see also:

• HIV / AIDS

• AIDS is diagnosed when the immune system of a person infected with HIV becomes severely compromised (measured by CD4 cell count) and⁄or the person becomes ill with an opportunistic infection or illness.
• without treatment, AIDS usually develops 8 to 10 years after initial HIV infection;
• with early HIV diagnosis and treatment, this may be delayed by many years.
• the 1st documented case in Australia is thought to be Harvey, a 72yr old Sydney man who had never traveled overseas and became ill in Feb 1981 was later diagnosed with pneumocystis pneumonia which killed him by Sept 1981 - further tests in the 1990s showed he did indeed have HIV.¹⁾

• in 2008 the CDC moved towards a HIV staging model to classify the disease²⁾:
  • HIV infection, stage 1:
    • No AIDS-defining condition and either CD4+ T-lymphocyte count of >500 cells/µL or CD4+ T-lymphocyte percentage of total lymphocytes of >29.
  • HIV infection, stage 2:
    • No AIDS-defining condition and either CD4+ T-lymphocyte count of 200–499 cells/µL or CD4+ T-lymphocyte percentage of total lymphocytes of 14–28.
  • HIV infection, stage 3 (AIDS):
    • see AIDS definition
  • HIV infection, stage unknown:
    • No information available on CD4+ T-lymphocyte count or percentage and no information available on AIDS-defining conditions.

CD4+ T-cell count below 200 cells/µl

OR

CD4+ T-cell percentage of total lymphocytes of less than 14%

OR

presence of an AIDS-defining illness in a person with HIV infection

Documentation of an AIDS-defining condition supersedes a CD4+ T-lymphocyte count of >200 cells/µL and a CD4+ T-lymphocyte percentage of total lymphocytes of >14.

Criteria for HIV Infection:

Children aged 18 months to <13 years are categorized as HIV infected for surveillance purposes if at least one of laboratory criteria or the other criterion is met.

Criteria for AIDS:

Children aged 18 months to <13 years are categorized for surveillance purposes as having AIDS if the criteria for HIV infection are met and at least one of the AIDS-defining conditions has been documented

see http://www.cdc.gov/mmwr/preview/mmwrhtml/rr5710a1.htm

Criteria for Definitive or Presumptive HIV Infection:

A child aged <18 months is categorized for surveillance purposes as definitively or presumptively HIV infected if born to an HIV-infected mother and if the laboratory criterion or at least one of the other criteria is met.

see http://www.cdc.gov/mmwr/preview/mmwrhtml/rr5710a1.htm

The following is from the CDC (2008)³⁾:

• Bacterial infections, multiple or recurrent%
• Candidiasis of bronchi, trachea, or lungs
• Candidiasis of oesophagus†
• Cervical cancer, invasive§
• Coccidioidomycosis, disseminated or extrapulmonary
• Cryptococcosis, extrapulmonary
• Cryptosporidiosis, chronic intestinal (>1 month's duration)
• Cytomegalovirus disease (other than liver, spleen, or nodes), onset at age >1 month
• Cytomegalovirus retinitis (with loss of vision)†
• Encephalopathy, HIV related
• Herpes simplex: chronic ulcers (>1 month's duration) or bronchitis, pneumonitis, or esophagitis (onset at age >1 month)
• Histoplasmosis, disseminated or extrapulmonary
• Isosporiasis, chronic intestinal (>1 month's duration)
• Kaposi sarcoma†
• Lymphoid interstitial pneumonia or pulmonary lymphoid hyperplasia complex%†
• Lymphoma, Burkitt (or equivalent term)
• Lymphoma, immunoblastic (or equivalent term)
• Lymphoma, primary, of brain
• Mycobacterium avium complex or Mycobacterium kansasii, disseminated or extrapulmonary†
• Mycobacterium tuberculosis of any site, pulmonary,†§ disseminated,† or extrapulmonary†
• Mycobacterium, other species or unidentified species, disseminated† or extrapulmonary†
• Pneumocystis jirovecii pneumonia†
• pneumonia, recurrent†§
• progressive multifocal leukoencephalopathy (PML)
• Salmonella septicemia, recurrent
• toxoplasmosis of brain, onset at age >1 month†
• Wasting syndrome attributed to HIV

% Only among children aged <13 years. (CDC. 1994 Revised classification system for human immunodeficiency virus infection in children less than 13 years of age. MMWR 1994;43[No. RR-12].)

† Condition that might be diagnosed presumptively.

§ Only among adults and adolescents aged >13 years. (CDC. 1993 Revised classification system for HIV infection and expanded surveillance case definition for AIDS among adolescents and adults. MMWR 1992;41[No. RR-17].)