Influenza type A and B
Influenza type A and B
According to historical evidence, pandemics have occurred in a period of ten to forty years since the 16th century. One of the major pandemics was the Spanish flu, which claimed around 50 million lives (Hampson, & Mackenzie, 2006).Influenza is a pandemic that has a significant impact on both an individual and population mortality and morbidity (Tosh,P.K et al 2010).The Virus which was identified as the cause of flu was first discovered in 1933.This was through the an experimental animal which was a ferret. It was after this incidence that there was an adaptation of the virus to the laboratory mouse and later the dissemination in the allantois on the development of the chicken embryos. This formed the basis on the invention of the very first crude but effective vaccine for influenza (Hampson, & Mackenzie, 2006)
There was also an observation which was made on the viruses agglutinate erythrocytes which led to the first in-vitro analysis of the isolates of influenza. In a short period there was also the discovery of the capacity that the influenza virus had. The virus was able to undergo antigenic change, this was through the practical sense and also through the in-vitro antigenic analyses this was after there was various report on the failure of the vaccine (Hampson, & Mackenzie, 2006).
Influenza is said to be a seasonal epidemic and is quite normal in very cold and temperate climates. However, influenza also occurs in tropical and sub tropical areas infections occur throughout the year. Recent studies have showed that influenza in both the tropics and temperate climates have the same impact. The Spanish flu also spread as far as Latin America during the Columbia exchange this shows that influenza is a highly contagious disease (Hampson, & Mackenzie, 2006).
There are around, three types of influenza virus that is A, B and C .These types of virus are distinguished by their different internal proteins that includes the matrix protein and nucleoprotein. However these viruses are classified under the same genus which is the orthomyxovirus under the family of Orthomyxoviridae.They are also named according to the type of location, the year of isolation and the isolate number of the location. What differentiates influenza C from A and B is that influenza it is linked to the common cold that children have. Infuenza A and B cause severe diseases and outbreaks (Hampson, & Mackenzie, 2006).
Individuals who show symptoms of Influenza ought to be prescribed for medicine within 48 hours. The most vulnerable people include pregnant women, antiviral therapy is highly recommended. There are periodic tables which explain and guide the antiviral therapy procedures. This updates depend on the vulnerability of each strain. There are currently no tests which can distinguish between influenza A and B .Influenza A is seasonal which is also known as; H1N1 or H3N2 a and there are no rapid test at all.
The most complicated forms of influenza is often associated with combined bacterial and viral pneumonia. This can lead into farther complications in the central nervous system though aseptic meningitis, encephalitis among others. It is thus important for anybody who shows of Influenza A and B to get medical attention (Boyd et al).
There are two major surface Glycoprotein antigens in Influenza A and B, this is the haemagglutinin (H or HA) this is a principle antigen, which is important for self attachment and the enzymically active neuraminidase (NA or N)which helps in the release and maturation of the virus.In order for the various to be infectious HA has to go through a stage known as the post-translational, where it is divided into two the HA1 and HA2.This occurs in the presence of a trypsin like protease (Hampson, & Mackenzie,2006).
It is only Influenza type A and B which can cause human epidemic. Due to the several antigenic changes that take place in both in Types of influenza. It is very hard to detect or predict when and where pandemic influenza may occur. There are major antigenic shift which happens in Influenza A. This major change, involves the evolution of a new Influenza type A .In this change there is a new haemagglutinin gene encoding occurs with a different subtype which comes from an avian influenza or through the adaptation of the avian virus. This makes the influenza to be transmitted among humans. Even though the avian influenza does not readily infect humans, it is feared that at any time a new human influenza may appear. This is because over the past three years there have been cases avian influenza that is H5N1 which had a mortality of close to 20%.(Hampson, & Mackenzie,2006).
Anybody who was to prevent get any influenza infection or spread it to others ought to get immunized so long as there are efficient supplies. The center for Disease Control and prevention has focused on worldwide immunization. This includes children who are between the ages of six months and eighteen years and people who are above fifty years of age. Vaccination has been emphasized on children under the age of five years. According to studies, the immunization of school going children does not develop flu-like symptoms. The community also benefits at large, since the virus does not spread easily (Line & Williams, 2009).
The proton channels for both Virus that is A and B have to function in order for the virus particle to replicate. The two types of virus enter the infected cell through endocytosis and the virus particle must be acidic in nature while it is still in the endosome. This is a condition to release a genetic material in the cytoplasm. The proton channel must be acidic (Pinto & Lamb, 2005).
Both the proton channels of influenza type A and B; that is A/M2 and BM2 proteins are homotetrameric. This is the type III integral membrane which contains a small N-terminal ectodoma with the C-terminal cytoplasmic tail and a single transmembrane domain. The trasmembranes acts as a membrane anchor and at the same time as a signal sequence during the process of the synthesis of the protein. The membrane spanning domains are all twenty amino acid long while the N-terminal domain of the influenza type B protein is shorter than that of the type A Influenza protein (Pinto & Lamb, 2005)
When it comes to cross linking both type and type B behave as homotetramers and the sedimentation experiments. The post-translational modification occurs to the type A influenza proteain. However, they are not really important for ion channel to function. The change of the protons must thus, occur within the pore, which is formed by four identical subunits. These four sub-units is part of the transmembrane domain of the proteain.The protons have to function together with the Amino acids which shape the lining of the pore (Pinto & Lamb, 2005).
The mechanism of the proton transportation, in the aqueous is not yet clear. However there are certain observations that have been made. The single channel conductance of the wild-type (wt)3 A/M2ion channel is low and it is only able to transport 105 . Another aspect to take note is the kinetic effect when measured. When the hydrogen is replaced by the deuterium there is a decrease in the conductance by a quantity greater than the ratio of the diffusion coefficient of the isotopes. This means that the movement of the hydronium ions in bulk is not responsible for the transportation of the proton. There are two mechanisms that have been mentioned as a means of transport of the transport. The first mechanism is via the imidazole and the second one which occurs via the water, the short lived proton can allow the shuttling of protons one water molecule to another (Pinto & Lamb, 2005).
The properties of the A/M2 ion (influenza Type A) is very selective for the proton. One may therefore, ask if the selection occurs through the Proton wire or the shuttling of water molecules or where the imidazole of transmembrane transmits the protons. Another fact to consider is how the channel can transport enough protons through the membrane to facilitate the acidification in order for uncoating to occur (Pinto & Lamb, 2005).
It is also important to note that Influenza affects a wide range of species a wide range of species it includes, horses, pigs, birds and man. While influenza B is only associated with man alone. Influenza A is found among birds including the waterfowl which is considered to be the most important host. The virus in influenza A can spread into other species including man. Keeping poultry is therefore considered to be dangerous especially in considering the chances that the virus can spread at any moment (Hovden et al 2007).
When you compare Infuenza, A and B, the virus in type A actually mutate more frequently than type B. This means that Influenza B is actually more stable that is antigenic ally. The slow mutations of Influenza can be attributed to the longer host specific adaptations and co-evolution in man. Influenza A therefore remains the most infectious type which can lead to high mortality rates (Hovden et al 2007).
It is very hard to estimate the number of influenza death related disease .this is because influenza often worsens underlying disease that one may have. These underlying diseases atre thus recorded as the primary course of death. Influenza death is therefore measured or monitored as the number of excess deaths. The most common symptoms of Influenza include headaches, sore throat, cough and Myalgia.”Influenza A H3N2 causes more severe illness while the B viruses intermediate and influenza A H1N1 cases present with the mildest manifestation”(Hovden,p237,2007)
Influenza type A remains the most dangerous and anybody who contracts it has a high probability to be hospitalized. The challenge that people face regarding any type of influenza is how to predict so as to take precautions. Health officials have to be prepared for any outbreak, since it spreads rapidly. What makes it hard to find the best cure of influenza A is due to its ability to replicate faster than Influenza type B.
Reference
Boyd, M.& Clezy, K, et al(2006).” Pandemic influenza: clinical issues”.MJA 185(10)45-47.pdf file
Hampson, A.W & Mackenzie, S.J (2006).”The influenza viruses”.MJA 185(10) pdf file
Hovden, A., Cox R.J., & Haaheim, L.R (2007) “Influenza: the virus and prophylaxis with
inactivated influenza vaccine in “at risk” groups,
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Laine, C and Williams, S (2009).In the clinic Influenza. Pdf file
Pinto, L.H. and Lamb, R.A. (2005).”The M2 Proton Channels of
Influenza A and B Viruses” The Journal Of Biological Chemistry the Journal Of Biological Chemistry (281)14 8997–9000.
Tosh,P.K Jacobson, R.M & Poland, S.A (2010). “Influenza Vaccines: From Surveillance Through Production to Protection” 85(31:257-273 doi:W.4065/mcp.2009.06J5
