Development and Evaluation of a Novel RT‐PCR System for Reliable and Rapid SARS‐CoV‐2 Screening of Blood Donations

Li, Meng; Zhao, Yuwei; Li, Ying; Chen, Xue; Luo, Dongxia; Luo, Mei; Hou, Jue; Liu, Juan; Liu, Humin; Wang, Huan; Dong, Yufang; Zhang, Lanjiang; Ji, Maosheng; Zhao, Xin; Wei, Caibing; Li, Wen; Gao, Jialiang; Shan, Hua; Fu, Xuemei

BACKGROUND: The ongoing outbreak of SARS‐CoV‐2 has caused great global concerns. In contrast to SARS, some SARS‐CoV‐2 infected people can be asymptomatic or only have mild non‐specific symptoms. Furthermore, there is evidence that SARS‐CoV‐2 may be infectious during an asymptomatic incubation period. With the discovery that SARS‐CoV‐2 can be detected in plasma or serum, blood safety is worthy of consideration. STUDY DESIGN AND METHODS: We developed a NAT screening system for SARS‐CoV‐2 targeting nucleocapsid protein (N) and open reading frame 1ab (ORF 1ab) gene which could screen 5076 samples every 24 hours. 2019‐nCoV RNA standard was used to evaluate linearity of standard curves. Diagnostic sensitivity and reproducibility were evaluated using artificial SARS‐CoV‐2 virus. Specificity was evaluated with 61 other respiratory pathogens. Diagnostic performance was evaluated by testing 2 sputum and 9 oropharyngeal swab specimens. The RT‐PCR assay was used to screen SARS‐CoV‐2 RNA in blood donors specimens collected during the outbreak of SARS‐CoV‐2 in Chengdu. RESULTS: LOD of the SARS‐CoV‐2 RT‐PCR assay for N and ORF 1ab gene were 12.5 and 27.58 copies/mL, respectively. Intra‐assay and inter‐assay for SARS‐CoV‐2 RT‐PCR assay based on Ct were acceptably low. No cross‐reactivity was observed with other respiratory virus and bacterial isolates. The overall agreement value between SARS‐CoV‐2 RT‐PCR assay and clinical diagnostic results were 100%. A total of 16 287 blood specimens collected from blood donors during SARS‐CoV‐2 surveillance were tested negative. CONCLUSIONS: A high throughput NAT screening system was developed for SARS‐CoV‐2 screening of blood donations during the outbreak of SARS‐CoV‐2.