they were members of high-risk groups) and had not yet been used. None of the letters required, by its terms, that collection centers or plasma fractionators segregate or destroy products collected or manufactured prior to the date of the letters. The Committee believes, however, that collection centers or plasma fractionators could have interpreted these recommendations as requiring that they withdraw or at least segregate all products that they had collected from unscreened donors and were currently in their stocks. Because these letters asserted that they were based upon a consensus of the collection centers and the plasma fractionators, the Committee believes that the letters suggested that these practices were ongoing at most, if not all, blood collection centers and blood products manufacturers at the time that the letters were issued.

The Committee has not been able to determine definitively what the intended legal effect of these letters was or precisely how the letters were understood by their recipients. There are reports, both in testimony prepared for this Committee (McAuley interview; Gury 1982) and in the summary of the Public Health Service's Workshop to Identify Opportunities for Prevention of Acquired Immune Deficiency Syndrome (1983), suggesting that blood and plasma collection centers were engaging in some types of donor screening activities as early as December 1982 (Silvergleid interview; Gury 1982; see also Chapter 5). On December 17, 1982, Alpha Therapeutics began excluding the use of plasma from all donors who had been in Haiti, had used IV drugs, or, if male, had sexual contact with another man (Gury 1982). Alpha Therapeutics also adopted a policy effective December 26, 1982, that its affiliates should no longer send it any unscreened plasma (Gury 1982). There are, in addition, indications from the National Hemophilia Foundation's (NHF) Medical and Scientific Advisory Council (MASAC) (NHF 1983) and from recommendations of the ABRA issued on January 28, 1983, that most plasma fractionators and collection centers were moving toward donor screening and donor education programs in January 1983. Hence, it is impossible to know to what extent the stock of plasma or whole blood present in March 1983 contained blood or plasma that had not been subjected at least to some forms of donor screening.

On the other hand, donor screening practices may have varied substantially up to this point and may have been routine only in some organizations. Nor is there evidence that plasma fractionators were engaging in precisely the segregation and selective processing activities suggested by the Petricciani letters (1983a,b,c). Hence, it seems reasonable to suppose that there were substantial stocks of products in plasma fractionators' inventories and elsewhere that had not been screened in accordance with the FDA letters' directions.