Evolution of an epidemic 2007 lecture twoaids and the hiv life cycle bruce d. Once hiv is in the body, it targets and infects a certain type of white blood cell called a cd4 cell. Hiv specifically targets cd4 cells, the bodys principal defenders against infection, using them to make copies of themselves. Hiv replication or hiv life cycle refers to how the hiv virus reproduces itself using the genetic makeup of the host cell human cell. Knowing how hiv infects the body helps people understand prevention and treatment options, and why its important to start antiretroviral treatment as soon as possible after testing positive. Aidslifecycle packing list items notated with an asterisk are mandatory the following lists outline mandatory and suggested items. A virus is a small infectious organism that can only replicate inside living cells of other organisms. The life cycle of hiv and hiv disease december 2011possible benefits of starting at 350500 an increasing number of observational results and early clinical studies suggest lower rates of aids and other healthrelated. Evolution of an epidemic 2007 lecture two aids and. This study warrants further investigation in other populations to confirm the association. The centers for disease control and prevention cdc report that the virus attacks the immune system, eventually leaving the body prone to. This infographic illustrates the hiv replication cycle, which begins when hiv fuses with the surface of the host cell. Hiv is an acronym for human immunodeficiency virus, the virus that causes aids, or acquired immune deficiency syndrome.
This process, which is carried out in seven steps or stages, is called the hiv life cycle. Aids is the leading cause of infectious disease mortality, surpassing tuberculosis and malaria. From the howard hughes medical institute, the 2007 holiday lectures on science. Structure, life cycle, and pathogenecity jonathan richard hughes university of tennessee knoxville. There are seven 7 stages or steps of the hiv virus replication cycle. Participants riders, roadies, and staff raise money throughout the year.
Click on the links below to open the document in your browser and then print it. This animation describes the structure of the hiv virus, receptormediated attachment to. How hiv infects the body and the lifecycle of hiv avert. To understand each stage in the hiv life cycle, it helps to first imagine what hiv looks like. View hiv life cycle ppts online, safely and virusfree. Definitionthe hiv life cycle defines the steps and changes the virus undergoes from its first contact with a target cell to the production of new infectious viral particles that can initiate the. Aids occurs when a persons immune system is so damaged it cannot fight diseases and certain cancers. Alc participants are allowed to brin,g one gear bag weighing. In order to understand how hiv and aids are connected we need to take a closer look at how the immune system works. The demographic impact of hiv and aids across the family. Aids is a condition in humans in which progressive failure of the immune system allows lifethreatening opportunistic infections and cancers to. The series of steps that hiv follows to multiply in the body.
During the first stage the transmitted hiv replicates rapidly, and some persons may experience an acute flulike illness that usually persists for one to two weeks. The event raises awareness about the ongoing hivaids epidemic and funds services such as hiv testing, prevention, care, and much more. Antiretroviral therapy art is the use of hiv medicines to treat hiv. A detailed understanding of the hiv life cycle, from cell attachment and entry to translation and assembly of new viruses, can help researchers identify targets for drug therapy.
Its a lifechanging ride not a race through some of californias most beautiful countryside. The hivaids prevention research synthesis prs project identifies evidencebased hiv behavioral interventions ebis listed in the compendium of evidencebased hiv behavioral interventions to help hiv prevention planners and providers in the united states choose the interventions most appropriate for their communities. Although there are currently no hiv drugs that block this stage, several drugs are in. Timing of the components of the hiv life cycle in productively. With a weakened immune system, patients are vulnerable to infections that are normally easy to fend off. Hiv uses the machinery of the cd4 cells to multiply and spread throughout the body. The human immunodeficiency virus hiv is a lent virus that causes hiv.
A collection of patient education fact sheets on hivaids treatments and conditions, in english and spanish. Hiv is spread through contact with the blood, semen, preseminal fluid, rectal fluids, vaginal fluids, or breast milk of a person with hiv. The outside of hiv has an outer shell envelope of proteins, fats and sugars. Also, an extensive listing of aidsrelated internet web site addresses. The right treatment can prevent hiv from developing into aids and extend life expectancy. Acquired immune deficiency syndrome, better known by its acronym aids, results from, and is the final stage of infection with the bloodborne human immunodeficiency virus hiv. Structure, life cycle, and pathogenecity tennessee research. Basic concepts replication cycle producesfunctional rnas and proteinsgenomic rna or dna and structural proteins 100s1,000s new particles produced by each cyclereferred to as burst sizemany are defectiveend of eclipse phase replication may be cytolytic or noncytolytic steps in viral replication. After fusion, the virus releases rna, its genetic material, into the. Effectively, the virus has now hijacked the host cells own replication system. Fact sheets about hivaids treatment information, the prevention of mothertochild transmission, and hiv treatment side effects.
Click above to view or download this fact sheet as a pdf slide presentation. A recent study of the effect of the gene deletion on hiv1aids suggested that the null genotype was associated with greater risk of hiv acquisition, higher viral load, and shorter aidsfree survival. The shell of the capsid disintegrates and the hiv protein called reverse transcriptase transcribes the viral rna into dna. Hiv virus has a protein coat and a genetic material which is. Each of these steps is used as a target to make hiv drugs to inhibit the progress of hiv.
This turns the cell into a sort of hiv factory so it can make many more copies of itself. The main cellular target of hiv is a special class of white blood cells critical to the immune system known as helper t lymphocytes, or helper t cells. Once hiv binds to an immune cell, it hides its dna inside the cells dna. Hiv stands for human immunodeficiency virus, a pathogen that works by attacking the human immune system. Each step in the hiv 1 life cycle is a potential target for antiviral intervention 165. Multiple choice questions on aids mcq biology learning. Natural killer cells or nk cells attack tumour cells and virusinfected cells. Pathophysiology of the human immunodeficiency virus bipai. Today, a person with hiv who adheres to antiretroviral therapy can expect to live a nearnormal life span. We estimate the time required for hiv to complete separate stages of its infection cycle in productively infected cd4. Different antihiv drugs target different steps in the process of hiv. The infective agent, human immunodeficiency virus hiv, has already infected more than 60 million people around the world. Learn vocabulary, terms, and more with flashcards, games, and other study tools. Human immunodeficiency virus hiv is a lentivirus a member of the retrovirus family that causes acquired immunodeficiency syndrome aids.
Hiv then takes over or hijacks these cells and turns them into factories that produce thousands of copies of the virus. Follow each stage in the hiv life cycle, as hiv attacks a cd4 cell and uses the machinery of the cell to multiply. Introduction aids is the deadliest epidemic of our time. Family and household lifecycle conceptual framework. As a result, when the cellular dna is transcribed, so is the viral dna to form an rna. Find, read and cite all the research you need on researchgate. Antiretroviral therapy or art is the use of hiv medicines to treat hiv infection. In the united states, hiv is spread mainly by having anal or vaginal sex or sharing injection drug equipment. Unlike some other viruses, the human body cant get rid of hiv completely, even with treatment. Start studying describe the life cycle of hiv, the course of infection, how aids is defined and developed, how aids is treated. If youd like to find out more about the hiv lifecycle, take a look at our science of hiv and aids section. It is the virus that can lead to acquired immunodeficiency syndrome or aids if not treated. After fusion, the virus releases rna, its genetic material, into the host cell. Hiv medicines protect the immune system by blocking hiv at different stages of the hiv life cycle.
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