Diagnosis of HIV infection

Diagnosis of HIV infection:

Since June 5, 1981, many definitions have been developed for epidemiological surveillance such as the Bangui definition and the 1994 expanded World Health Organization AIDS case definition. However, clinical staging of patients was not an intended use for these systems as they are neither sensitive, nor specific. In developing countries, the World Health Organization staging system for HIV infection and disease, using clinical and laboratory data, is used and in developed countries, the Centers for Disease Control (CDC) Classification System is used.

WHO disease staging system for HIV infection and disease :

In 1990, the World Health Organization (WHO) grouped these infections and conditions together by introducing a staging system for patients infected with HIV-1. An update took place in September 2005. Most of these conditions are opportunistic infections that are easily treatable in healthy people.
Stage I: HIV infection is asymptomatic and not categorized as AIDS
Stage II: includes minor mucocutaneous manifestations and recurrent upper respiratory tract infections
Stage III: includes unexplained chronic diarrhea for longer than a month, severe bacterial infections and pulmonary tuberculosis
Stage IV: includes toxoplasmosis of the brain, candidiasis of the esophagus, trachea, bronchi or lungs and Kaposi's sarcoma; these diseases are indicators of AIDS.

CDC classification system for HIV infection:

In the beginning, the Centers for Disease Control and Prevention (CDC) did not have an official name for the disease, often referring to it by way of the diseases that were associated with it, for example, lymphadenopathy, the disease after which the discoverers of HIV originally named the virus. They also used Kaposi's Sarcoma and Opportunistic Infections, the name by which a task force had been set up in 1981. In the general press, the term GRID, which stood for Gay-Related Immune Deficiency, had been coined. However, after determining that AIDS was not isolated to the homosexual community, the term GRID became misleading and AIDS was introduced at a meeting in July 1982.By September 1982 the CDC started using the name AIDS, and properly defined the illness. In 1993, the CDC expanded their definition of AIDS to include all HIV positive people with a CD4+ T cell count below 200 per µL of blood or 14% of all lymphocytes.The majority of new AIDS cases in developed countries use either this definition or the pre-1993 CDC definition. The AIDS diagnosis still stands even if, after treatment, the CD4+ T cell count rises to above 200 per µL of blood or other AIDS-defining illnesses are cured.

Revised World Health Organization (WHO) Clinical Staging of HIV/AIDS For Adults and Adolescents (2005):

(This is the interim African Region version for persons aged 15 years or more who have had a positive HIV antibody test or other laboratory evidence of HIV infection) (It must be noted that the UN defines adolescents as persons aged 10−19 years but for surveillance purposes, the category of adults and adolescents comprises people aged 15 years and over)

1.Primary HIV infection

Asymptomatic
Acute retroviral syndrome

2.Clinical stage 1

Asymptomatic
Persistent generalized lymphadenopathy

3.Clinical stage 2

Moderate and unexplained weight loss (<10% of presumed or measured body weight)
Recurrent respiratory tract infections (such as sinusitis, bronchitis, otitis media, pharyngitis)
Herpes zoster
Recurrent oral ulcerations
Papular pruritic eruptions
Angular cheilitis
Seborrhoeic dermatitis
Fungal finger nail infections

3.Clinical stage 3

Conditions where a presumptive diagnosis can be made on the basis of clinical signs or simple investigations
Unexplained chronic diarrhoea for longer than one month
Unexplained persistent fever (intermittent or constant for longer than one month)
Severe weight loss (>10% of presumed or measured body weight)
Oral candidiasis
Oral hairy leukoplakia
Pulmonary tuberculosis (TB) diagnosed in last two years
Severe presumed bacterial infections (e.g. pneumonia, empyema, meningitis, bacteraemia, pyomyositis, bone or joint infection)
Acute necrotizing ulcerative stomatitis, gingivitis or periodontitis

Conditions where confirmatory diagnostic testing is necessary
Unexplained anaemia (<>

4. Clinical stage 4

Conditions where a presumptive diagnosis can be made on the basis of clinical signs or simple investigations
HIV wasting syndrome
Pneumocystis pneumonia
Recurrent severe or radiological bacterial pneumonia
Chronic herpes simplex infection (orolabial, genital or anorectal of more than one month’s duration)
Oesophageal candidiasis
Extrapulmonary Tuberculosis
Kaposi’s sarcoma
Central nervous system toxoplasmosis
HIV encephalopathy

Conditions where confirmatory diagnostic testing is necessary:
Extrapulmonary cryptococcosis including meningitis
Disseminated non-tuberculous mycobacteria infection
Progressive multifocal leukoencephalopathy
Candida of trachea, bronchi or lungs
Cryptosporidiosis
Isosporiasis
Visceral herpes simplex infection
Cytomegalovirus (CMV) infection (retinitis or of an organ other than liver, spleen or lymph nodes)
Any disseminated mycosis (e.g. histoplasmosis, coccidiomycosis, penicilliosis)
Recurrent non-typhoidal salmonella septicaemia
Lymphoma (cerebral or B cell non-Hodgkin)
Invasive cervical carcinoma
Visceral leishmaniasis