Reliability of the Siemens Enzygnost and Novagnost Epstein–Barr Virus assays for routine laboratory diagnosis: agreement with clinical diagnosis and comparison with the Merifluor Epstein–Barr Virus immunofluorescence assay

BMC Infectious Diseases

Table 2 Serological assay interpretation per the Novagnost assay

VCA IgM	VCA IgG	EBNA-1	Patient status	Alternative interpretation
–	–	–	Probably not infected^a
+	–	–	Primary early phase infection	● Possible cross-reactivity with primary CMV infection IgM
+	+	–	Primary acute infection
–	+	+	Past infection
–	+	–	Uncertain result	● Primary infection without VCA IgM
–	+	–	Uncertain result	● Past infection with EBNA loss
–	–	+	Uncertain result	Very rare profile of past infection:
				● Possible loss of VCA IgG
				● Possible EBNA false positive
+	+	+	Uncertain result	● Just past primary infection
				● Viral reactivation
				● Cross-reaction with CMV primary infection IgM
				● Nonspecific polyclonal IgM stimulation from a previous cross-reacting
				● infectious agent