HIV (Human Immunodeficiency Virus) Year 1 Medical 2024-2025 PDF

HIV (Human immunodeficiency virus) Balsam Qubais Saeed, PhD November 1st, 2023 Objectives HIV/AIDS infection Know HIV/AIDS infection List the diagnosis methods of HIV/AIDS infection Describe the mode of transmission Know the prevention of HIV transmission  Hu...

HIV (Human immunodeficiency virus) Balsam Qubais Saeed, PhD November 1st, 2023 Objectives HIV/AIDS infection Know HIV/AIDS infection List the diagnosis methods of HIV/AIDS infection Describe the mode of transmission Know the prevention of HIV transmission  Human immunodeficiency virus (HIV) The human immunodeficiency virus (HIV) is an enveloped retrovirus (RNA virus replicates by making DNA copies of its RNA using reverse transcriptase) that contains 2 copies of a single-stranded RNA genome. Two strains are recognized HIV-1 & HIV-2. Majority of global infections are due to HIV-1. Over time HIV causes acquired immunodeficiency syndrome (AIDS), the last stage of HIV disease, a condition in which there is progressive failure of the immune system leading to life-threatening opportunistic infections. HIV destroys CD4 T cells — white blood cells that play a large role in helping the body fight disease. The fewer CD4 T cells you have, the weaker immune system becomes.  Cause of acquired immunodeficiency syndrome (AIDS) The cause of this infectious disease is the human immunodeficiency virus (HIV), an ssRNA-RT virus of the Retroviridae family, can be classified into HIV-1 and HIV-2. HIV-1 and HIV-2 are transmitted through the same routes HIV-1 is more globally expanded and virulent. More common worldwide HIV-2 is much less virulent and comes from West Africa. HIV-2 is less easily transmitted HIV-2 is less pathogenic Duration of HIV-2 infection is shorter How is HIV acquired unprotected vaginal intercourse sexual contact (high risk sexual behaviour; sex workers) sharing needles Contaminated blood or blood products, Use of contaminated instruments (e.g. dentist's equipment) Needle stick injury Mother to child (vertical transfer) and this can occur in-utero via placenta, at birth or postnatal via breast milk. Not by kissing nor by mosquitoes fluids such as saliva & tears there is no evidence that they play a role in infection HIV is not transmitted by Coughing, sneezing Public baths Insect bites Handshakes Touching, hugging Work or school contact Using telephones Water, food Sharing cups, glasses, Kissing plates, or other utensils DR. S.K CHATURVEDI Human Immunodeficiency Vi work http://tse1.mm.bing.net/th?id=OIP.M663d39c09d41e7b431245e3f677447b4H0w=299h=224c=0pid=1.9rs=0p=0r=0 A virus spread through body fluids and affects specific cells of the immune system, called CD4 cells or T cells. A virus that kills the CD4 cells (T cells) damaging the immune system. A virus that replicates inside the human body, so it must invade a healthy cell in the body to survive. CD4 Also known as "T4" or "helper T cell," the CD4 cell is the primary target of HIV. 8  Pathophysiology HIV is a pathogen that is spread across mucus membranes. The HIV attaches to CD4 molecule and CCR5 (a chemokine co- receptor), the virus surface fuses with the cellular membrane which allows it entry into a T-helper lymphocyte. After integrating with the host genome the HIV provirus forms followed by transcription and the production of viral mRNAs. The HIV structural proteins are assembled in the host cell which then continues to infect other cells.  Symptoms of HIV 1. Primary infection (Acute HIV) Some people infected by HIV develop a flu-like illness within 2 to 4 weeks after the virus enters the body, may last for a few weeks. The primary HIV infection is characterized by the following symptoms: Fever Joint pain Skin rash Sore throat Swollen lymph nodes  Symptoms of HIV 2. Clinical latent infection (Chronic HIV) In this stage of infection, HIV is still present in the body and in white blood cells. many people may not have any symptoms or infections during this time. is characterized by the following signs and symptoms and can last for decades: Fever Fatigue Diarrhea Weight loss Oral thrush Shingles Persistent generalized lymphadenopathy  HIV Diagnosis HIV can be diagnosed through blood or saliva testing. Blood tests are the most common way to diagnose HIV. By Antigen\ Antibody tests. Direct test Antibody tests. Indirect test Nucleic acid tests (NATs).  Direct test – Polymerase chain reaction (PCR) tests are used to detect HIV in the blood (can usually detect HIV the soonest - about 10 to 33 days after exposure). Indirect test - to detect antibodies to the virus - HIV-1 testing consists of initial screening with an enzyme-linked immunosorbent assay (ELISA) to detect antibodies to HIV-1. Specimens with a nonreactive result from the initial ELISA are considered HIV-negative unless new exposure to an infected partner or partner of unknown HIV status has occurred. Specimens with a reactive ELISA result are retested in duplicate. If the result of either duplicate test is reactive, the specimen is reported as repeatedly reactive. confirmatory testing with a more specific supplemental test such as Western blot. Only specimens that are repeatedly positive by ELISA and positive by Western blot are considered HIV-positive and indicative of HIV infection Nucleic acid tests (NATs): A NAT can detect HIV sooner than other types of tests.  Management Antiviral: Reduction in viral load and increase drug treatment in CD4 cell count monitoring prevention social services work factors psychological and social well-being use of complementary therapies palliative care (ie care not aimed at prolonging life but at improving symptoms while living.)  AIDS AIDS stands for acquired immunodeficiency syndrome. AIDS is the final stage of HIV infection. It can take years for a person infected with HIV, even without treatment, to reach this stage. Having AIDS means that the virus has weakened the immune system to the point at which the body has a difficult time fighting infections. When someone has one or more of these infections and a low number of T cells, he or she has AIDS. The patient is now prone to opportunistic infections  AIDS AIDS stands for acquired immunodeficiency syndrome. AIDS is the final stage of HIV infection. It can take years for a person infected with HIV, even without treatment, to reach this stage. A normal CD4 count will be approximately 500 to 1600 cells per cubic millimetre of blood. In AIDS patient the CD4 count will be less than 200 cells per cubic millimetre of blood. a low number of T cells , Lead to opportunistic infections (oral candida infection , Pneumocystis carinii pneumonia) opportunistic infections can affect people with a poorly functioning or suppressed immune system. diagnosis of AIDS The Centers for Disease Control and Prevention considers HIV-infected persons who have CD4 counts below 200 to have AIDS, regardless of whether they are sick or well How does HIV become AIDS? The patients with HIV infection, with few or no symptoms, for years before it turns into AIDS. AIDS is diagnosed when the CD4 T cell count falls below 200 or you have an AIDS-defining complication, such as a serious infection or cancer.  AIDS symptoms When CD4+ T cell numbers decline below a critical level, cell- mediated immunity is lost, and infections with a variety of opportunistic microbes appear. The first symptoms often include moderate and unexplained weight loss, recurring respiratory tract infections (such as sinusitis, bronchitis, otitis media, pharyngitis), prostatitis, skin rashes, and oral ulcerations.  Complications Complication of HIV disease is its progression to acquired immunodeficiency syndrome (AIDS). AIDS occurs when lymphocyte count falls below a level (less than 200 cells per microliters) and is characterized by one or more of the following: Pneumocystis pneumonia (PCP). Tuberculosis (TB) Cytomegalovirus : causing damage to your eyes, digestive tract, lungs or other organs. Candidiasis (thrush): Candidiasis is a common HIV-related infection. It causes inflammation and a thick, white coating on your mouth, tongue, esophagus or vagina. Cryptococcal meningitis: Meningitis is an inflammation of the membranes and fluid surrounding your brain and spinal cord (meninges). Toxoplasmosis: This potentially deadly infection is caused by Toxoplasma gondii,  Complications Cancers common to HIV/AIDS Lymphoma. This cancer starts in the white blood cells. Kaposi's sarcoma. A tumor of the blood vessel walls, Kaposi's sarcoma usually appears as pink, red or purple lesions on the skin and mouth. In people with darker skin, the lesions may look dark brown or black. Kaposi's sarcoma can also affect the internal organs, including the digestive tract and lungs. HPV-related cancers. These are cancers caused by human papillomavirus (HPV) infection. They include anal, oral and cervical cancer.  Other complications Wasting syndrome (weight loss of more than 10 percent of a person's body weight) Neurological complications. Kidney disease. Liver disease  Prevention Prevention consists of taking measures to avoid exposure to the virus e.g. using condoms, not sharing needles, screening of donated blood and discarding contaminated samples. Adequate autoclaving of all medical equipment & avoiding recapping of used needles to prevent needlestick injuries. Health education is an important aspect of HIV prevention. This can be in different formats e.g. HIV awareness week and seminars Prevention