The Relationship between the Human Immunodeficiency Virus and the Acquired Immunodeficiency Syndrome (Draft)

DRAFT
has lengthened slightly in recent years (Hessol et al., 1994). Even taking into consideration
the benefits of improved PCP prophylaxis and treatment, if AZT were contributing to or
causing disease, one would expect a decrease in survival figures, rather than an increase that
parallels the use of AZT.
It has also been argued that HIV cannot cause AIDS because the body develops HIVspecific antibodies following primary infection (Duesberg, 1987-1994; Thomas et al., 1994).
This reasoning ignores numerous examples of viruses other than HIV that can be pathogenic
after evidence of immunity appears (Oldstone, 1989). Primary poliovirus infection is a classic
example of a disease in which high titers of neutralizing antibodies develop in all infected
individuals, yet a small percentage of individuals develop subsequent paralysis (Kurth, 1990).
Measles virus may persist for years in brain cells, eventually causing a chronic neurologic
disease despite the presence of antibodies (Gershon, 1990). Viruses such as
cytomegalovirus, herpes simplex and varicella zoster may be activated after years of latency
even in the presence of abundant antibodies (Weiss and Jaffe, 1990). Lentiviruses with long
and variable latency periods, such as visna virus in sheep, cause central nervous system
damage even after the specific production of neutralizing antibodies (Haase, 1990).
Geographic Considerations
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 in populations with a high seroprevalence of HIV antibodies.
Conversely, in populations with low seroprevalence of HIV antibodies, AIDS is extremely rare
(U.S.. Bureau of the Census, 1994). Malawi, a country in southem Africa with 8.2 million
inhabitants, reported 31,857 cases of AIDS to the WHO as of June 1994; this is the highest
case rate in the region (WHO, I1994a; Latif, 1994). The rate of HIV seroprevalence in this
country is high, even among persons not considered to be at high risk for AIDS, such as
pregnant women and blood donors. In two large surveys of pregnant women reported in
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