Dried blood spots, valid screening for viral hepatitis and human immunodeficiency virus in real-life

Table 1 Descriptive summary and characteristics of viral infections

Viral infection	Total, n	Mono- + Co-infected, n	N with quantitative analysis	Median	IQR (25-75)
Blood donors	99	0	NA
HBV	85	78 + 5 HIV + 2 HCV	78	144	19-2780
HCV	116	111 + 3 HIV + 2 HBV	105	225000	4300-1110000
HIV	114	106 + 5 HBV + 3 HCV	112	0	0-19

IQR: Interquartile range [expressed as IU/mL (HBV and HCV) and copies/mL (HIV)]. HBV: Hepatitis B virus; HCV: Hepatitis C virus; HIV: Human immunodeficiency virus.

Table 2 Sensitivity and specificity of serological testing by Abbott Architect of dried blood spots compared to plasma samples

	Plasma, n		DBS, n		Sensitivity (%)		Specificity (%) (95%CI)		ROC	PPV	NPV
	Negative	Positive	Negative	Positive	(95%CI)
Anti-HCV	288	116	292	112	96.6	(91.4; 99.1)	100.0	(98.7; 100)	0.98	100.0%	98.6%
HBsAg	318	86	319	85	96.5	(90.1; 99.3)	99.4	(97.7; 99.9)	0.98	97.6%	99.1%
Anti-HBc	232	172	286	118	68.0	(60.5; 74.9)	99.6	(97.6; 100)	0.84	99.2%	80.8%
Anti-HBs	246	158	337	67	42.4	(34.6; 50.5)	100.0	(98.5; 100)	0.71	100.0%	73.0%
Anti-HIV	289	115	290	114	98.3	(93.9; 99.8)	99.7	(98.1; 100)	0.99	99.1%	99.3%

ROC: Area under the receiver operating curve; PPV: Positive predicting value; NPV: Negative predicting value.