Environmental Engineering Reference
In-Depth Information
Every day about 13,000 more people—most of them be-
tween the ages of 15 and 24—become infected with HIV.
According to former U.S. Secretary of State Colin Pow-
ell, “AIDS is...nowmoredestructive than any army,
any conflict, and any weapon of mass destruction.”
Within 7-10 years, at least half of all HIV-infected
people will develop AIDS. This long incubation period
means that infected people often spread the virus for
several years without knowing they are infected.
There
is no vaccine to prevent HIV and no cure for AIDS. Once
you get AIDS, you will eventually die from it,
although
drugs may help some infected people live longer. Un-
fortunately, only a tiny fraction of those suffering from
AIDS can afford to use these costly drugs. Between
1980 and 2005, about 23 million people (502,000 in the
United States) died of AIDS-related diseases.
AIDS has caused the life expectancy of the 700
million people living in sub-Saharan Africa to drop
from 62 to 47 years. The premature deaths of teachers,
health-care workers, and other young productive
adults in such countries leads to diminished education
and health care, decreased food production and eco-
nomic development, and disintegrating families. Such
deaths drastically alter a country's age structure dia-
gram (Figure 14-4). Between 2004 and 2020, the WHO
estimates 60 million more deaths from AIDS. By 2020,
its death toll could reach 5 million per year.
According to the WHO, a global strategy to slow
the spread of AIDS should have five major priorities.
First,
shrink the number of people capable of infecting
others by quickly reducing the number of new infec-
tions below the number of deaths.
Second,
concentrate
on the groups in a society that are most likely to spread
the disease, such as truck drivers, sex workers, and
soldiers.
Third,
provide free HIV testing and pressure
people to get tested.
Fourth,
implement a mass-advertising and educa-
tion program geared toward adults and schoolchild-
ren to help prevent the disease, emphasizing absti-
nence and condom use.
Fifth,
provide free or low-cost
drugs to slow the progress of the disease.
Implementing such a program will require action
by government officials and a massive aid program by
developed nations. These countries will need to send
both monetary aid and workers to help rebuild devas-
tated societies.
100+
95-99
90-94
85-89
80-84
75-79
70-74
65-69
60-64
55-59
50-54
45-49
40-44
35-39
30-34
25-29
20-24
15-19
10-14
5-9
0-4
With AIDS
Without AIDS
Males
Females
120
100 80 60
40
20
02040
60
80 100
120
Population (thousands)
Figure 14-4
Global outlook:
AIDS can affect the age structure
of a population. This figure shows the projected age structure of
Botswana's population in 2020 with and without AIDS. (Data
from U.S. Census Bureau)
Science Case Study: Malaria
Malaria kills about 3 million people per year and has
probably killed more people than all of the wars ever
fought.
About one of every five people in the world—most
of them living in poor African countries—is at risk from
malaria (Figure 14-5). Worldwide, an estimated 300-500
million people are infected with the protozoan para-
sites that cause this disease, and 270-500 million new
cases are reported each year. Malaria is not just a con-
cern for the people living in the areas where it occurs,
but also for anyone traveling to these areas—including
Examine the HIV virus and how it replicates itself by using a
host cell at Environmental ScienceNow.
x
H
OW
W
OULD
Y
OU
V
OTE
?
Should developed and devel-
oping countries mount a global crash program to reduce the
spread of AIDS and to help countries affected by this dis-
ease? Cast your vote online at http://biology.brookscole
.com/miller11.
Figure 14-5
Global outlook:
distribution of malaria. About 40%
of the world's population live in areas in which malaria is pre-
sent. Malaria kills about 3 million people each year. (Data from
the World Health Organization and U.S. Centers for Disease
Control and Prevention)
