AIDS Defining Diseases

Table of contents:

AIDS Defining Diseases
AIDS Defining Diseases

Video: AIDS Defining Diseases

Отличия серверных жестких дисков от десктопных
Video: Defining AIDS and AIDS defining illnesses | Infectious diseases | NCLEX-RN | Khan Academy 2023, January

AIDS-defining diseases

With advanced immunodeficiency, so-called opportunistic infections and tumors can occur that would not develop in a person with a healthy immune system. They are a sign of advanced HIV infection or immunodeficiency and are also referred to as AIDS-defining diseases. Many of these clinical pictures can also occur in patients who are not infected with HIV, but who have a massive weakening of their immune system due to hereditary immunodeficiencies, treatments against cancer or after organ transplants…


  • Continue reading
  • more on the subject
  • Advice, downloads & tools
  • Classification of HIV infection
  • Asymptomatic HIV infection (Category A)
  • Clinical signs of impaired cellular immune defense (Category B)
  • AIDS (Category C)
  • The categories in laboratory medicine
  • Case definition of AIDS

Classification of HIV infection

The classification of an HIV infection is based on the so-called CDC classification (named after the US Centers for Disease Control and Prevention).

The following section describes “indicator diseases” for the three stages (categories) of HIV infection. Each of these diseases is able to weaken the immune system temporarily or in the long term. This can be recognized both by a significant decrease in CD4 + helper lymphocytes in the blood findings (immune status, FACS) and by an increased susceptibility to infection. In this way, infectious diseases force the progression of the HIV infection and thus also the outbreak of AIDS. According to the definition, the advanced stage of HIV infection (Category C: AIDS) is present when one of the diseases that define AIDS occurs. The clinical categories of the CDC classifications are as follows:

Asymptomatic HIV infection (Category A)

These include:

  • Acute (primary) HIV infection.
  • Prolonged swelling of the lymph nodes (lymphadenopathy).
  • Symptom-free (asymptomatic) HIV infection.

Clinical signs of impaired cellular immune defense (Category B)

These include the following symptoms or illnesses:

  • Extensive shingles (herpes zoster with involvement of several dermatomes or recurrence in one dermatome).
  • Fungal infection of the mouth and throat (oropharyngeal candidiasis).
  • Oral hairy leukoplakia, whitish, streaky changes in the lining of the mouth of the cheeks or on the side of the tongue (cannot be wiped off, Epstein-Barr virus infection).
  • Genital fungal infection (vulvo-vaginal candidiasis) lasting four weeks or difficult to treat.
  • In women, inflammation in the pelvis (fallopian tubes, ovarian inflammation, abscesses).
  • Locally very superficial cervical cancer or its precursors.
  • HIV-induced platelet deficiency (thrombocytopenia) with an increased tendency to bleed.
  • Peripheral nerve damage caused by HIV (peripheral polyneuropathy).
  • Constitutional symptoms such as fever (from 38.5 ° C), diarrhea for more than a month.
  • Listeriosis (bacterial infection, usually from spoiled or contaminated food).
  • Bacillary angiomatosis, a rare skin disease caused by bacteria (Bartonella henselae and Bartonella quintana).

AIDS (Category C)

In AIDS, HIV infection is at a very advanced stage. The HI virus has already destroyed many CD4 + T lymphocytes and usually reduced their number in the blood to less than 200 per microliter. Clinical AIDS is characterized by the occurrence of at least one of the so-called AIDS-defining diseases. This also corresponds to the Austrian definition of AIDS. In some countries, a mere reduction of CD4 + T lymphocytes to values ​​below 200 per microliter (or below 14 percent) is assigned to the AIDS stage.

AIDS-defining diseases include:

illness Pathogen Symptoms
Pneumocystis jirovecii pneumonia Pneumocystis jiroveci (formerly carinii) (Askomycetes) Dry cough, shortness of breath, fever
Cerebral toxoplasmosis Toxoplasma gondii Headache, subfebrile temperatures, slowing down, seizures, various neurological deficits
tuberculosis Mycobacterium tuberculosis Fever, night sweats, weight loss, productive cough, shortness of breath
Atypical mycobacterial infections Mycobacterium avium complex, kansasii etc. (MOTT) Fever, diarrhea, weight loss, abdominal pain, anemia, night sweats, chills
Recurrent bacterial pneumonia within a year (pneumonia) Streptococci, staphylococci etc. Cough, sputum, shortness of breath, fever
Cytomegalovirus (CMV), retinitis (inflammation of the retina), pneumonia, gastrointestinal tract disease, encephalitis, polyradiculitis, or generalized CMV infection Cytomegalovirus (CMV) (herpes virus) Eye symptoms, symptoms of the gastrointestinal tract, less often of the central nervous system (CNS) or the lungs
Candidiasis of the esophagus (esophagus), windpipe (trachea), bronchi, or lungs Candida spp. typical local symptoms
Kaposi's sarcoma Human herpes virus (HHV) 8 associated Spots, plaques, or lumps (skin, mucous membrane)
Progressive multifocal leukoencephalopathy JC virus (in the brain) Memory and language disorders, changes in personality, increasing neurological deficits
HIV encephalopathy HIV Impairment of concentration and memory, reduced drive as well as disorders of gait and fine motor skills, depression, disinhibition
invasive cervical cancer HPV-associated Discharge, bleeding, possibly pain
Cryptococcal infection that is not in the lungs, such as meningitis Cryptococcus neoformans (yeast fungus) Headache, loss of appetite, fever, dizziness, vomiting, painful stiff neck (meningism), photophobia, neurological deficits
Herpes simplex infections, e.g. chronic ulcers, bronchitis, pneumonia, esophagitis HSV 1/2 typical local symptoms, e.g. on the tongue, the hard palate, in the esophagus or in the genital area
Salmonella septicemia (recurrent) Salmonella spp. (except Salmonella typhi) Vomiting diarrhea, fever, chills, headache
Malignant lymphomas (non-Hodgkin lymphoma, Burkitt tumor, immunoblastic lymphoma, primary lymphoma of the CNS) partly associated with Epstein-Barr virus (EBV) Symptoms on the part of the affected organs
Coccidioidomycosis Coccidioides immitis (mold) flu symptoms, fever, enlarged spleen (splenomegaly), bronchopulmonary symptoms (cough, shortness of breath, etc.)
Intestinal or extrapulmonary cryptosporidiosis (enteritis lasting one month) Cryptosporidium (Protozoon) Watery diarrhea, painful need to stool and urinate, loss of electrolytes, dehydration
Isosporiasis, chronic, intestinal, lasting> 1 month Isospora belli (Protozoon) Discomfort of the gastrointestinal tract, e.g. watery diarrhea, abdominal cramps
Disseminated or extrapulmonary histoplasmosis Histoplasma capsulatum (mushroom) Extremely rare in Europe; disseminated infestation of skin and organs

The categories in laboratory medicine

In laboratory medicine, the following categories are distinguished in connection with HIV / AIDS:

  • Category 1: more than 500 CD4 + T lymphocytes per microliter of blood
  • Category 2: 200 to 500 CD4 + T lymphocytes per microliter of blood
  • Category 3: less than 200 CD4 + T lymphocytes per microliter of blood (or CD4 + T lymphocytes below 14 percent)

These categories can occur in all three clinical stages of HIV infection (category A, B, or C). For more information, see the laboratory values ​​table under HIV / AIDS.

Case definition of AIDS

The EU Commission has established a uniform case definition for the surveillance of AIDS in Europe. According to this, an AIDS case is given if a person has one of the clinical findings (AIDS-defining diseases) that are specified in the European case definition for AIDS. This does not include the criterion of the number of CD4 + T lymphocytes.

For more information on the European case definition of AIDS, see the following websites:

  • EuroHIV under "Case definitions"
  • Decision of the Commission of the European Communities on "Establishing case definitions for communicable diseases reporting to the Community network" (2008).

Popular by topic