Primary screening of blood donors by nat testing for HCV-RNA: development of an "in-house" method and results.
An "in-house" RT-PCR method was developed that allows the simultaneous detection of the RNA of the Hepatitis C Virus (HCV) and an artificial RNA employed as an external control. Samples were analyzed in pools of 6-12 donations, each donation included in two pools, one horizontal and one vertical, permitting the immediate identification of a reactive donation, obviating the need for pool dismembering. The whole process took 6-8 hours per day and results were issued in parallel to serology. The method was shown to detect all six HCV genotypes and a sensitivity of 500 IU/mL was achieved (95% hit rate). Until July 2005, 139,678 donations were tested and 315 (0.23%) were found reactive for HCV-RNA. Except for five false-positives, all 310 presented the corresponding antibody as well, so the yield of NAT-only donations was zero, presenting a specificity of 99.83%. Detection of a window period donation, in the population studied, will probably demand testing of a larger number of donations. International experience is showing a rate of 1:200,000 - 1:500,000 of isolated HCV-RNA reactive donations.
Wendel
Silvano
S
Banco de Sangue, Hospital Sírio Libanês, São Paulo, SP, Brasil. snwendel@uninet.com.br
Levi
José Eduardo
JE
Takaoka
Deise Tihe
DT
Silva
Isabela Cristina
IC
Castro
Juliana Polachini de
JP
Torezan-Filho
Mário A
MA
Ghaname
Jorge
J
Gioachini
Romualdo
R
Brandão
Joselito
J
Durigon
Edison Luis
EL
D001782:Blood Donors; D015153:Blotting, Western; D005838:Genotype; D016174:Hepacivirus / Q000235:genetics* / Q000302:isolation & purification; D006526:Hepatitis C / Q000175:diagnosis*; D006801:Humans; D021141:Nucleic Acid Amplification Techniques / Q000379:methods*; D012367:RNA, Viral / Q000097:blood*; D015203:Reproducibility of Results; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012680:Sensitivity and Specificity
D012367:RNA, Viral