Vertical transmission of hepatitis C virus

No. 96-The Reproductive Care of Women Living With Hepatitis C Infection

OBJECTIVE

hepatitis C virus (HCV) is an increasingly important public health problem worldwide. Health care workers providing care to women of childbearing age are uniquely placed in their practices to identify a significant proportion of at-risk patients and to provide appropriate screening and counselling. The primary objective of this guideline is to provide accurate, current information to those offering reproductive care to women living with HCV. This document is also intended to raise awareness of HCV in both the medical and general populations.

OPTIONS

the areas of clinical practice considered in formulating this guideline are disease prevention, targeted screening of individuals at risk of contracting HCV, management of identified patients in the context of reproductive care, and the appropriate referral of patients to those with particular expertise.

OUTCOMES

implementation of these guidelines should facilitate identification of infected individuals. It should also result in improved physical and mental well-being for patients and their families and reduction in transmission rates.

EVIDENCE

the literature between 1966 and 2000, including non- English language publications, was extensively searched utilizing Medline. A multidisciplinary group consisting of experts within the fields of obstetrics and gynaecology, infectious diseases, hepatology, and public health convened in Montreal in February 2000. The working group also included a patient and a representative from the Hepatitis C Society of Canada. The level of evidence for the recommendations has been determined using the criteria described by the Canadian Task Force on Periodic Health Examination.

BENEFITS, HARMS AND COSTS

the public health benefits of increased identification of at-risk individuals, diagnosis, treatment, implementation of risk reduction behaviours, and reduced transmission rates, both on an individual and at the community level, are significant. However, it must be remembered that the diagnosis of a chronic disease may have far reaching effects for the individual patient and her family.

RECOMMENDATIONS

VALIDATION: references were collected through Medline searches and comparison made to existing current guidelines for assessment of consistency. External reviewers expert in their field were also consulted.

Threshold Dynamics of a Stochastic SIR Model with Vertical Transmission and Vaccination

A stochastic SIR model with vertical transmission and vaccination is proposed and investigated in this paper. The threshold dynamics are explored when the noise is small. The conditions for the extinction or persistence of infectious diseases are deduced. Our results show that large noise can lead to the extinction of infectious diseases which is conducive to epidemic diseases control.

Hepatitis C Seroprevalence Among HIV-Infected Childbearing Women in New York State in 2006

OBJECTIVE

To identify factors associated with maternal hepatitis C virus (HCV) seroprevalence and transmission of HCV as identified by qualitative HCV ribonucleic acid (RNA) in the infants of human immunodeficiency virus (HIV) infected women delivering in New York State (NYS) in 2006.

STUDY DESIGN

In this retrospective cohort study of HIV-exposed infants born in NYS, leftover infant plasma from HIV diagnostic testing was de-identified and tested for HCV. If HCV antibodies were detected, a second specimen collected when the infant was >2 months old was tested for HCV qualitative RNA. Multivariate logistic regression was used to identify factors associated with HCV seropositivity.

RESULTS

In a final sample of 553 live birth events with perinatal HIV exposure, 21 (3.8 %) of tested infant specimens had HCV antibodies indicative of maternal HCV seropositivity. Maternal age at delivery of >35 years, Hispanic ethnicity, white race and injection drug use (IDU) were significantly associated with HCV seropositivity in multivariate analysis. No cases of HCV vertical transmission were identified among HCV exposed infant specimens.

CONCLUSIONS

This statewide population-based study of HIV-infected childbearing women shows HCV seroprevalence of 3.8 %. Maternal age of >35 years and IDU are the strongest predictors of HCV seropositivity. Although no viral transmission was documented, more comprehensive longitudinal testing would be required to conclude that HCV transmission did not occur.

Vertical Hepatitis C Virus Transmission is not Related to Mother-Child Class-1 HLA Concordance

Mother-child human leukocyte antigen (HLA) diversity is protective for vertical transmission of some viruses. The aim of this study is to evaluate the role of mother-child HLA diversity on hepatitis C virus (HCV) vertical transmission. Forty consecutive HCV infected and 46 consecutive control uninfected children born to HCV-RNA positive mothers were evaluated for HLA class-1 type concordance with their mothers. No significant difference in the degree of HLA concordance was found between HCV infected and uninfected children both when A, B, C ( p=0.30) and when only A and B alleles were evaluated ( p=0.59). Mother-infant HLA concordance does not affect HCV vertical transmission.

Hepatitis B and C in pregnancy: a review and recommendations for care

Our objective was to provide a comprehensive review of the current knowledge regarding pregnancy and hepatitis B virus (HBV) or hepatitis C virus (HCV) infection as well as recent efforts to reduce the rate of mother-to-child transmission (MTCT). Maternal infection with either HBV or HCV has been linked to adverse pregnancy and birth outcomes, including MTCT. MTCT for HBV has been reduced to approximately 5% overall in countries including the US that have instituted postpartum neonatal HBV vaccination and immunoprophylaxis with hepatitis B immune globulin. However, the rate of transmission of HBV to newborns is nearly 30% when maternal HBV levels are greater than 200 000 IU ml(-1) (>6 log10 copies ml(-1)). For these patients, new guidelines from the European Association for the Study of the Liver (EASL) and the Asian Pacific Association for the Study of the Liver (APASL) indicate that, in addition to neonatal vaccination and immunoprophylaxis, treating with antiviral agents such as tenofovir disoproxil fumarate or telbivudine during pregnancy beginning at 32 weeks of gestation is safe and effective in preventing MTCT. In contrast to HBV, no therapeutic agents are yet available or recommended to further decrease the risk of MTCT of HCV, which remains 3 to 10%. HCV MTCT can be minimized by avoiding fetal scalp electrodes and birth trauma whenever possible. Young women with HCV should be referred for treatment post delivery, and neonates should be closely followed to rule out infection. New, better-tolerated treatment regimens for HCV are now available, which should improve outcomes for all infected individuals.

[Epidemiology of hepatitis C virus infection]

Hepatitis C is a major cause of chronic liver disease worldwide. There is a significant variation in the prevalence of hepatitis C virus (HCV) infection according to the geographic region studied. These discrepancies reflect not only distinct epidemiological characteristics among the populations, but also differences in the methodologies used for the estimates. Despite scarce data, estimates indicate that Brazil is a country with an intermediate prevalence of HCV infection, ranging from 1% to 2%. The most important risk factors for HCV acquisition include injection drug use, blood product transfusion, organ transplantation, hemodialysis, occupational injury, sexual transmission and vertical transmission. Because there is no vaccine and no post-exposure prophylaxis for HCV, the focus of primary prevention efforts should be identification and removal of the risk factors. In this article we review literature regarding the prevalence of HCV infection, particularly in Brazil. In addition, we discuss the pattern of HCV infection according to the age groups and risk factors for HCV acquisition.

[Epidemiology of hepatitis C virus infection]

Hepatitis C is a major cause of chronic liver disease worldwide. There is a significant variation in the prevalence of hepatitis C virus (HCV) infection according to the geographic region studied. These discrepancies reflect not only distinct epidemiological characteristics among the populations, but also differences in the methodologies used for the estimates. Despite scarce data, estimates indicate that Brazil is a country with an intermediate prevalence of HCV infection, ranging from 1% to 2%. The most important risk factors for HCV acquisition include injection drug use, blood product transfusion, organ transplantation, hemodialysis, occupational injury, sexual transmission and vertical transmission. Because there is no vaccine and no post-exposure prophylaxis for HCV, the focus of primary prevention efforts should be identification and removal of the risk factors. In this article we review literature regarding the prevalence of HCV infection, particularly in Brazil. In addition, we discuss the pattern of HCV infection according to the age groups and risk factors for HCV acquisition.

[Epidemiology of hepatitis C virus infection]

Hepatitis C is a major cause of chronic liver disease worldwide. There is a significant variation in the prevalence of hepatitis C virus (HCV) infection according to the geographic region studied. These discrepancies reflect not only distinct epidemiological characteristics among the populations, but also differences in the methodologies used for the estimates. Despite scarce data, estimates indicate that Brazil is a country with an intermediate prevalence of HCV infection, ranging from 1% to 2%. The most important risk factors for HCV acquisition include injection drug use, blood product transfusion, organ transplantation, hemodialysis, occupational injury, sexual transmission and vertical transmission. Because there is no vaccine and no post-exposure prophylaxis for HCV, the focus of primary prevention efforts should be identification and removal of the risk factors. In this article we review literature regarding the prevalence of HCV infection, particularly in Brazil. In addition, we discuss the pattern of HCV infection according to the age groups and risk factors for HCV acquisition.

Transmission of hepatitis C virus infection from asymptomatic mother to child in southern India

BACKGROUND

Little information is available on the mother-to-child transmission of hepatitis C virus (HCV) in India, and no interventions to decrease transmission rates have been identified. Hence, we performed a long-term prospective study in infants born to HCV-positive mothers, with the aim of evaluating vertical transmission of HCV and correlated risks factors.

METHODS

Three thousand one hundred and fifteen healthy asymptomatic pregnant women were included in the study. We used third-generation (Murex anti-HCV) ELISA and HCV RNA reverse transcription PCR (RT-PCR) for screening, and the commercial line probe assay (Inno-LiPA) and direct sequencing HCV genotyping assays were performed to confirm the transmitted HCV genotypes.

RESULTS

Of the total 3115 healthy asymptomatic pregnant women, 18 (0.6%) were positive for anti-HCV. Of the 18 anti-HCV-positive women, eight (44.4%) were positive for HCV RNA RT-PCR. HCV transmission was observed in two of the eight babies born to eight HCV RNA-positive mothers who were followed up for 12 months. HCV genotyping of the mother/child pairs revealed the persistent presence of mixed genotypes 1a and 4 throughout the follow-up period. None of the non-viremic (HCV RNA-negative) mothers transmitted HCV infection to their baby. In our study approximately 25% of vertical/perinatal transmission of HCV was observed among HCV RNA-positive antenatal women.

CONCLUSIONS

This study is of importance as it is the first report from India of a successful attempt to analyze the rate of vertical/perinatal transmission of HCV from infected mothers to their children by a prospective longitudinal follow-up study, and to characterize the pattern of genotype(s) of HCV present in the infected mother/baby pairs, so as to confirm the source of HCV acquired by the newborn babies.

Re-evaluation of the true rate of hepatitis C virus mother-to-child transmission and its novel risk factors based on our two prospective studies

OBJECTIVE

To re-evaluate the true hepatitis C virus (HCV) mother-to-child transmission (MTCT) rate and its novel risk factors.

STUDY DESIGN

A comparative study based on our own two prospective studies done during the two periods, 'early' (1989-1994) and 'recent' (1995-2004).

RESULTS

All carrier infants became HCV RNA-positive within 3 months after birth. The MTCT and de-carrier rates were, respectively, higher (14.2%) and lower (16.7%) in the recent period, although liver dysfunction of carrier infants was found very frequently (66.7%) in both groups. MTCT occurred significantly when the maternal viral load, serum alanine aminotransferase (sALT) levels and blood loss at delivery were, respectively, more than 10(5) copies/mL, 110 IU/L, and 500 g. No MTCT was found when elective cesarean section was done.

CONCLUSIONS

The true HCV MTCT and de-carrier rates were found to be much higher and lower than those reported previously. The maternal liver dysfunction (sALT >or=110 IU/mL) and blood loss (>or=500 g) at delivery are the next risk factors to maternal viral load (>or=10(5) copies/mL) for MTCT.

HCV/HIV co-infection, HCV viral load and mode of delivery: risk factors for mother-to-child transmission of hepatitis C virus?

BACKGROUND

Hepatitis C virus (HCV) infection in children is mainly acquired via maternal transmission. Our aim was to identify mother-to-child-transmission (MTC) risk factors, namely those associated with maternal virological characteristics and mode of delivery.

METHODS

Women were included between October 1998 and September 2002 in six hospitals in Southern France on the basis of positive HCV serological status. Recorded data included maternal characteristics, circumstances of delivery and laboratory data concerning mother and child. Paediatric follow-up lasted 1 year, and 2 years for children with circulating HCV RNA.

RESULTS

A total of 214 mother-and-child pairs were analysed; 55 (26%) were HCV/HIV co-infected. The probability of HCV transmission was three-fold higher for HCV/HIV-co-infected women (P = 0.05). Twelve children were HCV RNA positive at 1 year of age (MTC = 5.6%); three became HCV RNA negative between 12 (M12) and 18 months of age (M18) and recovered normal alanine aminotransferase levels. Circulating HCV RNA was found in 137 (69%) mothers. Mothers of infected children all displayed HCV viraemia (MTC = 8.8%): six children were born of HCV/HIV-co-infected HCV RNA positive women (MTC = 13.6%) and six from HCV monoinfected women with positive HCV RNA (MTC = 6.5%). When maternal HCV RNA levels were below 6 log-IU/ml, the rate of transmission was significantly higher in the case of HCV/HIV co-infection (odds ratio = 8.3, 95% confidence interval, 1.4-47.5) P = 0.01. This association did not, however, exist for HCV RNA-positive mothers with levels of at least 6 log-IU/ml. Rate of transmission did not differ significantly between children born by vaginal delivery or caesarean section after membrane rupture and those born by elective caesarean section independently of HIV status.

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Osteoprogenitor cells and osteoblasts are targets for hepatitis C virus

The goal of this study was to determine whether human osteoblasts might harbor the hepatitis C virus. We tested for positive-strand and negative-strand (replicative) hepatitis C virus RNA by reverse transcriptase-polymerase chain reaction, by in situ reverse transcriptase-polymerase chain reaction for intracellular localization of the hepatitis C virus, and by amplicon sequencing in in vitro differentiated mature osteoblasts from STRO-1+ osteoprogenitor cells from patients with chronic hepatitis C and from healthy individuals. We only detected the hepatitis C virus genome in STRO-1+ cells and mature osteoblasts from carriers with chronic hepatitis C, and we found hepatitis C virus negative strands expressed sporadically in these patients. Using in situ hepatitis C virus reverse transcriptase-polymerase chain reaction, we determined that the percentage of infected carrier osteoblasts ranged from 8.0-15.3%. These data provide evidence of hepatitis C virus presence and replication in human osteoprogenitors and osteoblasts, which may have important implications for bone allograft processing.

A ribonuclease protection assay for the direct detection and quantitation of hepatitis C virus RNA

A ribonuclease protection assay (RPA) was developed for the direct detection and quantitation of HCV RNA in infected patients' sera or plasma using HCV [(32)P]RNA from the conserved 5'-untranslated region (5'-UTR) as a probe. We were able to directly detect the presence of HCV RNA by RPA in several infected patients' samples. The viremic status of HCV infected patients with indeterminate recombinant immunoblot assay (RIBA II) was also determined by this assay. Polymerase chain reaction (PCR) was also performed on all these samples and were found to be positive with a concordance of 100% between the results of PCR and RPA. The RPA was able to detect approximately 1 pg of HCV RNA. A limited sequence heterogeneity among HCV isolates was also observed by this assay, suggesting that this may be a faster method of detecting heterogeneous HCV sequences in patients' samples. This simple and specific method could be used to quantitate HCV RNA in order to better determine viremia and follow the course of HCV infection especially when RIBA II results are indeterminate.

Influence of maternal human immunodeficiency virus (HIV) co-infection on vertical transmission of hepatitis C virus (HCV): a meta-analysis

BACKGROUND

Maternal co-infection with human immunodeficiency virus (HIV) has been implicated as a potentially important co-factor for enhanced vertical transmission of hepatitis C virus (HCV). In previous reports, however, methodological issues (notably small sample sizes) have limited accurate evaluation of the contribution of maternal co-infection with HIV on the risk of vertical transmission of HCV.

METHODS

A systematic review and subsequent meta-analysis of current published and unpublished reports was performed. Odds ratios (OR) and 95% CI for individual studies were calculated with maternal HIV serostatus as the exposure measure and HCV vertical transmission as the outcome measure. Overall summary estimates were then calculated using a random effects model that estimates a weighted average of OR from individual studies.

RESULTS

In total, 2382 infants from 10 studies were included in an analysis of HCV-infected mothers (defined by anti-HCV+ antibody assays) with and without concomitant HIV infection. The risk estimate (OR) of HCV vertical transmission was 2.82 (95% CI: 1.78-4.45; P = 0.00001) from anti-HCV+/HIV+ co-infected mothers compared with anti-HCV+/HIV- mothers. In a subanalysis of 1327 infants born to viraemic (HCV RNA+) mothers, the risk estimate of HCV vertical transmission was 1.97 (95% CI: 1.04-3.74; P = 0.04) from HCV viraemic/HIV+ co-infected mothers compared with HCV viraemic/HIV- mothers.

CONCLUSIONS

Results from this meta-analysis of observational studies suggest that the risk of HCV vertical transmission is higher in infants born to HIV co-infected mothers.

Multicentre Italian Study Group (MISG) for the standardisation of hepatitis C virus (HCV) PCR

BACKGROUND

Several studies on standardisation of NAT assays for diagnosis of hepatitis C virus (HCV) infection have been carried out in European countries. In fact the widespreading use of nucleic acid amplification technology (NAT) in diagnostic centres for the evaluation of the HCV infection, requires the application of reference external standards to control laboratory performance; but up to date they are not routinely used.

OBJECTIVES

Fifteen diagnostic centres of major Italian Hospitals participated to a quality control study for the standardisation of polymerase chain reaction (PCR)-based HCV-RNA detection, organised by the Committee for the Study of Biotechnology (CoSBio) of the Italian Society of Clinical Microbiology (AMCLI). All the participant centres (PC) used commercial assays, automated or semi-automated.

STUDY DESIGN

The study was performed in four rounds. Altogether each centre received 14 reference negative and 22 reference positive sera. The range of copies number per ml of the reference positive sera was 10(4)-10(7).

RESULTS AND CONCLUSIONS

Considering the 540 samples tested, 4.54% of false negative (FN) and 4.28% of false positive (FP) results were reported. Thereafter the sensitivity and the specificity were 95.65 and 95.89%, respectively. The errors were distributed among seven out of the 15 PCs. The percentage of FP results was uniformly distributed in each shipment, whereas FN results emerged with the sera at lower HCV genome copies number. The analysis of the data obtained suggests that FP as well as FN results may be attributable to errors or to others problems of laboratories. To improve the performance of Italian, as well as of laboratories throughout the world, the use of external reference standards in multicentre collaborative studies will be required.

Pregnancy and liver disease

Liver disease has an impact on women's health during pregnancy because of the complex interactions between the physiologic changes induced by pregnancy and the pathophysiologic changes of liver disease. In particular, liver diseases that predominantly afflict females, such as primary biliary cirrhosis and autoimmune hepatitis, pose a special problem for conception and management of pregnancy. Pregnancy, moreover, specifically is associated with several potentially life-threatening liver diseases. This article reviews comprehensively the impact of liver diseases on pregnancy and of pregnancy on liver function and liver disease.

Prospective study of mother-to-infant transmission of hepatitis C virus: a 10-year survey (1990-2000)

BACKGROUND

The purpose of this study was to determine the rate of vertical transmission of hepatitis C virus (HCV). We also aimed to analyze the time of clearance of maternal antibodies in the serum of non-infected babies.

METHODS

Between March 1990 and March 2000, 170 consecutive anti-HCV-positive women and their 188 babies entered this prospective study. All women were analyzed for HCV-RNA using polymerase chain reaction (PCR). The babies were followed-up until HCV-antibody clearance or until the diagnosis of HCV infection.

RESULTS

The vertical transmission rate was 2.7% overall, and it was higher in HIV co-infected women (5.4%, 2/37) than in HIV-negative women (2.0%, 3/151). All infected infants were born to mothers who had HCV viremia at delivery. The transmission rate was influenced by maternal levels of viremia. 37.2% of uninfected children became HCV-antibody negative by 6 months and 88.0% by 12 months. Babies born from HCV-RNA-positive mothers lost anti-HCV antibodies later (9.21 +/- 3.72 months) than babies born from HCV-RNA-negative mothers (7.47 +/- 3.46 months) ( p < 0.05, Kolmogorov-Smirnov test).

CONCLUSIONS

The risk of HCV vertical transmission is very low in HCV-positive/HIV-negative women and it is restricted to infants born to HCV viremic mothers. High maternal viral load is predictive of the vertical transmission. The clearance time of antibodies in non-infected babies is significantly longer if the mother is viremic.

Distribution of the different genotypes of HCV among patients attending a tertiary care hospital in south India

BACKGROUND

Genotyping of the hepatitis C virus (HCV) and assessment of viral load is important for designing therapeutic strategies and region specific diagnostic assays.

OBJECTIVES

To determine the distribution of HCV genotypes among patients attending a tertiary care hospital in south India, and to correlate this with viral load.

STUDY DESIGN

Ninety HCV RNA positive patients were recruited for the study. HCV genotyping was carried out using type-specific primers from the core region of the viral genome [J. Clin. Microbiol. 35 (1997) 201]. Viral load estimations were carried out using the Amplicor HCV Monitor (Versions 1.5 and 2, Roche Diagnostics, Branchburg, NJ, USA). Clinical details were elicited from patients' hospital records.

RESULTS

Genotype 3 was detected most frequently (62.2%) followed by infection with HCV genotype 1 (18.8%). There was no significant difference seen in alanine aminotransferase (ALT) values between the two genotypes. Genotype 1 was associated with a significantly higher viral load as compared with genotype 3 (P=0.001). Parenteral transmission accounted for 61% of all infection caused. Infection with genotype 1 was significantly associated with a history of haemodialysis (P=0.01). Genotype 3 was detected more frequently in patients from east India, as compared with its detection in patients from south India (P=0.004). Similarly, genotype 1 was detected with greater frequency in individuals from south India as compared with patients from east India (P=0.004). The concordance between Ohno's genotyping assay and nucleotide sequencing, for genotypes 1 and 3, was 75%.

CONCLUSIONS

HCV genotypes 1 and 3 accounted for 81% of HCV infections in patients from this geographical region. HCV genotype distribution showed regional differences and genotype 1 was associated with higher viral loads. Parenteral transmission was the major route for acquisition of HCV infection. Ohno's type-specific primer based genotyping assay can be used for distinguishing between HCV genotype 1 and non-1 HCV genotypes in laboratories that do not possess nucleotide sequencing facilities.

The epidemiology of hepatitis C virus infection

The prevalence of hepatitis C virus (HCV) infection varies in different populations, ranging from as low as 0.6% in volunteer blood donors to as high as 80% in injection drug users. The prevalence of HCV in a population can be predicted by risk factors associated with the transmission of infection. These risk factors include injection drug use, blood product transfusion, organ transplantation, hemodialysis, occupational injury, sexual transmission, and vertical transmission. We review the literature regarding the incidence and prevalence of HCV infection and the evidence supporting various modes of HCV transmission.

Vertical transmission of human immunodeficiency virus

Sensitive detection methods, such as DNA PCR and RNA PCR suggest that vertical transmission of human immunodeficiency virus (HIV) occurs at three major time periods; in utero, around the time of birth, and postpartum as a result of breastfeeding (Fig. 1). Detection of proviral DNA in infant's blood at birth suggests that transmission occurred prior to delivery. A working definition for time of infection is that HIV detection by DNA PCR in the first 48 h of life indicates in utero transmission, while peripartum transmission is considered if DNA PCR is negative the first 48 h, but then it is positive 7 or more days later [1]. Generally, in the breastfeeding population, breast milk transmission is thought to occur if virus is not detected by PCR at 3-5 months of life but is detected thereafter within the breastfeeding period [2]. Using these definitions and guidelines, studies has suggested that in developed countries the majority, or two thirds of vertical transmission occur peripartum, and one-third in utero [3-6]. The low rate of breastfeeding transmission is due to the practice of advising known HIV-positive mothers not to feed breast milk. However, since the implementation of antiretroviral treatment in prophylaxis of HIV-positive mothers, some studies have suggested that in utero infection accounts for a larger percentage of vertical transmissions [7]. In developing countries, although the majority of infections occurs also peripartum, a significant percentage, 10-17%, is thought to be due to breastfeeding [2, 8, 9].

Prevalence and risk factors for intrafamilial transmission of hepatitis C virus in Karachi, Pakistan

Household contacts of hepatitis C virus (HCV)-positive patients are considered at increased risk of HCV infection. This cross-sectional study during April through June 1999 assessed the prevalence and risk behaviours associated with HCV seropositivity among the household contacts of HCV seropositive thalassaemic children in Karachi, Pakistan. Among the 341 household contacts of 86 thalassaemic HCV seropositive children who were tested, 70 (20.5%) were positive for anti-HCV antibodies. The stratified analysis showed that HCV seroprevalence among the contacts did not differ significantly by the gender of the index patient and the type of relationship of contact with the index patient. However, HCV seroprevalences among the fathers and mothers of male index patients was substantially higher compared to those of female index patients. HCV RNA was recovered and genotyped from nine index patients and corresponding nine HCV-seropositive household contacts. HCV genotype 3a and 3b were found in 89% (8/9) and 11% (1/9) of the pairs, respectively. The final multivariable conditional logistic regression model revealed that after adjusting for the effect of ethnicity and past hospital admission history, the HCV-seropositive household contacts were more likely than HCV seronegative household contacts to have been bitten by the carrier [adjusted matched odds ratio (mOR)=2.6, 95% CI 1.3-5.2] or have shared a toothbrush with the carrier (adjusted mOR=8.2; 95% CI 1.56-43.5). Control efforts should focus on the risk behaviours.

Mother-to-infant transmission of hepatitis C virus: rate of infection and assessment of viral load and IgM anti-HCV as risk factors

One hundred twenty-six mother-infant couples were studied and 105 exposed babies were monitored for at least 12 months to define the risk of mother-to-infant HCV transmission. Infection occurred in 5 out of 76 infants (6.6%) born to 69 viraemic mothers and in none of 29 born to 26 non-viraemic mothers. Only one child was HCV RNA positive one month after birth, while the remaining children became positive at the 3rd to 4th month. HCV genotypes of the babies matched those of their mothers. No difference was found between women who transmitted the virus and those who did not with regard to age, history of drug abuse, HIV infection, ALT abnormal values, HCV genotype, type of delivery, and breast-feeding. Four out of 5 infected infants were born to mothers with IgM anti-HCV (P = 0.04). The mean viral titre in transmitting women (10(7.2)) was higher than in non-transmitting (10(6.5)), and the proportion of mothers with viral load > or = 10(7) was statistically higher in transmitting than non-transmitting women (P = 0.03). These data show that HCV perinatal infection is a rare event and suggest that IgM positivity and high viral load (> or = 10(7)) in the mother are independent variables correlated with HCV transmission (O.R. = 14.5; 95% CI: 1.3-160.7 and O.R. = 16.3; 95% CI: 1.5-179.9, respectively).

Different outcomes of vertical transmission of hepatitis C virus in a twin pregnancy

The risk of vertical transmission of hepatitis C virus (HCV) from mother to infant has been well documented, but the exact mode of transmission is still unclear. In a set of monochorionic diamniotic monozygous twins, only the second baby was infected with HCV from the mother who was positive for serum HCV-RNA. The babies had an uncomplicated vaginal delivery 3 min apart and they were both bottle fed from the outset. The second baby developed clinical hepatitis that persisted to 30 months follow up. The intrauterine environment should have been identical for these twins, and therefore, the maternal HCV factors, including viral load are not the sole determining factors for mother-to-infant transmission of HCV.

The cutaneous manifestations of viral hepatitis

Viral hepatitis is a common disease with significant morbidity and mortality that is found throughout the world. It is a known cause of acute and chronic liver disease. Because the disease can be asymptomatic in its acute stages, the diagnosis is often missed. This article reviews the extrahepatic manifestations of the disease, in particular the visible cutaneous lesions, which offer clues to the diagnosis of viral hepatitis. Familiarity with the most common skin lesions associated with each type of hepatitis virus will be useful in identifying previously undiagnosed individuals. This article serves as a review of the most widely published associations between skin diseases and specific subtypes of viral hepatitis.

Hepatitis C: an epidemiological review

The aim of the study was to analyse the current literature regarding the mode of transmission of HCV and its global prevalence in different groups of people. A systematic review of the literature on the epidemiology of hepatitis C from 1991 to 2000 using computerized bibliographic databases which include Medline, Current Content and Embase. The prevalence of hepatitis C virus (HCV) varies tremendously in different parts of the world, with the highest incidence in the Eastern parts of the globe compared with the Western parts. Furthermore, certain groups of individuals such as intravenous drug users are at increased risk of acquiring this disease irrespective of the geographical location. Although the main route of transmission is via contaminated blood, curiously enough in up to 50% of the cases no recognizable transmission factor/route could be identified. Therefore, a number of other routes of transmission such as sexual or household exposure to infected contacts have been investigated with conflicting results. Hepatitis C infection is an important public health issue globally. Better understanding of routes of transmission will help to combat the spread of disease. In order to prevent a world wide epidemic of this disease, urgent measures are required to (i) develop a strategy to inform and educate the public regarding this disease and (ii) expedite the efforts to develop a vaccine.

[Hepatitis C and pregnancy]

PURPOSE

Today, the natural course of hepatitis C virus (HCV) infection during pregnancy and the prevalence of mother-to-child transmission are better known.

CURRENT KNOWLEDGE AND KEY POINTS

Antenatal screening for HCV infection needs to be proposed to women with risk factors. Viral replication needs to be confirmed by PCR in pregnant women with antibodies against HCV. To date, the clinical course of pregnancy and the mode of delivery have not been changed by HCV infection. Rates of vertical transmission of HCV are about 6% in women with HCV alone and 15% in women co-infected with HIV. A screening for HCV markers is required 18 months after delivery for infants born to HCV mothers. Because of the relatively low rate of HCV vertical transmission, pregnancy can be allowed in infected women. However, taking into account the efficacy of new antiviral strategies, treatment of HCV infection could be proposed before pregnancy.

FUTURE PROSPECTS AND PROJECTS

In case of HCV infection, a careful follow-up of both mother and newborns is required. Long-term follow-up of infected infants is needed to assess the consequences of perinatal HCV infection.

Vertical transmission of hepatitis C virus in a cohort of 2,447 HIV-seronegative pregnant women: a 24-month prospective study

BACKGROUND

Mother to infant transmission of hepatitis C virus (HCV) has been extensively studied in mothers with human immunodeficiency virus (HIV) infection, whereas fewer data are available on the vertical HCV transmission in HIV-negative women.

METHODS

Between January 1995 and June 1997, 78 consecutive HCV-positive/HIV-negative women with their offspring entered this prospective study aimed to define the prevalence of and risk factors for HCV vertical transmission. Risk factors for HCV were carefully sought, and HCV viral load and genotype were determined in all positive mothers. The infants were tested for alanine aminotransferase (ALT) and HCV-RNA at birth and at 4, 8, 12, 18, and 24 months of age.

RESULTS

Eight of 60 (13.3%) infants born to HCV-RNA positive mothers acquired HCV infection, but only 2 (3,3%) were still infected by the end of follow-up. Infants' genotypes matched that of the mothers. ALT levels were in the normal range in all study subjects throughout the follow-up. High maternal viral load (P < 0.05), possession of HCV risk factors (P < 0.004), and history of blood transfusion (P < 0.05) were associated with increased risk of HCV vertical transmission.

CONCLUSIONS

This long-term prospective study shows that, although vertical transmission from HIV-negative mothers occurs in 13% of cases, there is a high rate of spontaneous viral clearance (75%). High maternal viral load and mothers belonging to HCV risk categories were the only variables predictive of the vertical transmission.

[Breastfeeding and hepatitis C virus (HCV): the need for a careful appraisal]

We review the available data on the possible role of breast-feeding in hepatitis C virus (HCV) transmission to infants of HCV-RNA-positive mothers. Current knowledge about HCV excretion through breast milk, HCV infection of breast-fed infants by mothers contaminated after delivery, and vertical transmission risk to infants breast-fed by chronic HCV viremic mothers are presented. Vertical transmission risk by breast-feeding HCV-RNA-positive mothers is unclear: no study has been performed with the aim and the required methodology to evaluate HCV transmission risk related to breast-feeding duration. Recommendations to HCV-RNA-positive mothers who wish to breast-feed their infant are discussed in light of present knowledge about HCV secretion in breast milk, mother-to-infant HCV transmission, and historical records on vertical transmission of other viruses to infants breast-fed by their viremic mothers.

Dominant role of host selective pressure in driving hepatitis C virus evolution in perinatal infection

The dynamics of the genetic diversification of hepatitis C virus (HCV) populations was addressed in perinatal infection. Clonal sequences of hypervariable region 1 of the putative E2 envelope protein of HCV were obtained from four HCV-infected newborns (sequential samples spanning a period of 6 to 13 months after birth) and from their mothers (all samples collected at delivery). The data show that the variants detected between birth and the third month of life in samples from the four newborns were present in the HCV populations of their mothers at delivery. In the newborns, a unique viral variant (or a small group of closely related variants) remained stable for weeks despite active viral replication. Diversification of the intrahost HCV population was observed 6 to 13 months after birth and was substantially higher in two of the four subjects, as documented by the intersample genetic distance (GD) (P = 0.007). Importantly, a significant correlation between increasing GD and high values for the intersample K(a)/K(s) ratio (the ratio between anoffymous and synonymous substitutions; an index of the action of selective forces) was observed, as documented by the increase of both parameters over time (P = 0.01). These data argue for a dominant role of positive selection for amino acid changes in driving the pattern of genetic diversification of HCV populations, indicate that the intrahost evolution of HCV populations is compatible with a Darwinian model system, and may have implications in the designing of future antiviral strategies.

Hepatitis C virus infection in children

The prevalence of hepatitis C virus (HCV) infection is relatively low in childhood, with anti-HCV prevalence rates of 0.1-0.4% in the Western world. To date, blood transfusion has been the principal route of acquisition of HCV in children, but there is evidence that vertical transmission is overtaking it. The overall risk of vertical perinatal transmission of HCV is about 5%, although it increases with HIV co-infection and higher maternal viraemia. The mode of delivery and breastfeeding do not seem to affect the vertical transmission of HCV. Diagnosis of perinatal transmission relies on determination of ALT levels and the presence of HCV after the second month, while maternal anti-HCV antibodies may persist until 18 months of life. After infancy, a variable percentage of perinatally infected children are anti-HCV negative; thus, detection of HCV-RNA is necessary for accurate diagnosis. The natural history of HCV in childhood is not well understood and the outcome depends on host and viral factors. The rate of progression to chronicity is about 60-80% in both post-transfusion and vertically acquired HCV infection. Compared with adult patients, chronic hepatitis C in children is characterized by both low ALT levels and low viral load, as well as by the mildest histological and immunohistochemical forms of chronic hepatitis. The prognosis is usually worse in multitransfused, thalassaemic children and those who have had cancer. Experience of treatment of chronic hepatitis C in children is limited, with about 40% having a sustained response to the interferon therapy. It is necessary to perform long-term follow-up and multicentre treatment studies to improve knowledge of the natural history of HCV in children, as well as that of the efficacy of anti-viral therapy in childhood.

Mother-to-infant transmission of hepatitis C virus

The rate of mother-to-infant transmission of hepatitis C virus (HCV) is approximately 5%, but is higher when the mother is co-infected with HIV Vertical transmission is restricted to infants whose mothers are viraemic. The risk of transmission increases with increasing maternal viral load but a specific cut-off value predicting infection cannot be defined. There is no specific HCV genotype which is preferentially transmitted. The mode of delivery (caesarean versus vaginal) does not appear to influence the rate of transmission, but firm evidence is lacking. There is no evidence to suggest an increased risk of HCV transmission through breast feeding. Pregnancy is not contra-indicated in HCV-infected women. Without drugs to treat established infections in mothers and infants and interventions to prevent vertical transmission, routine HCV screening is not recommended in pregnant women.

Treatment of chronic hepatitis C in pediatric patients

Although HCV infection in children shares some clinical features with that in adults, it is clearly different in several ways. These differences may have important implications for treatment. Some differences, such as milder disease, less frequent extrahepatic manifestations, and fewer comorbid conditions causing progression, argue against aggressive treatment in childhood. Other factors, such as less severe liver disease, shorter disease duration, possibly higher rates of sustained virologic response, and better tolerance of IFN, may be reasons to pursue treatment before advanced hepatic injury occurs. Given the relatively small number of pediatric patients with HCV infection and the gaps in the current understanding of natural history and effects of therapy in these patients, treatment should be undertaken only in clinical trials, so that careful data collection and monitoring can define more precisely the safety and efficacy of IFN therapy in children.

Mother-to-infant transmission of hepatitis C virus: molecular evidence of superinfection by homologous virus in children

BACKGROUND/AIM

Vertical transmission of hepatitis C virus (HCV) is well established but its incidence is low. To assess the molecular evidence of mother-to-infant transmission or intrafamilial transmission of HCV, the NS5 B region and the hypervariable region 1 (HVR1) of the E2/NS1 region of the HCV genome from each member of a family were investigated.

METHODS

A 35-year-old mother with chronic hepatitis C virus infection and her four infected boys were studied. The same HCV 1a genotype was found in all five. Phylogenetic analysis was done by the neighbor-joining, the maximum likelihood, and the maximum parsimony methods.

RESULTS

Comparison of the phylogenetic trees in the NS5B and HVR1 regions showed that the sequences in the children were more closely related to the population of variants of their own mother than to any genotype la sequence available in the databases. However, four HVR1 clones from two brothers (E2 and E3) had a strong homology, but were significantly divergent from the variants of the mother.

CONCLUSIONS

These results suggest that a cluster of HCV strains exists in the family and that E3 could have been superinfected by E2 HCV strains and reciprocally. In conclusion, phylogenetic analysis through variable regions of the genome suggests that at least two modes of transmission are involved in this family: perinatal and horizontal.

Association of GB virus C (GBV-C)/hepatitis G virus (HGV) with haematological diseases of different malignant potential

Among risk groups for GB virus C (GBV-C)/HGV infection, patients with haematological diseases are particularly exposed due to the combination of transfusional support and immunodeficiency status. To examine any association between GBV-C/HGV positivity and different malignancy potential of hematological diseases, we investigated two groups of patients, one with clonal stem cell disease with long latency period (myelodysplasia, myeloproliferative disease) and one with malignant haematological diseases (Hodgkin's lymphoma, non-Hodgkin's lymphoma, acute leukemia, multiple myeloma). Virus positivity was compared with the data from cytogenetic analysis at first diagnosis. The frequency of GBV-C/HGV infection in these patients was studied using reverse transcription-polymerase chain reaction (RT-PCR) and E2 antibody assay. Serum GBV-C RNA was found in 29/47 (62%) patients. The prevalence of GBV-C RNA in the group of oncological cases (72%) was significantly higher (P= .02) than in the patients with clonal stem cell diseases (28%). Among the GBV-C negative cases, only 25% had malignant haematological diseases. The data from GBV-C/ HGV tested cases for which cytogenetic analysis was carried out indicated an association of GBV-C/HGV positivity with genomic destabilization in general. Of the cases with numerical and structural aberrations, 64% were GBV-C positive. A correlation could not be confirmed between GBV-C/HGV and liver enzyme levels, blood transfusions, chemotherapy treatment, or viral coinfection. These findings suggest a high risk of GBV-C/HGV infection in patients with haematological disorders especially in the group of malignant diseases. These observations may indicate that the persistence of GBV-C/HGV in these patients could be associated with susceptibility to genomic destabilisation.

Improved sensitivity of reverse transcriptase polymerase chain reaction for hepatitis C virus using random hexamer primers

The use of specific primers and random primers for the detection of hepatitis C virus RNA by reverse transcriptase-polymerase chain reaction was compared. The cDNA obtained from using both methods was amplified by the same protocol. Of the 30 plasma specimens tested, 6 (20%) were hepatitis C virus RNA-positive using specific primers and 19 (63%) were positive using random primers, demonstrating that the use of random hexamer-primed reverse transcriptase-polymerase chain reaction significantly improves the sensitivity (p < 0.01).

Automation of polymerase chain reaction-based systems for detection of hepatitis C virus RNA

Polymerase chain reaction-based molecular assays are gaining increasing importance in the diagnosis and monitoring of infectious diseases. Over the past several years, the development and application of these techniques has initiated a revolution in the diagnosis and monitoring of hepatitis C infection. Presently, molecular assays are exclusively done in especially dedicated laboratories. Advances in automation will bring these technologies into routine diagnostic laboratories and will make them widely used.