Volume 52, Issue 8, 15 April 2011

Our findings indicate that vancomycin may not be useful for treating MRSA infections with MICs >1 mg/L. Aggressive vancomycin dosing, producing an adequate drug exposure, is also associated with a high risk of nephrotoxicity, especially for ICU patients.

We evaluated 320 patients receiving vancomycin therapy for complicated MRSA bacteremia. Vancomycin trough concentrations, <15 mg/L, infective endocarditis, and a vancomycin MIC>1 mg/L by Etest predicted failure. Optimization of vancomycin therapy is warranted to improve patient outcomes.

Mutations in Varicella zoster virus (VZV) thymidine kinase can cause resistance of VZV to Acyclovir. In stem cell transplant recipients with Acyclovir-resistant VZV disease, we demonstrate temporal as well as spatial compartmentalization of such mutations with important implications for sampling.

In our investigation of a group A Streptococcus outbreak in a long-term acute care hospital, the single risk factor remaining significantly associated with GAS infection on multivariable analysis was having a roommate infected or colonized with GAS.

MSRA isolates with high vancomycin MIC have been associated with treatment failure. Predicting the likelihood of high vancomycin MIC may be useful for clinical decision making. We present a simple tool to help predict vancomycin MIC in MRSA bacteremia.

Sera from H5N1 vaccinees and IVIG were analyzed for cross-reactive Abs against HA of influenza A viruses. Data quantitatively show the presence of two populations of heterosubtypic neutralizing Abs against either Group 1 only or Group 1+2 viruses.

Q fever serological results vary between testing centers with major implications for the diagnosis and treatment of Q fever. Clinicians need to be aware of the discrepancies. An international standard of Q fever serological investigation should be developed.

Modeling of expanding antiretroviral treatment to all HIV-infected adults already in care in San Francisco predicts reductions in new HIV infections at 5 years of 59% among men who have sex with men (MSM). Addition of annual HIV testing for MSM to universal treatment decreases new infections by 76%.

Of 682 antiretroviral-naïve patients initiating antiretroviral therapy in a prospective, multicenter HIV-1 drug resistance monitoring study involving 8 sites in Hong Kong, Malaysia, and Thailand, the prevalence of patients with ≥1 drug resistance mutation(s) was 13.8%. Primary HIV drug resistance is emerging after rapid scaling-up of antiretroviral therapy in Asia.

Age-adjusted fracture rates among HIV patients in the HOPS were higher than in the general population from 2000 to 2006. Clinicians should regularly assess HIV+ patients for fracture risk, especially those with low nadir CD4 cell count or other established risk factors.

HIV-infected breastfeeding infants acquired multiclass drug resistance (MCR) after their mothers started highly active antiretroviral therapy (HAART). MCR was more frequent in infants whose mothers started HAART by 6 months postpartum or were exclusively breastfeeding when they reported HAART use.