The Relationship between AIDS and HIV June 7, 2000 Convincing
evidence that HIV causes AIDS also comes from the geographic
correlation between rates of HIV antibody positivity and
incidence of disease. Numerous studies have shown that AIDS is
common only in populations with a high seroprevalence of HIV
antibodies. Conversely, in populations in which HIV antibody
seroprevalence is low, AIDS is extremely rare (U.S. Bureau of
the Census, 1994). Malawi, a country in southern Africa with 8.2
million inhabitants, reported 34,167 cases of AIDS to the WHO as
of December 1994 (WHO, 1995a). This is the highest case rate in
the region. The rate of HIV seroprevalence in Malawi is also
high, as evidenced by serosurveys of pregnant women and blood
donors (U.S. Bureau of the Census, 1994). In one survey,
approximately 23 percent of more than 6,600 pregnant women in
urban areas were HIV-positive (Dallabetta et al., 1993).
Approximately 20 percent of 547 blood donors in a 1990 survey
were HIV-positive (Kool et al., 1990). In