Abstract: Objective Infection status one case of low concentrations of HIV RNA window period blood donor was confirmed by combined serological and molecular biological Methods. Methods On serological ELISA Results qualified blood specimens for nucleic acid detection,1 case of low concentration of HIV window period were found via the method of qualitative and quantitative detection of nucleic acids （NAT）,the donor's samples in different periods of blood specimens of HIV viral load were detected. Results The first time blood donor samples tested negative by ELISA serology,nucleic acid reactive qualitative test,followed by quantitative nucleic acid testing is less than 20 copies / mL; for follow-up samples collected serological and nucleic acid testing,final confirmation serum turn positive. Conclution The blood donor is a very low viral load of 1 HIV window period of blood donors,NAT detection technology and ELISA detection combined to further protect the safety of clinical use of blood.

Key words: HIV, Window period, Enzyme-linked immunosorbent assay, Nucleic acid test