Acquired Immuno Deficiency Syndrome (AIDS):
1. General:
- It is a viral infectious disease which is caused by HIV (Human immunodeficiency virus) or HTLV-3 (Human T-Lymphocyte virus-3) or LAV (Lymphadenopathy associated virus).
- This virus belongs to the retrovirus family.
- This virus was discovered by Montagnier (1982).
- This virus infects helper T-lymphocytes.
- This virus does not survive in the air.
- It destroys the infected CD or T-cells. which are formed in the thymus during childhood?
- A healthy man contains about 300-400 million T4 cells.
2. Structure of HIV:
- AIDS virus is an RNA retrovirus. Its RNA forms DNA in a host cell.
- Structurally, AIDSA virus is bounded by a bilayer of phospholipids in which GP-120 & GP-41 glycoproteins remain embedded. It has 2 single-stranded RNA molecules & each RNA is attached with a reverse transcriptase enzyme. There are two protein layers around the RNA molecules viz.-P-24 proteins (Inner) & P-17 proteins (outer).
- With the help of reverse transcriptase enzyme, HIV can synthesis DNA from RNA. Two subtypes of HIV has been found-HIV-1 and HIV-2. HIV 1 is responsible for AIDS.
3. Modes of Infection of HIV:
- Infection takes place by blood contact.
- Infection is possible by sexual contact.
- The virus infects embryo in the uterus, as in filters through the endometrium of the uterus.
- This virus is also found in the colostrum.
- Maximum 80% transmission occurs homosexuality
4. Symptoms:
- Constant loss of body weight.
- Prolonged diarrhoea.
- Prolonged fever.
- Swelling of lymph nodes.
- Prolonged coughing.
- An aids-infected person normally develops Pneumocystis carinae pneumonia and Kaposi sarcoma.
- Profuse sweating.
