Thursday, May 19, 2022

What Are The Types Of Hiv

Hiv Infections And Aids

Doing It Types of HIV Tests

General Goal:To know the major causes of this disease, how it istransmitted, and understand the basic processes thatresult in the progression from HIV infection to AIDS.

Specific Educational Objectives: The student should be able to:

  • recite the most likely causes of HIV/AIDS and how this viral infection is usually acquired in the United States .
  • describe how the virus attaches to human cells. Also know the human cell receptors that the virus attaches to .
  • describe the three different HIV/AIDS disease stages and what happens to the immune system during those disease stages.
  • describe the various means of diagnosing HIV/AIDS and when to use which test. You should also know CDC’s definition for AIDS.
  • list the most common opportunistic infections that occur in HIV/AIDS patients.
  • describe the basic treatment regimen .
  • list ways of preventing HIV infections
  • Lecture:Dr. Neal R. Chamberlain

    References:

  • A wonderful and informative website to visit is fromJohns Hopkins Medical Center Called“TheBody”. Go there you will learn alot!
  • Good article at Webpathon HIV and AIDS.
  • For recent updates on vaccines go to
  • Chen RY, Kilby JM, and Saag MS. Enfuvirtide. 2002 Expert. Opin. Investig. Drugs.Dec 11:1837-43.
  • How Do I Know If I Have Hiv

    The only way to know for sure if you have HIV is to get tested. Testing is relatively simple. You can ask your health care provider for an HIV test. Many medical clinics, substance abuse programs, community health centers, and hospitals offer them too. You can also buy a home testing kit at a pharmacy or online.

    To find an HIV testing location near you, use the HIV Services Locator.

    HIV self-testing is also an option. Self-testing allows people to take an HIV test and find out their result in their own home or other private location. You can buy a self-test kit at a pharmacy or online. Some health departments or community-based organizations also provide self-test kits for free.

    Read the U.S. Food and Drug Administrations fact sheet on the OraQuick In-Home HIV Test, the only FDA-approved in-home HIV test.

    The coronavirus pandemic has made it more difficult for some people to access traditional places where HIV testing is provided. Self-testing allows people to get tested for HIV while still following stay-at-home orders and social distancing practices. Ask your local health department or HIV service organization if they offer self-testing kits.

    Topics

    S For Removal And Inactivation Of The Infectious Agent

    The production and purification of individual proteins from plasma is not sufficient to completely rem ove HIV. Therefore additional validated procedures for an effective depletion and inactivation of viruses must be applied . No transmissions of HIV by plasma derivatives have been reported since the consistent implementation of effective methods for removing and inactivating viruses in the production process. Accordingly, the experimentally determined inactivation capacity of the manufacturing process is supported by epidemiologic data.

    HIV is sensitive to heat and detergents . HIV can be inactivated by the solvent-detergent technique, with reagents such as tri-n-butyl phosphate and Triton X-100 or polysorbate 80 . Pasteurisation at 60 °C for 10 h reliably inactivates HIV even in the presence of stabilisers . Heat treatment of lyophilized products inactivates HIV, provided there is appropriate residual moisture of about 1% .

    Because of the heat sensitivity of plasma proteins the inactivation procedures must be carried out under appropriate validated conditions . The product should optimally maintain its biologic activity and native conformation, while potentially contaminating viruses should be inactivated under the production conditions . Treatment with -propiolactone and UV light is effective when applied at low protein concentrations, but not in plasma . The transmission of HIV by PCC preparations was not prevented by treatment with -propiolactone .

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    Selection Pressure By Antiretroviral Drugs

    The antiretroviral treatment with nucleoside RT inhibitors induces a selection pressure in parts of the RT that are close to the enzymatic pocket in a direction such that the wild-type enzyme is inhibited by the drugs, and thus HIVs carrying wild-type RT are no longer produced. HIV strains with a mutated enzyme that are resistant to the drug will continue to replicate and adapt, and most replicate as fast as the wild-type virus. In a similar way, a mutated HIV strain can escape from the action of the immune system which is favored when random mutations are found in the gp120 protein, especially in the crown of the V3 loop. Usually for the first 5 years after infection, those HIV strains that are not cleared by immune action continue to replicate and will contribute to the HIV quasispecies population found in the sexual and cerebral compartment and in the blood .

    Definition Of Exclusion Criteria

    Human immunodeficiency virus

    Blood donor eligibility is regulated by the Guidelines on the Collection of Blood and Blood Components and on Use of Blood Products . Criteria are defined for the permanent or temporary deferral from donation with respect to the transmission of HIV. Permanently deferred from donation are the following:

    • Persons with a confirmed HIV infection.

    • Persons with non-prescribed IV or IM drug use.

    • Persons whose sexual behaviour puts them at high risk of acquiring severe infectious diseases like HBV, HCV or HIV that can be transmitted by blood:

    • heterosexual persons with high-risk sexual behaviour, i.e. sexual contacts with multiple sex partners,

    • men who have sexual contacts with men

    • male and female sex workers.

    Temporary deferral from donating blood is valid for persons:

    • who entered Germany from a country or a region, where they had been continuously resident for more than 6 months, with a comparatively high prevalence of HBV, HCV, HIV or HTLV-1/-2 infections,

    • who had sexual contacts with persons belonging to a group with an enhanced risk of infection with HBV, HCV, HIV and/or HTLV-1/-2 ,

    • with tattoos or body piercing.

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    Screening And Diagnostic Tests

    If doctors suspect exposure to HIV infection, they do a screening test for HIV. Doctors also recommend that all adults and adolescents, particularly pregnant women, have a screening test regardless of what their risk appears to be. Anyone who is concerned about being infected with HIV can request to be tested. Such testing is confidential and often free of charge.

    The current combination screening test tests for two things that suggest HIV infection:

    • to HIV

    • HIV antigens

    Antibodies are proteins produced by the immune system to help defend the body against a particular attack, such as that by HIV. Antigens are foreign substances that can trigger an immune response.

    The body takes several weeks to produce enough antibodies to be detected by the test, so results of the antibody test are negative during the first few weeks after the virus enters the body . However, results of the p24 antigen test can be positive as early as 2 weeks after the initial infection. The combination tests can be done quickly by a laboratory. Also, a version of these tests can be done in a doctor’s office or clinic . If results are positive, doctors do a test to distinguish HIV-1 from HIV-2 and a test to detect the amount of HIV RNA in the blood .

    Other, older rapid bedside tests are also available. These tests can be done using a sample of blood or saliva. If results of these rapid screening tests are positive, they are confirmed by ELISA or by repetition of one or more other rapid tests.

    Prevalence And Incidence Of Blood

    Prior to the introduction of compulsory testing for HIV antibodies in May and October 1985, about 1,380 haemophiliacs and about 200 transfusion recipients were infected in Germany with HIV by blood donations and plasma derivatives . With the introduction of antibody screening tests and obligatory virus inactivation procedures in the production process of plasma derivatives, the number of HIV and hepatitis virus infections by transfusion declined significantly, especially in the first 2 years. Since 2004, HIV antibody testing and HIV NAT further reduced the potential HIV burden of the source material . Since 1990/1991 no HIV infections have been transmitted by plasma derivatives .

    According to reports to the Paul Ehrlich Institute, 2 HIV transmissions by cellular blood components have occurred after the introduction of NAT screening in 2004 . Both transmissions were due to very recent infections and a failure of the NAT systems used. In the case of 2007, presumably a low viral load and mutations in the primer binding region were responsible for the false-negative test results . Regarding the transmission reported in 2009, the HIV-positive donor sample was repeatedly tested negative with the NAT system used .

    As recommended for HIV-infected donors, plasma and lymphocytes of the HIV-infected recipient should also be stored in order to possibly clarify the origin of infection and the transmission using molecular methods .

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    What Are Vaccines And What Do They Do

    Vaccines are products made from very small amounts of weak or dead germs that can cause diseases. They help your immune system fight infections faster and more effectively.

    When you get a vaccine, it sparks your immune response, helping your body fight off and remember the germ so it can attack it if the germ ever invades again. And since vaccines are made of very small amounts of weak or dead germs, they wont make you sick.

    Vaccines are usually administered by a shot, but sometimes can be administered by mouth or nasal spray. They are widely used to prevent diseases like polio, chicken pox, measles, mumps, rubella, influenza , hepatitis A and B, and human papillomavirus .

    Mechanism Of Hiv Infection

    HIV Testing | Different Types of HIV Tests | HIV Test

    Once in the body, HIV attaches to several types of white blood cells. The most important are certain helper T lymphocytes involves white blood cells that travel through the bloodstream and into tissues, searching for and attacking microorganisms and… read more ). Helper T lymphocytes activate and coordinate other cells of the immune system. On their surface, these lymphocytes have a receptor called CD4, which enables HIV to attach to them. Thus, these helper lymphocytes are designated as CD4+.

    ). Once inside a CD4+ lymphocyte, the virus uses an enzyme called reverse transcriptase to make a copy of its RNA, but the copy is made as deoxyribonucleic acid that contain the code for a specific protein that functions in one or more types of cells in the body. Chromosomes are structures within cells… read more ). HIV mutates easily at this point because reverse transcriptase is prone to making errors during the conversion of HIV RNA to DNA. These mutations make HIV more difficult to control because the many mutations increase the chance of producing HIV that can resist attacks by the persons immune system and/or antiretroviral drugs.

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    Preventive Treatment Before Exposure

    Taking an antiretroviral drug before being exposed to HIV can reduce the risk of HIV infection. Such preventive treatment is called preexposure prophylaxis . However, PrEP is expensive and is effective only if people take the drug every day. Thus, PrEP is recommended only for people who have a very high risk of becoming infected, such as people who have a partner who is infected with HIV.

    PrEP may also be recommended for people who engage in high-risk sexual activities, such as the following:

    • Men who have anal sex with men without using a condom

    • Heterosexual men and women who do not regularly use condoms during sex with partners whose HIV status is unknown and who are at increased risk of HIV infection

    People who use PrEP still need to use other methods to prevent HIV infection, including consistent use of condoms and not sharing needles to inject drugs.

    Mutation Rate And Quasispecies

    The replication cycle of HIV within the cytoplasm of a susceptible CD4 T lymphocyte, macrophage or dendritic cell starts after entry into the cell and cleavage of the core followed by synthesis of one new DNA strain. The reverse transcriptase synthesizes the first DNA strain using the viral RNA as a template. After RNA digestion by the RNase activity the RT synthesizes the second complementary strand. Finally, the double-stranded DNA molecule is released into the nucleus and integrated into the human host cell genome .

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    Emerging Recombinant Strains Continue To Challenge Researchers

    One of the primary barriers to treating or developing effective vaccine for HIV is the high genetic diversity of the virus itself. While viruses that use double-strand DNA to replicate are relatively stable, retroviruses like HIV go backward in their replication cycle and are far less stable. As a result, HIV is highly prone to mutationmutating, in fact, about a million times more frequently than cells using DNA.

    As the virus’ genetic diversity widens and different viral subtypes are passed from person to person, the mixed genetic material can create new HIV hybrids. While most of these hybrids die, the few surviving ones often exhibit greater resistance to HIV therapy and, in some cases, faster disease progression.

    The variability of HIV, therefore, creates something of a “moving target” for researchers, with new recombinant strains able to resist or altogether evade neutralizing agents. Some, like the A3/02 strain identified by Swedish researchers in 2013, are able to deplete a person’s immune defenses far more aggressively than previously known strains.

    A Note About Treatment

    HIV strains and types

    While theres currently no cure for HIV, treatments have come an incredibly long way since the virus was first identified. Due to advances in treatment, people living with HIV can have long, healthy lives.

    There are now many types of antiretroviral drugs available to treat HIV. According to the National Institutes of Health , taking antiretroviral medications each day as directed can reduce viral load to undetectable levels in 6 months or less .

    Not only can having an undetectable viral load keep the immune system healthy, but it can also prevent transmission of HIV to others. People with an undetectable viral load have no risk of transmitting HIV to their partners via sex.

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    Feasibility And Validation Of Procedures For Removal/ Inactivation Of The Infectious Agent

    Validation of the various removal and inactivation steps must be carried out following the actual production processes using HIV . HIV can be propagated to sufficient amounts in cell culture, enabling the spiking of the different source materials under laboratory conditions. Individual steps have to be investigated mimicking the different production processes with regard to their virus removal or inactivation capacity by determining the infectious titres at the start and the end of each production step. Because HIV-1 and HIV-2 are considered to have identical inactivation characteristics, it is sufficient to use HIV-1 for the validation of an inactivation method. Although HIV-1 and SIVmac239 2) show similar properties in inactivation experiments , the use of SIV is not accepted.

    Quick Answers For Clinicians

    The length of time after exposure before HIV infection can be detected depends on the type of test used. Nucleic acid amplification testing can identify HIV 10-33 days after infection. Fourth generation antigen/antibody tests can detect HIV 18-45 days after infection. Antibody-only tests require additional time to yield reliable results because the patient must mount an immune response to the HIV infection before antibodies can be detected. NAAT is not generally recommended for initial screening in asymptomatic patients. However, NAAT is recommended in certain cases, such as in patients who present with symptoms of HIV infection with known recent exposure, in infants born to individuals with HIV, and for monitoring of disease .

    If a rapid test result is negative in a patient with a possible exposure, testing should be repeated after the window period to confirm the negative result. In general, repeat testing should be considered in high-risk patients if clinically indicated.

    The use of preexposure prophylaxis can reduce the accuracy of diagnostic tests, including antibody testing, antigen testing, and nucleic acid amplification testing .

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    Cancers Common In People With Hiv Infection

    Kaposi sarcoma Kaposi Sarcoma Kaposi sarcoma is a skin cancer that causes multiple flat pink, red, or purple patches or bumps on the skin. It is caused by human herpesvirus type 8 infection. One or a few spots may appear… read more , a cancer caused by a sexually transmitted herpesvirus, appears as painless, red to purple, raised patches on the skin. It occurs mainly in men who have sex with men.

    Cancers of the immune system . Often, lymph nodes in the neck, under the arms, or in the groin enlarge rapidly and painlessly… read more ) may develop, sometimes first appearing in the brain. When the brain is affected, these cancers can cause weakness of an arm or a leg, headache, confusion, or personality changes.

    Having AIDS increases the risk of other cancers. They include cancer of the cervix, anus, testes, and lungs as well as melanoma and other skin cancers. Men who have sex with men are prone to developing cancer of the rectum due to the same human papillomaviruses Human Papillomavirus Infection Human papillomavirus causes warts. Some types of HPV cause skin warts, and other types cause genital warts . Infection with some HPV… read more that cause cancer of the cervix in women.

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      Through Needles Or Other Instruments

      Health care workers who are accidentally pricked with an HIV-contaminated needle have about a 1 in 300 chance of contracting HIV unless they are treated as soon as possible after exposure. Such treatment reduces the chance of infection to less than 1 in 1,500. The risk increases if the needle penetrates deeply or if the needle is hollow and contains HIV-contaminated blood rather than simply being coated with blood .

      Infected fluid splashing into the mouth or eyes has less than a 1 in 1,000 chance of causing infection.

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