Despite significant advancement in vaccine and virus research, influenza continues to be a major public health concern. Each year in the United States of America, influenza viruses are responsible for seasonal epidemics resulting in over 200,000 hospitalizations and 30,000–50,000 deaths. Accurate and early diagnosis of influenza viral infections are critical for rapid initiation of antiviral therapy to reduce influenza related morbidity and mortality both during seasonal epidemics and pandemics. Several different approaches are currently available for diagnosis of influenza infections in humans. These include viral isolation in cell culture, immunofluorescence assays, nucleic acid amplification tests, immunochromatography-based rapid diagnostic tests, etc. Newer diagnostic approaches are being developed to overcome the limitations associated with some of the conventional detection methods. This review discusses diagnostic approaches currently available for detection of influenza viruses in humans.

We evaluated the feasibility of using nanoparticle (NP)-based assays for improving detection sensitivity of human immunodeficiency virus type 1 (HIV-

We developed a europium nanoparticle-based immunoassay (ENIA) for the sensitive detection of anthrax protective antigen (PA). The ENIA exhibited a linear dose-dependent pattern within the detection range of 0.01 to 100 ng/ml and was approximately 100-fold more sensitive than enzyme-linked immunosorbent assay (ELISA). False-positive results were not observed with serum samples from healthy adults, mouse plasma without PA, or plasma samples collected from mice injected with anthrax lethal factor or edema factor alone. For the detection of plasma samples spiked with PA, the detection sensitivities for ENIA and ELISA were 100% (11/11 samples) and 36.4% (4/11 samples), respectively. The assay exhibited a linear but qualitative correlation between the PA injected and the PA detected in murine blood ( r = 0.97731; P < 0.0001). Anthrax PA was also detected in the circulation of mice infected with spores from a toxigenic Sterne-like strain of Bacillus anthracis , but only in the later stages of infection. These results indicate that the universal labeling technology based on europium nanoparticles and its application may provide a rapid and sensitive testing platform for clinical diagnosis and laboratory research.

Accurate laboratory diagnosis of HIV is essential to reduce the risk of HIV-positive individuals transmitting HIV-1 infection. The goal of this study was to identify and assess a panel of host derived plasma miRNAs that could to serve as a prognostic and predictive biomarker to detect early/acute HIV-1 infection. A total of 372 microRNAs were analyzed in nine plasma samples from HIV-1 infected individuals in the early phase of infection and three healthy controls using the miRNA PCR-array. Seventeen microRNAs were selected and validated in 80 plasma samples from HIV-1 infected individuals in the early phase of infection (20 each of eclipse stage, RNA+ stage, Ag + stage, and Ag + Ab+ stage of HIV-1 patients) and 25 healthy controls. Using the validation study results a plasma miRNA panel was developed and evaluated to detect early/acute HIV-1 infection in 49 blinded samples. We identified an miRNA panel (PeHIV-1) containing four differentially expressed miRNAs (miR-16-5p, miR-20b-5p, miR-195-5p, and miR-223-3p) that could distinguish early HIV-1 infection from healthy controls with high AUC (1·000[1·00-1·00]), sensitivity (100%), and specificity (100%).We also found that miR-223-3p demonstrates 100% sensitivity and specificity (AUC 1·00[1·00-1·00]) and could distinguish eclipse stage of HIV-1 infection from healthy controls. To detect eclipse stage of HIV-1 infection we also developed a four-miRNA based (miR-16-5p, miR-206, let-7 g-3p, and miR-181c-3p) panel (PE) with AUC 0·999 (0·995-1·000), 100% sensitivity and 95·8% specificity. The miRNA panel, PeHIV-1 is a potential biomarker for detecting early/acute stage of HIV-1infection and could help initiate early antiretroviral treatment, thus preventing the spread of HIV-1 infection.

Nanotechnology-based techniques are being widely evaluated in medical testing and could provide a new generation of diagnostic assays due to their high degrees of sensitivity, high specificity, multiplexing capabilities, and ability to operate without enzymes. In this article, we have modified a nanoparticle-based biobarcode amplification (BCA) assay for early and sensitive detection of HIV-1 capsid (p24) antigen by using antip24 antibody-coated microplates to capture viral antigen (p24) and streptavidin-coated nanoparticle-based biobarcode DNAs for signal amplification, followed by detection using a chip-based scanometric method. The modified BCA assay exhibited a linear dose-dependent pattern within the detection range of 0.1 to 500 pg/ml and was approximately 150-fold more sensitive than conventional enzyme-linked immunosorbent assay (ELISA). No false positive results were observed in 30 HIV-1-negative samples, while all 45 HIV-1 RNA positive samples were found HIV-1 p24 antigen positive by the BCA assay. In addition, the BCA assay detected HIV-1 infection 3 days earlier than ELISA in seroconversion samples. Preliminary evaluation based on testing a small number of samples indicates that the HIV-1 p24 antigen BCA may provide a new tool for sensitive and early detection of HIV-1 p24 antigen in settings where HIV-1 RNA testing is currently not routinely performed.

The HIV epidemic in Cameroon is characterized by a high degree of viral genetic diversity with circulating recombinant forms (CRFs) being predominant. The goal of our study was to determine recent trends in virus evolution and emergence of drug resistance in blood donors and HIV positive patients.