Fahad almajid.MD KKUH.1434 Definition: Infection with Human immundefeciency Virus (HIV) which leads to : Chronic and without treatment usually fatal infection characterized by : A} progressive immunodeficiency B} Long latency period C} Opportunistic infection HIV=Human Immunodeficiency Virus It is an RNA virus belong to the family Retroviredae. It is called Retrovirus : Retrovirus: information in the form of RNA is transcribed into DNA in the host cell. There are two viruses : HIV1 and HIV2. It causes diseases by disrupting the immune system function as measured by CD4 cell depletion called : AIDS=Acquired Immune Deficiency Syndrome. HIV1 : Predominate world wide HIV2 : Predominate in western africa The hallmark of HIV Disease: Infection and viral replication within T-lymphocyte expressing the CD4 antigen resulting in : Qualitative defect in CD4 responsiveness Progressive depletion in CD4 cell counts : AND This effect on helper-inducer lymphocyte will increase the risk of: 1) Opportunistic infections such as Pneumocystis Jiroveci 2) Neoplasm such as Lymphoma and Kaposi sarcoma 1 st recogonised in USA 1981 CDC reported the occurance of : 1) Unexplained occurance of pneumocyctis pneumonia in 5 healthy homosexual in LA 2) Kaposi saarcoma in 25 healthy homosexual men in NY and LA.....later on ; 3) The disease became recogonised in both male and female with (IUDs) as well as 4) Recipients of blood transfusion and haemophilics 1983 : HIV was isolated from patient with lymphadenopathy 1984 : HIV was demonstradted to be the causative agent of AIDS 1985 : ELISA test was developed HIV infection/AIDS is a global pandemic Cases reported everywhere. Ranging 3036 million. More than 95% reside in low and middle income countries 50% are females 2.5 million are children (less than 13 ) Epidemic was first recognised in USA and shortly thereafter in western Europe. More than 2/3 rd of all people with HIV live in sub-saharan africa Asia 4.9 million people living with HIV. National HIV prevalence is highest in southeast Asia 4.0 million. HIV prevalence is increasing in Indonesia and Vietnam. Epidemic is expanding in Eastern Europe and central asia : 1.6 million Total: 34.0 million Europe 2.3 million [2.1 million 2.5 million] Africa 22.9 million [21.7 million 24.2 million] South-East Asia 3.5 million [3.0 million 3.9 million] Western Pacific 1.3 million [1.1 million 1.5 million] Americas 3.0 million [2.6 million 3.5 million] Adults and children estimated to be living with HIV, by WHO Region, 2010 Eastern Mediterranean [ ] Total: 2.7 million [2.4 million 2.9 million] Europe [ ] Africa 1.9 million [1.7 million 2.1 million] South-East Asia [ ] Western Pacific [ ] Americas [ ] Estimated number of adults and children newly infected with HIV, by WHO Region, 2010 Eastern Mediterranean [ ] Total: 1.8 million [1.6 million 1.9 million] Europe [ ] Africa 1.2 million [1.1 million 1.4 million] South-East Asia [ ] Western Pacific [ ] Americas [ ] Estimated adult and child deaths from AIDS, by WHO Region, 2010 Eastern Mediterranean [ ] The ranges around the estimates in this table define the boundaries within which the actual numbers lie, based on the best available information. Regional HIV and AIDS statistics and features 2010 TOTAL 34.0 million [31.6 million 35.2 million] 2.7 million [2.4 million 2.9 million] Adults and children newly infected with HIV Adults and children living with HIV Sub-Saharan Africa Middle East and North Africa South and South-East Asia East Asia Latin America Caribbean Eastern Europe and Central Asia Western and Central Europe North America Oceania 22.9 million [21.6 million 24.1 million] 4.0 million [3.6 million 4.5 million] 1.5 million [1.2 million 1.7 million] 1.5 million [1.3 million 1.7 million] 1.3 million [1.0 million 1.9 million] 1.9 million [1.7 million 2.1 million] [ ] [ ] [ ] [ ] [ ] [ 1.1 million] [ ] [ ] [ ] [ ] [ ] [9400 ] [ ] 3300 [2400 4200] 1.8 million [1.6 million 1.9 million] Adult & child deaths due to AIDS 1.2 million [1.1 million 1.4 million] [ ] [ ] [ ] [ ] [ ] [ ] 9000 [6900 ] 9900 [8900 ] 1600 [1200 2000] 0.8% [0.8% - 0.8%] Adult prevalence (15 49) [%] 5.0% [4.7% 5.2%] 0.3% [0.3% 0.3%] 0.4% [0.3% 0.5%] 0.9% [0.8% 1.1%] 0.6% [0.5% 0.9%] 0.2% [0.2% 0.3%] 0.1% [0.1% 0.1%] 0.9% [0.8% 1.0%] 0.2% [0.2% 0.2%] 0.3% [0.2% 0.3%] HIV is a fragile virus.It cannot live for very long outside the body HIV is primarily found in the Blood, Semen, or Vaginal fluid of an infected person. HIV and AIDS Transmission Sexual (heterosexual,msm,others) Heterosexual is the most common mode of transmission worldwide. Vertical transmission from pregnant woman to the newborn (MTCT) is the main mode of infection in children. Blood and body fluid. IVDU. No evidence of spread by : casual contact or by insects such as by mosquito Structure of the virus It is an RNA virus It is an icosahedral structure of : 1) Lipid Envelope (env) derived from infected cell, containing numerous external spikes formed by two major enveloe protiens : a) The external gp 120 b) The transmembrane gp 41 2) Nucleocapsid (gag) with P24 major core protien 3) Polymearse (pol) 1) Attachment : This takes place through receptor specific : A) CD4---gp120 B) CO-receptor..1) CCXR5 2) CXCR4 2) Penetration 3) Upcoating 4) Reverse transcription Formation of cDNA 4) Integration 5) Transcription of proviral DNA A) formation of genomic RNA b) formation of structual mRNA 6) Translation of structural m RNA a) Formation of viral structural protien b) Packaging of genomic RNA of strucrural protien 7) Final assembly a) insertion of viral specific glycoprotien into plasma membrane b) Budding c) Release of mature virions 8) Final maturation BY cleavage of gag and pol by polymerase enzyme Pathogenesis HIV infection Rapid develpment of screening test blood donors were routinely screened for antibody 1996 : blood banks added the p24 antigen capture assay to detect early cases. ELISA: is the screening test,used to screen blood products and patients. Sensitivity of more than 99.5% The fourth generation test: EIA test : combine detection of antibody to HIV and detection of p24 antigen. Extremely sensitive but specificity is not optimal..low risk..only 10% who are positive by this test turned to be real positive, Western blot: confirmatory test PCR: (polymerase chain reaction) used as 1) confirmatory test and 2) To asses the viral load WESREN BLOT HIV Progression Staging (WHO): Acute HIV infection Clinical stage1: Asymptomatic infection Clinical stage2: Mild symptoms, lymphadenopathy. Clinical stage3: Moderate symptoms Clinical stage4: Sever symptoms, advanced immune deficiency Clinical stage 1 Asymptomatic Persistent generalized lymphadenopathylymphadenopathy Clinical stage 2 Moderate and unexplained weight loss (10% of presumed or measured body weight) Oral candidiasis Oral hairy leukoplakia Immunological staging: CD4 positive T lymphocytes level is the main method of assessing the immune status of the HIV positive patient. 1. >500 cells/mm normal immunity cells/mm mild deficiency cells/mm moderate immune deficiency. 4.