1 / 38

Terminology

HIV Human Immunodeficiency Virus. AIDS Acquired Immune Deficiency Syndrome. Terminology. Classification of HIV. 2 types of HIV: HIV - 1 HIV - 2. Genetic forms of HIV - 1. some phylogenetic groups :

theola
Télécharger la présentation

Terminology

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. HIV Human Immunodeficiency Virus AIDS Acquired Immune Deficiency Syndrome Terminology

  2. Classification of HIV 2 types of HIV: HIV - 1 HIV - 2

  3. Genetic forms of HIV - 1 somephylogeneticgroups: M (main) 9 subtypes (A – D, F – H, J i K) O (outlier) (rare) N (novel) (rare) P CRF (CirculatingRecombinantForms)

  4. Replication cycle of HIV - Viralgp 120 binds to CD4 receptor of a lymphocyte • Coreceptors for entry: CCR5 or CXCR4 arehelpful • Fusion of HIV withcellularmembrane of lymphocyteoccurs – virusentersthecell • Viral RNA isconverted (transcripted) into DNA by reversetranscriptase • HIV DNA (provirus) integrateswith DNA of a lymphocyte • RNA copies of a provirusaremade (mRNA) – transcription • mRNAistransported to thecytoplasm and makesthe host cellproduce long chains of viral protein (translation) • HIV core protein and genomic RNA gatherinsidethecell and immatureviralparticles form and bud offfromthecell • Chain of viral protein iscutintopieces by protease. Thatresultsin forming infectiousviralparticles.

  5. Targets of HIV Therapy Integrase Inhibitors Nucleus Entry Inhibitors: Fusion, CD4, CCR5 CXCR4 RNA Protease DNA Reverse transcriptase HIV CD4+ T-Cell Protease inhibitors Reverse transcriptase inhibitors: NRTI (nucleosides, nucleotides) NNRTI

  6. Global estimates for adults and children, 2008 • People living with HIV33.4 million[31.1 – 35.8 million] • New HIV infections in 20082.7 million [ 2.4 – 3.0 million] • Deaths due to AIDS in 20082.0 million[1.7 – 2.4 million]

  7. Adults and children estimated to be living with HIV, 2008 Eastern Europe & Central Asia 1.5 million [1.4 – 1.7 million] Western & Central Europe 850 000 [710 000 – 970 000] North America 1.4 million [1.2 – 1.6 million] East Asia 850 000 [700 000 – 1.0 million] Middle East&North Africa 310 000 [250 000 – 380 000] Caribbean 240 000 [220 000 – 260 000] South & South-East Asia 3.8 million [3.4 – 4.3 million] Sub-Saharan Africa 22.4 million [20.8 – 24.1 million] Latin America 2.0 million [1.8 – 2.2 million] Oceania 59 000 [51 000 – 68 000] Total: 33.4 million (31.1 – 35.8 million)

  8. HIV infection in the three geographical areas and EU/EEA, WHO European Region, 2004–10 Data not reported or not available from Austria, Russia, Monaco. Source: ECDC/WHO. HIV/AIDS Surveillance in Europe, 2010

  9. HIV infections diagnosed in 2010 per 100 000 population: all cases Source: ECDC/WHO. HIV/AIDS Surveillance in Europe, 2010

  10. HIV infections, 2004–10: transmission groups in WHO European Region, East Source: ECDC/WHO. HIV/AIDS Surveillance in Europe, 2010

  11. HIV infections, 2004–09: transmission groups in WHO European Region, Centre Source: ECDC/WHO. HIV/AIDS Surveillance in Europe, 2010

  12. Distribution of three most common AIDS indicative diseases by transmission group, WHO European Region, 2010 *pulmonary in adults and adolescents

  13. HIV – routes of transmission • Contaminated blood products • Sexual intercourse • Mother- to- child (vertical route)

  14. HIV – routes of transmission Contaminated blood products -blood transfusion -skin penetrating procedures -contact of contaminated body fluid with mucose membrane or non intact skin

  15. Risk of HIV transmission after single exposure to contaminated blood • Percutaneus - needlestick in HCW 0,32% - sharing needles by IDU 0,67% • Mucous membranes 0,09% • Non-intact skin - lower risk (several cases reported) • Exposure to other contaminated fluids - still lower risk

  16. Circumstances increasing the risk of transmission • Deep penetration 16,1% • Blood visible on the tool 5,2% • Needle just withdrawn from the vein 5,1% • End-stage AIDS 6,4% Applying retrovir in post exposure prophylaxis decreases the risk by 80%

  17. HIV – routes of transmission Sexual intercourse Risk about 0,5 %

  18. Risk of pathogen transmission resulting from a single sexual contact with infected person HIV 0,5% Gonorrhea 22-25%

  19. HIV – routes of transmission Mother–to-child transmission (vertical transmission) Frequency 30% - 1% ( in Africa 40% )

  20. Vertical transmission of HIV • Transmissionrateisrelated to HIV infectionstage and viralloadinthemother • Mainroutes: - delivery - breastfeeding - transplacental

  21. Infectious body fluids in HIV positive individual • Blood and its derivates • Seminal fluid • Discharge from genital tract - vaginal exsudate - cervical mucus • Human milk • Cerebro-spinal fluid • Synovial fluid, amniotic fluid, pericardial fluid, pleural fluid, peritoneal fluid. • Any fluid contaminated with blood • Samples of tissues, transplants • Concentrate of virus used in research laboratories

  22. Cells with CD4 receptor on surface • T lymphocytes (T helper) • T-cell precursors in the bone marrow and thymus • Monocytes/macrophages • Dendritic cells (in the lymphatic organs, gut, genitourinary tract, submucosal tissue) • Microglia cells (in the central nervous system) • Retinal cells Co-receptors: CCR5, CXCR4

  23. Pathogenesis • HIV enters the susceptible cells, replicates and spreads in the body of the host. • Cell - mediated immunity is activated and kills the virus particles. • Specific antibodies are produces to fight the infection (humoral immunity). • Some viruses reach the reservoirs ( eg.lymph nodes, brain, urogenitary tract) and are safe from antibodies and killer cells. • The rate of replication gets established (set point). • HIV destroys T-lymphocytes (lysis, apoptosis), new lymphocytes are being produced (balance). • T-lymphocytes count declines (immunodeficiency)

  24. Surface pathogens • Skin Streptococci, staphylococci • Mucose membranes Streptococci, staphylococci, candida sp., anaerobic bacteria (fusobacterium) Pulmonary alveoli – cryptococci, Pneumocystis carinii GI tract – Escherichia coli Saprofites are useful in immunocompetent patient.

  25. Latent infectionsEarly colonization of the body

  26. Sequelae of lymphocytes CD4 deficiency • Activation of surface pathogens Candida albicans Cryptococcus neoformans Pneumocystis carinii • Reactivation of latent infections Herpes simplex virus (HSV) Varicella-zoster virus (VZV) - shingles Cytomegalovirus (CMV) Toxoplasma Epstein – Barr virus (EBV) • Developing of neoplasms Kaposi`s sarcoma Non-Hodgkin`s lymphoma Cervical carcinoma • Insufficient serologic response to new antigens New infection – serologic diagnostic tests unreliable, Vaccination – poor response (if any)

  27. HIV / AIDS HIV infection ↓ Depletion of CD4 lymphocytes ↓ Immunodeficiency ↓ Opportunistic infections (reactivation) Specific tumors

  28. HIV testing Standard serologic test: - ELISA repeatedly reactive ( 2 different samples) + - Western-Blot reactive = HIV serology positive Window period 2-6 weeks (rarely up to 3 months) (Time delay from infection to positive test) Viral detection: (newborns, occupational exposures) - HIV RNA (PCR) - p-24 antigen - culture of the virus

  29. False negative ELISA test • Diagnosticwindow 14 days – 3 months (6 months) • Seroreversionintheendstage of infection • Agammaglobulinaemia

  30. False negative ELISA test • Diagnosticwindow 14 days – 3 months (6 months) • Seroreversionintheendstage of infection • Agammaglobulinaemia

  31. False positive ELISA test • Cross reactiveantibodies - collagenoses - autoimmunologicdisorders - liverdiseases - multiplesclerosis - endstagekidneydisease • Vaccinationagainst HIV 68% of personshaveantibodies

  32. Rapid detection testing (needs confirmation with ELISA and WB) Clinical use: - in labor (no prenatal HIV test) - in patient who is a source of needlestick injury to health care provider - evaluation of acutely ill patient with possible PCP

More Related