[Letter to Peter Duesberg from Harold W. Jaffe]

DEPARTMENT OF HEALTH & HUMAN SERVICES Public Health Service
Centers for Disease Contro
Atlanta GA 30333
March 5, 1993
Prof. Peter Duesberg
Dept. of Molecular and Cell Biology
c/o Stanley/Donner Administrative Services Unit
229 Stanley Hall
Berkeley, California 94720
Dear Prof. Duesberg:
I am writing in response to your letter of February 11, 1993. Through the end of December
1992, a total of 253,448 persons with AIDS had been reported to CDC. The attached table
indicates the reported results of testing for antibodies to HIV by enzyme immunoassay (ETA)
and/or Western blot (WB) in these persons. The CDC estimates that approximately one million
Americans are now infected with HIV, of whom approximately 900,000 have not developed one
of the clinical conditions included in the 1987 AIDS case surveillance definition. Of these
persons, an estimated 125,000 will be reportable under the 1993 revision of the case definition
because they have CD4+ T-lymphocyte counts of less than 200 cells/ul. As part of its
surveillance activities, CDC does not routinely collect behavioral or medical data on persons with
AIDS beyond what is necessary to classify them into HIV transmission categories.
The major risk factors for AIDS - receptive anal intercourse in gay men, injecting drug use,
transfusion therapy, and use of clotting factor concentrates - were all in existence for years to
decades preceding the AIDS epidemic. Yet it was not until the early 1980's that the lifethreatening diseases that we now associate with AIDS occurred as an almost simultaneous
epidemic in persons with these risk factors. The increase in the rate of these diseases was
remarkable. For example, we can estimate that in the 1970's no more than 100 cases of
Pneumcy stis garinij pneumonia (PCP) occurred each year. By 1985, annual PCP cases had
risen to 7,000, and in 1990, 20,000 cases were diagnosed. As you know, the antiviral drug AZT
was not licensed until 1987, yet almost 40,000 AIDS cases had been diagnosed before that year.
In my view, all available epidemiologic studies done since the identification of HIV support the
conclusion that HLV is the etiolog ic agent of AIDS. Perhaps the most compelling early studies
were those in which HIV-infected persons were identified as blood donors to persons who
developed AIDS following transfusion, More recently we have the examples of health-care
workers who become infected following an occupational exposure to lIVy-contaminated blood,
then developed immunodeficiency, followed by an AIDS-defining illness.

5571095.0256.055