Asif Iqbal Khattak M.Phil. Microbiology Educational Adviser Mobile: +92 (0) 335-8984165 Email: microbiologist119@gmail.com Skype: +92334-8984165 Instagram: https://www.instagram.com/microbiologist119/ linkedin: https://www.linkedin.com/in/asif-iqbal-khan-091966b4/

1. Presentation on AIDS by
Asif Iqbal khattak
M.Phil. Microbiology
3rd semester

2. AIDS Contents:
• AIDS Introduction
• HIV particle
• HIV Structure
• Discovery
• Types
• Classification
• Genome
• HIV genes
• Replication
• Symptom
• Transmission
• Reservoir

4. AIDS
•Acquired Immunodeficiency syndrome first described in
1981
•When the immune system becomes weakened by HIV, the
illness progresses to AIDS.
•AIDS is a serious condition that weakens the body's immune
system.

5. HIV
Human Immunodeficiency Virus
H = Infects only Human beings
I = Immunodeficiency virus weakens the immune
system and increases the risk of infection
V = Virus that attacks the body

6. HIV particles

8. SizeHIV is 120nm in diameter.
An HIV particle is around 100-150 billionths of a meter in
diameter.
That's about the same as :0.1 microns 4 millionths of an inch.
one twentieth of the length of an E.coli bacterium.
 One seventieth of the diameter of a human CD4+ white blood
cell.

9. HIV-1 and HIV-2
• HIV-1 and HIV-2 are
• Transmitted through the same routes
• Associated with similar opportunistic infections
• HIV-1 is more common worldwide
• HIV-2 is found in West Africa, Mozambique, and Angola

10. Conti…
• Discovered independently by Luc Montagnier of France and Robert
Gallo of the US in 1983-84.
•HIV-1 isolated in 1984, and HIV-2 in 1986.
•Belong to the lentivirus subfamily of the
Retroviridae.
•Enveloped RNA virus, 120nm in diameter.
•HIV-2 shares 40% nucleotide homology with HIV-1.

11. Strains
• Two types of HIV have been characterized: HIV-1 and HIV-2.
• HIV-1 is the virus that was initially discovered .
• It is more virulent, more infective and is the cause of the majority
of HIV infections globally.
• HIV-2 The lower infectivity of HIV-2 compared to HIV-1 implies
that fewer of those exposed to HIV-2 will be infected per
exposure.
• Because of its relatively poor capacity for transmission, HIV-2 is
largely confined to West Africa.

12. Structure
•The core contains two copies of its plus single-stranded
RNA genome and several enzymes.
•Genome consists of 9200 nucleotides (HIV-1):
•gag core proteins - p15, p17 and p24
•pol - p16 (protease), p31 (integrase/endonuclease)
•env - gp160 (gp120:outer membrane part, gp41: trans
membrane part)
•Other regulatory genes i.e. tat, rev, vif, nef, vpr and vpu

13. CLASSIFICATION
•HIV is a member of the genus Lentivirus part of the family
Retroviridae.
•Lenti viruses have many morphologies and biological
properties in common.
• Many species are infected by lentivirus, which are
characteristically responsible for long-duration illnesses with a
long incubation period.

14. • CD4 cells .
• CCR5 (CC-CKR-5) chemokine receptor protein.
• Chemokine co receptor, called CXCR-4
• Scavenger receptor
Receptors

15. GENOME
• The two +RNA are linked near their 5’ ends.
• HIV genome contains nine genes.
• 3 major or structural genes.
• And 5 non structural or regulatory genes.

16. Structural genes
I) Gag gene
core and shell protein consist of p17, p7, p9, p24.
ii) Pol gene:
The pol gene encodes polymerase (reverse
transcriptase), endonuclease and integrase/ ligase. (p31,
p51, p64)
iii) Env gene:
It encodes the envelope glycoprotein gp160 which is
cleaved into two envelope components gp120 and gp41.

17. Non-structural (regulatory) genes
Tat gene:Tat gene codes for a protein p16 and promotes
full transcription of that RNA strand.
Rev gene: Regulator of expression of viral proteins, it
codes for a protein p19 that promotes the expression of
viral proteins.
Nef gene: Negative expression factor, that codes for a
protein that may down regulate the transcription of HIV
genome by acting on its negative regulatory region (NR).
This region is responsible for the latent state of virus.

18. Structure

19. Replication
• Attachment
• Penetration
• Uncoating
• Reverse transcription
• Integration
• Transcription
• Translation
• Assembly
• Maturation
• Release

22. Life cycle
• The first step of infection is the binding of gp120 to the
CD4 receptor of the cell, which is followed by penetration
and Uncoating.
• The RNA genome is then reverse transcribed into a DNA
provirus which is integrated into the cell genome.
• This is followed by the synthesis and maturation of virus
progeny.

23. Reservoir
•Humans.
•HIV is thought to have recently evolved
from chimpanzee viruses.

24. HIV Disease
Progression of HIV disease is measured by:
 CD4+ count
 Degree of immune suppression
 Lower CD4+ count means decreasing
immunity
 Viral load
 Amount of virus in the blood
 Higher viral load means more immune
suppression

25. Symptoms:
• Headache More sweating at night
• Fever Discoloration
• Fatigue Diarrhea
• Chest pain Bronchitis
• Joint pain Wasting (extreme weight loss)
• Muscular pain Less breathing
• Vomiting Infections of the mouth and esophagus.
• Flu Abdominal pain
• Hypertension coughing
• loss of coordination vision loss
• Loss of memory

26. Progression of HIV Infection
• HIGH viral load (number of copies of HIV in the
blood)
• LOW CD4 count (type of white blood cell)
• Increasing clinical symptoms (such as opportunistic
infections)

27. Modes of HIV/AIDS Transmission

28. Through Bodily Fluids
•Blood products
•Semen
•Vaginal fluids
•Breast Milk
•CSF

29. Through IV Drug Use
•Sharing Needles
•Without sterilization
•Increases the chances of contracting HIV

30. Through Sex
•Intercourse (penile penetration into the vagina)
•Oral
•Anal
•Digital Sex

31. Mother-to-Baby
• Before Birth
• During Birth
• Postpartum
• After the birth

32. Transmission of HIV
•HIV is transmitted by
• Direct contact with infected blood
• Sexual contact: oral, anal, or vaginal
• Direct contact with semen or vaginal and cervical secretions
• HIV-infected mothers to infants during pregnancy, delivery,
or breastfeeding
•Barber instrument

33. Transmission of HIV
DR. S.K CHATURVEDI
HIV is not transmitted by
• Public baths
• Handshakes
• Work or school contact
• Using telephones
• Sharing cups, glasses,
plates, or other utensils
• Coughing, sneezing
• Insect bites
• Touching, hugging
• Water, food
• Kissing

34. Opportunistic Infections
associated with AIDS
•Bacterial
•Tuberculosis (TB)
•Strep pneumonia
•Viral
•Kaposi Sarcoma
•Herpes
•Influenza (flu)

35. Opportunistic Infections
associated with AIDS
•Parasitic
• Pneumocystis carinii
•Fungal
• Candida
• Cryptococcus
• Taxoplasmosis

36. Natural History of HIV Infection
•Virus can be transmitted during each stage
• Seroconversion
• Infection with HIV, antibodies develop
• Asymptomatic
• No signs of HIV, immune system controls virus production
• Symptomatic
• Physical signs of HIV infection, some immune suppression
• AIDS
• Opportunistic infections, end-stage disease

37. Natural History of HIV Infection
• Immune suppression
• HIV attacks white blood cells, called CD4 cells, that protect
body from illness
• Over time, the body’s ability to fight common infections is
lost
• Opportunistic infections occur

38. Impact of Global HIV
Negative economic impact on countries
Overstrained healthcare systems
Decreasing life expectancy
Reversal of child survival gains
Increased numbers of orphans

39. Mode of Transmission of HIV
5.95
3.45
2.07
2.7
85.83
Sexual IDUs Blood & blood proucts Perinatal Unidentified

40. HIV Transmission in United States and Rest of the World

41. AIDS is a Global Problem
33 million people worldwide have HIV/AIDS.
571,378 people in the United States are
HIV-positive.
New HIV infections occur every 6 seconds.

42. Treatment Options

43. Antiretroviral Drugs
• No vaccine
• Highly active Antiretroviral (HAART) therapy
• Nucleoside Reverse Transcriptase inhibitors
• AZT (Zidovudine)
• Non-Nucleoside Transcriptase inhibitors
• Viramune (Nevirapine)
• Protease inhibitors
• Norvir (Ritonavir)

44. Four ways to protect yourself?
• Abstinence
• Monogamous Relationship(only one sex partner)
• Protected Sex
• Sterile needles

45. Prevention

46. Prevention of HIV Transmission
• Strategies to prevent HIV transmission
• Personal strategies
• Public health strategies
• Safe practices: no risk of HIV transmission
• Risk reduction: reduces but does not eliminate risk

47. Prevention of HIV Transmission
Public health strategies to prevent HIV transmission
• Screen all blood and blood products
• Educate in safer sex practices
• Identify and treat STIs/other infections
• Provide referral for treatment of drug dependence
• Apply the comprehensive PPTCT approach to prevent vertical
transmission of HIV

48. Blood Detection Tests
• Enzyme-Linked Immunosorbent Assay
• Enzyme Immunoassay (EIA)
• Radio Immunoprecipitation Assay (RIP)
• Indirect Fluorescent Antibody Assay (/IFA)
• Polymerase Chain Reaction (PCR)
• Western Blot Confirmatory test

49. HIV Disease: Summary
• HIV multiplies inside the CD4+ cells, destroying them
• As CD4+ cell count decreases and viral load increases, the
immune defences are weakened
• HIV-infected people become vulnerable to opportunistic
infections
• HIV is a chronic viral infection with no known cure
• Without ARV treatment, HIV progresses to symptomatic disease
and AIDS

50. Thank you for
listening my
presentation.