HIV/AIDS
BY
OGUNBAYODE OLUWAKEMI
KHARKOV NATIONAL MEDICAL UNIVERSITY
DEPARTMENT OF IMMUNOLOGY
FUN FACT#
• Did you know that worlds AIDS DAY is on 1st December ?
The first reported case of HIV was in 1981.. The syndrome was characterized by a predisposition to opportunistic infections, it was suspected that AIDS was caused by a previously unknown virus, as it spreads thought contact with bodily fluids, and in 1983 HIV 1 was isolated
There are two closely related HIVs ;
HIV-1, HIV-2 the later which is less virulent. They majority of cases is found in HIV-1, HIV-2 is predominantly found in west Africa. Both HIV-1 and HIV-2, have their origin from non human primate. Based on similarities in sequence with SIMIAN IMMUNODEFICIENCY virus. HIV is likely to be the evolutionary product of closely related SIVs that crossed from nonhuman to human in the early twenties
‘the leading hypothesis is that SIVs were transmitted to humans through cutaneous or mucosal exposure to infected animal blood
ETIOLOGY
RNA virus, family retroviridae, subfamily lentivirus
Proteins: envelope glycoprotein, group specifies ag, polymerase
The virus is not stable in the environment, temperatures of 52-54 degrees can kill the virus in 20-30 mins , and 100 degrees celsius in 5 minutes
Detergents and antiseptics can also inactivate the virus
EPIDEMIOLOGY
EPIDEMIOLOGY contd..
HAART drug therapy (HIGHLY Active antretoviral therapy) has slowed the pandemic in countries with money
2 nucleoside transcriptase inbh+ 1 protease inhb+1 non nucleoside inhb OR 1 fusion inhb OR 1 integrase inhb
BUT…..
There's is as yet no cure- we cant get get rid of virus from an infected individual
There is no vaccine- can block primary infection
Cant stop taking antiviral drug- if you stop the virus will return because they integrate in to the human DNA
Drugs are expensive
AIDS IS a becoming in third world countries
HOW IS HIV TRANSMITTED?
SEXUAL
Transfusion and blood and its products
Vertical (perinatal, intranatal, postnatal)
HIV is transmitted primarily via unprotected sexual intercourse (including anal (most dangerous) and even oral sex), contaminated blood transfusions, hypodermic needles, and from mother to child during pregnancy, delivery, or breastfeeding. Some bodily fluids, such as saliva and tears, do not transmit HIV
But not through respiratory alimentary, or vector
HIV does not usually cause AIDS immediately and controversy
still remain as to precisely how the virus
damages the immune system and whether all HIV-1 infected individuals will necessarily develop disease. Great strides have been made since the identification of HIV but much remains a puzzle and a cure or a vaccine are exclusive
PATHOGENESISAFTER the virus enter the
• Body------ dendritic cells-------lymph nodes (cd4 tcells)
Gp120 + cd4 receptor
Gp41+ccr5/cxcr4.
• The capsid of the virus are released into the cd4 t cells,
• Rna are converted to dna via reverse transriptase enzyme
• HIV Dna gets into the human dna genome and integrates it
• The cd4 tcell are begin killed by the cd8 t cells because they express abnormal protins by the MHC class 1
And over time the cd4 tcells decrease
PATHIGENESIS CONTD..
Cytopathic effect:
Fusion of the cd4 t cell so as to prevent it from antibodies
NEF gene:
Down regulates the class 1 molecule, and the cytotoxic t cells (cd8) find it difficult to kill cd4 t cells
TAT gene: impairs the production of cytokines
HEAVY glycosylation of gp120: hides some epitome( particular spots that can trigger the immune system to produce antibodies)
CLINICAL COURSE
• Incubation period 2 weeks – 10 years
• 1 acute infection: 4-8 weeks
• 2 virus carrier- 4-8 weeks
• AIDS- 1-2 YEARS
CLINICAL MANIFESTATION
• Stage of acute infection (ARS): basically characterized by flu like symptoms
( fever, headache…) virus are present antibodies are also present CD8 increase
• Viral carriage ( asymptomatic): no symptoms CD4:CD8 is decreased. Virus and antibodies are present
• Progressive lymphadenopathy (PLA): enlarged lymph nodes in extrainguinal region >1cm in 2 or more site. CD4 decreases <500ml, CD8 cells increase, CD4:CD8 decrease
• AIDS related complex: accompanied by many opportunistic infections MTB, pneumocystis Caroni, Kaposi sarcoma, CMV, candidiasis, toxoplasmosis, Cryptococcus CD4 >200ml<500ml
• AIDS: AIDS related complex + decrease level of CD4 <200ml+ cachexia, polyneuropathy, dementia etc….
DIAGNOSIS
• ELISA Test — ELISA, which stands for enzyme-linked immunosorbent assay, is used to detect HIV infection. If an ELISA test is positive, the Western blot test is usually administered to confirm the diagnosis. If an ELISA test is negative, but you think you may have HIV, you should be tested again in one to three months.
• ELISA is quite sensitive in chronic HIV infection, but because antibodies aren't produced immediately upon infection, you may test negative during a window of a few weeks to a few months after being infected. Even though your test result may be negative during this window, you may have a high level of the virus and be at risk of transmitting infection.
• Western Blot — This is a very sensitive blood test used to confirm a positive ELISA test result.
• Saliva Tests — A cotton pad is used to obtain saliva from the inside of your cheek. The pad is placed in a vial and submitted to a laboratory for testing. Results are available in three days. Positive results should be confirmed with a blood test.
• Viral Load Test — This test measures the amount of HIV in your blood. Generally, it's used to monitor treatment progress or detect early HIV infection. Three technologies measure HIV viral load in the blood — reverse transcription polymerase chain reaction (RT-PCR), branched DNA (bDNA) and nucleic acid sequence-based amplification assay (NASBA). The basic principles of these tests are similar. HIV is detected using DNA sequences that bind specifically to those in the virus. It is important to note that results may vary between tests
STOP STIGMATISATION
OUR HEARTS GOES OUT TO ALL THOSE WHO HAVE DIED OF AIDS
THANKS A LOT !!!!!
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