Comparative Serological Study for the Prevalence of Anti-MERS Coronavirus Antibodies in High- and Low-Risk Groups in Qatar

Table 3

Comparative serological analysis of reactive and borderline samples from blood donors (BD).

		rS1-ELISA	Full virus IIFT		rS1-IIFT	ppNT
	Sample identifier	IgG (OD, ratio, endpoint titer)	IgG titer	IgM titer	IgG titer	IC50 titer (EMC/JordanN3)
Reactive ()	BD 2014/597	(0.905, 2.114, 201)	0	0	0	<50
	BD 2015/1303	(0.397, 1.3, 101)	10000	0	0	<50
	BD 2015/3004	(0.439, 1.26, 201)	0	0	0	<50
	BD 2015/3119	(0.402, 1.06, 401)	0	0	0	<50
	BD 2015/3380	(0.477, 1.1, 101)	10000	0	0	<50
	BD 2015/3513	(0.497, 1.39, 401)	0	0	0	<50
	BD 2015/4435	(0.661, 1.74, 201)	0	0	0	<50
Borderline ()	BD 2012/2644	(0.333, 0.83, 101)	0	0	0	<50
	BD 2015/1816	(0.456, 0.823,201)	0	0	0	<50
	BD 2015/4708	(0.408, 1.07, 101)	0	0	0	<50
Selected negative (showing 3/13)	BD 2015/2859	(0.034, 0.076, <101)	0	0	0	<50
	BD 2015/2988	(0.039, 0.112, <101)	0	0	0	<50
	BD 2015/3379	(0.065, 0. 16, <101)	0	320	0	531/502

Initial screening was done with rS1-ELISA, and reactive samples were further tested with various serological assays as indicated above. 13 negative samples from the initial screening with rS1-ELISA were selected for comparison, and one was found positive with full virus IgM and ppNT. Positive samples are shown in italic.