Report on the Global HIV/AIDS epidemic

Report on the global HIV/AIDS epidemic - June 2000
Now, AIDS has begun to introduce a completely new shape, the "population chimney". The base of the pyramid is less broad. Many HIV-infected women die or
become infertile long before the end of their reproductive years, which means that
fewer babies are being born; and up to a third of the infants born to HIV-positive
mothers will acquire and succumb to the infection. But the dramatic change in the
population pyramid comes around 10 or 15 years after the age at which people first
become sexually active, when those infected with HIV early in their sexual lives begin
to die off. The populations of women above their early 20s and men above their early
30s shrink radically. As only those who have not been infected survive to older ages,
the pyramid becomes a chimney.
The chimney is illustrated in Figure 7, which shows the dramatic impact that AIDS is
predicted to have on the structure of the population of Botswana, where over a third
of the 775 000 adults are now infected with HIV. The red pyramid shows the population structure as it would be in the absence of an AIDS epidemic. More children would
be born (because more mothers would survive and remain fertile throughout their
reproductive years) and fewer would die because they acquired the virus from their
mothers. Far fewer young adults would die before old age.
Figure 7. Projected population structure with and without the AIDS
epidemic, Botswana, 2020
with AIDS without AIDS
80
75 #I
70f
65 males females E
60
55
50
S 45EE E
40
35
30
25
20
15
10
5
0
140120100 80 60 40 20 0 20 40 60 80 100120140
population (thousands)
Source: US Census Bureau, World Population Profile 2000
The implications of this change in population structure are truly shocking. According
to the United States Census Bureau, there will be more adults in their 60s and 70s
in Botswana in 20 years' time than there will be adults in their 40s and 50s. This projection is based on the assumption that patterns of new infection will not change

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