objective(s) the aim of this study was to characterize the hepatitis b virus surface protein genotypes and sequence variations among hepatitis b virus surface antigen (hbsag) positive chronic patients in hormozgan province, south of iran. materials and methods a total of 8 patients enrolled in this study. the surface gene was amplified and directly sequenced. genotypes and nucleotide/amino acid...

A virus infecting a host faces a heterogeneous and a spatially structured environment. Using a mathematical model that incorporates two types of target cells and spatial structuring, we investigate conditions for viral within-host diversification. We show that branching occurs for a wide range of parameters but that it always requires some spatial structure. Applying our model to the case of HI...

The non-structural protein 1 (NS1) of influenza A virus (IAV), coded by its third most diverse gene, interacts with multiple molecules within infected cells. NS1 is involved in host immune response regulation and is a potential contributor to the virus host range. Early phylogenetic analyses using 50 sequences led to the classification of NS1 gene variants into groups (alleles) A and B. We rean...

Through accumulation of genetic mutations in the neuraminidase gene, the influenza virus can become resistant to antiviral drugs such as oseltamivir. Quantifying the fitness of emergent drug-resistant influenza viruses, relative to contemporary circulating viruses, provides valuable information to complement existing efforts in the surveillance of drug-resistance. We have previously developed a...

Most emerging infectious diseases in humans originate from animal reservoirs; to contain and eradicate these diseases we need to understand how and why some pathogens become capable of crossing host species barriers. Influenza virus illustrates the interaction of factors that limit the transmission and subsequent establishment of an infection in a novel host species. Influenza species barriers ...

An SI epidemic model for a host with two viral infections circulating within the population is developed, analyzed, and numerically simulated. The model is a system of four differential equations which includes a state for susceptible individuals, two states for individuals infected with a single virus, one which is vertically transmitted and the other which is horizontally transmitted, and a f...

objective: monitoring of influenza virus shedding and optimization of multiplicities of infection (moi) is important in the investigation of a virus one step growth cycle and for obtaining a high yield of virus in vaccine development and conventional basic diagnostic methods. however, eluted infectious viruses may still be present immediately after virus inoculation and when cells are washed fo...