The efficacy of individual-donation and minipool testing to detect low-level hepatitis B virus DNA in Taiwan.
BACKGROUND
Financial constraints are the main concern in implementing nucleic acid testing (NAT) as routine blood screening in Taiwan. The PROCLEIX ULTRIO assay (Ultrio) on the TIGRIS System (Novartis Diagnostics) was evaluated for its operational performance both for individual-donation testing (IDT) and in minipools of 4 (MP4) to develop a feasible solution.


METHODS
Analytical sensitivity was determined by testing WHO international standards. We tested 10,290 blood donors, 4210 in IDT and 6080 in MP4. Potential hepatitis B virus (HBV) yield donors (hepatitis B surface antigen [HBsAg] negative/NAT reactive) were evaluated for up to 9 months' follow-up. Discordant results between the Ultrio assay and the HBsAg tests were further analyzed by HBV antibody serology, alternative NATs, HBV DNA quantification, and sequencing.


RESULTS
The 95% limits of detection in IU/mL (95% confidence interval) were as follows: human immunodeficiency virus Type 1 (HIV-1), 18 (12-34); hepatitis C virus (HCV), 4.4 (2.8-8.9); and HBV, 6.3 (4.4-11). The retest rates were 0.55% for IDT and 0.33% for MP4. No HIV or HCV yield cases were found, while there were 12 potential HBV yield cases, nine from IDT and three from MP4 testing. Eleven of them were successfully genotyped as B2. Ten of them returned for follow-up and mostly were determined as occult HBV infection (OBI). The IDT yield rate of 9 in 4210 (0.21%) was fourfold greater than the MP4 yield rate of 3 in 6080 (0.05%; p < 0.05).


CONCLUSIONS
The higher yield rate for IDT versus MP4 demonstrates the benefit to implement a more sensitive NAT strategy in regions having significant OBI carriers such as Taiwan.
Yang
Meng-Hua
MH
Taipei Blood Center, Taiwan Blood Services Foundation, Taipei, Taiwan.
Li
Lei
L
Hung
Ying-Shen
YS
Hung
Cheng-Shen
CS
Allain
Jean-Pierre
JP
Lin
Kuo-Sin
KS
Tsai
Su-Jen Lin
SJ
D001771:Blood Banks / Q000592:standards; D001782:Blood Donors; D004279:DNA, Viral / Q000097:blood; D005500:Follow-Up Studies; D005838:Genotype; D006678:HIV / Q000235:genetics / Q000302:isolation & purification; D015658:HIV Infections / Q000175:diagnosis / Q000517:prevention & control / Q000635:transmission; D016174:Hepacivirus / Q000235:genetics / Q000302:isolation & purification; D006509:Hepatitis B / Q000175:diagnosis / Q000517:prevention & control* / Q000635:transmission*; D006514:Hepatitis B Surface Antigens / Q000235:genetics; D006515:Hepatitis B virus / Q000235:genetics / Q000302:isolation & purification*; D006526:Hepatitis C / Q000175:diagnosis / Q000517:prevention & control / Q000635:transmission; D006801:Humans; D008403:Mass Screening / Q000379:methods / Q000592:standards; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013624:Taiwan; D000094902:Blood Banking / Q000379:methods*
D004279:DNA, Viral; D006514:Hepatitis B Surface Antigens