Use of blood donation history of people with HIV infection to identify recipients at risk.

OBJECTIVE: To determine whether previous blood donations from HIV-positive patients posed a threat to recipients.
DESIGN: Interviewer-administered questionnaire survey.
SETTING: Regional HIV outpatient referral clinic for southern Alberta. PATIENTS: All 478 patients attending the clinic from May 1, 1993, to Mar. 31, 1994; 366 were excluded: 335 had not donated blood, and 31 could not provide reliable information regarding possible donations.
INTERVENTIONS: Patients were asked at a routine clinic visit regarding the dates, frequency and location of previous blood donations. The Canadian Red Cross was informed, with patient consent, if the previous donations posed a potential risk of HIV transmission. OUTCOME MEASURES: Number of HIV-positive patients whose donations posed a possible or definite risk to recipients.
RESULTS: A total of 545 units of blood had been donated by the 112 patients in the study; 57 units (donated by 29 patients) posed a possible risk, and 12 (given by 11 patients) posed a definite risk of HIV transmission to the recipients. Thirty-two of these donors had been unknown to the Red Cross through its "look-back" and "trace-back" protocols. Only 1 of the 13 patients found to be HIV positive by the Red Cross openly admitted donating blood to undergo HIV antibody testing; the remainder were either ill-informed or did not perceive themselves to be at risk. The patients were highly mobile, 36.7% donating blood at some time in a province other than the one where they had received their positive HIV test result.
CONCLUSION: Asking HIV-positive patients about their blood donation history, although subject to recall bias, is a simple and inexpensive method for identifying high-risk blood donations. The Red Cross should routinely be notified, with patient consent, of all donations posing a risk in order to enhance the prospect for identifying HIV-positive blood recipients.