Study of the natural development of something (such as an organism or a disease) over a period of time, with or without the intervention of treatment.

National Centre in HIV Epidemiology and Clinical Research. Based at the University of NSW in Sydney, NCHECR is one of Australia's leading medical research centres and is recognised internationally as a leader in the field of research into HIV/AIDS and viral hepatitis.

National Centre in HIV Social Research. Located at the University of NSW in Sydney, NCHSR website. ">NCHSR conducts research which describes and analyses the social understandings, meanings and practices of peoples, institutions and communities in relation to HIV, Hepatitis C and other communicable diseases. For further information, see the NCHSR website.

Non-Government Organisation.

National HIV/AIDS Support Project [Papua New Guinea]

A type of anti-HIV drug that works by inhibiting a stage of the HIV life cycle called reverse transcription. Non-nucleosides work in a similar way, but are chemically different.