Orthomyxovirus (influenza) - Research Paper Example

Severe, hospitalizations as well as death normally occur when such pandemic occurs. Though, the pandemic is less serious, it causes extensive morbidity when it occurs. Wilson and von Itzstein points out that two attributes of the virus occurring during replication and its evolution are the ones that makes this virus to be successful in its epidemiological (165). These attributes are its ability to circulate freely in the avian water reservoirs, and emerge without being predicted and spread easily in people.

The second attribute is its comparatively quick and unpredictable antigenic transformation that is associated with its evolution the moment they infect the human population. This short paper details some aspects of the influenza virus. Discuss the virus morphology Influence virus is highly pleomorphic; this implies that the envelope of the virus can appear in spherical or filamentous shapes. However, as Jin and Leser (98) explain, the virus’s has a spherical morphology with 50 to 120 nm particles in diameter.

The virus also has a filamentous virions measuring 20 nm in diameter, while the measure 200 to 300 nm long. At the same time, the virus has some 500 distinctive spear-like surface protrusions that emerge on the envelope each protruding about 10 nm. Other types of the virus fro example hemagglutinin esterase (HEP) are thickly dispersed on surface, while others like hemagglutinin (HA) spaced sparsely apart. Various strains of this virus differ in the way they form their filaments. Genome: Ito and Gorman (66) explains that influenza A and B viruses have six to eight fragments of linear single stranded RNA, each of this RNA has one or more protein, but type C has got seven fragments.

Accordingly, the whole length of genome measures about 10000 nucleotides long. However, the length of genome varies extensively among these three groups of viruses, the difference sometimes occurs even in the same type among the various strains (Jin, and Leser, 99). Structure: the influence has an orthomyxovirus comprising of an envelope, layer of protein, polymerase complex and a nucleocapsid, and has a capsid envelop. Replication There have been extensive studies done on replication of influenza viruses mainly on type A strains, thus replication discussed in this section will mainly be linked to this strain.

Ito and Gorman points out that the influenza virus is able to infect a cell by binding it’s HA or HEF protein a cell’s protein receptor (67). The virus then goes through the process of endocytosis, during this process the low PH observed in the late phase of endocytosis results in conformational transformation in the cleavage –activated HA. This leads to a joining (fusion) of the viral and vesicular film. The fusion of the viral and vesicular discharges its contents of the viruses into the cell’s cytoplasm.

Before the fusion takes place, M2 protein from type B viruses produces protons in the within of virion. Transmission The influenza viruses spread its disease via airborne. Accordingly, Hilleman (144) explains that the viruses are deposited in the lower part of the respiratory tract, however, they main part that they infect is the tracheobronchial mucosa. According to Hilleman the virus takes about six hours to replicate and the end of the process it kills the cell (145). The virus then attaches itself to the permissive cell through the hemaggulitinin; this is attached to the cell membrane that has glycolipids that have N-acetylneuraminic acid that has a receptor, where the virus is attached.

After this the virus is then surrounded by the pinocytosis and moves to the endosomes. The endosomes have acid and this makes the virus envelope to merge with the plasma layer of the endosome, the virus then