(2020/02/24)Viral load of SARS-CoV-2 in clinical samples(+中文摘要轉譯)

研究蒐集2名北京病患,自住院後每天的咽喉棉棒、痰、尿液、及糞便檢體,以RT-PCR檢測檢體中的病毒量。在這2名病患中,咽喉棉棒及痰液的病毒量於發病後5-6天達到高峰,痰液中的病毒量通常大於咽喉棉棒;尿液及糞便檢體無檢出病毒RNA。研究另外蒐集80名不同感染期患者呼吸道檢體。整體而言,感染初期,病毒量已經很高(>1×106 copies/mL):一鑒於死亡個案發病後8天採檢的痰液檢體,病毒量已高達1.34×1011 copies/mL;2名因與感染者接觸主動追蹤個案在發病前RT-PCR已為陽性反應,顯示感染個案在發病前可能已有傳染力。在17名確診病患的糞便檢體中,有9名RT-PCR呈陽性反應,病毒量約為550~1.21×105 copies/mL。(國衛院莊淑鈞博士整理)

An outbreak caused by a novel human coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was first detected in Wuhan in December 2019,1 and has since spread within China and to other countries. Real-time RT-PCR assays are recommended for diagnosis of SARS-CoV-2 infection.2 However, viral dynamics in infected patients are still yet to be fully determined. Here, we report our findings from different types of clinical specimens collected from 82 infected individuals.

Serial samples (throat swabs, sputum, urine, and stool) from two patients in Beijing were collected daily after their hospitalisation (patient 1, days 3–12 post-onset; patient 2, days 4–15 post-onset). These samples were examined by an N-gene-specific quantitative RT-PCR assay, as described elsewhere.3 The viral loads in throat swab and sputum samples peaked at around 5–6 days after symptom onset, ranging from around 104 to 107 copies per mL during this time (figure A, B). This pattern of changes in viral load is distinct from the one observed in patients with SARS, which normally peaked at around 10 days after onset.4 Sputum samples generally showed higher viral loads than throat swab samples. No viral RNA was detected in urine or stool samples from these two patients.

Author:Yang Pan, Daitao Zhang, Peng Yang, et al.