Part1: Natural History and Classification of HIV Disease

 

Time

Stage

Symptoms

0

Initial infection

None

1-4 weeks

Seroconversion

Rash, fever

0-4 years

Asymptomatic

None

1-6 years

Symptomatic

Mild

4-10 years

AIDS

Moderate - Severe

 

These changes are caused by the continuous damage to the immune system by HIV over many years.

We measure these changes in 3 ways:

1.     Examining the patient for signs of immune deficiency
2.     ‘Viral load tests’: measuring the amount of virus in 1ml of blood
3.     CD4+ve lymphocyte count:
   
     ·       these are the main target for HIV
   
     ·       they also control the body’s defence against infection

 

Time

Stage

Viral Load

CD4 count

0

Initial infection

-

600-1200

1-4 weeks

Seroconversion

Millions

50-400 (variable)

0-4 years

Asymptomatic

Thousands

400-600

1-6 years

Symptomatic

Thousands

200-500

4-10 years

AIDS

Thousands

0-300