Blood donors who are repeatedly reactive for hepatitis C virus on enzyme immunoassay and positive on recombinant immunoblot assay: evidence of failure to identify some risk factors.

BACKGROUND

Despite the introduction of surrogate testing and subsequent antibody testing of donor blood, transmission of hepatitis C virus (HCV) still occurs. The institution from which this report originates is a medical center, and many of the blood donors have also been seen as patients at the institution. This provided an opportunity for comparison of donor questionnaire responses and medical history information and for correlation of those findings with HCV test results.

STUDY DESIGN AND METHODS

HCV polymerase chain reaction (PCR) testing was performed on nine stored frozen sera from donors or former donors with previous positive results on HCV enzyme immunoassay (EIA) (first- or second-generation) and recombinant immunoblot assay (RIBA) (first- or second-generation). The medical histories were also reviewed for 22 of 23 such HCV EIA-repeatedly reactive, RIBA-positive donors and 88 randomly chosen HCV-negative donors. The lifestyle information was compared with the donors' responses on the blood donation questionnaires. The data were then correlated with available clinical and laboratory evidence of HCV transmission to transfusion recipients.

RESULTS

For eight donors, there were no recipients of their blood to be assessed. For 9 of the remaining 15 donors, there were recipients who were tested for HCV. Recipients of blood from 5 of these 9 donors were repeatedly reactive for HCV; while recipients of blood from 4 donors were not. Donor PCR positivity correlated with apparent transmission (p = 0.047). Twelve of 20 HCV EIA-positive donors for whom history and questionnaires were available for comparison had at least one suggestive lifestyle or established risk factor in their medical records, while none of 88 HCV-negative controls did (p < 0.0001). The data did not indicate that paid donation correlated with failure to disclose these factors.

CONCLUSION

Despite more explicit and intrusive donor questioning, it is still not possible to identify all possible risk factors at donations, though many donors who do not disclose all their risk factors are eliminated from the pool by the increasingly sensitive donor tests. As long as tests are not completely foolproof, workers must be vigilant regarding the ability to elicit complete information on a donor's risk. Further study is required to determine the best way(s) to do so.