found within the immune system and are called T-helper cells. The process of trans-
mission of the HIV virus involves the following stages:1 HIV binds to the CD4 molecule of T-helper cell.
2 HIV virus is internalized into the cytoplasm of the cell.
3 The cell itself generates a pro-viral DNA, which is a copy of the host cell.
4 This pro-virus enters the nucleus of the host cell.
5 The host cell produces new viral particles, which it reads off from the viral code of the
viral DNA.
6 These viral particles bud off and infect new cells.
7 Eventually, after much replication, the host T-helper cell dies.The progression from HIV to AIDS
The progression from HIV to HIV disease and AIDS varies in time. AIDS reflects a reduc-
tion in T-helper cells and specifically those that are CD4-positive T-cells. This causes
immune deficiency and the appearance of opportunistic infections. The progression from
initial HIV seroconversion through to AIDS tends to go through the following stages:1 the initial viral seroconversion illness;
2 an asymptomatic stage;
3 enlargement of the lymph nodes, onset of opportunistic infections;
4 AIDS-related complex (ARC);
5 AIDS.The prevalence of HIV and AIDS
Because of the recent identification of HIV and AIDS and due to the long disease-free
interval from seroconversion to AIDS, data on the prevalence and incidence of HIV and
AIDS are limited. However, estimates of the number of cases globally show that 30.6
million people are living with HIV/AIDS and 11.7 million have died from HIV/AIDS.
By continent, data concerning the prevalence of reported incidences of AIDS from the
late 1970s to the end of 1994 indicate the following case statistics: Africa, 350,000;
USA, 400,000; Europe, 127,000; Americas (excluding USA), 123,000; Asia, 20,000;
Oceania, 5000; total, 1,025,000. In the UK, from 1982 to March 1997, 32,200 people
have been diagnosed as HIV+, of whom 15,500 have progressed to AIDS and 12,800
have died from HIV/AIDS-related diseases. In terms of current data, in the UK there are
16,000 people living with a diagnosed HIV infection and in 1997 the following numbers
of new cases were reported across the world: North America, 44,000; Caribbean,
47,000; Latin America, 180,000; Western Europe, 30,000; North Africa and Middle
East, 19,000; sub-Saharan Africa, 4 million; Eastern Europe and Central Asia, 100,000;
East Asia and Pacific, 180,000; South and South East Asia, 1.3 million; Australia and
New Zealand, 600; a total of just over 5.9 million.330 HEALTH PSYCHOLOGY