Human Immunodeficiency Virus infection and Acquired Immune Deficiency Syndrome, Retrovirus, microbiology

1. HUMAN
IMMUNODEFICIENCY
VIRUS
- HIV (RETROVIRUSES) [Microbiology]

2. Introduction
Family - Retroviridae
Genome - RNA
Two Main types
HIV - 1 & HIV - 2

3. Morphology
● Spherical
● Enveloped
● Size = 90- 120nm
● Genome - Two identical
copies of ssRNA
● Nucleocapsid
● Lipoprotein envelope
● Envelope projecting spike
● Transmembrane pedicle
● Reverse transcriptase
enzyme

4. MODES OF TRANSMISSION
1. Sexual
2. Parenteral
3. Perinatal

5. CLINICAL FEATURES
● The CD4 antigen on the cell surface its the receptor of virus.
● Classification system for HIV & AIDS
- GROUP 1 = acute HIV infection
- GROUP 2 = asymptomatic infection
- GROUP 3 = persistent generalized lymphadenopathy.
- GROUP 4 = subgroup A - constitutional disease -ARC
subgroup B - Neurological Diseases
Subgroup C - 1&2 == secondary infectious diseases
Subgroup D - Sec. Cancers
Subgroup E - other conditions

6. LAB DIAGNOSIS
1. Specific tests for HIV
1) Antigen detection : p24 Ag ; ELISA
2) Virus isolation : isolated from CD4 lymphocytes of peripheral
blood, bone marrow and serum.; when Ab are absent.
3) Detection of viral nucleic acid : by PCR
4) ANTIBODY DETECTION : Takes weeks, first 3-4 weeks IgM Ab,
then IgG.

8. PREVENTION
1. Sexual contact : condoms can prevent
2. Sharing needles
3. Blood : screening before transmission
4. Control of infection.

9. PROPHYLAXIS
No effective vaccine yet
Because of high mutation rate of the virus.

10. Thankyou