Phases of HIV AIDS 1 Infection 2 Window period

Phases of HIV/AIDS 1. Infection 2. Window period 3. Seroconversion 4. Asymptomatic period 5. HIV/AIDS - related illness 6. AIDS 1

CD 4 counts • Number of CD 4 cells in blood provides a measure of immune system damage • CD 4 count reflects phase of disease • CD 4 count: 500 – 1200: 200 – 500: < 200: Normal Beginning of HIV illness AIDS 2

Window period • Time between infection & enough antibodies for a positive HIV test • Duration: approximately 3 months • No symptoms or signs of illness • HIV test is negative • Virus is multiplying rapidly - viral load is high • Person is very infectious 3

Seroconversion • Point at which HIV test becomes positive • Body starts making antibodies to HIV a few weeks after infection • HIV test becomes positive when antibody levels are high enough to be measured • Happens about 3 months after infection • Person may have a mild flu-like illness, lasting a week or two • Afterwards, the person is well again 4

Asymptomatic period • Time period between seroconversion and onset of HIV/AIDS-related illness • Duration variable: < 1 year to > 15 years • Most people remain healthy (asymptomatic) for about three years • Duration may depend on socio-economic factors • The CD 4 count is above 500 cells/ml 5

HIV/AIDS-related illness • Time period between onset of illness & diagnosis of AIDS • Duration is variable: average about 5 years • Illnesses initially mild, with gradual increase in frequency and severity • CD 4 count is between 500 & 200 cells/ml 6

AIDS • Final phase of HIV/AIDS • Duration: without antiretroviral drugs, less than 2 years with antiretrovirals, potentially many years • CD 4 count is below 200 cells/ml • Viral loads are high & the person is very infectious • HIV test may become negative 7

Phases of HIV/AIDS 1. Infection: The moment the virus gets into the body 2. Window period: The time between infection & enough antibodies for a positive HIV test 3. Seroconversion: The body starts to make antibodies to HIV 8

Phases of HIV/AIDS 4. Asymptomatic period: No illness 5. HIV/AIDS-related illness: Less serious illnesses 6. AIDS: Serious illnesses 9

Important facts • Duration of different phases of HIV/AIDS will vary in different people • It is not possible to predict the course of the disease in any one person • Factors affecting the course of HIV/AIDS include nutrition, emotional stress, and access to health care • People infected with HIV can infect others at any phase of the disease 10

Re-infection • Different strains of HIV exist within the same HIV type • It is possible to be re-infected with a different strain • When re-infection occurs, the immune system is weakened more rapidly • NB Re-infection can hasten the progression of the disease 11

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