Feasibility of human T-lymphotropic virus type I screening using pooled sera.
OBJECTIVE
The human T-cell lymphotropic virus type I (HTLV-I) seroprevalence rate among volunteer blood donors in Taiwan is low. To study the feasibility of HTLV-I enzyme immunoassay (EIA) screening using pooled sera, we prospectively compared its sensitivity to that of the routine test for each donor.


METHODS
HTLV-I EIA tests for each serum sample and a pooled-sera test with 50 samples from voluntary donated blood samples were performed concurrently to assess the effectiveness and cost savings of this screening method.


RESULTS
Of 135,606 blood samples from volunteer donors tested for HTLV-I infection, 60 samples (0.044%) were HTLV-I EIA-positive using the routine method. Among these, the positive results were confirmed by Western blot in 22 samples (36.7%). In the pooled-sera test, 17 of 2,713 pooled samples were EIA-positive and these results were all confirmed by Western blot. Five of the 22 (22.7%) EIA-positive samples had a false-negative result in the pooled-sera test. Serial dilution in these five cases revealed that the maximum dilution before loss of sensitivity was 8-fold for two specimens and 16-fold for three specimens.


CONCLUSIONS
In this study, the 50-pooled sera test had higher specificity (100%), but lower sensitivity (77.3%), than the routine HTLV-I screening. Our results suggest that use of a pooling method with five samples would leave a reasonable safety margin and be feasible for HTLV-I mass screening in areas with low seroprevalence for HTLV-I infection.
Chang
Chao-Sung
CS
Blood Bank, Kaohsiung Municipal Hsiao-kang Hospital, Kaohsiung, Taiwan.
Wu
Ya-Wen
YW
Pan
Ya-Chun
YC
Chen
Zi-Yue
ZY
Wang
Ching-Shan
CS
D001800:Blood Specimen Collection / Q000379:methods*; D015153:Blotting, Western; D005240:Feasibility Studies; D015481:HTLV-I Antibodies / Q000302:isolation & purification; D015490:HTLV-I Infections / Q000453:epidemiology*; D015368:Human T-lymphotropic virus 1 / Q000302:isolation & purification*; D006801:Humans; D008403:Mass Screening / Q000379:methods*; D012680:Sensitivity and Specificity; D016036:Seroepidemiologic Studies; D013624:Taiwan / Q000453:epidemiology
D015481:HTLV-I Antibodies