Central line-associated bloodstream infections among critically-ill patients in the era of bundle care.

BACKGROUND/PURPOSE: Patients admitted to intensive care units (ICUs) are at high risk for central line-associated bloodstream infections (CLABSIs). Bundle care has been documented to reduce CLABSI rates in Western countries, however, few reports were from Asian countries and the differences in the epidemiology or outcomes of critically-ill patients with CLABSIs after implementation of bundle care remain unknown. We aimed to evaluate the incidence, microbiological characteristics, and factors associated with mortality in critically-ill patients after implementation of bundle care. METHODS: Prospective surveillance was performed on patients admitted to ICUs at the National Taiwan University Hospital, Taipei, Taiwan from January 2012 to June 2013. The demographic, microbiological, and clinical data of patients who developed CLABSI according to the National Healthcare Safety Network definition were reviewed. A total of 181 episodes of CLABSI were assessed in 156 patients over 46,020 central-catheter days. RESULTS: The incidence of CLABSI was 3.93 per 1000 central-catheter days. The predominant causative microorganisms isolated from CLABSI episodes were Gram-negative bacteria (39.2%), followed by Gram-positive bacteria (33.2%) and Candida spp. (27.6%). Median time from insertion of a central catheter to occurrence of CLABSI was 8 days. In multivariate analysis, the independent factors associated with mortality were higher Pitt bacteremia score [odds ratio (OR) 1.41; 95% confidence interval (CI) 1.18-1.68] and longer interval between onset of CLABSIs and catheter removal (OR 1.10; 95% CI 1.02-1.20), respectively. CONCLUSION: In institutions with a high proportion of CLABSI caused by Gram-negative bacteria, severity of bacteremia and delay in catheter removal were significant factors associated with mortality.

In vitro activity of aminoglycosides against clinical isolates of Acinetobacter baumannii complex and other nonfermentative Gram-negative bacilli causing healthcare-associated bloodstream infections in Taiwan.

BACKGROUND/PURPOSE: Aminoglycosides possess in vitro activity against aerobic and facultative Gram-negative bacilli. However, nationwide surveillance on susceptibility data of Acinetobacter baumannii complex and Pseudomonas aeruginosa to aminoglycosides was limited, and aminoglycoside resistance has emerged in the past decade. We study the in vitro susceptibility of A. baumannii complex and other nonfermentative Gram-negative bacilli (NFGNB) to aminoglycosides. METHODS: A total of 378 NFGNB blood isolates causing healthcare-associated bloodstream infections during 2008 and 2013 at four medical centers in Taiwan were tested for their susceptibilities to four aminoglycosides using the agar dilution method (gentamicin, amikacin, tobramycin, and isepamicin) and disc diffusion method (isepamicin). RESULTS: A. baumannii was highly resistant to all four aminoglycosides (range of susceptibility, 0-4%), whereas >80% of Acinetobacter nosocomialis and Acinetobacter pittii blood isolates were susceptible to amikacin (susceptibility: 96% and 91%, respectively), tobramycin (susceptibility: 92% and 80%, respectively), and isepamicin (susceptibility: 96% and 80%, respectively). All aminoglycosides except gentamicin possessed good in vitro activity (>94%) against P. aeruginosa. Amikacin has the best in vitro activity against P. aeruginosa (susceptibility, 98%), followed by A. nosocomialis (96%), and A. pittii (91%), whereas tobramycin and isepamicin were less potent against A. pittii (both 80%). Aminoglycoside resistances were prevalent in Stenotrophomonas maltophilia and Burkholderia cepacia complex blood isolates in Taiwan. CONCLUSION: Genospecies among the A. baumannii complex had heterogeneous susceptibility profiles to aminoglycosides. Aminoglycosides, except gentamicin, remained good in vitro antimicrobial activity against P. aeruginosa. Further in vivo clinical data and continuous resistance monitoring are warranted for clinical practice guidance.

Klebsiella pneumoniae bacteremia and capsular serotypes, Taiwan.

Capsular serotypes of 225 Klebsiella pneumoniae isolates in Taiwan were identified by using PCR. Patients infected with K1 serotypes (41 isolates) had increased community-onset bacteremia, more nonfatal diseases and liver abscesses, lower Pittsburgh bacteremia scores and mortality rates, and fewer urinary tract infections than patients infected with non-K1/K2 serotypes (147 isolates).

Clinical manifestations and inflammatory cytokine responses in patients with severe acute respiratory syndrome.

BACKGROUND AND PURPOSE: Severe acute respiratory syndrome (SARS) is a highly transmissible disease with significant morbidity and mortality. Death from SARS is most often due to rapidly progressive respiratory compromise (acute respiratory distress syndrome, ARDS) and subsequent multi-organ dysfunction. However, the mechanisms evoking respiratory distress and a fulminant systemic response remain unclear. In order to elucidate the pathogenic mechanisms of SARS, we analyzed clinical manifestations and levels of serum cytokines of SARS patients. METHODS: Fourteen hospitalized patients with a diagnosis of SARS-associated coronavirus infection at National Taiwan University Hospital from March to May 2003 were included. Data on clinical manifestations, parameters of laboratory tests, complications and final outcomes of patients were collected retrospectively. Serial plasma inflammatory cytokines, including interleukin (IL)-1beta (IL-1beta), IL-6, IL-8 and tumor necrosis factor-alpha (TNF-alpha) of preserved serum were measured by enzyme immunoassay. RESULTS: All 14 patients had fever, dry cough and dyspnea. Twelve were intubated during hospitalization. The median duration from onset of fever to the nadir level or most severe condition was 9 days for hypoxia, 7 days for lymphocytopenia, 6.5 days for thrombocytopenia, 9.5 days for maximal pulmonary infiltrates; to peak serum levels was 9 days for C-reactive protein (CRP), 10.5 days for IL-6, 13.5 days for IL-8 and 12 days for TNF-alpha; to defervescence was 13 days. There was no significant elevation of serum IL-1beta levels in any of the 14 patients. There were no significant differences in peak levels of IL-6, IL-8 and TNF-alpha between patients with and without ARDS. The 8 patients who died tended to have higher peak levels of serum TNF-alpha compared to those who survived (14 vs 9.1 pg/mL; p = 0.06). CONCLUSION: Rapid elevation of inflammatory cytokines-IL-6, IL-8 and TNF-alpha might play a role in the development of SARS-related ARDS. The timing of elevations in inflammatory cytokines and CRP is correlated with progression of pulmonary infiltrates of SARS patients. The peak level of serum TNF-alpha tends to be higher in patients who die of SARS than in those who survive. Our results indicate that CRP and TNF-alpha might be used as prognostic markers of SARS.

Molecular epidemiology of clinical isolates of methicillin-resistant Staphylococcus aureus in Taiwan.

During July 2000 and October 2001, a total of 595 clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA) were collected from six medical centers distributed in northern, central, and southern Taiwan. Specimen sources included blood (n = 279), pus (n = 173), sputum (n = 94), body fluids (n = 21), catheter tips (n = 20), and urine (n = 8). Pulsed-field gel electrophoresis (PFGE) with SmaI digestion was used to fingerprint these isolates. A total of 31 genotypes with 97 type-subtypes were identified. Subtypes could be identified in 7 genotypes. While there were 6 to 15 genotypes in each hospital, 433 isolates (73%) were shown to belong to a major type (genotype A, with 29 subtypes). This genotype was not only the type prevailing in all six hospitals but also the predominant clone in each hospital, accounting for 46 to 89% of all isolates in each hospital. Genotype C (16 subtypes) was the second dominant genotype, accounting for 9% of all isolates, and was distributed in five hospitals. Genotypes D (11 subtypes), E (5 subtypes), and B (6 subtypes) were distributed in five, four, and three hospitals, respectively. The other 26 types (30 type-subtypes) were minor. We conclude that the majority of MRSA clinical isolates shared a common PFGE pattern, indicating the presence of a single, epidemic MRSA clone prevailing in major hospitals in Taiwan.