1996 January Australian HIV Surveillance Report

The Australian HIV Surveillance Report has been published on a quarterly basis from July 1990. Reports published from January 1994 are available below. Each report includes article(s) on topics of general interest in the epidemiology of HIV and related infections updates on the number of cases of newly diagnosed HIV infection and AIDS in Australia estimates of HIV incidence and prevalence among people seen through a network of sexual health clinics in Australia.

The Australian HIV Surveillance Update provides a brief summary of HIV and AIDS diagnoses in the most recent quarter, the most recent year and cumulative counts. The Australian HIV Surveillance Update was published separately prior to the July 2000 issue of the Australian HIV Surveillance Report. Updates post April 2000 are included in the Australian HIV Surveilance Report.

Key findings
  • There has been recent interest in both the scientific and popular media concerning subtypes of the human immunodeficiency virus (HIV). Since the first published sequence of HIV-1 in 1985, it has been recognised that extensive genetic variability of HIV-1 exists, both between and within individuals. This variation is most obvious in the¬†envelope (env) gene of HIV-1, and analysis of the sequences that make up the env gene allows HIV-1 to be classified into multiple genetic subtypes (or clades).
  • There are two subtype groups of HIV-1. Within the main group (M), which has been most extensively analysed, are subtypes A-H, while the outlier (O) group includes divergent sequences from Cameroon and France, which may differ among themselves as much¬†as they do from the M group.
  • Certain subtypes of HIV-1 appear to predominate in different geographical regions. For example, it is known that two subtypes predominate in Thailand; subtype E is the most common and has been isolated in people apparently infected by heterosexual contact, and subtype B occurs mainly among injecting drug users.
  • There are a number of reasons why subtyping of HIV is important. Knowledge of circulating subtypes allows one to follow the movement of HIV or indicate the origin of HIV strains in communities, assisting the targeting of appropriate interventions.
  • Knowledge of subtype variation is also necessary in the design of HIV vaccines and may have relevance to therapy if different pathogenic features of individual subtypes are identified.