Quantification of Hepatitis E Virus ORF2 Protein by a Novel Sandwich ELISA.

Hepatitis E virus (HEV) causes acute hepatitis in humans, which can progress to chronicity in immunosuppressed individuals. Almost all reported HEV infections are caused by genotypes 1-4. The structural ORF2 protein is the major antigen detected in the blood of HEV-infected individuals.

Development and characterization of secondary standards for nucleic acid amplification technology (NAAT) assays for detection of hepatitis E virus.

Background: To harmonize assays for detection of HEV RNA, a World Health Organization International Standard (WHO IS) was established. The WHO IS represents the highest order standard for HEV RNA but is limited in quantity. Secondary standards are needed to limit the use of WHO IS and minimize the need to replace it.

Chitinase 3-like 1 is a profibrogenic factor overexpressed in the aging liver and in patients with liver cirrhosis.

Older age at the time of infection with hepatitis viruses is associated with an increased risk of liver fibrosis progression. We hypothesized that the pace of fibrosis progression may reflect changes in gene expression within the aging liver. We compared gene expression in liver specimens from 54 adult donors without evidence of fibrosis, including 36 over 40 y old and 18 between 18 and 40 y old.

Genomic and Phylogenetic Analysis of Zika Virus Isolates from Asymptomatic Blood Donors in the United States and Puerto Rico, 2016.

Zika virus (ZIKV) caused a public health threat in the United States in 2016, leading to rapid development and implementation of blood screening assays for ZIKV RNA. Several ZIKV sequences from clinical cases have been reported, but none from asymptomatic/pre-symptomatic infections. We isolated and sequenced ZIKV from asymptomatic/pre-symptomatic blood donor (ABD-ZIKV) samples and compared with reported clinical sequences.

Differential Pattern of Soluble Immune Markers in Asymptomatic Dengue, West Nile and Zika Virus Infections.

Infections with dengue virus (DENV), West Nile virus (WNV) and Zika virus (ZIKV) usually present similar mild symptoms at early stages, and most infections (~80%) are asymptomatic. However, these infections may progress to severe disease with different clinical manifestations. In this study we attempted to identify unique characteristics for each infection at the presymptomatic/asymptomatic stage of infection and compared levels of soluble immune markers that have been shown to be altered during clinical course of these viral infections.

A Zika Reference Panel for Molecular-Based Diagnostic Devices as a US Food and Drug Administration Response Tool to a Public Health Emergency.

In 2015, Zika virus (ZIKV) appeared as an emerging pathogen, generating a global and urgent need for accurate diagnostic devices. During this public health crisis, several nucleic acid testing (NAT)-based Zika assays were submitted to the US Food and Drug Administration (FDA) for Emergency Use Authorization. The FDA's Center for Devices and Radiological Health, in collaboration with the FDA's Center for Biologics Evaluation and Research, responded to this Zika emergency by developing and producing a reference panel (RP) for Zika RNA (Zika FDA-RP) suitable for performance assessment of ZIKV NAT-based in vitro diagnostic devices.

PD1 and PDL1 molecules control suppressor activity of regulatory T cells in chronic Chagas cardiomyopathy patients.

Introduction: Chagas disease, caused by the protozoan Trypanosoma cruzi (T. cruzi), is the fourth most important tropical disease, which affects approximately 7 million people worldwide. The mechanisms involved in the development of this disease are not completely well understood.

Production and characterization of Zika virus RNA reference reagents as a response to a public health emergency.

Background: The emergence of Zika virus (ZIKV) in 2015 to 2016 created a global public health crisis and an urgent need for accurate detection assays. Nucleic acid testing (NAT) is the most specific and sensitive technology for early detection of ZIKV. Various NAT protocols have been created, but until recently, assessment of assay performance and comparative studies were hampered by the lack of available standards and reference reagents.

Complete Genome Sequences of Zika Virus Strains Used for the Formulation of CBER/FDA RNA Reference Reagents and Lot Release Panels for Nucleic Acid Technology Testing.

We report here the complete genome sequences of two Zika virus strains (FSS13025 and PRVABC59) used for formulation of CBER/FDA RNA reference reagents and lot release panels for use with nucleic acid technology (NAT) testing.