objective of this study was to examine the epidemiology and microbiology of bacteremia in adult patients who visited the ED of a medical center in southern Taiwan. METHODS A retrospective observational study of the epidemiology and microbiology of bacteremia was conducted in the ED of a medical center involving 6,137 adult patients and 13,903 blood cultures. RESULTS A total of 831 consecutive patients with 890 episodes of bacteremia were obtained from January 1 to December 31, 2004, indicating a positive culture rate of 13.5% (1,872/13,903). Among these episodes, 525 (59%) were defined as true community-acquired infections followed by 263 (29.5%) as health care-associated infections and 102 (11.5%) as nosocomial infections. Of the 972 isolates, 289 (29.7%) were gram-positive species and 683 (70.3%) were gram-negative species. Urinary tract infections (32.2%, 287/890) were most common in these patients, with Escherichia coli (30.8%, 299/972) being the most common pathogen. Bacteremia caused by Staphylococcus aureus was more common in nosocomial than true community-acquired infections (31.3% vs. 12%) and had significantly higher possibility of resistance to methicillin in infections not purely acquired from community (odds ratio = 24.92; 95% confidence interval, 9.88-62.87). The overall crude mortality rate was 21% and nearly half of the mortalities occurred within 3 days of visiting the ED. All patients discharged inadvertently were uneventful (n = 65, two lost at follow-up). CONCLUSIONS Categories of bacteremia acquisition was associated with different distribution of pathogens, antimicrobial resistance, and clinical outcome. Traditional classification might overestimate the problem of drug resistance in community-acquired infections. The concept of health care-associated infection should be introduced to avoid overemphasis of drug-resistant problem in true community-acquired infection.

Expression of matrix metalloproteinases and their tissue inhibitors in the serum and cerebrospinal fluid of patients with HIV-1 infection and syphilis or neurosyphilis

The potential mechanisms for altered matrix metalloproteinase (MMP) or tissue inhibitors of matrix metalloproteinase (TIMP) function in patients with syphilis and HIV-1 co-infection (HIV-S) was unclear. To determine the expression of MMP-2, 9 and TIMP-1, 2, 4 in the serum and cerebrospinal fluid (CSF) of HIV-S patients, a total of 20 HIV-S patients and 8 controls were enrolled in a HIV-1 clinical cohort for diagnosis of neurosyphilis in Taiwan. Serum and CSF concentrations of MMP-2, 9, and TIMP-1, 2, 4 were determined by ELISA. Gelatin zymography was used to detect the expression of MMP-2 and MMP-9 in the CSF. Neurosyphilis was defined as a CSF white blood cell count ≥ 20 cells/μL or a reactive CSF Venereal Disease Research Laboratory (VDRL). All the patients with HIV-S were males. Most (85%) had sex with men (MSM) and serum rapid plasma reagin (RPR) titers of ≥ 1:32. The median age was 35 years (IQR 30-43). The median CD4 T cell counts at the time of the diagnosis of syphilis were 270 cells/μL (IQR 96-484). Ten patients (50%) had neurosyphilis based on a reactive CSF VDRL test (n=8) or increased CSF white cell counts ≥ 20/μL (n=2). The concentrations of CSF MMP-9, TIMP-1, and TIMP-2 were significantly higher in patients with HIV-S than the controls (P<0.05). The CSF TIMP-4 concentrations were significantly lower in those with HIV-S (452 pg/ml) than controls (3101 pg/ml), P<0001. There were no significant differences in serum concentrations between the groups. The only finding that distinguished HIV-1 patients with from those without neurosyphilis is a significant higher expression of CSF MMP-9. In conclusion, the MMP/TIMP system was found to be dysregulated in patients with HIV-S regardless of whether they met the laboratory definition of neurosyphilis. The CSF level of MMP-9 was the only measure that distinguished those with or without neurosyphilis.