Table 3.

Tabulated data on the prevalence of viral load in case-positive COVID-19 patients, asymptomatic donors, or in a random pool of blood donations [5, 17, 30, 35, 36, 37, 38, 39, 46, 47, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60]

First author [Ref.]	Location	Type and timing of blood collection	Positive for RNA	CT value	Notes
Chen [49]*	Guangzhou Eighth People's hospital	Serum; positives collected 6-12 days after onset	6/57	24-39	6/6 progressed to severe stage 12/57 who were not blood positive were severe cases
Chan [46]	Hong Kong	Plasma; 4–13 days after onset	10/47	NS	Used RdRp-P2 assay; did not state clinical symptoms of patients
Lescure [50]	France: Paris + Bordeaux	Plasma/WB − collected day 7–9, and 12 after onset of symptoms	1/5	37.1	Patient was old and died after 24 days
Wang [51]	China: Hubei, Shandong, Beijing	Collected throughout the illness	3/307	34.6	205 patients, 307 blood specimen samples
Chan [52]*	China: Shenzen	Serum sample; positive sample came 6 days after onset	1/7	40	Single RNAaemia patient had the most severe disease
Zhou [47]*	China: Wuhan (Jin Yin Tan Hospital)	Blood collected 18–29 days after onset	0/5	NS	All patients had severe pneumonia; only 5 serum samples obtained from all 7 patients
Huang [5]*	China: Wuhan (Jin Yin Tan Hospital)	Plasma	6/41	35.1	All patients had pneumonia. 2/6 were placed in ICU care
Kim [53]	Korea	Serum detected 3–5 days after onset	6/74	NA	Measured in copies/µL (127)
Peng [54]*	China: Guangzhou (Sun Yat-sen Hospital)	Blood − 3 days from onset	2/9	NA	Measured qRT-PCR, copies/mL (8.04 and 9.1)
Zhang [55]*	China: Wuhan Pulmonary Hospital	Whole blood	6/15	30.3–32.1	None of the blood positves were oral/anal swabs positive; 2/6 had severe diseases
Yu [30]*	China: Beijing Ditan Hospital	Plasma; unclear timing	0/4	Cutoff 38	Unclear whether from 4 samples of 4 different patients
Huang [56]*	China: Guangzhou Medical University	Blood; 10–12 days after onset	1/16	30.10–37.57	All 16 patients admitted in ICU
Chen [57]*	China: General Hospital of Central Theatre Command, Wuhan	Serum	5/48	34.58–39.01	The number of patients tested positive for N gene was 3, and 5 for the ORF1 antibody; all 5 were from critically ill group, 2 of which died; serum samples from moderate or severe group tested negative
Wu [58]	China: Renmin Hospital, Wuhan	Blood; NS timing	4/132	NS	Did not specify clinical symptoms of these 4 patients
Zheng [35]**	China: Zhejiang University	Serum: after admission	39/95	Cutoff <38	6/22 were from mild patients; 33/75 were from severe patients
		Serum 4 weeks after admission	5/55		All 5 remaining samples that tested positive were from severe patients
Corman [60]	Germany	Plasma (7/8 blood samples from that 1 patient tested negative)	1/18	NS	Patient had ARDS; low detection, yielding 179 copies/mL
Cappy [36]	France: Paris	Blood samples from asymptomatic donors	3/311	CT >37	These 311 are all positive patients that reported sickness. Donor 1's products were transfused with no transmission recorded; unknown statuses of all 311 patients
Percivalle [37]	Italy: Lodi Red Zone (10 cities)	Blood samples from asymptomatic donors	20/390	NS	8 reported no symptoms, while the rest developed mild symptoms −390/2,272 total blood donors
Chang [17]	China: Hubei (12 blood centres)	Whole blood and platelet products from a random pool of donations	0/98,342	NS	Unknown how many of those 98,342 donors are actually COVID-19 positive
Change [59]#	China: Wuhan Blood Centre	Whole blood and platelet products from a random pool of donors	4/2,420	NS	All 4 donors were asymptomatic during time of donation; 2 remained asymptomatic, while the other 2 developed fever
Xu [38]#	China: Guangzhou	Whole blood products from a random pool of donors	0/2,199	NS	7 donors were reactive for SARS-CoV-2 antibodies, but ultimately all tested negative for viral RNA
Waheed [39]#	Pakistan: Kashmir	FFP from a random pool of donors	2/690	NS	Both donors remained asymptomatic

^*Articles that were pooled for meta-analysis whereby the study was conducted in China and came from one local origin.

^**Zheng had two data reported but only one data was used.

^#Articles that were pooled in a separate meta-analysis forest plot as they were data showcasing single origin blood centres performing RT-PCRs, on donated blood products.