Transmission of HCV between spouses

Sexual transmission of viral hepatitis

Identification and vaccination of adults at risk for hepatitis B virus acquisition through sexual contact is a key strategy to reduce new hepatitis B virus infections among at-risk adults. Hepatitis C has emerged as a sexually transmitted infection among men with male sex partners (MSM). Several biological and behavioral factors have been linked to hepatitis C virus transmission among MSM, including human immunodeficiency virus coinfection; participation in sexual practices that result in mucosal damage or result in exposure to blood; presence of sexually transmitted diseases (STIs), particularly ulcerative STIs; multiple/casual sex partners; and unprotected anal intercourse.

Hepatitis C virus transmission and its risk factors within families of patients infected with hepatitis C virus in southern Iran: Khuzestan

AIM: To determine whether hepatitis C virus (HCV) infection of index cases increases intrafamilial transmission (sexual and nonsexual contacts) of HCV.

METHODS: In a case-control descriptive study we enrolled 300-household contacts of 60 index cases (40 males and 20 females) of HCV infection and 360 pair-matched controls in Ahwaz JundiShapour University Hospitals from August 1, 1998 to September 1, 2003. The control group consisted of first time blood donors referred to the Regional Blood Transfusion Organization. Serum samples and demographic data and a medical history including the existence of risk factors for HCV (after a questionnaire on the risk factors for parenteral exposure) were obtained from each subject. Antibodies to HCV were detected employing a commercially available second-generation enzyme immunoassay (EIA, Abbott II). Positive serum specimens were retested using a second-generation recombinant immunoblot assay (RIBA-2) and a polymerase chain reaction for HCV RNA. Data analysis was carried out for intra-household clustering.

RESULTS: Only 4 of 300 (1.33%) cases of household contacts without percutaneous risk factors were positive for HCV Ab while the remaining 296 family contacts were negative for anti-HCV. The mean age of the index cases was 28.4 (Std 15.22) years. The anti-HCV prevalences in parents, spouses, children of the index cases were 0.87% (1/115), 3.39% (2/59)) and 0.79% (1/126), respectively. Among couple partners negative for anti-HCV antibodies, the mean duration of the sexual relationship was 6 years. The two-couple partners positive for anti-HCV antibodies married the index cases for longer than 15 years. The prevalence of positive HCV Ab among household contacts (1.33%) was not significantly higher than that in the controls (1%) (P > 0.06).

CONCLUSION: Intrafamilial transmission of HCV is not the significant transmission route and sexual transmission does not seem to play a role in the intrafamilial spread of HCV infection. Intrafamilial transmission of HCV is possible but occurs at a low rate.

Correlates of HCV seropositivity among familial contacts of HCV positive patients

BACKGROUND

Determinants of intrafamilial HCV transmission are still being debated. The aim of this study is to investigate the correlates of HCV seropositivity among familial contacts of HCV positive patients in Italy.

METHODS

A cross-sectional study was conducted with 175 HCV positive patients (index cases), recruited from Policlinico Gemelli in Rome as well as other hospitals in Central Italy between 1995 and 2000 (40% female, mean age 57 +/- 15.2 years), and 259 familial contacts. Differences in proportions of qualitative variables were tested with non-parametric tests (chi2, Yates correction, Fisher exact test), and a p value < 0.05 was considered significant. A multivariate analysis was conducted using logistic regression in order to verify which variables statistically have an influence on HCV positivity in contact individuals.

RESULTS

Seropositivity for HCV was found in 8.9% of the contacts. From the univariate analysis, risk factors significantly associated to HCV positivity in the contacts were: intravenous drug addiction (p = 0.004) and intercourse with drug addicts (p = 0.005). The only variables associated significantly and independently to HCV seropositivity in patients' contacts were intercourse with drug addicts (OR = 19.28; 95% CI: 2.01 - 184.94), the retirement status from work (OR = 3.76; 95% CI: 1.17 - 11.98), the time of the relationship (OR = 1.06; 95% CI: 1.00 - 1.11) and tattoos (OR = 7.68; 95% CI: 1.00 - 60.20).

CONCLUSION

The present study confirms that having intercourse with a drug addict is the most significant risk factor for intrafamilial HCV transmission. The association with retirement status from work could be related to both a long-term relationship with an index case and past exposure to common risk factors.

Hepatitis C virus and lichen planus

Hepatitis C virus (HCV) is an important factor in the development of chronic liver disease and hepatocellular carcinoma. In recent years it has become known that HCV induces various extrahepatic manifestations including mixed cryoglobulinemia, membranoproliferative glomerulonephritis, Sjögren's syndrome, autoimmune thyroiditis, malignant lymphoma, porphyria cutanea tarda and lichen planus. Although the mechanisms of extrahepatic manifestations remain unclear, it is known that interferon (IFN) therapy and coadministration of IFN with ribavirin are effective in promoting the disappearance or alleviation of such extrahepatic lesions, which have tended to be overlooked. The present review focuses on lichen planus, one of the major extrahepatic manifestations.

Hepatitis C seroprevalence and risk behaviors in patients attending sexually transmitted disease clinics

BACKGROUND

Hepatitis C virus (HCV) is a major global problem, transmitted primarily by percutaneous exposure to contaminated blood.

GOAL

The goal of the study was to determine the seroprevalence of and risk factors for HCV among patients attending two urban STD clinics in Alberta.

STUDY DESIGN

Anonymous unlinked serosurveys were performed with use of leftover sera. Self-administered questionnaires collected information on demographics, sexual behaviors, and drug use.

RESULTS

The seroprevalence of HCV was 3.4% (209 of 6,668 patients). Univariate analysis revealed that infection was higher among nontherapeutic needle users (RR = 80.9), those coinfected with HIV (RR = 8.09), individuals over the age of 20 years (RR = 6.68), those of aboriginal ethnicity (RR = 5.54), those with a history of STD (RR = 3.43), men (RR = 2.2), and bisexuals (RR = 2.23). Not utilizing condoms and engaging in prostitution or exchanging money or drugs for sex were also risk factors. In multivariate analysis, nontherapeutic needle use remained highly significant (RR = 60.54-65.51). Other significant factors included sex, age, ethnicity, a history of STD, and HIV infection (RR = 1.72, 4.62, 3.18, 1.69, and 2.56, respectively). Sexual orientation and sexual practices were not significant without a history of drug use.

CONCLUSION

Nontherapeutic needle use is the strongest predictor of HCV infection.

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.

Hepatitis C virus infection in Chicago women with or at risk for HIV infection: evidence for sexual transmission

BACKGROUND AND OBJECTIVES

The importance of sexual transmission of hepatitis C virus (HCV) infection is unclear. We attempted to define its role in women with or at risk for HIV infection.

GOAL OF THIS STUDY

To ascertain if high-risk sexual behavior was independently associated with HCV infection.

STUDY DESIGN

Risk factors were assessed cross-sectionally in Chicago women newly enrolled in the Women's Interagency HIV Study. Women who had (n = 243) or were at risk for HIV infection (n = 53) were tested for HCV antibodies (Ab).

RESULTS

Of 296 women, 123 (42%) were HCV Ab positive; prevalence was 90% in women who injected drugs (IDU) compared with 12% in noninjectors (odds ratio [OR], 64.0, 95% confidence interval [CI], 29.9 to 137.0). A multivariate model showed associations with IDU (OR, 110.3, 95% CI, 33.3 to 365.8), prior gonorrhea (OR, 3.6, 95% CI, 1.4 to 8.9), and sex with a male IDU (OR, 2.7, 95% CI, 1.1 to 7.0).

CONCLUSION

Injection drug use is the strongest predictor of HCV infection, but sexual risk factors are also independently associated.

Sexual transmission of hepatitis C virus and prevention with intramuscular immunoglobulin

The sexual transmission of hepatitis C virus (HCV) has long been debated. The prevalence of infected at-risk partners varies from 0% to 30%. In a prospective study, the risk of infection was quantified in steady heterosexual partners and the prophylactic effect of normal human polyvalent immune serum globulin (ISG) was evaluated. A total of 899 at-risk partners of HCV-infected patients were enrolled in a single-blind randomized controlled trial and assigned to receive every 2 month 4 mL of intramuscular ISG from unscreened donors (450 partners) or placebo (499 partners). Seven partners developed acute HCV infection (increased aminotransferase levels and appearance of HCV-RNA): six of the placebo group (incidence density [ID] 12.00/1,000 person year; 95% confidence interval [CI] 3.0 to 21.61), and only one of the ISG-treated group (ID 1.98/1,000 person year; 95% CI 0 to 5.86). The risk of infection was significantly higher in controls versus treated individuals (p = 0.03). Six couples had genotype 1b (85%), and one couple had genotype 1a; HCV sequence homology strongly supported sexual transmission. Our trial demonstrates that HCV infection can be sexually transmitted and quantifies the risk of sexual transmission: for every year of at-risk sexual relationship, almost 1% of the partners became infected. Intramuscular ISG is safe and well tolerated. Unlike ISG from screened donors, ISG from donors unscreened for anti-HCV contains high titers of anti-gpE1/gpE2 neutralizing antibodies and high neutralizing activity. Anti-HCV hyperimmune globulin could be prepared from anti-HCV-positive blood units and could be used to protect sexual partners and in other at-risk situations of exposure to HCV infection.

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.

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.

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.

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.

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.

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.

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.

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 analysis of intraspousal transmission of hepatitis C virus

BACKGROUND/AIMS

Although intraspousal transmission of hepatitis C virus (HCV) has been speculated, there is no direct evidence.

METHODS

To investigate whether transmission of HCV occurs by this route, 295 spouses of persons diagnosed with HCV were studied. Of these, 25 (8.8%) tested positive for anti-HCV. Next, the HCV genotype was determined by polymerase chain reaction using a mixed primer set, and cDNA was obtained in 17 of the 25 couples for comparison of the genotypes.

RESULTS

Of these 17, 14 (82.4%) spouses were shown to be infected with HCV of the same genotype. Analysis of the nucleotide sequences of putative E1 gene of eight couples having the same HCV genotype revealed that five couples had remarkably high nucleotide sequence homologies (> 97%), whereas samples obtained from the remaining three couples showed relatively low homology (91-92%). Nucleotide sequence homologies were significantly higher between spouses than between non-spouse pairs of isolates. Phylogenetic analysis using the neighbor-joining method suggests that infection in these five couples probably occurred after marriage. Furthermore, none of the five couples had shared other possible transmission routes such as intravenous drug use, dental treatment or acupuncture.

CONCLUSION

These data strongly suggest the occurrence of intraspousal transmission of HCV.

Evaluation of sexual transmission in patients with chronic hepatitis C infection

BACKGROUND

The transmission of hepatitis C virus (HCV) by parenteral exposure is well documented. However, a proportion of patients with acute or chronic HCV infection have an unknown source of infection.

OBJECTIVES

The purpose of this study is to evaluate the role of sexual transmission in HCV infection.

STUDY DESIGN

68 patients (median age, 50 years) with chronic hepatitis C and their spouses were tested for the presence of antibody to HCV (anti-HCV) by multi-antigen and chimeric C25 antigen enzyme immunoassays and for HCV RNA by the polymerase chain reaction. Information on sexual activity and risk factors for HCV infection were obtained from all couples via a questionnaire.

RESULTS

All index patients were positive for both anti-HCV and HCV RNA. Antibody to HCV was detected in four (5.9%) of their spouses. One anti-HCV-positive spouse had a history of blood transfusion while the other three (4.4%, 95% CI = 1.5-12.2%) had no known risk factors for HCV infection and thus may have been exposed to HCV via sexual transmission. Two of these 3 spouses had positive serum HCV RNA and had identical HCV genotype to the index patients. The length of sexual exposure was significantly longer in the couples who both were anti-HCV-positive than in patients whose spouses were anti-HCV negative (median: 25 vs. 10 years, P = 0.02, Mann-Whitney test). In our 68 index patients, 96% had antibodies to the recombinant proteins from the C22 (core) and C33C (NS3) regions, and 82% and 76% had antibodies to the proteins from the NS5 and C100-3 (NS4) regions. Identical anti-HCV profiles were noted in two of the four anti-HCV-positive couples.

CONCLUSIONS

Our results indicate that sexual transmission, although uncommon, should be considered as a risk factor for HCV infection, especially in spouses who have had long-term intimate relationships with a chronic hepatitis C patient.

Viral hepatitis. Current concepts for dental practice

The transmission of blood-borne viruses in the dental office is a potential hazard to patients and dental staff, particularly to oral and maxillofacial surgeons. Hepatitis B virus has been a recognized hazard for several years, and in the past oral surgeons and other dental health care staff have been infected as a result of occupational exposure. Hepatitis C virus in contrast does not appear to be a major occupational hazard to dental staff, nevertheless, infection with this virus can lead to significant morbidity and may have oral manifestations. Hepatitis D virus can be nosocomally transmitted, but vaccination against the hepatitis B virus minimizes this problem. Hepatitis E virus is not of clinical relevance to dentistry, although dental staff who are in areas of endemic infection can become infected as a result of enteric transmission. A number of other putative viral agents may also cause hepatitis, but additional data is awaited, and their significance to dental practice is unknown. This article summarizes current data on hepatitis viruses A, B, C, D, and E.

Heterosexual transmission of hepatitis C virus and the possible role of coexistent human immunodeficiency virus infection in the index case. A multicentre study of 423 pairings

OBJECTIVES

To define the role that sexual transmission plays in the spread of hepatitis C virus (HCV) infection, and to examine the influence of coexistent human immunodeficiency virus (HIV) infection on this mode of transmission.

DESIGN

A multicentre, seroprevalence study of anti-HCV performed in the stable heterosexual partners (SHP) of index cases reactive for anti-HCV.

SETTING

Department of Internal Medicine and Section of Gastroenterology of three University Hospitals, Spain.

SUBJECTS

A total of 423 stable heterosexual partners of index cases reactive for anti-HCV. This included a group of 142 intravenous drug users (IVDU), 120 of whom were coinfected with HIV. Additionally, 2886 first-time voluntary blood donors selected at random were included to compare the prevalence of anti-HCV.

MAIN OUTCOME MEASURES

Serum samples were screened for anti-HCV by a commercially available, second-generation enzyme-linked immunoassay. Tests repeatedly reactive for anti-HCV were analysed by a four-antigen, recombinant immunoblot assay. Anti-HIV was tested by enzyme immunoassay and Western blot was used for confirmation of positive cases.

RESULTS

The prevalence of anti-HCV, was 7.1% in SHP and 1.2% in random donors (P < 0.001). This prevalence was higher in SHP of index cases coinfected with HIV in comparison with that shown in the SHP of index cases only reactive for the anti-HCV (9.1 vs. 6.3%; P = 0.2), particularly when a younger and more homogeneous group such as the SHP of IVDU index cases was considered alone (9.2 vs. 0%; P = 0.1). However, the SHP of IVDU index cases coinfected with HIV were almost three times more likely to be infected with HIV than HCV (24.2 vs. 9.2%).

CONCLUSIONS

These data suggest that HCV infection may be sexually transmitted but with low efficiency, and this could be increased in the presence of coexistent HIV infection in the index case.

Intrafamilial transmission of hepatitis C virus

Family members of hepatitis C virus (HCV)-infected hemodialysis patients had a high rate (8.1%) of HCV infection and were often infected by the same genotype of HCV as the renal patients. Renal patients who had a longer history of hemodialysis or more frequent arteriovenous shunt replacement posed a higher risk to their household contacts, especially to their primary-care providers at home.

Transmission of hepatitis C in an isolated area in Japan: community-acquired infection. The South Kiso Hepatitis Study Group

BACKGROUND/AIMS

The spread of hepatitis C virus (HCV) infection not due to drug needle sharing or transfusion is largely unknown in communities. A search for risk factors for HCV infection in an endemic area might elucidate inapparent modes of transmission.

METHODS

We conducted screening for hepatitis virus markers and parenteral exposures to blood among 435 inhabitants in an isolated area known for its endemicity for non-A, non-B hepatitis and in a nonendemic area with 1542 inhabitants.

RESULTS

The prevalence of hepatitis B surface antigen was the same in both areas. The prevalence of antibody to HCV verified by the recombinant immunoblot assay was 32.4% in the highly endemic area and 2.3% in the nonendemic area (P < 0.001). Risk factors for HCV infection in the highly endemic area were complex but included folk remedies such as acupuncture and "vacuuming" for congested blood in muscle by the use of a warm glass bottle.

CONCLUSIONS

Folk remedies such as acupuncture and cutting of the skin using nonsterilized knives should be considered as possible routes of HCV transmission not associated with blood transfusion or sharing of drug paraphernalia.

Prevalence of hepatitis C virus infection in the household contacts of patients with HCV-related chronic liver disease

It is still controversial whether the familial environment plays a role in the diffusion of HCV infection. The aim of this study was to evaluate the prevalence of anti-HCV positivity in the household contacts of patients with HCV-related chronic hepatitis. Nearly all the household contacts of 113 subjects with anti-HCV+ chronic hepatitis (100/113 spouses and 260/290 children) were investigated. Anti-HCV was determined by means of ELISA II and was confirmed by RIBA II. Anti-HCV positivity was found in 27% of the spouses and in 1.9% of the children. Prevalence of anti-HCV positivity in spouses correlated positively with the duration of the marital status. Seventeen/32 (53.1%) of anti-HCV-positive subjects were found to have chronic hepatitis. This study indicates that intrafamilial diffusion of HCV infection is mostly accounted for by horizontal, in particular spouse to spouse, transmission and that spouse to spouse transmission of HCV infection correlates positively with the duration of marital status.

Intrafamilial transmission of hepatitis C virus: the important role of inapparent transmission

To evaluate the intrafamilial transmission of hepatitis C virus (HCV) 104 index patients with type C chronic liver disease and their 307 family contacts were interviewed. After a questionnaire on the risk factors of parenteral exposure, blood samples were obtained and tested for liver biochemistry and anti-HCV antibody by enzyme-linked immunosorbent assay (Abbott II). Overall, 52 family contacts (17%) were positive for anti-HCV, indicating a higher anti-HCV prevalence among family contacts than among the general population in Taiwan. The anti-HCV prevalences in parents, spouses, children, and other contacts of the patients were 54% (14/26), 28% (25/91), 6.9% (10/143), and 6.4% (3/47), respectively. The contacts of index patients had increasingly greater risk of HCV infection when they became older and had lived longer with index patients. All family contacts were divided into two groups categorized by whether the index patients had or did not have a history of parenteral exposure. Among 126 family contacts of the 42 patients without parenteral exposure, blood transfusion and surgery were the factors significantly associated with HCV infection in these family contacts (odds ratio = 7.26, 95% confidence interval = 2.32-32.67; odds ratio = 3.95, 95% CI = 1.29-12.11, respectively). Risk factors were not significantly associated with HCV infection among 181 family contacts of the 62 index patients with parenteral exposure. It is concluded that the index patients without parenteral exposure appeared to have acquired the disease from HCV-infected family members with risk factors. Most of the index patients had a history of parenteral exposure and in turn served as the source of the disease for family members.

Sexual transmission of hepatitis C virus

We tested 50 heterosexual partners of hepatitis C viraemic (HCV) individuals, using second generation HCV antibody assays and a validated polymerase chain reaction assay. In none of them were HCV antibodies or HCV-RNA detected. The median duration of the sexual relationship was 13 years. This study, with the most sensitive techniques for detection of HCV, indicates that the risk of sexual transmission of HCV is absent or very low.

Low risk of sexual transmission of hepatitis C virus

Sexual transmission of hepatitis C virus (HCV) was studied between 104 anti-HCV positive index cases (99 haemophilic men, five women) who have attended the Oxford Haemophilia Centre and 104 (98 female, 6 male) longstanding sexual partners. Ninety-one percent of the index cases were HCV RNA positive by the polymerase chain reaction (PCR) and 56% were anti-human immunodeficiency virus (HIV) positive. Three (2.9%) sexual partners (each a female partner of a different HCV RNA positive haemophilic man) were anti-HCV, and HCV RNA, positive. All had other risk factors for HCV infection. Of 59 partners who were tested for anti-HIV four (7%) were positive and only one of these was also anti-HCV positive. There was no association between HIV positivity in the index cases and HCV positivity in their partners. Our results confirm a low risk of sexual transmission of HCV.

Sexual transmission of hepatitis C virus and HIV-1 infection in female intravenous drug users

We examined the relationship between the presence of antibody to HCV and sexually transmitted diseases in 151 female, intravenous drug users aged 17-43 years. Anti-HCV was present in 49 of 66 HIV-1-negative women (74.2%), and 63 of 85 HIV-1-positive women (74.1%). Anti-HCV seropositivity was significantly related to sexually transmitted infections (Ureaplasma urealyticum infections excluded) in HIV-1-seronegative women, but not in HIV-1-positive women. Also, in HIV-1-negative subjects. Trichomonas vaginalis infections (and infections with M. hominis) were significantly related to anti-HCV seropositivity, and a positive relation between the number of sexual partners and the presence of anti-HCV was demonstrated. In HIV-1-positive subjects a shared use of needles and syringes was more likely, and an increased parenteral exposure to HCV may decrease the relative contribution by sexual transmission. However, in HIV-1-negative subjects, sexual transmission of HCV appears to be both a possible and important means of transmission.