Table 2.

Clinical and virological features of HCV, HBV, and HIV

	HCV	HBV	HIV
Structure	50 nm; enveloped nucleocapsid; positive singlestranded RNA genome	42 nm; enveloped nucleocapsid; partially double-stranded DNA genome	120 nm, enveloped nucleocapsid; positive singlestrand RNA virus
Family	Flaviviridae	Hepadnaviridae	Retroviridae
Entry factors	Glycosaminoglycans, CD81, SR-BI, claudin-1, occludin-1	unknown	CD4, CCR4, CXCR5, DCSIGN
Replication strategy	Synthesis of a complementary negative-strand RNA, using the viral genome as a template, from which genomic positive-strand RNA is produced	Reverse transcription of HBV RNA into a covalently closed circular DNA which serves as a template for HBV transcripts	conversion of the singles-tranded HIV RNA to double-stranded HIV DNA by viral reverse transcriptase, followed by integration of HIV DNA within the host genome
Mutation rate	High (1 in 1 000 bases per year)	Low (1 in 100 000 bases per year)	High (1 in 10 000 bases par replication cycle)
Genotypes	6 main genotypes (1 to 6), with several subtypes within each genotype (more than 50 in total)	8 genotypes (A to H), with 22 subtypes	HIV-1 which include one major group (M) divided into nine subtypes (A to D, F to H, J, K) and two minor groups (O, N) HIV-2 which include 2 groups (A and B)
Transmission	Intravenous drug use, blood transfusions, perinatal	intravenous drug use, blood transfusions, perinatal, sexual contact	intravenous drug use, blood transfusions, perinatal, sexual contact
Infection site	Liver	Liver	CD4+ T cells
Public health impact
Chronically infected individuals	130 million	350 million	35 million
New infections/year	3 to 4 million	4 million	3 million
Related deaths/year.	350 000	500 000 to 1.2 million	2 million
Rate of co-infection with HCV		10 to 30%	10%
Infection outcome
Spontaneous recovery	20%	90% of adults, 10% of children	0%
Disease outcome	liver cirrhosis (20–30% of chronically infected patients) hepatocellular carcinoma (5% of patients with liver cirrhosis)	liver cirrhosis (2–5% of chronically infected patients) hepatocellular carcinoma (5% of patients with liver cirrhosis)	acquired immunodeficiency syndrome (AIDS); susceptibility to lifethreatening opportunistic infections
Available Therapy & recovery rates with therapy	pegylated interferon alpha I combination with ribavirin/HCV clearance in 50%–80% of individuals, depending on HCV genotype liver transplantation/systematic reinfection of the graft	interferon alpha, nucleoside and nucleotide analogues resulting in efficient control of viral infection liver transplantation/prevention of graft reinfection using antiviral treatment and anti-HBs antibodies	highly active antiretroviral therapy (HAART: nucleoside analogue reverse transcriptase inhibitors, protease inhibitor and/or nonnucleoside reverse transcriptase inhibitor) No HIV clearance
Vaccine	Absent	Present Based on recombinant HBsAg which induce neutralizing HBsAg-specific antibodies and CD4+ and CD8+ T cell responses	Absent