Interaction between HIV-1 and HCV infections: towards a new entity?
Journal of Antimicrobial Chemotherapy
Interaction between HIV-1 and HCV infections: towards a new entity?
Maria Winnock 1
Dominique Salmon-Céron 0
François Dabis 1
Geneviève Chêne 1
0 Department of Internal Medicine, Hôpital Cochin , Paris , France
1 INSERM U593, Université Victor Ségalen , 146 rue Léo Saignat, 33076 Bordeaux
Since human immunodeficiency virus (HIV) and hepatitis C virus (HCV) share the same modes of transmission, HIV-HCV co-infected patients are relatively common. Until recently, the clinical course of HCV in co-infected patients was overshadowed by the high morbidity and mortality of HIV disease. Recent reductions in morbidity and mortality among HIV-infected patients due to the advent of highly active antiretroviral therapy (HAART), have contributed to the emergence of HCV as a significant viral pathogen in this population. This article reviews the current evidence on the epidemiology and clinical implications of an interaction between HIV-1 and HCV infections.
prevalence; epidemiology; fibrosis; liver; HAART
Introduction
A computer-based literature review was undertaken using Medline
(PubMed, Pascal, Excerpta Medica) as the primary database. The
specific subject heading keywords used for the search strategy were
HIV infection (MeSH major topic) and HCV (MeSH terms).
Abstracts were systematically reviewed from 2000 to the present and
relevant papers were searched manually. Additional references were
identified from review articles, from the reference list of articles
identified by the Medline search, and by a systematic review of
Current Contents (Clinical Medicine and Life Sciences), using
‘Hepatitis’ as keyword.
Epidemiology and transmission
Approximately 40 million people have been infected with human
immunodeficiency virus (HIV) worldwide. Hepatitis C virus (HCV)
infects an estimated 3% of the world population and represents a viral
pandemic that is four to five times more prevalent than HIV infection.
In the United States and Europe, 13–43% of HIV-infected persons
are also infected with HCV1–10 with up to 85% being chronically
infected as indicated by the presence of HCV RNA (Table 1).9,11
The prevalence of HIV–HCV co-infection varies markedly
depending on the route of HIV infection, being higher among
injection drug users9,12–18 and haemophiliacs,19,20 compared with
homosexual men13,15,16 (Table 2).
The predominant recognized co-infection route is by parenteral
exposure to blood. The two groups with the highest risk of acquiring
HCV have been blood transfusion recipients and intravenous drug
users (IVDU), but their relative importance has changed over the last
two decades. Before 1990, blood transfusions accounted for a
substantial proportion of HCV transmissions.
Since the advent of routine screening of blood donations,
prevalence rates of positive test results for HCV and HIV have declined
significantly. In 2002, in the American Red Cross blood donor
population, estimates of residual risk in donations among repeat
donors, after testing with nucleic acid amplification technology, were
reported to be 1 per 1 935 000 and 1 per 2 135 000 for HCV and HIV,
respectively.21 The implementation of this sensitive technique in
Europe will also reduce the residual risk of contaminated blood and
blood products as a source of HIV and HCV infections.22,23
Currently, most newly acquired cases of hepatitis C (68%) are
related to injecting drug use.24 Contamination in health workers
frequently exposed to blood as well as nosocomial and iatrogenic
exposure account altogether for about 5% and a source is not
identified in about 10% of cases.24
Although both HIV and HCV share the same routes of
transmission, the relative efficiency of transmission of these two viruses
varies. HCV is approximately 10 times more infectious than HIV by
percutaneous blood exposure to small volumes of blood, being
transmitted by 15–30 of every 1000 accidental needle-stick injuries,25
compared with 3 per 1000 for HIV.26 In contrast, HIV is more
transmissible than HCV between heterosexual partners and from a mother
to her infant.1,27–29
The prevalence of anti-HCV antibodies among female sexual
partners of HCV-positive men is 3%, whereas the anti-HIV
prevalence among female sexual partners of HIV-positive men is four
times greater.27 HIV co-infection in an individual with hepatitis C
seems to increase the likelihood of sexual transmission of HCV.
Indeed, anti-HCV positivity was observed in 18.7% of subjects who
had a steady partner with anti-HIV-positive test results, as opposed
to only 1.6% of subjects who had partners presenting only HCV
viraemia.30
HCV Ab+ (%)
aCPCRA, Community programs for clinical research on AIDS.
9,12–18
13,15,16
19,20
1–10
Percentage with
antibodies to HCV
Before the administration of antiretroviral therapy to HIV-infected
women, HIV was transmitted to 20% of infants born to HIV-infected
mothers.29,31 In contrast, the rate of mother-to-infant transmission in
women with sole HCV vir (...truncated)