Jan 11, 2020 hepatitis a virus structure, genome, epidemiology, transmission, replication, pathogenesis, clinical manifestation, lab diagnosis, treatment, vaccination, prevention and control. Human immunodeficiency virus type 2 hiv2 seroprevalence and characterization of a distinct hiv2 genetic subtype from the natural range of simian immunodeficiency virusinfected sooty mangabeys. Hiv2 is restricted to west africa, although there are imported cases in the uk. Advances in the treatment of human immunodeficiency virus hiv infection have resulted in a fundamental shift in its epidemiology, from a highly lethal infectious disease to a potentially chronic and manageable condition. Hiv aids baylor college of medicine houston, texas. Hiv the human immunodeficiency virus is a lentivirus that causes the acquired immunodeficiency syndrome aids, a condition in humans in. Global impact of human immunodeficiency virus and aids. Since it was first recognised in 1981 it has killed more than 25 million people. Antiretroviral therapies can achieve reduction in blood levels of the hiv virus below the limits of. Hiv is one of the worlds most serious health problems. Two major types of the aids virus, hiv 1 and hiv2, have been identified. The human immunodeficiency virus hiv aids epidemic has already devastated many individuals, families, and communities. This is known as escape mutation as the viral epitopes escape recognition by the host immune response. Hiv is transmitted primarily through blood and genital fluids and to newborn infants from infected mothers.
General properties of viruses replicate independently of the chromosome of cells, but dependent on cells infect animals and people, plants, and bacteria bacteriophage extracellular forms virions are metabolically inert contain either dna or rna range in size from about 28 nm to. Two of the viral genes, tat and rev, are essential for virus replication and encode novel transactivators that interact specifically with their cognate rna target elements. Hepatitis a virus structure, genome, epidemiology, transmission, replication, pathogenesis, clinical manifestation, lab diagnosis, treatment, vaccination, prevention and control. Hiv virology and pathogenetic mechanisms of infection. Thus, hiv 1 and hiv 2 each had a zoonotic origin but now spread directly from human to human. Hiv the human immunodeficiency virus is a lentivirus that causes the acquired immunodeficiency syndrome aids, a condition in humans in which. In addition to the differences in morphology and genetics mentioned above, the baltimore classification scheme groups viruses according to how the mrna is produced during the replicative cycle of the virus. Human immunodeficiency virus an overview sciencedirect topics. Kursk state medical university department of microbiology hiv human immunodeficiency virus student. In this blog post, i am posting 10 multiple choice questions which covers various topicsareas of virology. The genetic nature of hiv evades the development of a preventive vaccine and a cure for hiv infection remains a distant hope. Viruses are the smallest obligate intracellular parasites that require living host cells in order to multiply and being alive. Stability of hepatitis c virus, hiv, and hepatitis b virus.
Hiv is different in structure from other retroviruses. Epidemiology of human immunodeficiency virus in the united. Over time, the hiv virus will spread throughout the body and kill most of the specific cells of the immune system called cd4 cells or t cells leading to the depletion of these important immune cells. We analyzed 61 crf01ae v3 clonal sequences of known. The steps occurring in infection involve an interaction of hiv not only with the cd4 molecule on cells but. Dec 27, 2010 human immunodeficiency virus acquired immunodeficiency syndrome first described in 1981 hiv1 isolated in 1984, and hiv2 in 1986 belong to the lentivirus subf slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. Thus, overall rates of the most severe clinical presentations of the infection, i. The symptoms are similar to those of rhinovirus colds runny nose, sore throat, cough, headache, fever, chills. Mcq on microbiology virus mcq biology learning biology. Not all virus infections produce a protective immune response in this way. Apr 22, 2017 it has been known for some time that hiv targets t cells, but i had not heard of any other types of cells being specifically targeted by the virus. A divorced mother of four tests positive for hiv1 infection during investigation of a febrile illness with disseminated lymphadenopathy. The human immunodeficiency viruses hiv are two species of lentivirus a subgroup of. Hepatitis a is a 2732 nm spherical particle with icosahedral symmetry containing a linear singlestranded rna genome with a size of 7.
The human immunodeficiency viruses 1 and 2 hiv1, hiv2 originated from the simian immunodeficiency viruses sivs of primates. In the united states, hiv is spread mainly by having anal or vaginal sex or sharing injection drug equipment. Nov 29, 2018 hiv is a virus that targets and alters the immune system, increasing the risk and impact of other infections and diseases. This includes bacteria, archaea, viruses, fungi, prions, protozoa and algae, collectively known as microbes. The epidemic has left millions of children orphaned, has disrupted village and community life, and increasingly contributes to the erosion of civil order and economic growth. Other characteristics such as host specificity, tissue specificity, capsid shape, and special genes or enzymes may also be used to describe groups of similar viruses. Some of the answer keys has been provided at the bottom. Hiv is an approximately 100 nm icosahedral structure with 72 external spikes that are formed by the two major envelope glycoproteins gp120 and gp41. Spatiotemporal analysis and epidemiological characterization of the human immunodeficiency virus hiv in libya within a twenty five year period. The oral microbiome in human immunodeficiency virus hiv.
Hiv human immunodeficiency virus causes the disease known as aids acquired immune deficiency syndrome. The human immunodeficiency virus hiv is grouped to the genus lentivirus within the family of retroviridae, subfamily orthoretrovirinae. Cognitive symptoms, behavioral symptoms, motor symptoms, due to infection of microglial cells by mtropic viruses. In addition, the virus has been found in other cell types, including haematopoietic. Jan 15, 2020 the most commonly used system of virus classification was developed by nobel prizewinning biologist david baltimore in the early 1970s. Human immunodeficiency virus hiv is a complex rna virus of the genus lentivirus within the retroviridae family. Human immunodeficiency virus hiv serological diagnostic and supplemental tests are prescription devices for the qualitative detection of hiv antigens andor detection of antibodies against hiv in human body fluids or tissues. Genetic regulation of human immunodeficiency virus.
The human immunodeficiency virus hivaids epidemic has already devastated many individuals, families, and communities. Hiv, the human immunodeficiency virus, is the virus that causes aids, a debilitating and deadly disease of the human immune system. The epidemic has left millions of children orphaned, has disrupted village and community life, and increasingly contributes. Learn vocabulary, terms, and more with flashcards, games, and other study tools. That virion replicates to generate viremia and persistent infection in all of the lymphoid tissue in the body. Genotypic methods could be used, but the prediction algorithms may be inaccurate for nonb subtypes like crf01ae and the correlation with the phenotypic approach has not been assessed. Transmission of hiv 1 results in the establishment of a new infection, typically starting from a single virus particle. Hiv 2 is restricted to west africa, although there are imported cases in the uk. Your comments on videos will be key as we iterate content. Two major types of the aids virus, hiv 1 and hiv 2, have been identified. Human immunodeficiency virus type 2 microbiology society. On the basis of genetic characteristics and differences in the viral antigens, hiv is classified into the types 1 and 2 hiv 1, hiv 2. The most commonly used system of virus classification was developed by nobel prizewinning biologist david baltimore in the early 1970s. Hiv is a virus that targets and alters the immune system, increasing the risk and impact of other infections and diseases.
Division of microbiology and infectious diseases national institutes of health mark l. Biosafety in microbiological and biomedical laboratories. Hiv, virus replication, antigenic variation, virulence. Thus, hiv1 and hiv2 each had a zoonotic origin but now spread directly from human to human.
May 15, 2016 hiv the human immunodeficiency virus is a lentivirus that causes the acquired immunodeficiency syndrome aids, a condition in humans in which progressive failure of the immune system allows opportunistic infections and cancers to prosper unlike some other viruses, the human body cannot get rid of hiv. X4 viruses tend to appear later in about 50% of hiv1 subtype binfected individuals, but seldom with other subtypes, as they progress to aids. Summary the human immunodeficiency virus hiv epidemic emerged in the early 1980s with hiv infection as a highly lethal disease among men who have sex with men and among frequent recipients of blood product transfusions. Genotypic prediction of hiv1 crf01ae tropism journal of. The lentivirus human immunodeficiency virus hiv causes aids by interacting with a large number of different cells in the body and escaping the host immune response against it. Human immunodeficiency virus hiv infection is associated with a range of oral conditions, and increased numbers of diseaseassociated microbial species have previously been found in. From the departments of psychology, medicine and microbiologyimmu nology. Human immunodeficiency virus hiv infection, the cause of acquired immune deficiency syndrome aids has become a significant threat to global public health faster than any previous epidemic mann and tarantola 1996.
Hiv or aids the human immunodeficiency virus hiv is the cause of one of the most destructive human pandemics in recorded history. The hiv virus cause the disease hiv by attacking the bodys own immune system. On the basis of genetic characteristics and differences in the viral antigens, hiv is classified into the types 1 and 2 hiv1, hiv2. Viruses can infect any type of cell, ranging from human cells to. Transmission of hiv1 results in the establishment of a new infection, typically starting from a single virus particle. Pdf over the past three decades of intense research on the contribution of viral and host factors determining the variability in hiv1 infection.
Advances in the treatment of hiv infection have resulted in a fundamental shift in its epidemiology, to a potentially chronic and manageable condition. Hiv is spread through contact with the blood, semen, preseminal fluid, rectal fluids, vaginal fluids, or breast milk of a person with hiv. Human immunodeficiency virus and aids microbiology book. The human immunodeficiency viruses 1 and 2 hiv 1, hiv 2 originated from the simian immunodeficiency viruses sivs of primates. For example, herpes viruses can be classified as a dsdna enveloped virus. The human immunodeficiency virus hiv is grouped to the genus. Structure of human immunodeficiency virus hiv microbeonline. Hiv infection is identified either by the detection of hiv specific antibodies in serum or plasma or by demonstrating the presence of the virus by nucleic acid detection using polymerase chain reaction pcr, p24 antigen testing or, rarely these days, by growing virus in cell culture.
It is composed of two copies of positive sense singlestranded rna that codes for the viruss nine genes enclosed by a conical capsid composed of 2,000 copies of the viral protein p24. Microbiology is the study of all living organisms that are too small to be visible with the naked eye. Hiv infects cells that are critical to the human immune system and destroys their ability to fight infections. Classification of virus virology online microbiology notes. Director, scientific and clinical affairs advanced sterilization products johnson and johnson, inc. The hiv virus can rapidly mutate or change its genome constantly. In humans, the major site of virus replication is the epithelial cells of the respiratory tract and about onethird of colds are caused by coronaviruses. Director, division of parasitic diseases centers for disease control and prevention martin s. Without treatment, the infection might progress to an advanced disease.
Hiv the human immunodeficiency virus is a lentivirus that causes the acquired immunodeficiency syndrome aids, a condition in humans in which progressive failure of the immune system allows opportunistic infections and cancers to prosper unlike some other viruses, the human body cannot get rid of hiv. Therefore, people who have developed aids are unable to fight off infections by. I also found it interesting that the antiretroviral therapy typically used in treating hiv infections in t cells does not work effectively on macrophages. It has been known for some time that hiv targets t cells, but i had not heard of any other types of cells being specifically targeted by the virus.
It is roughly spherical with a diameter of about 120 nm, around 60 times smaller than a red blood cell. Hiv 1 subtype crf01ae predominates in south asia and has spread throughout the world. Human immunodeficiency virus hiv has a complex life cycle in which both cellular and virusencoded factors participate to determine the level of virus production. Renal failure and mesangial hyperplasia, due to infection of mesangial cells nephritic macrophages by. Hsv and hiv co infection viruses work synergistically to enhance spread. Pathogenesis of human immunodeficiency virus infection. The virus tropism must be determined before using ccr5 antagonists. Human immunodeficiency virus an overview sciencedirect. The viral loads of 99 hepatitis c virus hcv, 41 hiv, and 101 hepatitis b virus hbv patient samples were measured before and after storage at. Hiv1 subtype crf01ae predominates in south asia and has spread throughout the world. Human immunodeficiency virus acquired immunodeficiency syndrome first described in 1981 hiv1 isolated in 1984, and hiv2 in 1986 belong to the lentivirus subf slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. Coronaviruses cause respiratory and enteric disease in a variety of animals. A divorced mother of four tests positive for hiv 1 infection during investigation of a febrile illness with disseminated lymphadenopathy. The tests are intended for use as an aid in the diagnosis of infection with hiv.
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