abstract potato virus a (pva) is one of the members of genus potyvirus. pva particles are straight to slightly flexuous rods and contain of single stranded rna. in the spring and summer of 2005, sampling accomplished to determine potato virus a from potato fields in northern and razavi khorasan provinces. samples with mosaic, shining and rolling of leaves carried in ice chamber to laboratory fo...

Vector-borne disease transmission is a common dissemination mode used by many pathogens to spread in a host population. Similar to directly transmitted diseases, the within-host interaction of a vector-borne pathogen and a host's immune system influences the pathogen's transmission potential between hosts via vectors. Yet there are few theoretical studies on virulence-transmission trade-offs an...

Infectious pathogens compete and are subject to natural selection at multiple levels. For example, viral strains compete for access to host resources within an infected host and, at the same time, compete for access to susceptible hosts within the host population. Here we propose a novel approach to study the interplay between within- and between-host competition. This approach allows for a sin...

An important component of pathogen evolution at the population level is evolution within hosts. Unless evolution within hosts is very slow compared to the duration of infection, the composition of pathogen genotypes within a host is likely to change during the course of an infection, thus altering the composition of genotypes available for transmission as infection progresses. We develop a nest...

Coronavirus Disease 2019 (COVID-19) is a viral pneumonia emerged in December 2019 in Wuhan, China. Its cause is a new virus from the coronavirus family scientifically named Coronavirus Acute Respiratory Syndrome 2 (SARS-CoV-2). In this review study, articles published in English until March 23, 2020 on new coronavirus infection were reviewed. These articles are obtained by searching in PubMed, ...

The emergence and spread of drug resistant virus variants reflects both within-host and between-host processes. We develop an epidemiological model that can be used to address the spread of resistance at the population level, and a virus dynamics model that can be used to study the dynamics of virus over the time course of an individual’s infection. The dynamics depend in an important way on th...

Viruses encode secreted and cell-surface expressed proteins essential to modulate host immune defenses and establish productive infections. However, to date there has been no systematic study of the extracellular interactome of any human virus. Here we utilize the E3 proteins, diverse and rapidly evolving transmembrane-containing proteins encoded by human adenoviruses, as a model system to surv...

Avian influenza virus reassortants resembling the 1918 human pandemic virus can become transmissible among mammals by acquiring mutations in hemagglutinin (HA) and polymerase. Using the ferret model, we trace the evolutionary pathway by which an avian-like virus evolves the capacity for mammalian replication and airborne transmission. During initial infection, within-host HA diversity increased...