To determine risk for West Nile virus (WNV) neuroinvasive disease in North Dakota, we tested plasma samples from blood donors for WNV IgG and compared infection rates with reported WNV neuroinvasive disease incidence. We estimate that 1 in 244 WNV infections leads to neuroinvasive disease; risk is substantially increased among men and older persons.

These results demonstrate that our HBV-LAMP assay is rapid, sensitive and specific, and capable of detecting the major HBV genotypes. This assay could be used in clinical point-of-care settings, mainly in endemic and resource-limited environments for HBV diagnostics, donor screening, epidemiological studies, and therapeutic monitoring of patients undergoing antiviral treatment.

West Nile virus (WNV), an arbovirus maintained in a bird-mosquito enzootic cycle, can infect other vertebrates including humans. WNV was first reported in the US in 1999 where, to date, three genotypes belonging to WNV lineage I have been described (NY99, WN02, SW/WN03). We report here the WNV sequences obtained from two birds, one mosquito, and 29 selected human samples acquired during the US epidemics from 2006–2011 and our examination of the evolutionary dynamics in the open-reading frame of WNV isolates reported from 1999–2011. Maximum-likelihood and Bayesian methods were used to perform the phylogenetic analyses and selection pressure analyses were conducted with the HyPhy package. Phylogenetic analysis identified human WNV isolates within the main WNV genotypes that have circulated in the US. Within genotype SW/WN03, we have identified a cluster with strains derived from blood donors and birds from Idaho and North Dakota collected during 2006–2007, termed here MW/WN06. Using different codon-based and branch-site selection models, we detected a number of codons subjected to positive pressure in WNV genes. The mean nucleotide substitution rate for WNV isolates obtained from humans was calculated to be 5.06×10−4 substitutions/site/year (s/s/y). The Bayesian skyline plot shows that after a period of high genetic variability following the introduction of WNV into the US, the WNV population appears to have reached genetic stability. The establishment of WNV in the US represents a unique opportunity to understand how an arbovirus adapts and evolves in a naïve environment. We describe a novel, well-supported cluster of WNV formed by strains collected from humans and birds from Idaho and North Dakota. Adequate genetic surveillance is essential to public health since new mutants could potentially affect viral pathogenesis, decrease performance of diagnostic assays, and negatively impact the efficacy of vaccines and the development of specific therapies.

Background Current diagnostic tests for Hepatitis C Virus (HCV) involve phlebotomy and serologic testing for HCV antibodies (anti-HCV) and RNA, which are not always feasible. Dried blood spots (DBS) present a minimally invasive sampling method and are suitable for sample collection, storage and testing. Objectives To assess the utility of DBS in HCV detection, we evaluated the sensitivity and specificity of DBS for anti-HCV and HCV RNA detection compared to plasma specimens. Study design This cross-sectional validation study was conducted in the context of an existing prospective study of HCV in young injection drug users. Blood samples were collected by venipuncture into serum separator tubes (SST) and via finger stick onto Whatman 903® protein-saver cards. Plasma samples and eluates from the DBS were tested for anti-HCV using either a third generation enzyme-linked or chemiluminescent immunoassay (IA), and HCV RNA using discriminatory HCV transcription-mediated amplification assay (dHCV TMA). DBS results were compared to their corresponding plasma sample results. Results 148 participants were tested for anti-HCV and 132 participants were tested for HCV RNA. For anti-HCV, the sensitivity of DBS was 70%, specificity was 100%, positive predictive value (PPV) was 100%, negative predictive value (NPV) was 76% and Kappa was 0.69. For HCV RNA, the sensitivity of DBS was 90%, specificity was 100%, PPV was 100%, NPV was 94% and Kappa was 0.92. Conclusions DBS are sensitive and very specific in detecting anti-HCV and HCV RNA, demonstrate good correlation with plasma results, and have potential to facilitate diagnosis of HCV infection.

This report describes the first ZIKV-positive donors detected outside areas with active transmission. These donors most likely represent travel-acquired "tail-end infections" with prolonged RBC-associated ZIKV RNA. The lack of transmission to the recipient of an apheresis PLT may suggest that these units are not infectious.