Vertical transmission of hepatitis C virus

Hepatitis C virus and HIV coinfection

The world-wide prevalence of hepatitis C virus (HCV) is approximately 1%. Being primarily a blood-borne virus, the major risk factors for HCV include the receipt of blood and blood products, as well as intravenous drug use. As a result, many individuals infected with HIV are also infected with HCV. Any effect of coinfection on progression of either HIV or HCV is likely to have a tremendous impact on the mortality and morbidity of these individuals and should be considered when managing coinfected individuals. This review will describe the epidemiology and clinical manifestations of HCV and will consider the evidence for an impact of coinfection on the progression of both viruses.

Vertical transmission of hepatitis C virus: risk factors and infantile prognosis

OBJECTIVES

To clarify the incidence and risk factors of the vertical transmission of hepatitis C virus (HCV) and to determine the prognosis of the carrier infants.

METHODS

At our hospital, 1,941 non-pathological (non-HIV carriers) Japanese pregnant women were screened for anti-HCV antibodies. Sera of the antibody-positive women were examined by the reverse transcription polymerase chain reaction (RT-PCR) method, and the positive women and their infants were followed by testing HCV-related markers.

RESULTS

The HCV carrier rate among the pregnant women was 3.5% (68/1,941). Four among the 65 infants (6.2%) who were successfully followed for more than 6 months developed the HCV carrier-state. Of all the risk factors examined, only the elevation (> or = 110 IU/l) of maternal serum alanine aminotransferase (ALT) was found to be significant for HCV vertical transmission. Seventy-five and 50% of the carrier infants manifested chemical hepatitis and seroconverted to an HCV-RNA-negative status, respectively, during the follow-up period.

CONCLUSIONS

The frequency of HCV vertical transmission was 6.2%. Half of the carrier infants became seronegative for HCV-RNA. HCV vertical transmission was significantly affected by the maternal serum ALT level prior to delivery.

Vertical transmission of hepatitis C virus infection: usefulness of viremia detection in HIV-seronegative hepatitis C virus-seropositive mothers

Seventy mother-newborn pairs were studied for hepatitis C viremia to evaluate the risk of vertical transmission of hepatitis C virus from human immunodeficiency virus-negative mothers. Forty-five mothers were hepatitis C virus-RNA positive: 4 to 45 children were positive at birth and during follow-up. The level of viremia plays an important role in vertical transmission.

Hepatitis C virus seroconversion rate in a hyperendemic area of HCV in Japan: a prospective study

We have studied the prevalence, seroconversion rate of anti-hepatitis C virus (HCV), and the transmission of HCV in a cohort of individuals living in a hyperendemic area of HCV in Japan. We investigated 509 subjects, of which 375 could be studied again after 5 years. A remarkable high prevalence of anti-HCV (23.4-24.0%) was observed. Of 287 subjects negative at the first examination in 1990, 4 became positive until the second in 1995 (seroconversion rate: 0.28% per year). Furthermore, we investigated the route of transmission in HCV seroconverted subjects through a detailed interview. All of the HCV seroconverted subjects had past histories of medical treatment. Seroconversion rates of HCV in a hyperendemic area of HCV, were extremely high. Medical treatment was considered to be a causative route of HCV transmission.

Homology of E2 gene in 8 child-mother pairs infected with hepatitis C virus

The frequency of genetic homology of hepatitis C virus (HCV) E2 gene in 8 child-mother pairs was investigated. The route of HCV infection of all children suggested mother-to-child infection by their past history. In this study, we analyzed at least 5 complementary DNA (cDNA) clones for each case. In 6 of the 8 (75%) child-mother pairs, for the region between hypervariable region (HVR)-1 and HVR-2, the similarity of the nucleotide sequence of all 5 cDNA clones between each child and the mother was higher than that between the child and the other children, the other mothers and the sequences from GenBank. One of the 8 (13%) child-mother pairs showed a great similarity in parts of all cDNA clones. This was also confirmed by phylogenetic analyses of the sequences of cDNA clones from families and that from GenBank. These results suggested that the homology search of nucleotide sequence of this region was useful to confirm mother-to-child transmission of HCV.

Hepatitis C virus infection in pediatric patients

In contrast to our understanding of hepatitis C virus infection in adults, relatively little is known about the evolution and treatment of HCV infection in pediatric patients. Children at risk for HCV infection include recipients of multiple blood-product transfusions, organ transplantation and infants born to HCV-infected mothers. A proportion of HCV-infected pediatric patients do not have an identifiable risk factor. HCV infection is commonly detected in children previously presumed to have non-A, non-B hepatitis and cryptogenic liver disease. HCV infection usually leads to mild chronic liver disease in children but is also associated with chronic active hepatitis and cirrhosis. Interferon therapy is effective in a proportion of patients with chronic hepatitis C.

Use of polymerase chain reaction and antibody tests in the diagnosis of vertically transmitted hepatitis C virus infection

Data on patterns of polymerase chain reaction (PCR) and antibody test results in infants born to hepatitis C virus (HCV)-infected mothers were systematically reviewed to aid development of optimum testing schedules and diagnostic criteria for vertically exposed infants and to facilitate early identification of infected infants. Survival and cross-sectional analyses were used to estimate the timing of initial PCR positivity and subsequent PCR negativity in infected infants, and maternal antibody loss in uninfected infants was estimated as a weighted average of individual study findings. Of 74 eligible infants with strong evidence of HCV infection, an estimated 89% (90% confidence interval, 80-95%) were first PCR positive by 3 months of age, and less than 10% had subsequent PCR negativity attributable to intermittent viraemia or resolved infection in the first 18 months of life. The negative predictive value of PCR at 3 months of age was greater than 98% at an assumed rate of 5% vertical transmission, but as low as 88% at 25% transmission. The inclusion of 22 infants, each with a single PCR-positive result, increased the estimated frequency of resolved infections but made little difference to other estimates. A minority of PCR-positive infants had periods of antibody negativity by second- or third-generation assays, and among 297 uninfected infants, maternal antibody was not detected beyond 18 months. Thus, the majority of infected infants may be persistently PCR positive from 3 months of age, and the negative predictive value of PCR at 3 months is generally high. However, poor repeatability of PCR, inadequate infant follow-up, and inclusion of postnatally infected infants limits interpretation of the pooled data. Further studies using standardised PCR methodologies are needed.

Loss of circulating hepatitis C virus in children who developed a persistent carrier state after mother-to-baby transmission

Of the 15 babies born to mothers infected with hepatitis C virus (HCV) and followed since birth, three developed HCV RNA in their serum. HCV RNA disappeared in two infants within 2 mo, but it persisted in the remaining infant. Mother-to-baby transmission was diagnosed retrospectively in an additional eight children aged 0.8-13.6 y. The eight children were followed for 1.4-5.0 y (mean +/- SD: 3.2 +/- 1.3 y) until they were 3.3-16.7 y old (8.5 +/- 4.3 y). Serum HCV RNA disappeared and antibodies to HCV decreased in the titer in two of the children when they were 3 y old. The spontaneous loss of serum HCV RNA was not observed in any of the other 14 children with posttransfusion infection who were followed for 2.6-6.1 y (4.0 +/- 1.1 y), until 3-22 y from the time they received transfusions and when they were 8.4-22.8 y old (15.4 +/- 4.1 y). These results indicate that the vertical transmission of HCV is rare, and some children can resolve the infection after a few years, whereas the infection persists in children who are infected by transfusion.

The prevalence of HCV infection in a cohort of pregnant women, the related risk factors and the possibility of vertical transmission

The prevalence of antibodies for one or more HCV antigens was 2.3% of 1,347 mothers at childbirth. Compared with the principal factors studied, the presence of antibodies was more frequent in women who were carriers of HIV infection (3/3), in those who had suffered liver diseases (5/37) or who had had transfusion (3/25). This was as opposed to women who did not have any risk factor (p < 0.001). The prevalence of HCV-RNA was 1.3%; in relation to the antibody state, such a condition was more frequent in subjects with antibodies for 3 or 4 antigens (about 80%) compared with those who were positive for 1 or 2 antigens. HCV-RNA of the same genotype as the mother (type 1; 1a) was also found in the funicular blood of 2 of the 18 babies born to mothers who were positive for HCV-RNA. In the course of the follow-up (from the 3rd to the 18th month) the viral RNA was not found in any of the babies, nor was it found in the 2 who were positive at birth. Even the antibodies gradually disappeared, although slowly. At the 10th month, 91% of the babies resulted as having no antibodies and at the 18th month none of the babies resulted as having antibodies. Breast-feeding also appeared to have no influence on the transmission of the infection; out of 18 viremic mothers indeed 12 (67%) breast-fed their babies.

Hepatitis C virus RNA present in saliva but absent in breast-milk of the hepatitis C carrier mother

In order to examine whether saliva and breast-milk are mediators of the vertical transmission of hepatitis C virus (HCV) from an HCV carrier mother, serum, saliva, and breast-milk samples from 11 HCV carrier mothers were collected at the time of delivery, and at approximately 1- to 3-months intervals for as long as 30 months postpartum. Serum was also sampled from their children. All samples were analysed for the presence of HCV RNA, using the nested polymerase chain reaction method. No HCV RNA was detected in any breast-milk samples. In saliva, HCV RNA was detected in four of the 11 mothers (36%). These four mothers also had liver function abnormalities. Hepatitis C virus RNA was not detected in any serum samples of the children, and all children had normal liver function. The children were monitored for periods from 2 to 44 months. During this period, there was no evidence of virus transmission. Breast-milk is not likely to be a source of mother-to-child transmission of HCV. Maternal saliva may harbour HCV, but it may not result in infant infection.

Constitutive and induced cytokine production by human placenta and amniotic membrane at term

Results of our previous study on the immunity of human placenta and amniotic membranes revealed that in majority of cases these organs present constitutive non-specific antiviral immunity in the organ culture (OC) system. It is possible that interferons (IFNs), tumour necrosis factors (TNFs) and interleukin 6 (IL-6) may be responsible for the antiviral effect. Here, the constitutive and lipopolysaccharide (LPS)-induced production of these cytokines and, additionally, interleukin 10 (IL-10) were determined in OC of chorionic villi, decidua and amniotic membranes. Significant amounts of constitutive TNF-alpha (2-64 U/ml), IL-6 (200-12,000 U/ml) and IL-10 (1-70 ng/ml) were detected in the maternal decidua and chorionic villi of placenta. Amniotic membranes produced lower concentrations of the cytokines. LPS increased the production of cytokines from two- to eightfold. In contrast, activity of IFN released spontaneously was found only in four of 50 placentae and amniotic membranes. LPS and Newcastle disease virus (NDV) induced IFN production in the OC system. However, the increase of IFN after induction was also very small (up to 32 U/ml). Individual differentiation in the cytokines production was observed among placentas and amniotic membranes. TNF was identified as type alpha with addition TNF-beta, IFN as type alpha, beta and gamma.

A prospective study of vertical transmission of hepatitis C virus

AIM: To prospectively study the mechanism of mother to infant transmission of hepatitis C virus (HCV).

METHODS: Using a nested PCR for detection of HCV RNA and the second generation ELISA for detection of anti-HCV, 13 pregnant women who suffered from post transfusion hepatitis C (PT-HCV) and their 15 babies were studied to evaluate mother to infant transmission of HCV.

RESULTS: The total infection rate of HCV was 86.7% in the babies, including one case of clinical HCV (7.7%), three subclinical cases of HCV (23.1%), and nine inapparent cases of HCV (69.2%). The positive rates of anti-HCV and HCV RNA declined with the age of the babies, to 7.7% for anti-HCV and 15.4% for HCV RNA at the age of three years.

CONCLUSION: Babies born to mothers infected with HCV were vertically infected with HCV at a high rate, but the consequences were not serious. Four fetuses born, born through induced labor to mothers positive for anti-HCV and HCV, were all infected by HCV, suggesting that the mother to infant transmission of HCV mainly occurred in the uterus.

Hepatitis C virus infection and related liver disease in children of mothers with antibodies to the virus

OBJECTIVE

To evaluate the clinical, biochemical, and virologic features associated with hepatitis C virus (HCV) infection acquired early in life from mothers with antibodies to HCV (anti-HCV).

STUDY DESIGN

Multicenter prospective-retrospective study in Italian children.

PATIENTS

Two groups of children were investigated. Group 1 included 14 infants, born to mothers with anti-HCV but without human immunodeficiency virus infection, who became seropositive for HCV RNA during the first year of life and were thus considered infected. Group 2 included 16 children with chronic hepatitis C, aged 1 1/2 to 14 years, whose mothers were the unique potential source of infection. Both groups were followed for 12 to 48 months.

METHODS

Alanine transaminase (ALT), anti-HCV, and HCV RNA were investigated by the polymerase chain reaction on entry to the study and during follow-up.

RESULTS

All children in group 1 had anti-HCV throughout follow-up, and all had ALT abnormalities, ranging from 1.5 to 10.5 times the normal value during the first 12 months. During further follow-up, 5 of 10 children had HCV RNA with abnormal ALT values, 3 had a return to normal of the ALT values but continued to have viremia, and 2 eventually had normal ALT values and clearance of HCV RNA. Of the 16 children in group 2, all were free of symptoms and 62% had only slight ALT elevations; 7 who underwent liver biopsy had histologic features of minimal or moderate hepatitis.

CONCLUSIONS

HCV infection acquired early in life from mothers with anti-HCV is usually associated with biochemical features of liver damage during the first 12 months of life. Progression to chronicity seems to occur in the majority of cases, although HCV-associated liver disease is likely to be mild throughout infancy and childhood.

Acute hepatitis C viral infection during pregnancy: failure of mother to infant transmission

A pregnant woman developed an acute hepatitis C virus (HCV) type 3a infection during the second trimester of pregnancy. The clinical virological features are presented, including HCV RNA quantification of maternal serum samples collected during pregnancy. These findings are discussed in light of the child's remaining uninfected after 5 years of follow-up.

Aedes albopictus (Diptera:Culicidae) is incompetent as a vector of hepatitis C virus

In laboratory experiments, Aedes albopictus females were fed hepatitis C virus (HCV)-infected human blood with a unit-feeding apparatus. Pools of engorged females were tested at various time intervals after their blood meal for the presence of HCV RNA using two methods in parallel: reverse transcription-nested polymerase chain reaction (PCR) and PCR with the Amplicor HCV system. Comparable results were obtained with both methods. Mosquitoes were found to be positive only immediately and 24 h after feeding. Moreover, female progeny produced negative results. Our results indicate that the Ae.albopictus strain used is incompetent as a vector of HCV.

Hepatitis in the obstetric patient

The six agents identified thus far that cause viral hepatitis are reviewed, and their impact upon pregnancy is described. Although it is the most common cause of jaundice during pregnancy, viral hepatitis does not generally increase the risk of pregnancy complications, nor is it teratogenic. Vertical transmission of some types of viral hepatitis does occur, however.

[Descriptive epidemiology of hepatitis C virus infection in France in 1996]

This paper on the epidemiological aspects of the hepatitis C virus (HCV) infection in France presents the risk factors of the ways of contamination (transfusion, drug addiction, nosocomial, professional or sexual contamination, familial or mother-to-infant transmission). The estimated prevalence of HCV infection in France is comprised between 500,000 and 650,000 individuals, i.e. slightly above one percent of the French population. The epidemiological contribution of the study of HCV genotypes and the biological means evidencing HCV transmission are detailed, as well as the actual evolution of the HCV epidemy in France.

Routes of transmission of hepatitis C virus in an endemic rural area of Japan. Molecular epidemiologic study of hepatitis C virus infection

We conducted an epidemiological study to investigate the routes of transmission of hepatitis C virus (HCV) infection in an area endemic for HCV. Subjects were the 857 adult inhabitants of K area, Japan. The prevalence of antibody to HCV (anti-HCV) was 26.3%. The HCV genotype 1b was the most prevalent (89.3%) among the anti-HCV positive subjects. Molecular evolutionary analysis, based on the nucleotide sequences of the HCV core region from 23 participants with type 1b, showed that the isolates were distributed into more than 1 group. Multivariate regression analysis demonstrated that an age over 40 years, a history of blood transfusion, the presence of antibody to hepatitis B core antigen (anti-HBc), or a history of surgery were each independently associated with the presence of anti-HCV. No significant differences in the presence of anti-HCV prevalence were observed between the wives of men positive for anti-HCV (33.3%) and age-matched women (36.4%), or between the husbands of women positive for anti-HCV (36.4%) and age-matched men (38.3%), from the same area. Findings suggest that the various strains of HCV type 1b were transmitted via medical procedures, not by the intrafamilial route.

Mode of hepatitis C virus infection, epidemiology, and chronicity rate in the general population and risk groups

Since the discovery of the hepatitis C virus (HCV), it has become evident that this infectious agent is a primary cause of posttransfusion and sporadic non-A, non-B hepatitis. Identification and introduction of surrogate markers for posttransfusion hepatitis and later introduction of anti-HCV screening has decreased the incidence of posttransfusion hepatitis. Community-acquired HCV infection is less common than posttransfusion HCV hepatitis. HCV infection may lead to liver cirrhosis without prior evidence of laboratory or histologic infection. Populations at risk for HCV infection include patients receiving organ transplants, health care workers, infants born to HCV-infected mothers, and hemodialysis patients. Intravenous drug abusers and their sexual partners also demonstrate a high rate of HCV infection. Nosocomial HCV transmission may occur despite the observance of universal precautions. Dental or surgical intervention, salivary inoculation, family members infected with HCV, cocaine abuse, HIV infection, and lower socioeconomic status also each correlate with an increased risk of infection. HCV infection is associated with many immune-mediated diseases. There may also be some relationship between human leukocyte antigens and HCV infection. Since there currently is no HCV vaccine, prevention of exposure remains the only possibility for reducing HCV transmission and prevalence.

Mother-to-child transmission of a hepatitis C virus variant with an insertional mutation in its hypervariable region

BACKGROUND/AIMS

We have analyzed the molecular basis of mother-to-child transmission of hepatitis C virus.

METHODS/RESULTS

Healthy pregnant women were screened for anti-HCV antibody and babies born to hepatitis C virus carrier mothers were prospectively investigated. Among the 35 pairs studied, the hepatitis C virus genome was detectable in only one baby, who did not show any significant symptoms of hepatitis. The viral load in the blood of the mother was one of the highest of the 35, and the population of the hepatitis C virus genome was heterogeneous. Furthermore, she was found to have a mixed infection with type 1a and type 1b hepatitis C virus. However, the hepatitis C virus genome obtained from the baby was only from type 1b, less heterogeneous and composed of the clones which were detected in the blood of the mother. The selected hepatitis C virus had a 12-nucleotide insertion in the amino-terminus of the E2 hypervariable region of the genome.

CONCLUSIONS

The incidence of mother-to-child transmission of hepatitis C virus from carrier mothers was shown by this prospective study to be low. The presence of selection pressure during transmission was suggested. The biological significance of the virus with 12-nucleotide insertion has to be determined.

Hepatitis C in dialysis patients

Patients on hemodialysis have a higher prevalence of hepatitis C (HCV) infection compared with the general population. Several factors have been associated with an increased risk of HCV infection in hemodialysis patients, including number of blood transfusions, duration of hemodialysis, previous transplantation, intravenous drug abuse, male gender, and in-center hemodialysis. In addition, there is mounting evidence to suggest nosocomial transmission within hemodialysis units. Although the precise modes of transmission have not been identified, breakdown in standard infection control practices, physical proximity to an infected patient, and sharing of dialysis machines are possible causes. Nonetheless, at the present time, the Centers for disease Control and Prevention (CDC) does not recommend dedicated machines, patient isolation, or a ban on re-use in hemodialysis patients with HCV infection. Consequently, strict adherence to universal precautions and careful attention to hygiene are recommended to reduce the transmission of HCV in dialysis units.

Vertical transmission of hepatitis C virus: an epidemiological study on 2,980 pregnant women in Italy

The risk of mother-to-infant transmission of hepatitis C virus (HCV) varies according to the population studied and the tests used. Aim of the current study was to investigate HCV vertical transmission rate in children born to 30 HCV positive/HIV negative pregnant women in Italy. We investigated the potential vertical transmission of HCV by identifying HCV antibody seropositive pregnant women, by analyzing HCV-RNA in the peripheral blood using PCR and by prospectively following their offspring until 24 months of age. During the third trimester, 2,980 consecutive pregnant women were examined for anti-HCV antibodies by a second generation Enzyme-Linked Immunosorbent Assay (EIA2) and re-assayed by a second generation Recombinant Immunoblot Assay (RIBA2). A total of 32 mothers (1.07%) were positive for EIA2 test; 30 out of 32 had a reactive confirmatory RIBA2 test for HCV. All anti-HCV positive mothers were negative for HIV. These 30 mothers and their 30 babies formed the study cohort. Of the 30 anti-HCV positive mothers, 10 were also positive for serum HCV-RNA by PCR. All the babies born to the 30 anti-HCV positive mothers were initially negative for HCV-RNA (cord blood specimens), but three babies became positive at three months of age and remained positive thereafter. These babies had been born to 3 of the 10 mothers with viremia during the third trimester of pregnancy. These results suggest that HCV vertical transmission is possible in 10% of anti-HCV positives and in about 33% of the HCV-RNA seropositive mothers.

Chronic viral hepatitis in childhood

In endemic areas infection with hepatitis B virus is a common cause of chronic liver disease in childhood. High levels of viral replication and mild ALT abnormalities are the rule in children infected perinatally and many of them are likely to maintain viral replication through their youth. Conversely about 90% of children infected later in life clear HBeAg and achieve sustained remission of liver disease before reaching adulthood. The eventual outcome of infection and disease in these patients remains unpredictable as reactivation of liver damage and viral replication may occur after several years of sustained remission. Cirrhosis is a rare and early complication of chronic HBV infection in children, and a risk factor for hepatocellular carcinoma. IFN therapy can accelerate HBV DNA clearance, improving the spontaneous anti-HBe seroconversion rate in Caucasian children by two to three times. Hepatitis delta is the most severe form of chronic viral hepatitis in childhood. Cirrhosis can be diagnosed in up to 26% of patients at presentation, and few cases respond to IFN therapy. Hepatitis C is relatively rare in children. Before the discovery of HCV, blood transfusions were the most common source of infection. Hepatitis C is usually a mild, asymptomatic disease in otherwise healthy children, but has a poor propensity to spontaneous remission over the years. For this reason, and based on the experience in adults, IFN treatment is now being evaluated.

Anti-HCV seroprevalence and risk factors of hepatitis C virus infection in Moroccan population groups

Hepatitis C virus (HCV) seroprevalence and transmission routes were investigated in several groups of the Moroccan population. This study showed a low HCV seroprevalence in the Moroccan general population. However, haemodialysis patients and haemophiliacs were at higher risk of having HCV infection, since the prevalences were, respectively, 35.1 and 42.4% in comparison with the blood donors' prevalence (1.1%). These results indicated that parenteral exposure is the transmission pathway of HCV. To investigate the possibility of vertical HCV transmission, a cohort of healthy, unselected pregnant women were included in the study. A prevalence of 1% was found among them. Seven newborns were anti-HCV-positive, although, when RT-PCR was used to search for HCV RNA in their sera, none of them was viraemic. These data indicated that anti-HCV antibodies were passively acquired in these cases. We concluded that vertical transmission is absent when mothers are at low risk of contracting other parenterally or sexually transmitted diseases. Three percent of a group of patients of a centre for sexually transmitted diseases were repeatedly anti-HCV-positive, suggesting the possible sexual transmission of HCV. When screening 116 sera of anti-HIV-positive subjects, 19.8% were anti-HCV-positive. Furthermore, 17.9% of the sixty-seven patients who were proven to have sexually contracted HIV were also anti-HCV-positive. These data might reflect a likely cotransmission of these two viruses, hence suggesting HIV is a cofacter for HCV sexual transmission, as previously reported.

Capture and RT-PCR of hepatitis C virus RNA with safety primers

The principle and practice of the polymerase chain reaction (PCR) has had a major impact on medical research. This is a powerful method but it does have its limitations, especially for clinical diagnostic work. We describe some improvements of hepatitis C virus (HCV) amplification such as simplification of specimen preparation, elimination of false negative reactions influenced by point mutations, and fluorimetric detection. The aim of the method is to make the procedure as easy and as inexpensive as possible for routine laboratories and for blood screening. After rapid chemical denaturation of the clinical specimen with guanidine thiocyanate and simultaneous hybridization of biotinylated primers to template HCV RNA, the product was fixed to streptavidin-coated magnetic beads and potential inhibitors were removed in easy washing steps. To eliminate the influence of point mutations within the primer binding sites, primer sets with different lengths at their 3'-end were developed for capture, reverse transcription, and amplification of genomic fragments by PCR. Positive results were identified by fluorescence staining. The low cost of the method allows the quantitation of templates by testing of dilution series as is common in microbiological laboratories.

Mother-to-infant transmission of hepatitis C virus in human immunodeficiency virus-coinfected mother: a case report

We report a case of vertical transmission of HCV in a mother infected with both HCV and HIV. Our case suggests that coinfection with HIV, by causing an immune dysfunction, might be one of the risk factors for the transmission of HCV.

Sporadic transmission of hepatitis C

At the present time, people having contracted hepatitis C are not warned about the possible ways in which they can transmit this disease to others. This greatly increases the risk of sporadic transmission of the virus. Public health and medical authorities should institute programs to inform all such afflicted persons how to avoid communicating the disease to others.

Hepatitis C virus infection in pregnancy

OBJECTIVES

To evaluate the clinical aspects of hepatitis C virus (HCV) liver disease in anti-HCV+ve mothers, both during pregnancy and six months after delivery, and to assess the outcome of pregnancy.

SETTING

Obstetric department for high risk pregnancies of the University of Padova, Italy.

PARTICIPANTS

Seventeen hundred consecutive pregnant women were studied.

METHODS

Each woman underwent the following: 1. serological screening for hepatitis surface antigen (HBsAg), antibodies to HCV (anti-HCV), antibodies to human immunodeficiency virus type 1 (HIV1) within the first trimester of pregnancy; and 2. clinico-biochemical assessment in order to ascertain previous or active liver disease and risk factors for viral infections.

RESULTS

Twenty-nine (1.7%) of the 1700 women were found anti-HCV positive. Eight of them had an associated positivity for HIV infection. HCV-RNA was positive in 64.2% of anti-HCV positive women. Liver function tests (included transaminases) were within the normal range in 27 mothers (both during and six months after delivery). Only 2/29 women had a slight increase in AST/ALT; liver biopsy in these cases was compatible with mild chronic active chronic active hepatitis. In all women the outcome of pregnancy was favourable (12/29 anti-HCV positive mothers underwent caesarean delivery for causes independent from HCV infection).

CONCLUSIONS

A substantial proportion of anti-HCV positive pregnant mothers, even if asymptomatic, have circulating HCV-RNA. The pregnancy does not induce a deterioration of liver disease, and vice versa, HCV infection does not increase the risk of obstetric complications.

A rational approach to the management of hepatitis C infection

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HCV transmission in family members of subjects with HCV related chronic liver disease

To investigate the risk of sexual and intrafamilial transmission of HCV, 220 family members of 76 patients (index cases) with chronic type C viral liver disease were tested for serological markers of HCV. Of the family members, 129 were offspring, 64 sexual partners, 15 parents and 12 siblings of the index cases. Anti-HCV was tested in all the household contacts; HCV-RNA was tested in antibody positive samples. The serologic markers of HCV were tested in a control group of 168 family members of 81 patients with chronic hepatitis unrelated to HCV. The overall prevalence of anti-HCV was 8.2% compared to 0.6% in the control group (p < 0.001). Sexual partners were anti-HCV positive more frequently than the other contacts (20% vs 2.2%; p < 0.001), without any difference in males or females. No correlation was observed between the occurrence of HCV infection in contacts and age, severity of liver disease or risk factor for the acquisition of HCV in the index cases. Seven of the 18 (39%) anti-HCV positive family contacts had bio-chemical evidence of chronic liver disease, histologically confirmed in the 6 patients who underwent a liver biopsy. Liver chemistry was normal in all the HCV-negative contacts. Ten of the 18 anti-HCV positive contacts (55%) were HCV-RNA positive, Genotypes were the same (1b) in 4 of the 7 viremic couples of subjects: in 3 of the 6 couples of sexual partners and in the only mother/son couple. These data suggest the occurrence of intraspousal transmission of HCV, while intrafamiliar acquisition of HCV in non-sexual contacts seems to be rare.

Vertical transmission of hepatitis C virus in low-risk pregnant women

To assess the prevalence of hepatitis C virus (HCV) infection in pregnant women and the rate of vertical transmission in infected mothers belonging to a low-risk group, 1,388 women were tested for HCV antibody at delivery. Twenty-five anti-HCV-positive women with no apparent source of HCV exposure were recruited. A reverse transcriptase-polymerase chain reaction (RT-PCR) and a new quantitative branched DNA-based signal amplification assay (bDNA) were used to detect HCV RNA. The rate of anti-HCV positivity in pregnant women was 2.5% (36 of 1,388). Of the 25 cohort mothers, 18 (72%) were positive for HCV RNA by RT-PCR, 13 of whom were also positive by the bDNA assay (sensitivity 72.2%). Of the 25 infants of low-risk mothers tested at birth, 22 were anti-HCV positive, two were weakly reactive, one was negative, and none was viremic. Neither active humoral immunoresponse nor HCV RNA was detected in any of the infants over a period of 12 months. These data suggest a relatively high prevalence of anti-HCV in unselected pregnant women and a poor efficiency of vertical transmission of HCV in a low-risk population, irrespective of the viral burden of the mother-to-be.

Vertical transmission of hepatitis C virus infection

Vertical transmission of hepatitis C virus (HCV) was studied in 58 infants of 55 mothers (3 sets of twins). HCV RNA analyses by the polymerase chain reaction (PCR) and alanine aminotransferase (ALT) were performed on consecutive blood samples from birth to 18 months of age (0, 3, 9 and 18 months). Data on factors possibly influencing mother-to-infant transmission of HCV, such as concomitant human immunodeficiency virus (HIV) and hepatitis B virus infection during pregnancy, maternal HCV RNA status at delivery, mode of delivery, prematurity and breastfeeding habits were collected. In addition, 6 older siblings (age 4-10 years) of the infants were tested once for anti-HCV. Of the 55 mothers 52 (95%) had a history of intravenous drug use (IVDU). Two mothers were HIV positive. 40/54 (75%) tested mothers were HCV RNA positive. 16 (27%) infants were delivered by Caesarean section, and 50 (86%) infants were breastfed. All infants were HCV RNA negative on all occasions and anti-HCV negative at the age of 18 months. Maternally acquired anti-HCV antibodies disappeared and were not detected by 9 months in 78%. One of the 6 older siblings was anti-HCV and HCV RNA positive. We conclude that the risk of vertical HCV transmission is low in infants of HCV-positive/HIV-negative mothers, and that breastfeeding seems to be safe in this group.

Vertical transmission of hepatitis C virus infection

Since the virus responsible for non-A, non-B hepatitis was cloned in 1989, much has been learnt about the epidemiology, diagnosis and clinical spectrum of hepatitis C virus (HCV) infection. As the routes of transmission are elucidated, specific groups of children as well as adults are known to be at particular risk of infection. The women most at risk of HCV infection are those with a history of injecting drug use. Mother-to-child transmission has been documented, although the exact risk has not been quantified, and the factors influencing the risk remain to be evaluated. This article reviews current knowledge on vertical transmission of HCV, and provides some guidelines on the management of infants born to women infected with the virus.

Host dependent variation of hepatitis C virus: phylogenetic analyses

Hepatitis C virus quasispecies in six patients from three families were separated by single strand conformation polymorphism analysis and by determination of nucleotide sequences of envelope regions containing the E1 gene segment and hypervariable region-1 of each quasispecies. Four of the six patients had multiple quasispecies. Phylogenetic analyses indicated that all quasispecies from one individual were highly homologous to each other. The homology was higher in the E1 gene segment than in hypervariable region-1. Furthermore, all quasispecies found in members of one family (husband and wife) were also highly homologous, suggesting direct intrafamilial transmission. The direction of hepatitis C virus variation in hypervariable region-1, however, seems to differ depending on the host in intrafamilial transmission.

Mother-to-infant transmission of hepatitis C virus: a prospective study

To investigate the risk of mother-to-infant transmission of hepatitis C virus (HCV) and the natural course of HCV-infected infants, we prospectively studied 31 offspring of pregnant women who were anti-HCV positive and anti-HIV negative. Sera were serially tested for anti-HCV by the second-generation ELISA-test (ELISA-2) and for HCV-RNA by the polymerase chain reaction procedure. The mean period of follow up was 19 months (range 6-41 months). The presence of HCV-RNA in the mothers was associated with a high titre of anti-HCV by ELISA-2 or a positivity of the second generation recombinant immunoblot assay. At birth, 26 babies were positive for anti-HCV. Passively transferred maternal antibodies became undetectable within 2-15 months. HCV-RNA was detected in only 3 infants (9.7%) within 1-4 weeks after birth and persisted thereafter. The genotype of HCV-RNA in each of the infants was consistent with that of their mother. These 3 showed chronic transaminase elevation during the follow up that started at 1-2 months of age, although they revealed no clinical symptoms. Reelevation of anti-HCV titre was observed in the HCV-infected infants within 10 months of age, suggesting an endogenous production of anti-HCV. The mean titre of HCV-RNA in three mothers of infected infants was higher than that in the mothers of uninfected infants (10(5.3 +/- 0.3) vs 10(4.4 +/- 0.2)/ml).

CONCLUSION

Our findings indicate that HCV was most likely to have been transmitted from mothers to infants at the time of delivery and that it was capable of evoking the chronic carrier state.

Detection of hepatitis C virus antibodies and specific hepatitis C virus ribonucleic acid sequences in cord bloods from a heterogeneous prenatal population

OBJECTIVE

Our aim was to quantify the prevalence of at-risk pregnancies for maternal-fetal hepatitis C virus transmission in a heterogeneous prenatal population by detection of both hepatitis C virus-specific antibody and hepatitis C virus ribonucleic acid sequences in cord bloods from their deliveries.

STUDY DESIGN

An anonymous serosurvey of 1432 consecutive umbilical cord blood samples were analyzed for hepatitis C virus antibodies with a second-generation enzyme immunoassay with all hepatitis C virus antibody-positive samples batched and analyzed for both human immunodeficiency virus antibodies and hepatitis C virus ribonucleic acid sequences by polymerase chain reaction.

RESULTS

Forty-seven of the samples (3.2%) were positive for hepatitis C virus antibodies; seropositivity rates differed significantly by socioeconomic status but not by race. Significantly more of the antibody-positive women underwent cesarean section for delivery (31.9% vs 21.9%, p = 0.03). Three (6.4%) hepatitis C virus antibody-positive samples were also human immunodeficiency virus-antibody positive, whereas nine (19.1%) were hepatitis C virus ribonucleic acid positive.

CONCLUSION

As many as 19% of hepatitis C virus antibody-positive women in this study also had hepatitis C virus ribonucleic acid isolated from their delivery cord blood samples, which may indicate an increased risk of vertical hepatitis C virus transmission in those pregnancies. Hepatitis C virus-specific antibody and ribonucleic acid detection may also be markers for other pregnancy complications that result in higher rates of cesarean section for these women.

Detection of hepatitis C viral sequences in serum by ‘nested’ polymerase chain reaction (PCR) and a commercial single-round PCR assay

BACKGROUND

Demonstration of the hepatitis C virus (HCV) genome is usually done with combined reverse transcription and polymerase chain reaction (RT-PCR) employing nested primer sets. Recently, a commercial PCR assay (Amplicor PCR assay), based on a simplified sample preparation procedure, a single, combined reverse transcription and polymerase chain reaction (RT-PCR), and a microwell plate capture and detection, has been developed.

OBJECTIVE

The aim of the present study was to compare the new Amplicor assay with an 'in-house' PCR. Additional testing included a third-generation enzyme immunoassay for anti-HCV antibodies, the Wellcozyme HCV Western Blot, which is equivalent to a third-generation recombinant immunoblot assay. Furthermore, HCV genotypes were classified.

STUDY DESIGN

Sera from a total of 127 patients were studied. After screening with a third-generation enzyme immunoassay (EIA), the Wellcozyme HCV Western Blot, was performed as well as the conventional RT-PCR and the Amplicor PCR. Specimens, which were found positive by testing with the Amplicor kit, were subjected to storage at room temperature for 96 h.

RESULTS

A total of 52 patients were found to be positive for anti-HCV by the third-generation EIA. With the Amplicor assay, the HCV genome was detected in 38 patients. In comparison with the 'in-house' assay, two discrepant results were found. Resolution of discrepant samples increased the total number of true positives to 39. A good correlation was found between a positive anti-HCV test result and the presence of HCV-RNA by RT-PCR. No significant reduction in the amount of amplification product was observed by retesting of suboptimally stored samples with the Amplicor assay.

CONCLUSION

Because of the rapidity and the improved ease of handling, the Amplicor assay was found to be a good contribution for detection of HCV in serum.

Epidemiology and prevention of hepatitis type C in Italy

Viral hepatitis type C is of public health importance in all parts of the world. In Italy, hepatitis C accounts for approximately 18% of the annually reported cases of acute viral hepatitis. The national rate of acute non-A, non-B hepatitis (the majority of which are hepatitis C) has significantly decreased during the last decades. At present, the onset of the disease occurs more frequently in individuals 15-24 years old, in men more frequently than in women and in persons living in the south of the country. During the last 5 years the rate of transfusion-associated hepatitis C has dropped (4.8 cases per 1,000,000 in 1989 versus 0.4 per 1,000,000 in 1993), while the percentage of patients who are intravenous drug abusers (IVDA) has increased from 18% to 33%. The high prevalence of anti-HCV (hepatitis C virus) antibody in blood and blood products recipients, IVDA and health-care workers with occupational exposure to blood indicates that HCV is efficiently transmitted parenterally. Data concerning transmission of HCV from mother to infant or by person-to-person contact, either by sexual or by non-sexual household contact, are controversial. However, there is almost universal agreement that the presence of concurrent infection with HCV and human immunodeficiency virus enhances the rate of vertical/perinatal HCV transmission as well as transmission through sexual and other types of person-to-person contact.(ABSTRACT TRUNCATED AT 250 WORDS)

Injection with nondisposable needles as an important route for transmission of acute community-acquired hepatitis C virus infection in Taiwan

A prospective case-controlled study was conducted in order to determine the transmission route of community-acquired hepatitis C virus (HCV) infection in Taiwan. Thirty-eight consecutive patients (25 men and 13 women) with acute community-acquired HCV infection and 76 age (within 3 years)- and sex-matched healthy control subjects without HCV infection were enrolled. Serum anti-HCV was tested by second generation immunoassay. The sera of 26 family members from 12 families of index patients were also tested for anti-HCV. A questionnaire covering the history of blood transfusion, surgery, intravenous drug abuse, prostitute contact, dental procedures, injection, acupuncture, tattooing, and ear-piercing was conducted among patients and control subjects. Univariate analysis revealed injection with nondisposable needles was an independent risk factor (P = 0.02, odds ratio = 4.17, 95% confidence interval = 1.24-14.47) associated with HCV infection. Other risk factors were not significant. Only 2 (7.7%) family members of index patients had an anti-HCV. In conclusion, more vigorous effort to prohibit the use of nondisposable needles should be promoted to interrupt the spread of community-acquired HCV infection in Taiwan. Of note, a significant number of patients (34.2%) contracted HCV infection without identifiable risk factors. Unidentified routes need to be investigated.

Molecular epidemiology of hepatitis C virus infection among intravenous drug users

BACKGROUND/AIMS

The clinico-pathological features of hepatitis C virus infection in intravenous drug users are different from those found in other hepatitis C virus-infected patients. Our aim was to test whether specific viral variants circulate within this particular patient population.

METHODS

We studied the distribution of hepatitis C virus genotypes in 90 drug addicts and 484 controls, according to the method described by Okamoto.

RESULTS

Hepatitis C virus type 1a and 3a infections were more frequent among intravenous drug users than in 125 age-matched controls (48.8% and 21.1% vs 17.6% and 11.2%), accounting for the majority of infections in intravenous drug users. Analysis of hepatitis C virus genotypes according to age showed that, in the general population, hepatitis C virus types 1a and 3a were more prevalent among patients younger than 40 years of age than in older individuals (17.6% and 11.2% vs 1.4% and 0.6%).

CONCLUSIONS

These findings suggest that hepatitis C virus types 1a and 3a were recently introduced in Italy, presumably via needle-sharing among intravenous drug users, and from this reservoir they are extending to the general population, particularly among younger subjects.

Ethnic differences in the prevalence of anti-hepatitis C antibodies and hepatitis B surface antigen in Israeli blood donors by age, sex, country of birth and origin

The presence of anti-hepatitis C virus (HCV) antibodies frequently indicates both persistent infection and infectivity. Consequently, blood donors found to be anti-HCV positive, are excluded from the donor pool. The aim of this study was to compare age, sex and ethnic differences in the prevalence of anti-HCV antibodies with that of hepatitis B surface antigen (HBsAg) among immigrant and Israeli-born blood donors. Anti-HCV antibodies were assayed by a second-generation enzyme-immunoassay (EIA) and HBsAg by a standard EIA in a sample of 136,977 blood donors in Israel during 1992. The overall age-adjusted prevalence of anti-HCV antibodies was 0.66% in men and 0.55% in women, and for HBsAg, 0.85% and 0.44%, respectively. There was a significant increase in the prevalence of anti-HCV antibody with age, and significant differences by country of birth, with the highest prevalence found among those born in the former USSR and eastern Europe. This contrasted with the findings for the prevalence of HBsAg, where the highest rates were among those born in northern Africa. Among Israeli-born donors, differences in the prevalence of anti-HCV antibodies by parental country of origin were minimal and much less than for HBsAg. Hence the prevalence of anti-HCV antibodies in Israel is strongly associated with age and country of birth but not with country of origin. There is little evidence of substantial vertical or intrafamilial transmission of HCV infection in Israel.