Brent Cornell

    
The Human Immunodeficiency Virus (HIV) is a retrovirus that infects helper T cells, disabling the body’s adaptive immune system

• It causes a variety of symptoms and infections collectively classed as Acquired Immuno-Deficiency Syndrome (AIDS)

Effects of HIV

• HIV specifically targets the helper T lymphocytes which regulate the adaptive immune system
• Following infection, the virus undergoes a period of inactivity (clinical latency) during which infected helper T cells reproduce
• Eventually, the virus becomes active again and begins to spread, destroying the T lymphocytes in the process (lysogenic cycle)
• With a reduction in the number of helper T cells, antibodies are unable to be produced, resulting in a lowered immunity
• The body becomes susceptible to opportunistic infections, eventually resulting in death if the condition is not managed

Progression of AIDS

Transmission of HIV

• HIV is transmitted through the exchange of body fluids (including unprotected sex, blood transfusions, breastfeeding, etc.)
• The risk of exposure to HIV through sexual contact can be minimised by using latex protection (i.e. condoms)
• A small minority of people are immune to HIV infection (they lack the CD4+ receptor on T_H cells that HIV requires for docking)
• HIV is a global issue, but is particularly prevalent in poorer nations with poor education and health systems

Mechanisms of HIV Infection