Kavisha K Patidar Assistant Professor Department of Microbiology Deogiri College Aurangabad HIV virus Unit3 Kavisha K Patidar Deogiri College Aurangabad HIV Human Immunodeficiency Virus causative agent of AIDS belongs to the lentivirus subgroup of the family ID: 935678
Download Presentation The PPT/PDF document "Topic – HIV virus Presented by" is the property of its rightful owner. Permission is granted to download and print the materials on this web site for personal, non-commercial use only, and to display it on your personal computer provided you do not modify the materials and that you retain all copyright notices contained in the materials. By downloading content from our website, you accept the terms of this agreement.
Slide1
Topic –HIV virusPresented byKavisha K Patidar Assistant ProfessorDepartment of MicrobiologyDeogiri College, Aurangabad
Slide2HIV virusUnit-3Kavisha K. PatidarDeogiri College Aurangabad
Slide3HIV: Human Immuno-deficiency Virus causative agent of AIDS belongs to the lentivirus subgroup of the family Retroviridae.Genome is diploid -2 identical ssRNA.Reverse transcriptase is associated with viral RNA.3 structural genes:-Gag genes- core and shell of virusEnv- synthesis of the envelope glycoprotein gp160Pol-polymerase reverse transcriptase
Slide4Slide5Slide6Slide7Slide8Receptor of virus is CD4 antigen.Primary pathogenic mechanism in HIV infection is damage caused to CD4+ T lymphocytes.T4 cells decreases in number.Infected T4 cells do not appear to release normal amounts of interleukin-2, gamma interferon and other lymphokines.Humoral immunity is also affected.AIDS patients are unable to respond to new antigens.Hypergammaglobulinemia- due to polyclonal activation of B-lymphocytes(IgG and IgA are raised, infants-IgM)Monocytes-macrophage function is also affected.In an infected person ,HIV can be isolated from the blood, lymphocytes, semen, saliva , tears, urine, cervical secretions and breast milk. AIDS is the only the last stage in the infection of HIV virus.
Slide9AIDS stagesAcute HIV infection:- 3-6 months infection(Low grade fever, malaise, headache etc).Seroconversion illness(viral multiplication, immune complexes)Asymptomatic or latent infection:- infectious, +Ab testCD4 lymphocytopenia, minor oppurtunistic infections, AIDS related complexCD4 T cells count-1000/ul to 500 or less by the stage of acute infection200 or less – clinical AIDS sets in.PGL- enlarged lymph nodesARC- weight loss, fatigue, unexplained fever, diaeehea, oppurtunistic infection
AIDS-
irreversible breakdown of immune system, progressive
oppurtunistic
infection
Slide10Lab DiagnosisImmunological tests:-Lymphocyte count below 2000/mm3T4:T8 cell ratio is reversed. Raised IgG and IgA levels.Lymph node biopsy showing profound abnormalities.Specific tests for HIV infectionAntigen detection- p24 antigen capture assay(ELISA which uses anti-p24 antibody as solid phase can be used for this)Virus Isolation – Once infected remains infected for life
Slide11PCR- gold standard for the diagnosis in all stages of HIV infection.DNA PCR (peripheral lymphocytes , primer -gag and LTR regions)and RNA PCRAntibody detection2-8 weeks to months for antibodies to appear after infection.ELISAWestern blotting
Slide12ProphylaxisPrevention of AIDS The three main transmission routes of HIV are sexual contact, exposure to infected body fluids or tissues, and from mother to fetus or child during the perinatal period.
Slide13Antiviral therapy/ Treatment
There is currently no cure for HIV infection. Treatment consists of
Highly Active Antiretroviral Therapy
, or HAART.
Current HAART options are combinations (or "cocktails") consisting of at least three drugs belonging to at least two types, or "classes," of
antiretroviral
agents. Typically, these classes are two
nucleoside analogue reverse transcriptase inhibitors
(NARTIs or NRTIs) plus either a
protease inhibitor
or a
non-nucleoside reverse transcriptase inhibitor
(NNRTI).
. A number of effective drugs have become available in recent years these include nucleoside analogues like
zidovudine
(
Azidothmidine
, AZT),
Dianosine
,
Zalcitabine
,
lamivudine
and protease inhibitors like
saquinavir
,
Ritonavir
,
Indinavir
, which have been used as
monotherapy
or in various combinations