Table 1.

The PCR detection and serology of SARS‐CoV‐2 after symptoms onset

Patient	Days from symptom onset	PCR result (viral copies/reaction) a	Sampling site	Serology result (realized on serum samples) b
1	8	Positive (unknown)	NPS
	32	Negative	NPS
	35	Negative	NPS
	39	Positive (590,000)	BAL	IgG 1.22 (doubtful)
		Positive (54)	Serum	IgA 0.89 (doubtful)
	42	Positive (478,000)	ETA
		Negative	NPS
	48	Positive (9,700)	BAL
		Positive (60,000)	ETA
		Negative	NPS
	55	Positive (11,950,000)	ETA
		Positive (62)	NPS
	67	Positive (low)	NPS
	68	Negative	Serum	IgG 0.74 (doubtful)
IgA 8.24 (positive)
	73	Negative	NPS
	77	Negative	NPS
2	1	Positivec	NPS
	34	Negative	NPS
	35	Positive (24,630,000)	BAL	IgG 0.61 (doubtful)
		Negative	Serum	IgA 5.34 (positive)
	41	Negative	NPS
	43	/		IgG 1.16 (doubtful)
IgA 2.97 (positive)
	45	Positive (97)	Plasma
	54	Negative	Serum

Abbreviations: BAL, bronchoalveolar lavage; ETA, endotracheal aspirate; IgA, immunoglobulin A; IgG, immunoglobulin G; NPS, nasopharyngeal swab; PCR, polymerase chain reaction; RT‐PCR, reverse transcription PCR; SARS‐CoV‐2, severe acute respiratory syndrome coronavirus 2.

^a SARS‐CoV‐2 was identified via RT‐PCR according to the current guidelines (Institut Pasteur and the WHO technical guidance). The assay targets two regions of the viral RNA‐dependent RNA polymerase (RdRp) gene and has the threshold limit of detection of 10 copies per reaction.

^b SARS‐CoV‐2 serological diagnostic was performed according manufacturer instructions:

– IgA were detected using the Euroimmun assays (negative: ratio <0.8; doubtful: 0.8‒1.1; positive: >1.1).

– IgG were detected using the Abbott architect assay (negative: ratio <0.49; doubtful: 0.49‒1.4; positive: >1.4).

^c Viral load was not available for this sample; the threshold cycle value was 27.