HIV attacks the immune system and weakens it over a long period of time. As a result, the immune system is no longer able to fulfil its function – defending against disease-causing pathogens.
Phases of HIV infection
If untreated, HIV infection goes through three stages from contamination with HIV through to the outbreak of Aids. The duration of these stages differs from one person to another. This is why the time in which HIV-positive people live free of symptoms can vary between a few months and fifteen years.
Stage 1: Primary infection
In the first few weeks following infection, the viral load increases rapidly. During this period, symptoms such as those experienced during a cold or mild flu often appear: fever, skin rash, fatigue, headaches, etc. Many affected people or doctors do not notice these symptoms at all or do not connect them with an HIV infection. In the phase of primary infection the risk of transmission is particularly high because of the high viral load.
The signs of illness disappear spontaneously after a few weeks because the immune system reacts to the attack by the virus. After that, the HIV infection is initially unobtrusive.
Stage 2: Latency phase (no or only general symptoms)
HIV-positive people generally remain symptom-free for years and are able to lead a normal life. Nevertheless the virus spreads insidiously and continuously puts a strain on the immune system. The immune system gets weaker and weaker because of the persistent stress on the system. Beyond a certain point it is no longer able to defend itself adequately against pathogens. The body now shows more frequent signs of immune deficiency. These can take the form of skin diseases, prolonged swelling of lymph nodes, severe night sweats and other symptoms.
Stage 3: Aids
By this stage the immune system is severely impaired and is no longer able to prevent severe, life-threatening diseases. If certain combinations of diseases occur, we refer to this as Aids. The range of such illnesses is broad. It extends from cancers to certain forms of pneumonia through to infection of the gullet with the yeast Candida albicans (oesophageal candidiasis). Once AIDS has broken out, the life expectancy – without treatment – is still a few months up to three years.