Influenza Research Paper
This remarkable feature results from the capability of the external layer of the influenza virus to subjected to frequent antigenic changes. The influenza virus structure (Fig. 1) is characteristic for their external layer of approximately 500 spike-like projects. The spikes are glycoproteins, neuraminidase (NA) and hemagglutinin (HA) which actually distinguish the influenza virus into three main types: the influenza A, the influenza B and the influenza C. These types have been identified worldwide with the A and B types causing disease in humans.
Depending on the type of hemagglutinin and neuraminidase glycoproteins, the influenza A virus can be subdivided into different serotypes with the subtypes H1N1 and H3N2 being the most commonly infect humans. The functional role of the HA molecule is that attaches to cell receptors and initiates the process of virus entry into cells. On the other hand the primary role of the NA glycoproteins is to remove sialic acid from glycoproteins. Sialic acids are cell receptors which are used by many viruses (such as influenza, parainfluenza, mumps, corona, noro, rota, and DNA tumor viruses) as receptors for cell entry. Inhibiting NA with oseltamivir suppresses both viral infection, and viral release from cultured human airway epithelial …show more content…
A reservoir that supports the growth of Legionella in water is amoebas and both can survive in a biofilm formation (Fig. 3) (22). When biofilm is disrupted then people potentially became sick after inhalation of bacteria-contaminated water droplets in their air environment. The virulence of LP depends upon the size of the particles in which the cells are contained (Table 1), the duration of exposure in a contaminated water environment and their site of deposition in the respiratory tract. Interaction of air and water is important in the spreading of the disease. Therefore airborne transmission of Legionellosis with the classical definition does not obviously exist, although a recent report from Portugal implies a probable person-to-person transmission of Legionellosis (23 ).
Similar to Legionellosis infection several other infectious diseases (psittacosis, aspergillosis, histoplasmosis, coccidioidomycosis) are acquired from environmental sources rather than from an infected person.
Transmission of Legionella is also possible through municipal water supply. This is facilitated by a relatively high water temperature (Legionella will multiply at 20-40◦C) and by modern plumbing systems where the increased turbulence causes generation of aerosols and droplets. Aerosols and droplets are also common in spa pools, mist machines and humidifiers. They generated water droplets of appropriate size