Table 3.

The specificity of the five evaluated IgG ELISA kits according to the negative control subgroups (n = 70).

Subgroup with IgG/IgM antibodies against	No. of samples	Specificity (%, 95% confidence interval)
		EDI	AnshLabs	Dia.Pro	NovaTec	Lionex
Other coronaviruses (SARS-CoV, MERS-CoV, HCoV-229E, NL63, OC43, and HKU1)*	20	19/20 (95.0%; 76.4–99.1%)	17/20 (85.0%; 64.0–94.8%)	19/20 (95.0%; 76.4–99.1%)	17/20 (85.0%; 64.0–94.8%)	20/20 (100%; 83.9–100%)
Non-CoV respiratory viruses (Influenza and RSV)*	15	15/15 (100%; 79.6–100%)	9/15 (60.0%; 35.8–80.2%)	14/15 (93.3%; 70.2–98.8%)	11/15 (73.3%; 48.1–89.1%)	15/15 (100%; 79.6–100%)
Non-respiratory viruses (HEV, HGV, HCV, HBV, DENV, WNV, CHIKV, B19, HSV-1, HSV-2, EBV, HHV-6, and HHV-8)*	33	32/33 (97.0%; 91.1–100%)	25/33 (75.8%; 61.1–90.4%)	33/33 (100%; 93.9–100%)	30/33 (90.9%; 81.1–100%)	32/33 (97.0%; 91.1–100%)
Nuclear antigens (ANAs)	2	2/2 (100%; 34.2–100%)	1/2 (50.0%; 9.5–90.6%)	2/2 (100%; 34.2–100%)	2/2 (100%; 34.2–100%)	2/2 (100%; 34.2–100%)
Overall specificity	70	68/70 (97.1%; 90.2–99.2)	53/70 (75.7%; 64.5–84.2)	68/70 (97.1%; 90.2–99.2)	60/70 (85.7%; 75.7–92.1)	69/70 98.6%; 92.3–99.8)

Abbreviations: *MERS, middle east respiratory syndrome coronavirus; SARS-CoV, severe acute respiratory syndrome coronavirus; RSV, respiratory syncytial virus; HSV-1, herpes simplex virus 1; HSV-2, herpes simplex virus 2; HHV-6, human herpes virus-6; HHV-8, human herpes virus-8; EBV, Epstein-Barr virus; HBV, hepatitis B virus; HCV, hepatitis C virus; HEV, hepatitis E virus; HGV, hepatitis G virus; B19, Parvovirus B19; WNV, West Nile virus.