Clinical Microbiology: Open Access

Viral Pathogenesis and the Factors Affecting Pathogenesis

Shan Derek^* Department of Microbiology and Clinical Microbiology, Giresun University Medical School, Giresun, Turkey
^*Correspondence: Shan Derek, Department of Microbiology and Clinical Microbiology, Giresun University Medical School, Giresun, Turkey, Email:

Received: 06-Dec-2021 Published: 27-Dec-2021

Descripition

Viral pathogenesis is the study of the process and mechanisms by which viruses cause disease in their target hosts, sometimes at the cellular or molecular level. Pathogenesis refers to the process by which an initial infection leads to illness. Viral sickness refers to the impact of viral replication on the host, as well as the host's subsequent immune response to the virus. Virulence factors allow viruses to establish an infection, spread throughout the body, and multiply. Microbial pathogens such as bacteria, viruses, fungi, and protozoa use virulence factors, which are cellular structures, chemicals, and regulatory mechanisms that allow them to feed on the host.

Pathogenesis is influenced by a number of factors. One of these criteria is the virulence of the virus that is invading. In order to produce disease, the virus must overcome various inhibitory effects in the host. Inhibitory effects include things like distance, physical barriers, and host defenses. Because the inhibitory effects are determined by genetics, they may vary from person to person. There are a few main overarching factors affecting viral diseases namely, virus tropism, virus factors, host factors.

Virus tropism

Virus tropism refers to a virus's preference for specific cell types within an organ for replication. The capacity of viral surface proteins to fuse or attach to surface receptors of specific target cells to establish infection determines tropism in most circumstances. As a result, viral surface protein binding specificity affects tropism as well as the death of specific cell types, and is thus a fundamental factor of virus pathogenicity. In order to initiate infection, co-receptors are sometimes required in addition to the binding of biological receptors on host cells to viral proteins. Other intracellular factors, such as tissue-specific transcription factors, can influence viral tropism in addition to cellular receptors. Tropism is also influenced by the virus's ability to access host tissues and organs. Physical obstacles, such as bile, digestive enzymes, and acidic environments, affect accessibility. Enteroviruses, for example, multiply in the colon because they can tolerate bile, digestive enzymes, and acidic environments.

Virus factors

The degree of viral pathogenicity will be determined by viral genetics encoding viral components. This is quantified as virulence, which can be used to compare the quantitative degree of pathology amongst viruses. In other words, different virus strains with different virus components can have varying degrees of virulence, which can be used to investigate the pathogenesis of viral variants with varying degrees of virulence. Virus genetics, which is the virulence determinant of structural or nonstructural proteins and non-coding sequences, has a big influence on virus components. A virus must encode unique virus components in its genome to overcome physical barriers and adjust host regulation of virus replication in order to successfully infect and cause disease in the host.

Viruses have also created a number of immunomodulation techniques to manipulate the immune response of their hosts. Virus-encoded decoy receptors that target cytokines and chemokines produced during the host immune response, as well as homologues of host cytokines, are common. As a result, viruses that can manipulate the host cell response to infection as a means of immune evasion are more dangerous.

Host factors

Host factors play an important role in viral pathogenesis. Several viral infections have shown a wide range of symptoms, from asymptomatic to symptomatic or even severe infection, based simply on host variables. Genetic variables, age, and immunocompetence, in particular, play a key role in determining whether the viral infection can be regulated by the host.