Cocirculation of pandemic H1N1 virus and seasonal H3N2 virus led to a mixed infection in patients. Pandemic H1N1 virus, however, took prevalence over seasonal influenza virus in the course of transmission. Therefore, competitive circulation of seasonal influenza A virus with the pandemic H1N1 virus seems less likely.

This article has an accompanying continuing medical education activity, also eligible for MOC credit, on page e124. Learning Objective-Upon completion of this activity, successful learners will be able to utilize the algorithm to prevent mother-to-child transmission of HBV in the management of pregnant women with chronic hepatitis B virus infection and their infants.

c "Candidatus Neoehrlichia mikurensis" was detected by PCR in 4.0% (34/841) of the rodents tested in this study. The 34 rodents represented nine species from seven regions of China. Phylogenetic analyses based on the partial groEL and nearly entire 16S rRNA gene sequences of the agent revealed genetic diversity, which was correlated with its geographic origins.

Background: The occurrence of acute mountain sickness (AMS), which develops in some individuals who ascend to altitudes above 2,500 m, may be associated with 4 hypoxia-related genes (HIF-1, VEGFA, HSP-70 and eNOS). Objectives: The aim of our study was to investigate the potential role of the 4 hypoxia-related genes in AMS pathogenesis. We therefore evaluated single-nucleotide polymorphisms (SNPs) of the genes in an association study using a case-control design. Methods: At an altitude of 4,600 m, 64 male Chinese patients with AMS, defined according to the Lake Louise consensus criteria, were compared to 64 Chinese men free of symptoms of AMS. Clinical data, such as age, history of diseases, oxygen saturation (SpO₂) and heart rate, were obtained. Genotypes of selected SNPs of these genes in patients were compared with those in controls. Results: The mean SpO₂ and heart rate of the AMS and control groups were similar before ascent to high altitude (p = 0.79, p = 0.62) but, 24 h after ascent, the mean SpO₂ of the AMS group was significantly lower than that of the control group (p = 0.001), and the mean heart rate of the AMS group was significantly higher than that of the control group (p = 0.001). Twenty-eight of the 48 SNPs investigated were successfully genotyped, and SNP allele frequencies were obtained. The rs3025039 SNP and the haplotype (rs1413711, rs833070 and rs3025000) in the VEGFA gene were significantly associated with AMS (p = 0.0435 and 0.024, respectively). Conclusions: Our study demonstrates a possible association between the VEGFA gene and AMS. We conclude that VEGFA may have an important role in the AMS process.

Although the clinical consequences of infection are comparable between vaccinated and unvaccinated patients, humoral and cellular immune responses in vaccinated patients are boosted for some weeks, indicating an additional benefit of vaccination against 2009 pandemic influenza A (H1N1) virus.