Oseltamivir-resistant pandemic (H1N1) 2009 virus infections, United States, 2010-11.

During October 2010-July 2011, 1.0% of pandemic (H1N1) 2009 viruses in the United States were oseltamivir resistant, compared with 0.5% during the 2009-10 influenza season. Of resistant viruses from 2010-11 and 2009-10, 26% and 89%, respectively, were from persons exposed to oseltamivir before specimen collection. Findings suggest limited community transmission of oseltamivir-resistant virus.

Prolonged shedding of pandemic influenza A (H1N1) 2009 virus in a pancreas-after-kidney transplant recipient.

Prolonged shedding of influenza virus has been reported in immunocompromised patients. Delayed viral clearance may contribute to antiviral resistance and nosocomial transmission. We report a case of a pancreas-after-kidney transplant recipient who had detectable pandemic influenza A virus for 12 months. Pyrosequencing analysis detected the H275Y mutation, which is associated with resistance to oseltamivir.

HIV-1 subtype diversity in Minnesota.

BACKGROUND: Genetic variation in human immunodeficiency virus (HIV)-1 poses significant public-health and clinical challenges. In North America, subtype B is most prevalent. HIV-1 subtyping is not integrated into routine HIV/acquired immunodeficiency syndrome surveillance in the United States. In 2003, the Minnesota Department of Health piloted HIV-1 subtyping with routine surveillance to describe the existence and variety of non-subtype B strains. METHODS: Targeted HIV-1 subtype surveillance was conducted on 98 African-born HIV-infected patients. Sentinel subtype surveillance was conducted in a Minneapolis sexually transmitted disease clinic on 28 newly diagnosed non-African HIV-positive patients. Subtype determination was based on a partial sequence of the gp41 region of the HIV-1 env gene. RESULTS: Subtyping was successful for 87 of 98 samples from African-born HIV-infected patients; 95% were non-B subtypes. The 7 subtypes observed were consistent with strains endemic in patients' birth regions. Subtyping was also completed for samples from 25 of 28 non-African-born patients; all were subtype B. CONCLUSIONS: Multiple HIV-1 subtypes are present in Minnesota. Our data suggest that most of the HIV cases in Minnesota among African-born patients are non-B subtypes. Population-based surveillance inclusive of groups at high risk for variant strains is needed to monitor the prevalence and variety of HIV subtypes in the United States.

A comparison of group A streptococci from invasive and uncomplicated infections: are virulent clones responsible for serious streptococcal infections?

From the mid-1980s, numerous reports of invasive group A streptococcal infections suggested that "highly virulent clones" were responsible. However, there have been virtually no extensive reports and comparisons of diverse temporal and geographic community isolates from uncomplicated throat infections to confirm the hypothesis. A unique collection of such "control" strains allowed in-depth assessment of association of M serotypes 1, 3, and 28 "clones" with invasive infections. Clones were defined by using small-fragment chromosomal restriction-enzyme analysis, pulsed-field gel electrophoresis, and M protein gene (emm) sequencing. After comparison with controls, no clone within these M serotypes had statistically increased association with invasive infections. The prevalence of specific virulence-associated clones appeared to essentially reflect their normal population prevalence. Although this does exclude other potential streptococcal factors, these findings suggest that host factors including individual and population-based immunity must also be significant in influencing infection potential.