HIV and AIDS

• HIV


  Human Immunodeficiency Virus
• AIDS


  Acquired Immune Deficiency Syndrome
• Scientists identified a type of chimpanzee in West Africa as the source of HIV infection in humans
• HIV is a member of retroviruses, which are capable of copying RNA into DNA

  
• HIV


  • It attacks and invades the immune system, typically the white blood cell (T-cells or CD4 cells) that the immune system must have to fight disease
  • T-cells augment or potentiate immune responses by activating WBCs to fight off infection

  
• Human Immunodeficiency Virus


  • H = Human – This particular virus can only infect human beings
  • I = Immunodeficiency – HIV weakens immune system by destroying important cells that fight disease and increases the risk of infection
  • V = Virus – A virus can only reproduce itself by taking over a cell in the body of its host

  
• Acquired Immune Deficiency Syndrome


  • A = Acquired, not inherited
  • I = Immuno – body's immune system includes all the organs and cells that work to fight off infection or disease
  • D = Deficiency – when immune system (CD4+ cells) is "deficient," or isn't working the way it should
  • S = Syndrome – is a collection of symptoms and signs of disease
• AIDS is a syndrome, rather than a single disease. It is a complex illness with a wide range of symptoms or a group of illnesses taking place at the same time
• Structure of HIV


  • Outer Structure
  • Inner Structure
• Life Cycle of HIV

  1. Binding

  2. Fusion

  3. Reverse Transcription

  4. Integration

  5. Transcription / Replication

  6. Assembly

  7. Budding and maturation

  
• These new virus particles released from the infected cell multiply, kill the helper T-cell in which it lives
• The reduction in the number of helper T-cells results in the complete inability of the body immune system to fight against and eventually results in opportunistic infections (OI)
• This acquired condition of immunodeficiency is called as AIDS
• Facts about HIV


  • HIV is fragile and easily destroyed by boiling, steaming or by various chemicals
  • HIV does not survive well outside the body
  • It does not spread or maintain infectiousness outside its host
  • HIV is unable to reproduce outside its living host except under laboratory conditions

  
• Facts about AIDS


  • AIDS - Acquired Immunodeficiency Syndrome
  • AIDS has become a pandemic disease
  • AIDS is the final stage of HIV infection
  • The clinical diagnosis shows the number of CD4 cells reach or fall below 200 per cubic millimeter of blood

  
• Stages of HIV Infection

  • Acute infection
  • Chronic infection
  • AIDS

  
• Opportunistic Infections (OI)


  • Bacterial: Tuberculosis (TB), Mycobacterium avium complex (MAC)
  • Viral: Kaposi Sarcoma, Cytomegalovirus (CMV)
  • Parasitic: Toxoplasmosis
  • Fungal: Candidiasis (Candida spp), Cryptococcosis (Cryptococcus spp), Pneumocystis carinii pneumonia (PCP), Histoplasmosis

  
• Symptoms of AIDS


  • Rapid weight loss
  • Dry cough
  • Recurring fever or profuse night sweat
  • Profound and unexplained fatigue
  • Swollen lymph glands in the armpits, groin
  • Diarrhea that lasts for more than a week
  • White spots or unusual blemishes on the tongue
  • Pneumonia
  • Persistent skin rash or flaky skin
  • Nausea abdominal cramps and vomitting
• Body fluids that transmit HIV

  • Blood
  • Semen
  • Vaginal fluid
  • Breast milk
  • Cerebrospinal fluid
• Modes of Transmission


  • Risky Sexual Behaviors: Unprotected sexual intercourses including vagina, oral and anal sex, Unprotected intercourse with multiple partners
  • In a healthcare setting: Needle prick injury, Infected-blood transfusion, Entry through any cuts, wounds, or other open abrasion of skin
  • Mother to the Baby: Crosses placenta, Breastfeeding
  • Needle sharing (Among drug abusers)
• HIV - Testing


  • People should consider an HIV test if they have multiple sexual partners with unprotected sex, they have sexually transmitted infections (STI), shared the needles while injecting drugs, they have engaged in any activity that has HIV infection risk factors
  • Testing Options: Blood detection tests - Enzyme-Linked

  
• the Baby


  • Crosses placenta
  • Breastfeeding
• Needle sharing


  (Among drug abusers)
• Please do not reproduce, redistribute or share without the prior express permission of the author.
• HIV - Testing


  • People should consider an HIV test if they have multiple sexual partners with unprotected sex
  • They have sexually transmitted infections (STI)
  • Shared the needles while injecting drugs
  • They have engaged in any activity that has HIV infection risk factors

  
• Testing Options


  • Blood detection tests
  • Urine detection tests
  • Oral testing
• Blood detection tests


  • Enzyme-Linked Immunosorbent Assay/Enzyme Immunoassay (ELISA/EIA)
  • Radio Immunoprecipitation Assay/Indirect Fluorescent Antibody Assay (RIP/IFA)
  • Polymerase Chain Reaction (PCR)
  • Western Blot Confirmatory test
• Urine detection tests


  • Urine Western Blot
  • As sensitive as testing blood
  • Safe way to screen for HIV
  • Can cause false positives in certain people at high risk for HIV

  
• Oral testing


  • Orasure/OraQuick
  • The only FDA approved HIV antibody testing
  • As sensitive and accurate as Western Blot
  • Sample is taken by oral swab
• Antiretroviral Therapy (ART)


  • The treatment for HIV
  • Involves combination of drugs
  • Recommended for all HIV patients
  • People with HIV should start ART as soon as possible provided there is no OI
  • Can't cure HIV, but help people with HIV live longer and healthier lives
  • Reduces the risk of HIV transmission (undetectable viral load)

  
• Antiretroviral Drugs & Mechanisms of Action

  • Entry Inhibitors
  • Nucleoside Reverse Transcriptase inhibitors (NRTI)
  • Non-Nucleoside Reverse Transcriptase inhibitors (NNRTI)
  • Integrase inhibitors (II) / Integrase strand transfer Inhibitors (INSTI)
  • Protease inhibitors (PI)
• Entry inhibitors


  1. CCR5 Antagonists

  2. Attachment inhibitors

  3. Post-attachment inhibitors

  4. Fusion Inhibitors
• CCR5 Antagonists


  CCR5 antagonists bind to the CCR5 chemokine co-receptor on host cells, inducing a conformational change that impedes CCR5 interaction with HIV gp120, thereby preventing HIV entry into host cells
• Attachment inhibitors


  Attachment inhibitors bind to the gp120 protein on the outer surface of the HIV, thereby preventing entry into CD4 cells
• Post-attachment inhibitors


  Post-attachment inhibitors block CD4 receptors
• Fusion Inhibitors


  Fusion inhibitors block the HIV envelope from merging with the host CD4 cell membrane (fusion). This prevents HIV from entering the CD4 cell.
• Nucleoside Reverse Transcriptase inhibitors (NRTIs)


  • They interrupt an early stage of the virus making copies of itself by attacking an enzyme called reverse transcriptase
  • These drugs may slow the spread of HIV in the body
  • They are also known as nucleoside analogs
• NRTIs


  • zidovudine, lamivudine, tenofovir, abacavir, emtricitabine
• Non-Nucleoside Reverse Transcriptase inhibitors (NNRTIs)


  Binds to the site on the reverse transcriptase different from the binding site of NRTIs
• NNRTIs


  • Nevirapine, efavirenz, doravirine, rilpivirine