Prognostic factors and clinical features of non-typhoid Salmonella bacteremia in adults.

BACKGROUND: Infections caused by non-typhoid Salmonella (NTS) have increased, and the increasing incidence of multidrug-resistant NTS bacteremia in adult patients has also been noted. This study aimed to investigate the clinical and microbiological characteristics of NTS bacteremia. METHODS: A total of 71 episodes of NTS bacteremia among 65 patients were identified between 2004 and 2006. Clinical characteristics were collected from medical records. The agar dilution method described by the Clinical and Laboratory Standards Institute was used to determine the in vitro activities of each antibiotic. Multiple logistic regression analysis was used to evaluate the relationship between patient characteristics and all other covariates studied for prognosis. RESULTS: Salmonella enteritidis was isolated in 30 cases (42.3%), Salmonella typhimurium in 22 (31.0%), and Salmonella choleraesuis in 19 (26.7%). Thirty-two (45.1%) isolates of 71 NTS bacteremias were susceptible to chloramphenicol, 37 (52.1%) to ampicillin, 47 (66.2%) to trimethoprim/sulfamethoxazole (TMP/SMX), 56 (78.9%) to moxifloxacin, 57 (80.3%) to ciprofloxacin and levofloxacin, and 71 (100%) to ceftriaxone. The crude 30-day mortality rate was 19.7%. In multiple logistic regression analysis, the following variables were independent and significant predictors of mortality: coma (odds ratio, 12.03) and inadequate antibiotic treatment (odds ratio, 6.63). CONCLUSION: S. enteritidis was the most frequently isolated serotype. High resistance rates of NTS to some readily available antimicrobials (ampicillin, chloramphenicol, TMP/SMX, fluoroquinolones) were found. Patients with the factor of coma or inadequate antibiotic treatment had poor prognosis.

Influenza A virus in Taiwan, 1980-2006: Phylogenetic and antigenic characteristics of the hemagglutinin gene.

Limited amount of information is available in Taiwan on the genetic or antigenic characteristics of influenza A virus prior to the establishment of a Taiwan surveillance network in 2000. Isolates of H1N1 and H3N2 viruses in Taiwan between 1980 and 2006 were studied, and part of the hemagglutinin gene was analyzed due to its importance in terms of viral infection and antibody neutralization. Results from a phylogenetic analysis indicate continuous evolutionary topology in H3N2 isolates, and two distinct H1N1 lineages. Many genetic relationships between vaccine strains and epidemic isolates appearing in Taiwan before other global locations were also observed and recorded in addition to a gradual increase in the number of N-linked glycosylation sites on partial HA1 proteins since 1980. The results from pairwise comparisons of HA1 nucleotide and deduced amino acid sequences indicate shared identities within groups organized according to their bootstrap and P-values of approximately 95.5-100% and 95.7-100% in H1N1 and 94.5-100% and 93.2-100% in H3N2 viruses, respectively. Comparisons of amino acid substitutions in the five antigenic regions reveal highly non-synonymous changes occurring in the Sb region of H1N1 and in the B region of H3N2. The results of an antigenic analysis using a hemagglutinin inhibition (HI) test indicate the presence of some epidemic strains 1-2 years earlier in Taiwan than in other parts of the world, as well as higher vaccine mismatch rates. This information supports the need for continuous surveillance of emerging influenza viruses in Taiwan, which will be useful for making global vaccine decisions.