Human Immunodeficiency Virus - Research Paper Example

? Human Immunodeficiency Virus Introduction Human Immunodeficiency Virus is simply known as HIV. This virus is responsible for Acquired immunodeficiency Syndrome, also referred to as AIDs. HIV retrovirus works by infecting the immune system cells. This infection results to the destruction or impairment of the function of the immune system cells. With the progression of the infection, the patient’s immune system grows weaker. This creates room for vulnerability to infections. AIDS is said to be the highest stage of HIV infection since a person with HIV can take 10-15 years prior to the development of AIDS (World Health Organization, 2012). HIV has not had a cure yet. However, antiretroviral drugs are use to slow down the immune system cells’ destruction. The discussion in this paper focuses on HIV phylogenetic classification and morphology, transmission and replication in the host, virulence and pathogeniciy factors, treatment, epidemiology and public control methods. Phylogenetic classification and morphology According to Fauci and Lane (n.d), HIV virion has a structure that is icosahedra. This virion contains external spikes. The spikes form from two main protein envelopes namely external gp120 and the transmembrane gp 41. On the surface of the infected cell, the viron buds form. These buds comprises of numerous host proteins. The main host proteins are Major Histocompartibility complex (MHC) class I and II antigens, which are incorporate into the host’s lipid bilayer. The strains classified as HIV-1 fall into three distinct groups. These categories are M or Major, Outlier or O and N or New or non M/non O. Group M nearly responsible for global pandemic. Group M forms properly defined clusters on phylogenetic trees. M group subtypes are labeled A-D, F-H, J-K. Other relevant clusters are circulating recombinant forms or CRFs. These recombination events form because of divergent HIV strains within host individuals. Transmission and replication For all persons infected with HIV, there is a variable degree of viruses in genital secretions and blood. This is the case regardless of whether or not the patient has visible symptoms. The transmission of HIV virus occurs when infected blood or secretions are exposed to tissues of the eye, vigina, anal area, and mouth, broken skin such as cuts or needle punctures. The most common transmission modes are sexual contact, needles sharing and infected mothers to newborns during labor pregnancy or breastfeeding. HIV is an RNA virus. The main process associated with HIV RNA is reverse transcription of genomic RNA to DNA. This process is facilitated by enzyme reverse transcriptase. Replication cycle starts when gp 120 protein binds with high affinity. Once gp120 binds to CD4, it undergoes a conformational change that facilitates binding to one of the co-receptor groups. After the envelope, protein binds to CD4 molecule fusion occurs with the host cell membrane through the exposed gp41 molecule. The virus then penetrates plasma membrane of target cell then coiling upon to combine both the virion and immune system cells (Lama and Planelles, 2007). Virulence and pathogenicity factors HIV buds through the cell membrane. The virus is characterized by a capacity to cause disease. One attribute of HIV is replication and transmission, toxic, adherence and attachment and aggressiveness. For the virus, attachment to host immune system cell membrane is essential for virulence. This provides the opportunity to combine with the cells and cause reduction in protecting the body from diseases. In order to persist in the host, HIV virus has to replicate making it contagious. As a result, the virus is infectious. In order to survive, it has to remain aggressive. Aggressiveness comes with the ability to invade, multiply and survive in the tissues of the host. This makes HIV resistance to host defense mechanism. This virus also has high toxicity, which makes it possible to invade as many cells as possible. As a result, host immune system cannot respond as much as possible. Other virulence factors include immunologic reactions and antigenic variations. Virulence pathogenicity factors for HIV are also the virulence factors. The virulence factors have several roles. These roles include facilitating microbial attachment and the ability to grow within the host without detection. Virulence also facilitates the inhibition of phagocytocis and regulation of intracellular survival (Casadevall and Pirofski, 2001). Treatment Thus far, there is no cure for HIV infection. However, there is a therapy available for treating this infection. This therapy is referred to as antiretroviral therapy or ART. In this therapy, the patient is required to take a combination or regimen of three or more anti-HIV medication. These medications have to be taken daily. The workings of ART therapy is prevention of HIV from multiplying and annihilating infection-fighting cells of CD4. The CD4 cells enable the body to fight off life-threatening cancer and infections. The treatment of HIV through ARV medication from destroying the immune system cells through prevention of multiplication and destruction. As a result, the body of HIV patients is provided with the capacity to fight cancer, infections and prevention of AIDS advancement. HIV infection diagnosis involves CD4 count, which should be 500-1200 cells/mm2, or AIDS defining conditions that include opportunistic diseases and cancers that are life threatening (Nih.gov, 2012). Epidemiology and public control methods HIV/AIDS epidemic was first recognized in 1981. However, it has evolved to become the greatest challenge globally with about 34 million persons living with HIV worldwide. Early epidemiologic studies identified the main transmission routes for HIV and developed prevention measures. HIV virus was first discovered in America and Europe. The greatest impact of the epidemic has been sub-Saharan African and most transmission occurred through heterosexuals. Southern Africa population represent about a third of worldwide national global HIV infection. The spread of HIV in the population can better indicated through HIV surveillance in women attending antenatal care. This gives clear indication of HIV trend within the population. In Asia, most countries have seen increasing explosive epidemics in the general population owing to the use of Injecting drug use IDU and sex work are conducive for HIV spread. The widely used methods of control are through ARV therapy, public awareness and education through seminars, healthy eating and practice of safe sex. Other methods are improvement of health practices to avoid transmission to avoid shared equipment like needles (Morison, 2001). Conclusion As discussed in this paper, HIV works through infecting the immune system cells thereby infecting their function in the body. The infected cells are called CD4 cells making them are below 500cells/mm2. In a normal human being, the CD4 count is about 500-1200 cells/mm2. The HIV virus falls in various categories namely M, O and N. Apparently, the transmission of HIV virus occurs through infected blood or secretions, which come into contact with body tissues in the eye, vigina, mouth, and broken tissues. The virulence and pathogenic factors that allow the spread of HIV are toxicity, replication and transmission adherence and attachment and aggressiveness. The treatment for this disease is through antiretroviral therapy, which slows down the replication rate of the virus making the body capable of fighting against diseases. In the world, sub Saharan Africa leads in HIV patients References Casadevall, A. and Pirofski, L. (2001). Host-pathogen interactions: the attributes of virulence. The journal of infectious diseases. 184, 337-344. Fauci, A. S. and Lane, H. C. (n.d). HIV neurology. Retrieved from http://www.mhprofessional.com/downloads/products/0071741038/hauser_neurology_c37_493-506.pdf Lama, J. and Planelles, J. (2007). Host factors influencing susceptibility to HIV infection and AIDS progression. Retrovirology journal. 4(52). Morison, l. (2001). The global epidemiology of HIV/AIDS. Oxford Journals. 58(1), 7-18. Nih.gov, (2012). HIV and its treatment. Retrieved from http://aidsinfo.nih.gov/contentfiles/HIVandItsTreatment_cbrochure_en.pdf World Health Organization. (2012). HIV/ AIDS. Retrieved from http://www.who.int/topics/hiv_aids/en/ Read More