One Of The Major Human Health Threats Biology Essay
AIDS ( Acquired Immune Deficiency Syndrome ) is one of the major human wellness menace which is caused by HIV ( human Immunodeficiency Virus ) . Worlds are the lone host for HIV. There are two familial types of HIV which are known as HIV-1 and HIV-2. Harmonizing to societal worker professor Poindexter, the bulk of infection is caused by HIV-1 in universe broad, whereas HIV-2 is most common in West Africa. HIV-1 is one of the deadliest viruses that are accounted for taking 1000000s of lives universe broad.
However the highest impact is recorded in developing states of Sub-Saharan Africa. I was born and raised in Ethiopia, which is located in the Easter portion of Africa. In Ethiopia HIV is one of the major public concerns among the population. Several surveies and researches have done to understand the virus and to happen out intervention and bar methods. Based on the consequence of several scientific research and surveies, this paper chiefly focuses on HIV-1 categorization, construction, life rhythm, disease, intervention, and public wellness impact.Based on Baltimore categorization method HIV ( Human Immunodeficiency Virus ) is classified under category VI in a member of Genus lentivirus. Viruss classified in this genus have features of long period of incubation and long continuance unwellness ( Card et al. , 41 ) .
HIV is a retrovirus with typical structural and fictional features. HIV is an enveloped virus which has a diameter of 1/10000 of a millimetre ( Card et al. , 26 ) .The envelope is composed of lipid, and it is acquired from the host cell of plasma membrane. The viral cistrons are surrounded by an icosahedral or conelike mirid bug which is composed viral proteins. Social scientist, Dr, Card explained that the slug shaped capsid environments two indistinguishable individual stranded and positive sense RNA genome per virion.
The genome RNA is converted into dual stranded Deoxyribonucleic acid utilizing rearward RNA polymerase. This genome of RNA encodes for three structural cistrons ( joke, pol, and env ) and six regulative proteins ( cheapness, rpm, vif, vpr, and vpu ) severally. The information contained in structural cistrons are used to do structural proteins for new viruses. For illustration, structural cistron of env encodes envelope protein called gp160, which is broken down by a viral enzyme to organize general practitioner 120 and gp 41.
These two glycoprotein gp120 and gp41 play a major function in the viral reproduction rhythm during fond regard and go outing the cell ( Card et al. , 28 ) . Dr. Card explained that membrane associated matrix and mirid bug protein, and besides enzymes such as rearward RNA polymerase, Rnase H and integrase are encoded by cistron joke. The six regulative cistrons encodes for protein that control the information needed to infect a mark cell. For case, nef cistron encodes protein that is necessary for the virus to retroflex, and the vpu encodes protein that promotes the new virus to bud off from the infected cell.The chief mark of HIV is the septic individual immune system.
The immune system map based on the white blood cell known as lymph cells to support the organic structure against foreign substance ( poindexter, 8 ) . The two types of lymph cells called B and T lymphocytes circulate in the blood and lymphatic fluids. When the foreign atoms enter into the organic structure, the B lymph cell generates antibodies to adhere with the foreign atoms. This binding allows other cells of the immune system to assail the foreign atom. Based on professor Poindexter, the T-cells are responsible for cell- mediated unsusceptibility which plays function in placing the infected organic structure and alarm the immune system for onslaught ( Poindexter, 8 ) . HIV uses a CD4 or besides knows as a assistant cell as a receptor. The assistant cells are subtype of T-cell that stimulates the immune response when the antigen binds to its surface called CD4 cells.A member of retroviruses such as HIV has a alone reproduction rhythm and map.
The first measure is the fond regard in which the virus protein gp120 binds to the CD4+ receptors. A societal worker, Dr. Card explained that during attachment the co-receptors CCR5 and CXC4 provide conformational alteration in gp120 by advancing farther binding with the CD4+ cells. This verification allows viral gp41 to blossom and infix its hydrophobic end point into the host cell membrane. When the gp41 folds back into the cell, it allows the virus to draw down to the cell and spread its membrane. Once the virus enters into the cell, it uncoated the mirid bug and release two RNA strands and three really of import enzymes known as contrary RNA polymerase, integrease, and peptidase ( Card et al. , 28 ) .
There are two of import sphere found in rearward RNA polymerase. These are ribonucleinase H active site and the polymerase active site. The individual isolated RNA is transcribed to RNA-DNA dual spiral in the polymerase active site. Then the ribonucleinase H-active site finishes the staying DNA strand by organizing dual stranded Deoxyribonucleic acid spiral ( Card et al. , 28 ) . After the written text measure the virus uses integrase which cleaves dineucleotide from each 3 ‘ terminal of the DNA and creates two gluey terminals. Based on Dr, Card description, this viral dsDNA transportation into the karyon and incorporate it with the host genome. This is the most of import measure for the virus because ; it can retroflex itself utilizing the host DNA as a mill.
The host cell transcribes the viral DNA into messenger RNA which travels into the cytol where edifice blocks of viral protein are synthesized. The following important measure is done by peptidase which cleaves longer protein into smaller nucleus protein. At this point the viral RNA strands and reproduction enzymes assemble around the nucleus protein organizing the mirid bug ( Card et al. , 29 ) . This immature virus is non infective, nevertheless when the virus leaves the cell it gets its envelope from the host and viral proteins and go mature and ready to infect other cells. The virus infection advancement in three different phases which are primary or acute infection, symptomless and diagnostic disease patterned advance ( AIDS ) .Acute infection is the first phase of HIV disease. When the virus first enters the organic structure it infects the CD4 cells and replicate in the lymph nodes with in two or three yearss.
Survey shows that 87 % of septic individuals develop flu-like symptoms within two to four hebdomads ( Poindexter, 9 ) . The symptoms occur in this phase are a high febrility, joint and musculus hurting, icinesss, concerns, dark workout suits, roseolas, and conceited secretory organs ( Poindexter, 10 ) . During this phase, the septic individual is extremely infective because there is a high sum of HIV nowadays in the venereal fluids ( Card et al. , 31 ) However, bulk of septic people do non recognize they are infected with HIV. The ground behind for this is the immune system does non bring forth antibodies to contend the virus every bit shortly as the virus enters the organic structure.
Harmonizing to Poindexter survey, the immune system produces antibodies after 6-12 hebdomads of infection. Therefore if a individual takes HIV trial before the antibodies are produced by the immune system, it is most likely possible to acquire a false negative consequence.The following phase the HIV+ individual is traveling to come in is symptomless period. At this phase the septic individual sheds the virus, and there are no marks or symptoms of HIV infection.
For this ground, this period is besides called clinical latency ( Card et al. , 31 ) . The period of clip the individual shows symptoms varies between single based on their overall wellness and immune system working. Based on Card survey, the mean clip of latency is 7 to 8 old ages. However, now demoing symptoms during this period does non intend the individual is healthy. During this phase the virus is actively multiplying, infecting and killing the immune system cells easy ( Card et al. , 31 ) . During this period the figure of CD4+ cells starts to worsen over clip.
Due to the diminishing figure of CD4+ cells, the septic individual may demo some mild symptoms such as conceited lymph nodes, weariness, weight loss, frequent febrility and workout suits and besides frequent or relentless barm infections ( Card et al. , 45 )The last phase called diagnostic period, HIV+ people experience more sever symptoms which include timeserving infections and diseases ( Poindexter, 10 ) . At this phase the virus multiplies quickly and big measures of the virus enter the blood stream. Due to this ground there are no adequate healthy CD4+ cells to support the organic structure against the virus. Therefore HIV+ people start to develop timeserving infections and go an AIDS patient. Opportunist infections are diseases that are caused by bacteriums, funguses or viruses. Harmonizing to Poindexter account, timeserving infections do non do diseases to people with healthy immune system, nevertheless it can do sever diseases to HIV+ people with a CD4+ cell count of less than 200 ( Poindexter, 10 ) .
Peoples who become an AIDS patient develop symptoms includes Pneumonia, Kaposiaa‚¬a„?s Sacroma ( a sort of malignant neoplastic disease ) , HIV blowing syndrome ( utmost weight loss ) , HIV encephalopathy ( AIDS dementedness ) and yeast infections of the windpipe, bronchial tube and gorge.Today there is no equal intervention exists for obliteration of the AIDS virus from those already infected with HIV. However, several antiretroviral drugs are available to maintain the sum of HIV in the organic structure at a low degree. It is really ambitious to do effectual drugs that cure AIDS disease. This is because viruses belong to retroviruses mutates rapidly ; therefore there is a high opportunity to go immune to the drug. For this ground, HAART ( Highly Active Antiretroviral Therapy ) is recommended by Doctors which require taking a combination of three or more antiretroviral drug ( Card et al. , 9 ) .
The drugs are chiefly mark to suppress viral enzyme activity. Harmonizing to research worker Poindexter, The most frequent prescribed interventions are grouped into three categories which are nucleoside/nucleotide rearward RNA polymerase inhibitors ( NRTIs ) , non-nucleoside contrary RNA polymerase inhibitors ( NNRTIs ) , and peptidase inhibitors ( PIs ) ( Poindexter, 18 ) . For illustration, NRTIs intervention based drugs are specifically produce to barricade the enzyme contrary RNA polymerase from transcribing the individual RNA stranded genome of the virus into DNA strand. Therefore the following measure of viral reproduction can be prevented.
Some illustrations of trade name names of NRTIs include Retrovir, Epivir and Emtriva. The usage of antiretroviral drugs has dramatically reduced the HIV transmittal from female parent to pamper vertically. Harmonizing to Poindexter, there is a 20 % to 30 % opportunity of conveying HIV from female parent to pamper without intervention. However, if pregnant adult females take antiretroviral drugs during gestation, performs a cesarian subdivisions during bringing and supply medicine to the new Born, there will be less than 2 % perpendicular HIV transmittal ( Poindexter, 18 ) . There are several side effects come along with this drug such as abdominal hurting, sickness and diarrhoea.
Professor Poindexter besides describes the other anti-HIV intervention called Protease inhibitors ( PIs ) target the suppression of viral enzyme called peptidase. Protease enzyme plants at a ulterior phase of viral rhythm where it cleaves the viral protein to go mature adequate to infect other cells. Therefore suppressing this enzyme will do the virus not infective. Some trade name names of PIs include Aptivus, Novir and Viracept. This drug besides causes side effects such as diarrhoea, sickness, digestive piece of land upset, and besides increases triglyceride degrees which lead to diabetes ( Poindexter, 19 )Despite the handiness of drugs, there is an increasing population of HIV septic individuals in Ethiopia. The ground behind this is that the limited entree to the drugs due to its cost.
In July 2003, the Ethiopia authorities introduces fee-based antiretroviral therapy. Harmonizing to World Health fact sheet, persons infected with HIV-1 are required to pay for their ain HIV medicine at a cost of US $ 28.00 which is an equal sum of $ 280.
00birr ( Ethiopian money ) . However, non merely the cost of the drug is the ground for an increasing population of HIV septic individuals. The deficiency of instruction about the consequence of the drug is besides plays a major function in HIV epidemic. The complex dosing agendas, drug interactions and toxicities along with drug conformity for taking life long is still a large challenge for taking the medicines decently. There is no vaccinum developed for HIV virus still now. The chief scheme bar of HIV/AIDS is utilizing standard safeguards including blood showing, non sharing crisp objects, standard safeguard in utilizing needle, safe sex and bar of female parent to child transmittal.AIDS is now recognized as the taking cause of grownup morbidity and mortality in Ethiopia. Harmonizing to World Health Organization study, there are several factors that speed up the impact of HIV epidemic such as poorness, nutrient deficits, and socio-economic position.
Harmonizing to the informations made by UNAIDS and the World Health Organization ( WHO ) , from the entire population of Ethiopia which is 88 million, it is estimated that 980,000 people are populating with HIV/AIDS and 67,000 people died from the virus. Heterosexual contact is one of the major transmittals of HIV among immature grownups. Luck of cognition about understanding the different mob of HIV transmittal and forestalling methods promote HIV epidemics in Ethiopia. Based on the information analysis, the prevalence of HIV/AIDS is higher among adult females ( 2.6 % ) compares to work forces ( 1.
8 % ) . The information besides indicates, adult females who are sex workers are the most at hazard by covering 25.3 % of the entire population populating with HIV/AIDS. The chief grounds that increase the exposure of HIV among adult females poorness, fortune of entree to instruction and besides physical and sexual maltreatments by spouses. Harmonizing to the fact sheet of World Health Organization, 29 % of people who live with HIV/AIDS received antiretroviral drug therapy.
Among this people, merely 8 % HIV+ pregnant adult females received antiretroviral drug. This indicates there is a high hazard of acquiring HIV+ new born babes through perpendicular transmittal. Based on UNAIDS study, in 2009 about 72,945 kids under the age of 15 were populating with HIV. It is really common to see kids who lost their parents with AIDS live under utmost emotional and physical emphasis. Harmonizing to the UNAID study, among the entire population 855,720 kids under the age of 18 had lost at least one parent with AIDS. These kids are forced to populate on the street due to favoritism by the society.
HIV has greatly affects and costs so many lives in developing states of sub-Saharan Africa. It has been the most ambitious undertaking for medical professional to happen a remedy for HIV/AIDS due to its rapid mutating behaviour. HIV is really alone comparisons to other retroviral viruses. The slug shaped capisd environments two indistinguishable individual stranded RNA and enzymes such as RNA polymerase, peptidase, and integrase which are indispensable for the reproduction of virus.
Without these three indispensable enzymes the stairss of viral reproduction will be unsuccessful. Therefore most antiretroviral drugs are developed to suppress the viral enzymatic activities such as NRTaa‚¬a„?s and PIs. However these retroviral drugs merely work in minimising the degree of HIV in the organic structure. A complete remedy of HIV is non ye discovered. The HIV infection has three phases which are acute, symptomless and diagnostic or latent. In these three phases the virus progresses throughout clip. In all three phases the septic individual is contagious to other people.
Despite the find of antiretroviral, HIV is still critical public wellness concern in Ethiopia. Harmonizing to USAIDS study adult females are the most at hazard of acquiring HIV compares to work forces. Based on the USAIDS information, kids are besides the chief victim of HIV infection in Ethiopia due to perpendicular transmittal path. The deficiency of cognition about bar and intervention is the chief factor for the epidemic of HIV in Ethiopia.
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