Prevalence of human metapneumovirus among hospitalized children younger than 1 year in Catalonia, Spain.

Human metapneumovirus was discovered recently respiratory virus implicated in both upper and lower respiratory tract infection. In children, the clinical symptoms of human metapneumovirus are similar to those produced by respiratory syncytial virus, ranging from mild to severe diseases such as bronchiolitis and pneumonia. The aim of the present study was to describe the prevalence of human metapneumovirus and other common respiratory viruses among admitted to hospital infants. From January 2006 to June 2006, 99 nasopharyngeal aspirates were collected from hospitalized children younger than 12 months in order to study respiratory viruses. Human metapneumovirus detection was performed by cell culture and two RT-PCR targeting on polymerase and fusion genes. The latter gene was used for phylogenetic analysis. In 67/99 children (67%) at least one viral pathogen was identified, the viruses detected most frequently were respiratory syncytial virus (35%), human metapneumovirus (25%) and rhinovirus (19%). The results obtained in this study, show that: (1) human metapneumovirus is one of the most important viruses among children less than 12 months; (2) children infected with human metapneumovirus were significantly older than those infected by respiratory syncytial virus; (3) human metapneumovirus was associated more frequently with pneumonia whereas respiratory syncytial virus was only detected in patients with bronchiolitis; (4) there was a clear epidemiological succession pattern with only a small overlap among the viruses detected most frequently; (5) all human metapneumovirus samples were clustered within sublineage A2.

Influence of vancomycin minimum inhibitory concentration on the treatment of methicillin-resistant Staphylococcus aureus bacteremia.

BACKGROUND: Vancomycin treatment failure in methicillin-resistant Staphylococcus aureus (MRSA) bacteremia is not uncommon, even when MRSA is susceptible to vancomycin. The aim of our study was to evaluate whether vancomycin minimum inhibitory concentration has any influence on the mortality associated with MRSA bacteremia. METHODS: A total of 414 episodes of MRSA bacteremia were prospectively followed-up from 1991 through 2005. MIC of vancomycin for the first isolate was determined by E-test. Clinical variables recorded were age, comorbidity, prior administration of vancomycin, use of corticosteroids, prognosis of underlying disease, source of bacteremia, the need for mechanical ventilation, shock, and mortality. A "treatment group" variable was created and defined as follows: (1) receipt of empirical vancomycin and an isolate with a vancomycin MIC of 1 microg/mL (38 episodes), (2) receipt of empirical vancomycin and an isolate with a vancomycin MIC of 1.5 microg/mL (90 episodes), (3) receipt of empirical vancomycin and an isolate with a vancomycin MIC of 2 microg/mL (40 episodes), and (4) receipt of inappropriate empirical therapy (246 episodes). Univariate and multivariate analyses were performed. RESULTS: Episodes caused by strains with a vancomycin MIC of 2 microg/mL were independently associated with a lower risk of shock (odds ratio [OR], 0.33; 95% confidence interval [CI], 0.15-0.75). Multivariate analysis selected receipt of empirical vancomycin and an isolate with a vancomycin MIC of 2 microg/mL (OR, 6.39; 95% CI, 1.68-24.3), receipt of inappropriate empirical therapy (OR, 3.62; 95% CI, 1.20-10.9), increasing age (OR, 1.02; 95% CI, 1.00-1.04), use of corticosteroids (OR, 1.85; 95% CI, 1.04-3.29), an ultimately (OR, 10.2; 95% CI, 2.85-36.8) or rapidly (OR, 1.81; 95% CI, 1.06-3.10) fatal underlying disease, high-risk (OR, 3.60; 95% CI, 1.89-6.88) and intermediate-risk (OR, 2.18; 95% CI, 1.17-4.04) sources of bacteremia, and shock (OR, 7.38; 95% CI, 4.11-13.3) as the best predictors of mortality. CONCLUSIONS: Mortality associated with MRSA bacteremia was significantly higher when the empirical antibiotic was inappropriate and when vancomycin was empirically used for treatment of infection with strains with a high vancomycin MIC (>1 microg/mL).