Which pathogen causes HIV

HIV & AIDS: clinical picture

HIV, the immunodeficiency virus, damages the human immune system. The immune system is our body's defense system and is divided into humoral and cellular immune defenses. It defends itself against invading pathogens, such as fungi, viruses or bacteria, in that the humoral defense forms so-called antibodies. When the immune system is weakened, even a harmless infection can cause life-threatening illness.
HIV belongs to the group of retroviruses. It damages the body's cellular defense mechanism by attaching itself to the T helper cells (also known as CD4 cells, T4 cells or also T4 helper cells) and multiplying in them. The body starts a defense reaction in which antibodies are formed. Unfortunately, these are not enough to fight HIV. In this way, the infected T helper cells are destroyed, which leads to a weakening of the immune system. The result: HIV - infected patients are often and seriously ill from other (so - called opportunistic) infections. The further an HIV infection progresses, the lower the number of T helper cells in the body and the weakened the immune system becomes.

Course of disease

HIV infections vary greatly from patient to patient. Serious signs of illness such as infections and other pathogens can appear in the early stages. But it is also possible that with a fully developed immunodeficiency no symptoms are visible.
The course of the disease is divided into individual stages:

  • Acute phase:
  • Symptoms resembling a flu-like infection can occur up to about 6 weeks after being infected. Infected people often complain of fever, headache and sore throat, swollen lymph nodes, and a rash can be visible. In this phase of the disease, the immune system defends itself against the viral invader and tries to stop it using the body's own defense cells. It is now producing antibodies. At this point in time, an infection cannot yet be detected in the blood (diagnostic window).

  • Latency phase (symptom-free stage):
  • This is followed by a symptom-free phase that can last for several years and in which the immune system tries to achieve a kind of balance between virus replication and defense. During this time, infected people hardly notice their infection, but the viruses continue to multiply inexorably. During this phase, infection can be detected with an HIV test.

  • AIDS Related Complex:
  • Since the immune system is already weakened, infectious diseases are increasing. The symptoms are similar to those in the acute phase: flu-like symptoms, night sweats, attacks of fever, swelling of the lymph nodes, skin changes, persistent diarrhea or fungal infections. In contrast to the acute phase of infection, the symptoms do not recede.

  • AIDS full screen:
  • One speaks of an AIDS full picture when the so-called AIDS-defining diseases are detected. These diseases, also known as opportunistic infections, are harmless to a healthy immune system. The number of T helper cells in the blood is also used as a measure of the state of the immune system. If the number falls below 200 to 400 per µl of blood, it is called AIDS.


AIDS-defining diseases

AIDS-defining diseases are mostly opportunistic or malignant diseases that do not occur in a healthy person, or do not occur in this way.
This includes:

Caused by viruses:

  • Cytomegalovirus infections
  • Viral hepatitis
  • Chronic herpes simplex infections

Caused by bacteria:

  • Tuberculosis (TB)
  • Infections from other mycobacteria
  • Inflammation of the esophagus
  • lung infection

Caused by fungi:

  • Fungal infections (candidiasis) of the airways and / or esophagus
  • Cryptococcal meningitis

Caused by parasites:

  • Pneumocystis carinii pneumonia (PCP)
  • Toxoplasmosis


  • Kaposi's sarcoma
  • cervical cancer



Author (s): äin-red