Sexual transmission of hepatitis C virus among monogamous heterosexual couples: the HCV partners study

Prevalence of hepatitis C in a Swiss sample of men who have sex with men: whom to screen for HCV infection?

BACKGROUND

While the numbers of hepatitis-C-virus (HCV) infections among men who have sex with men (MSM) who are co-infected with the human immunodeficiency virus (HIV) are on the rise, with vast evidence for sexual transmission of HCV in this population, concerns have also been raised regarding sexual HCV-transmission among MSM without HIV infection. Therefore, the aim of this study was to estimate the prevalence of hepatitis C among MSM without HIV diagnosis in Zurich (Switzerland).

METHODS

Participants were recruited from a gay health centre and various locations such as dark rooms, saunas and cruising areas in Zurich. Participants self-completed a questionnaire assessing known and suspected risk factors for HCV-infection, and provided a blood sample for detection of past (antibodies) and present (core antigen, RNA) infections with HCV.

RESULTS

In total, 840 MSM aged 17-79 (median: 33 years) underwent HCV-testing and completed the questionnaire, among whom 19 reported living with HIV. Overall, seven tested positive for HCV-antibodies, and two were also positive for HCV core antigen and HCV-RNA-these two were immigrants, one from a country where HCV is endemic. None of the seven were aware of their infection. The seroprevalence of hepatitis C among the 821 non-HIV-diagnosed MSM was 0.37% (95%-CI: 0.12-1.69%), and one man harboured replicating virus (0.12%; 0.02-0.69%), resulting in a number needed to test of 821 to detect one active infection. Significant univariable associations of lifetime HCV-infection were found with known HIV-diagnosis (OR=72.7), being tattooed (OR=10.4), non-injection use of cocaine/amphetamines (OR=8.8), and non-Swiss origin (OR=8.5). For MSM without HIV-diagnosis, the only variable marginally associated with positive HCV-serostatus was being tattooed (OR=8.3). No significant associations were observed with reported injection drug use, unprotected anal intercourse, sexual practices that may lead to mucosal trauma, or proxy measures for group sex and lesion-prone STIs.

CONCLUSIONS

Our findings suggest that in Switzerland, hepatitis C among MSM without diagnosed HIV is not more prevalent than in the general population. We found no evidence of elevated rates of sexual transmission of HCV among MSM without HIV-infection. Therefore, we currently see no reason for promoting HCV-testing among all MSM in Switzerland.

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HISTORIQUE :

De 20 % à 30 % des Canadiens qui vivent avec le VIH sont co-infectés par le virus de l’hépatite C (VHC), lequel est responsable d’une morbidité et d’une mortalité importantes. La prise en charge du VIH et du VHC est plus complexe en raison de l’évolution accélérée de la maladie hépatique, du choix et des critères d’initiation de la thérapie antirétrovirale et du traitement anti-VHC, de la prise en charge de la santé mentale et des toxicomanies, des obstacles socioéconomiques et des interactions entre les nouvelles thérapies antivirales à action directe du VHC et les antirétroviraux

OBJECTIF :

Élaborer des normes nationales de prise en charge des adultes co-infectés par le VHC et le VIH dans le contexte canadien.

MÉTHODOLOGIE :

Le Réseau canadien pour les essais VIH des Instituts de recherche en santé du Canada a réuni un groupe d’experts possédant des compétences cliniques en co-infection par le VIH et le VHC pour réviser les publications à jour ainsi que les lignes directrices et les protocoles en place. Après une vaste sollicitation afin d’obtenir des points de vue, le groupe de travail a approuvé des recommandations consensuelles, qu’il a caractérisées au moyen d’une échelle de qualité des preuves fondée sur la classe (bienfaits par rapport aux préjudices) et sur la catégorie (degré de certitude).

RÉSULTATS :

Toutes les personnes co-infectées par le VIH et le VHC devraient subir une évaluation en vue de recevoir un traitement du VHC. Les personnes qui ne sont pas en mesure d’entreprendre un traitement du VHC devraient être soignées pour le VIH afin de ralentir l’évolution de la maladie hépatique. La norme de traitement du VHC de génotype 1 est un régime comprenant de l’interféron pégylé et de la ribavirine dosée en fonction du poids, associés à un inhibiteur de la protéase du VHC. Pour les génotypes 2 ou 3, une bithérapie classique est recommandée pendant 24 semaines s’il y a clairance virologique à la semaine 4 ou, pour les génotypes 2 à 6, à 48 semaines. On peut envisager de reporter le traitement chez les personnes ayant une maladie hépatique légère. Le VIH ne devrait pas être considéré comme un obstacle à la transplantation hépatique chez les patients co-infectés.

EXPOSÉ :

Les recommandations ne se substituent pas au jugement clinique personnel.

HCV transmission in industrialized countries and resource-constrained areas

HCV is a blood-borne virus transmitted by percutaneous exposure to infected blood or blood-derived body fluids. The main routes of transmission are blood transfusions, medical procedures and injection drug use. In industrialized countries, HCV transmission through blood transfusions has been virtually eliminated and iatrogenic transmission occurs only sporadically during local breaches of infection control procedures. As most new cases originate from injection drug use, harm-reduction programmes (including opiate substitution, needle exchange and health education) can greatly reduce HCV transmission. Currently, the main approach to reduce the HCV disease burden is by increasing awareness of both the public and health-care providers to hepatitis C, enhancing screening opportunities and treatment of the infected population. In resource-limited countries, the priority is reducing transmission through blood transfusions and invasive medical procedures. This approach requires training of health-care providers and also structural changes and financial investments in countries where antibody screening, disposable materials and effective sterilization procedures are not routinely available. In these countries, reducing the HCV burden has been hampered by limited access to treatment, largely owing to the cost of drugs. Access to treatment is moving up on the agenda of international and non-governmental organizations in conjunction with the future availability of highly efficacious oral drug regimens.

Sexual Transmission of Hepatitis C Virus Between HIV Infected Subjects and Their Main Heterosexual Partners

BACKGROUND

Overall, 60-70% of the hepatitis c virus (HCV) transmission routes is parenteral, and in 30-40% of the cases is unknown (e.g. sexual route). Knowing these routes in HIV infected dyads is very important due to clinical and methodological reasons.

OBJECTIVES

The present study aimed to identify and quantitatively investigate HIV-infected individuals and their main heterosexual partners regarding the risk factors of HCV transmission.

PATIENTS AND METHODS

One hundred sixty eight of 984 couples were chosen through random generated numbers using a computer program from behavioral consultation center in Shiraz, Iran. We used actor partner independent model (APIM) and multilevel analysis to assess multiple risk factors for HCV, while partitioning the source of risk at the individual and couple levels.

RESULTS

Age of the index samples was 38.71 ± 7 years, and 33.2 ± 6.3 for their main heterosexual partners; the mean duration of sexual relationship for couples was 11.9 (median = 8.5) years. Multivariate analysis showed that actor risk factor of intravenous drug using (IDU) (AOR= 13.03; 95% CI: 3.9- 43.82) and actor cofactors of HIV positivity (AOR = 7.1; 95% CI: 1.37- 36.97), razor sharing (AOR = 4.81; 95% CI: 1.84- 12.55), sex (AOR = 8.83; 95% CI: 3.16- 24.87), and condom use in sexual activity with main partner (AOR = 0.15; 95% CI: 0.02- 0.44) were associated with actor HCV positivity.

CONCLUSIONS

Health care providers need to pay special attention to sexual transmission of HCV among HIV-infected individuals, and should recommend control/preventive measures for HCV sexual transmission.

Inactivation of hepatitis C virus infectivity by human breast milk

BACKGROUND

Hepatitis C virus (HCV) is spread through direct contact with blood, although alternative routes of transmission may contribute to the global burden. Perinatal infection occurs in up to 5% of HCV-infected mothers, and presence of HCV RNA in breast milk has been reported. We investigated the influence of breast milk on HCV infectiousness.

METHODS/RESULTS

Human breast milk reduced HCV infectivity in a dose-dependent manner. This effect was species-specific because milk from various animals did not inhibit HCV infection. Treatment of HCV with human breast milk did not compromise integrity of viral RNA or capsids but destroyed the lipid envelope. Fractionation of breast milk revealed that the antiviral activity is present in the cream fraction containing the fat. Proteolytic digestion of milk proteins had no influence on its antiviral activity, whereas prolonged storage at 4°C increased antiviral activity. Notably, pretreatment with a lipase inhibitor ablated the antiviral activity and specific free fatty acids of breast milk were antiviral.

CONCLUSIONS

The antiviral activity of breast milk is linked to endogenous lipase-dependent generation of free fatty acids, which destroy the viral lipid envelope. Therefore, nursing by HCV-positive mothers is unlikely to play a major role in vertical transmission.

Global control of hepatitis C: where challenge meets opportunity

We are entering an important new chapter in the story of hepatitis C virus (HCV) infection. There are clear challenges and opportunities. On the one hand, new HCV infections are still occurring, and an estimated 185 million people are or have previously been infected worldwide. Most HCV-infected persons are unaware of their status yet are at risk for life-threatening diseases such as cirrhosis and hepatocellular carcinoma (HCC), whose incidences are predicted to rise in the coming decade. On the other hand, new HCV infections can be prevented, and those that have already occurred can be detected and treated--viral eradication is even possible. How the story ends will largely be determined by the extent to which these rapidly advancing opportunities overcome the growing challenges and by the vigor of the public health response.

Effectiveness of Methadone Maintenance Treatment in Prevention of Hepatitis C Virus Transmission among Injecting Drug Users

BACKGROUND

Injecting drug users (IDUs) are a major and most important risk factor for rising hepatitis C virus (HCV) prevalence in Iran.

OBJECTIVES

The objective of this study was to determine the effectiveness of methadone maintenance treatment (MMT) in prevention of HCV infection transmission among IDUs.

PATIENTS AND METHODS

A mathematical modeling has been used to estimate number of HCV infections averted. The input parameters used in the model were collected by self-reported method from 259 IDUs before registering and one year after MMT. Nonparametric statistical tests have been used to compare risky injecting and sexual behaviors among IDUs before and after participating in MMT program. Deterministic sensitivity analyses were done to show the effects of parameters' uncertainty on outcome.

RESULTS

Of the 259 participants, 98.4% (255) were men, the mean age ± SD was 33.1 ± 7.58 years and HCV prevalence was 50%. The studied IDUs reported lower rate of risky injecting and sexual behavior after participation in MMT program. The cumulative incidence of HCV per 100 IDUs due to sharing injection and unsafe sexual contact with MMT program were 13.84 (95% CI: 6.17 -21.51), 0.0003 (0.0001 - 0.0005) and without it 36.48 (25.84 - 47.11) and 0.0004 (0.0002-0.0006) respectively.

CONCLUSIONS

The MMT program is an effective intervention to prevent HCV infection transmission, although it is essential to compare its effectiveness with other interventions before implementing it in nationwide.

Global control of hepatitis C: where challenge meets opportunity

We are entering an important new chapter in the story of hepatitis C virus (HCV) infection. There are clear challenges and opportunities. On the one hand, new HCV infections are still occurring, and an estimated 185 million people are or have previously been infected worldwide. Most HCV-infected persons are unaware of their status yet are at risk for life-threatening diseases such as cirrhosis and hepatocellular carcinoma (HCC), whose incidences are predicted to rise in the coming decade. On the other hand, new HCV infections can be prevented, and those that have already occurred can be detected and treated--viral eradication is even possible. How the story ends will largely be determined by the extent to which these rapidly advancing opportunities overcome the growing challenges and by the vigor of the public health response.

Hepatitis C virus and human immunodeficiency virus transmission routes: Differences and similarities

Bouare et al found that hepatitis C virus (HCV) infection in Malian women is mainly transmitted through medical procedures with contaminated supplies, and that human immunodeficiency virus (HIV) transmission is predominantly sexual. The results of this study confirm those of a recent case-control study in New York and Oregon which demonstrated that healthcare exposures represent an important source of new HCV infections in United States. HCV seroprevalence was only 0.2% in pregnant, young Malian women, indicating that hygiene improved in healthcare facilities over time. Heterosexual transmission of HCV is exceptional, and can occur, from males to females, in extremely rare occasions in case of vaginal mucosal damage or less rarely through anal intercourse. The Malian study did not show an association between HIV infection and hospitalization, transfusion, tattoo, dental care. Transmission by needle-stick injury occurs in 0.9%-2.2% of exposures from HCV-infected subjects and in 0.1%-0.3% of exposures from HIV-infected individuals. HCV is therefore more transmissible through percutaneous exposure.

CIHR Canadian HIV Trials Network Coinfection and Concurrent Diseases Core: Canadian guidelines for management and treatment of HIV/hepatitis C coinfection in adults

BACKGROUND

Hepatitis C virus (HCV) coinfection occurs in 20% to 30% of Canadians living with HIV, and is responsible for a heavy burden of morbidity and mortality. HIV-HCV management is more complex due to the accelerated progression of liver disease, the timing and nature of antiretroviral and HCV therapy, mental health and addictions management, socioeconomic obstacles and drug-drug interactions between new HCV direct-acting antiviral therapies and antiretroviral regimens.

OBJECTIVE

To develop national standards for the management of HCV-HIV coinfected adults in the Canadian context.

METHODS

A panel with specific clinical expertise in HIV-HCV co-infection was convened by The CIHR HIV Trials Network to review current literature, existing guidelines and protocols. Following broad solicitation for input, consensus recommendations were approved by the working group, and were characterized using a Class (benefit verses harm) and Level (strength of certainty) quality-of-evidence scale.

RESULTS

All HIV-HCV coinfected individuals should be assessed for HCV therapy. Individuals unable to initiate HCV therapy should initiate antiretroviral therapy to slow liver disease progression. Standard of care for genotype 1 is pegylated interferon and weight-based ribavirin dosing plus an HCV protease inhibitor; traditional dual therapy for 24 weeks (for genotype 2/3 with virological clearance at week 4); or 48 weeks (for genotypes 2-6). Therapy deferral for individuals with mild liver disease may be considered. HIV should not be considered a barrier to liver transplantation in coinfected patients.

DISCUSSION

Recommendations may not supersede individual clinical judgement.