Seroprevalence of hepatitis C virus infection and its association with natural infection of hepatitis B virus among preschool children in Taiwan

Taiwan is a hyperendemic area of hepatitis B virus (HBV) infection where chronic hepatitis B is the most important cause of liver cirrhosis and hepatoma. Since, diagnostic kit for detecting hepatitis C virus (HCV) infection has been developed, HCV was found to be another important etiology of chronic liver disease. In order to study the seroprevalence of HCV infection among preschool children after mass hepatitis B vaccination program in Taiwan, a community-based survey was carried out in 54 kindergartens in 10 urban areas, 10 rural areas, and two aboriginal areas randomly selected through stratified sampling. Serum specimens of 2538 preschool children were screened for the HCV antibodies (anti-HCV) by a commercially available third-generation microparticle enzyme immunoassay and for HBV markers by radioimmunoassay methods. The multivariate-adjusted odd ratios (OR_m) with their 95% confidence intervals (CI) were estimated through the multiple logistic regression analysis. A total of 58 children were anti-HCV seropositive, giving a prevalence of 2.3%. The prevalence of anti-HCV was 1.0% (5 of 484) among aboriginal children, a significantly decreased seroprevalence compared with those among other ethnic groups after multivariate adjustment. Boys had a higher anti-HCV seroprevalence, but not statistically significantly different from girls (OR_m: 1.6; 95% CI: 0.9–2.8; p = 0.08). The seroprevalence of the age group of 3–4 years was lower than that of the age group of 5–6 years (OR_m: 2.2; 95% CI: 1.1–4.2; p = 0.02). After multivariate adjustment, preschool children with natural HBV infection had a higher anti-HCV seroprevalence, but not statistically significantly different from those without natural HBV-infection (OR_m: 2.6; 95% CI: 0.9–7.4; p = 0.08 for HBV-infected vs. uninfected). HCV infection varies with gender, residential area, and natural HBV infection. HCV and HBV might share common transmission routes in Taiwan.     

Evaluation of risk factors for intrafamilial transmission of HCV infection in Egypt

The objectives of this study were to define the prevalence of intrafamilial transmission of HCV and evaluate the risk factors in this setting. A cross-sectional, family-based seroepidemiological study was performed in Cairo Liver Center and Oncology Diagnostic Unit, Ain Shams University. A total of 102 index patients (72 males and 30 females) with type C chronic liver disease and their 305 family contacts were studied. Only 265 family contacts were eligible for the study as they showed no previous history of exposure to risk factors. Overall, 15 family contacts (5.7%) were positive for anti-HCV, indicating a lower anti-HCV prevalence among family contacts than the general population in Egypt. Spouses were at higher risk of infection (16.7%) than family members (2.6%). Among the repeatedly positive samples for anti-HCV, only 3 samples were HCV-RNA positive (1.1%), all were spouses. Logistic regression analysis revealed that spouses reporting promiscuous sexual relations were at higher risk than those with normal sexual relations. Contacts sharing personal objects were also at higher risk to develop HCV infection. Index cases reporting previous blood transfusion (18.6%), i.v. antibilharzial therapy (33.3%), multiple sex partners (1.0%) or advanced liver diseases were more infective to their family contacts. The contacts of index cases had increasing risk of HCV infection with increase in age and duration of contact. The prevalence rate of intrafamilial spread of HCV infection is low compared to the rate among general population, emphasizing its limited role in transmitting HCV infection. Long duration of sexual contact and promiscuous sexual activities were major risk factors in this setting.     

Community-based study of hepatitis C virus infection and type 2 diabetes: an association affected by age and hepatitis severity status

Past studies of the relation between hepatitis C virus (HCV) infection and type 2 diabetes conflict. The authors aimed to elucidate the relation by using a large community-based sample with a wide range of liver conditions. Between October 1997 and February 1998, 2,327 consecutive subjects (aged > or =35 years) were enrolled at the public health facility in Taiwan. Blood sugar, hepatitis B surface antigen, and antibody for HCV (anti-HCV) were tested. Abdominal sonography was performed on viral-hepatitis-positive subjects. In univariate analysis, older age, lower educational levels, sedentary work, body mass index of > or 25 kg/m2, and anti-HCV positivity were significantly associated with type 2 diabetes (p<0.05), but smoking, alcohol consumption, gender, and hepatitis B surface antigen status were not. In multivariate logistic regression, anti-HCV positivity was strongly associated with type 2 diabetes in subjects aged 35-49 years (odds ratio (OR)=3.3, 95% confidence interval (CI): 1.4, 8.0) and 50-64-years (OR=1.6, 95% CI: 1.1, 2.5). Sonographic evidence of fatty liver (OR=2.4, 95% CI: 1.2, 4.8) and chronic liver disease (OR=2.0, 95% CI: 1.0, 4.2) in anti-HCV-positive subjects was moderately associated with type 2 diabetes after age and gender adjustment. Data suggest that HCV infection is moderately associated with type 2 diabetes; the association was strongest for subjects aged 35-49 years and increased with severity of the liver condition.     

HCV status knowledge and risk behaviours amongst intravenous drug users

The aim of this study was to identify relationships between injecting and sexual risk behaviours and hepatitis C virus (HCV) status knowledge in intravenous drug users (IDUs). It was a cross-sectional survey (March 1994–June 1995) in 10 drug abuse treatment or psychosocial centres in Paris, France. We used a structured questionnaire about sexual, injecting, HIV and HCV antibody testing practices and results during the previous 6months. Six hundred and twelve sexually active IDUs aged 18 or older who were current injecting drug users were interviewed. Of 592 respondent IDUs, 37% did not report consistent HCV testing and 34% reported being HCV-positive. HCV-positive IDUs were older than HCV-negatives and HCV-unknowns. HCV-unknowns and HCV-positives had a lower educational level than HCV-negatives. After adjusting for demographic characteristics and HIV status, the factors associated with being HCV-unknown were not using condoms (OR: 2.9; 95% CI: 1.9–4.6) as well as clean equipment (OR: 1.8; 95% CI: 1.2–3.0). Not using new equipment was negatively associated with being HCV-unknown (OR: 0.4; 95% CI: 0.2–0.6) and with being HCV-positive (OR: 0.5; 95% CI: 0.3–0.8). Our study suggests that particular sexual and injecting risk-behaviours are associated with not knowing HCV status. As HCV-unknown IDUs are likely to be at the risk of transmitting HCV or acquiring other infections. HCV testing should be encouraged and associated with sexual counselling. Special attention should be paid to disinfecting practices for HCV-positives and use of new injecting equipment should be recommended for HCV-negatives.     

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 biochemical 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 (lb) 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.     

Intrauterine device use does not increase the incidence of anti-hepatitis C seropositivity among monogamous women in Turkey

Background

The relationship between intrauterine device (IUD) use and anti-hepatitis C virus (HCV) status has not been investigated yet. The aims of this study were to compare anti-HCV seropositivity between IUD users and nonusers and to determine whether IUD use is an independent risk factor for anti-HCV seropositivity.

Study Design

This cross-sectional study included 302 married women who used either an IUD (n=164) or did not use any form of modern contraception (n=138). Statistical analysis was carried out using multiple logistic regression models.

Results

Most women were housewives and all indicated their husbands as the one and only lifetime sexual partner. None of the women have ever used intravenous drugs. There were no statistically significant differences between groups in any of the major risk factors for HCV exposure such as invasive dental procedures, parenteral injections, surgery and blood or blood product transfusions. Twenty-seven (8.9%) of the participants were anti-HCV-positive. Of these, 14 were IUD users and 13 were nonusers and there were no statistically significant differences between the two groups (p=.472). The most important risk factors for anti-HCV seropositivity were the number of deliveries (OR=1.41; 95% CI 1.07-1.86) and invasive dental procedures (OR=2.39; 95% CI 1.07-5.39).

Conclusions

IUD use is not associated with an increased incidence of anti-HCV seropositivity among monogamous women. The IUD may be an appropriate contraceptive option for women in stable monogamous partnership with HCV carriers and condom use should not be specifically recommended in this situation.     

Sexual Activity and Hepatitis B and C Virus Infection Among Young Adults After Introduction of a Vaccination Program in an Area of High Endemicity

Background

In areas where hepatitis is endemic, little is known about the sexual transmission of HBV after introduction of an HBV vaccination program.

Methods

We used a self-administered questionnaire and serological tests for HBsAg, anti-HBs, anti-HBc, and anti-HCV to examine the role of sexual activity, as well as sociodemographic status, lifestyle habits, and a history of vaccinations, transfusions, and surgery, in the transmission of HBV and HCV in Korea. The subjects were 865 female and 541 male university students (median age, 19 years; age range, 16–25).

Results

Overall seropositivity was 8.1% for HBsAg, 69.3% for anti-HBs, 21.3% for anti-HBc, and 0.4% for anti-HCV. Regarding HBV, 8% of the subjects were chronic carriers or had recently been infected, 22.8% were never exposed and nonvaccinated, 16.6% were exposed noncarriers, and 52.7% had most likely been vaccinated. We found a significant association between HBsAg seropositivity and history of sexual intercourse (Odds Ratio, 1.8; 95% CI, 1.1–2.8). Students without serologic evidence of immunization against HBV were more likely to have become HBsAg-positive after becoming sexually active.

Conclusions

Our findings suggest that sexual transmission does occur among adolescents and young adults who have not been vaccinated, whereas vaccination protects individuals from becoming an HBV carrier after becoming sexually active.Key words: hepatitis B virus, hepatitis C virus, sexual transmission, vaccination, endemic area     

Seroepidemiological survey of hepatitis C virus among commercial sex workers and pregnant women in Kinshasa, Democratic Republic of Congo

BACKGROUND: Studies conducted mainly in industrialized countries have shown that the transmission of hepatitis C virus (HCV) is mainly parenteral, and have emphasized the role of nosocomial transmission. In Equatorial Africa, the respective contributions of parenteral and non-parenteral routes of transmission are unknown. The potential role of sexual transmission in this area of high HCV endemicity, where sexually transmitted infections (STI) are frequent, is suggested by the fact that HCV infection is rare in infants and young adolescents, but increases thereafter with age. The present study, conducted in Democratic Republic of Congo, was designed to determine the prevalence of HCV infection and associated sexual risk factors in two female populations with different sexual behaviour. METHODS: Cross-sectional studies conducted among commercial sex workers (CSW; n = 1144) and pregnant women (n = 1092) in the late 1980s in Kinshasa showed a high frequency of at-risk sexual behaviour, STI and human immunodeficiency virus (HIV) infection, particularly among CSW. We screened samples collected during these epidemiological studies for antibodies to HCV using a second-generation ELISA with confirmation by a third-generation LIA. We also assessed sociodemographic variables, medical history, STI markers and sexual behaviour, and their potential association with HCV infection. RESULTS: The overall prevalence of anti-HCV was 6.6% (95% CI : 5.2-8.2) among CSW and 4.3% (95% CI : 3.2-5.7) among pregnant women (age-adjusted OR = 1.5, 95% CI : 1.0-2.1, P = 0.05). Multivariate analysis showed that the presence of anti-HCV among CSW was independently associated with a previous history of blood transfusion (P < 0.001), age >30 years (P < 0.001) and the presence of at least one biological marker of STI (P < 0.03). No such links were found among pregnant women (although the history of blood transfusions was not investigated in this group). Anti-HCV was not associated with sociodemographic variables or sexual behaviour in either group, or with individual markers of STI. Despite the high-risk sexual behaviour and the higher prevalence of STI in CSW, the difference in HCV seroprevalence between CSW and pregnant women (6.6% versus 4.3%) was small, particularly when compared with the difference in the seroprevalence of HIV (34.1% versus 2.8%). CONCLUSION: The role of sexual transmission in the spread of HCV seems to be limited. Parenteral transmission (including blood transfusion and injections), possibly related to the treatment of STI, probably plays a major role.     

Prevalence of markers for hepatitis A, B and C in the German population. Results of the German National Health Interview and Examination Survey 1998

The prevalence of serological parameters indicative of infection with hepatitis A, B and C was determined using sera collected from representative population samples in the former East German (new) federal states and the West German (old) federal states during the German National Health and Examination Survey in 1998. Sera were tested for antibodies to hepatitis A virus (HAV), to hepatitis B core antigen (HBc) and to hepatitis B surface antigen (HBsAg), hepatitis C Virus (HCV), as well as for the presence of HBsAg and HCV-RNA. The mean weighted prevalence of anti-HAV was 46.5% (95% CI: 45.3–47.7) and increased markedly with age. The mean weighted prevalence of past infection with hepatitis B was 7.7% (95% CI: 7.0–8.4) in the old federal states and 4.3% (95% CI: 3.2–5.3) in the new federal states, corresponding to an overall prevalence of 7.0% (95% CI: 6.4–7.6). The mean weighted prevalence of HBsAg carriage was 0.6% (95% CI: 0.4–0.8), while the prevalence of HCV antibodies was 0.4% (95% CI: 0.2–0.5).     

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.     

Risk factors for acute non-A, non-B hepatitis and their relationship to antibodies for hepatitis C virus: a case-control study.

A case-control study was carried out comparing 333 case subjects with non-A, non-B hepatitis and 1095 hospital control subjects. Of 333 case subjects, 197 (59%) were positive for hepatitis C antibody (anti-HCV). Excluding blood transfusion and intravenous drug use, surgical intervention and dental therapy were strongly associated with anti-HCV-positive cases: in particular, obstetric and gynecology surgical intervention was found to be strongly associated with HCV positivity (odds ratio [OR] = 32; 95% confidence interval [CI] = 7, 147). Raw shellfish consumption was a risk factor for anti-HCV-negative cases (OR = 2.2; 95% CI = 1.0, 5.1), thus suggesting an enterically transmitted virus in sporadic non-A, non-B hepatitis in Italy.     

Anti-hepatitis C virus antibodies amongst Italian homo-bisexual males

The authors report on an anti-hepatitis C virus antibody (HCV Ab) prevalence (6.9%) in 622 homo-bisexual males from Northern Italy, voluntarily attending an HIV and STDs screening program in the period 1984–89. The anti-HCV antibody prevalence shows a significant correlation with: i) presence of serological markers for HBV (O.R. = 3.12; 95% C.I. =1.53–6.52) and HIV (O.R. = 12.09; C.I. = 6.52–22.52) infection; ii) a stable relationship with an anti-HCV antibody positive partner (O.R. = 7.79; 95% C.I. = 2.50–23.90); iii) more than twenty different male partners per year (O.R. = 2.55; 95% C.I. =1.17–5.66). These data demonstrate the existence of a sexual transmission of HCV among homosexuals. This route might contribute in maintaining endemic levels of HCV infection in the homo-bisexual population and it might represent an important way of spreading the virus in the general population too.Corresponding author.     

Past excessive alcohol consumption: a major determinant of severe liver disease among newly referred hepatitis C virus infected patients in hepatology reference centers, France, 2001

PURPOSE: Our study aimed to identify factors associated with the occurrence of severe liver disease in hepatitis C virus (HCV) positive patients at first referral to hepatology reference centers in France in 2001. METHODS: Patients reported through the national hospital-based hepatitis C surveillance system in 2001 were included. The definition of severe liver disease was based on clinical, biological, and morphological evaluation; cirrhosis (+/- complication) and primary liver cancer were classified as severe liver disease. Patient characteristics were compared for those with and without severe liver disease. RESULTS: Of the 3404 newly referred patients in the 26 participating centers, 391 (11.5%) had severe liver disease. Male gender (adjusted odds ratios [aOR]=1.4; 95% confidence interval [CI], 1.0-1.9), age over 39 years at referral (aOR=3.8; 95% CI, 2.7-5.3), past excessive alcohol consumption (aOR=2.6; 95% CI, 1.9-3.5), and HIV seropositivity (aOR=1.9; 95% CI, 1.1-3.3) were each independently associated with an increased risk of severe liver disease. In the subgroup of patients with known age at time of HCV exposure, age over 39 years at time of exposure (aOR=1.6; 95% CI, 1.1-2.4), duration of HCV infection over 15 years (aOR=2.6; 95% CI, 1.8-3.7), known HBs antigen positivity (aOR=2.4; 95% CI, 1.1-5.2), and past excessive alcohol consumption (aOR=2.7; 95% CI, 1.8-3.9) were each associated with increased risk of severe liver disease. CONCLUSIONS: Our findings underscore the important role of past excessive alcohol consumption on the development of severe liver disease for HCV patients.     

The relationships of chronic hepatitis and cirrhosis to alcohol intake,hepatitis B and C,and delta virus infection: a case-control study in Albania.

The present study examined the effect of hepatitis B virus (HBV) and alcohol intake, and the role of hepatitis delta virus (HDV) and hepatitis C virus (HCV) in the aetiology of chronic liver disease in Albania. A total of 106 cases of liver cirrhosis or chronic hepatitis were compared to 195 control patients without these or other liver diseases. Adjusted odds ratios were 52.7 (95% CI 22.7-122) for HBV surface antigen, 26.9 (95% CI 4.9-147) for anti-HCV, 26.2 (95% CI 3-1-221) for anti-HDV, 2.4 (95% CI 1.3-4.4) for lifetime alcohol intake and 2.3 (95% CI 1-5.5) for duration of alcohol intake. Although not significant, an interaction was suggested between HBsAg and anti-HCV and between HBsAg and alcohol intake. Our study underlines the role of hepatitis viruses in the development of chronic liver diseases. Additionally, it suggests that heavy alcohol intake may magnify the effect of HBV on these diseases. HBV vaccination and alcohol abstention appear to be important strategies to reduce the risk of liver cirrhosis and chronic hepatitis in Albania.     

Risk factors associated with hepatitis C virus infection in Taiwanese government employees

This study evaluated the roles of multiple factors in hepatitis C virus (HCV) infection, with emphasis on the modification of various individual characteristics on the risk associated with percutaneous exposure to blood. Serum samples taken from 4869 men in Taiwan within a cohort study were tested for HCV antibody. The overall positive rate of anti-HCV was 1.6%. In a logistic regression, factors positively associated with anti-HCV positivity were previous blood transfusion (odds ratio [OR] = 7.28: 95% confidence interval [CI] = 4.26-12.45), a history of surgery (OR = 2.06: 95% CI = 1 23-3.46), and lower educational levels (OR = 1.94; 95% CI = 1.14-3.32). The anti-HCV positive rate was significantly lower in hepatitis B surface antigen (HBsAg) carriers than in non-carriers (OR = 0.60; 95% CI = 0.37-0.95). Ageing, lower educational levels, O blood group, and Taiwanese ethnicity enhanced the likelihood of HCV infection through blood transfusion/surgery, whereasHBsAg status, cigarette smoking, and habitual alcohol drinking reduced it.     

Prevalence and risk factors of hepatitis C in HIV-negative homosexual men in Sydney, Australia

OBJECTIVE: To determine the prevalence and risk factors for hepatitis C (HCV) in HIV-negative homosexual men in Sydney. METHODS: A cohort study was conducted in a sample of community-based, HIV-negative, homosexual men in Sydney. Participants underwent a face-to-face interview regarding sexual behaviour, sexually transmissible infections, and injecting drug use (IDU). RESULTS: Eight hundred and twenty-four men consented to HCV testing, and the prevalence was 0.85% (95% CI 0.34-1.74). HCV seropositivity was strongly associated with a history of IDU (OR = 60.43, 95% CI 6.70-544.79). All HCV seropositive individuals reported a history of either IDU or other means by which they may have had parenteral exposure to HCV. There was no evidence of an independent association between sexual behaviour and HCV infection. CONCLUSION: The prevalence of HCV in this cohort was about the same as in the general population in Australia, and there was no evidence for sexual transmission in this population.     

Human immunodeficiency virus and hepatitis C virus infections among patients attending sexually transmitted disease clinics, Regional 2, Thailand

A cross-sectional study of 400 patients attending sexually transmitted disease (STD) clinics at The Venereal Diseases and AIDS Centers, Regional 2, Thailand, was conducted from January to December 1996 in order to investigate the antibody prevalence to human immunodeficiency virus (HIV) and hepatitis C virus (HCV) and to describe some epidemiological characteristics among HIV and HCV co-infected individuals. The studied patients were interviewed and their blood specimens were collected for determining anti-HIV and anti-HCV antibodies. The results revealed that the prevalence of anti-HIV among studied patients was 25%, while 7.5% were positive for anti-HCV. The positivity of both antibodies present in the same individuals was 3.3% (13/400 cases). The highest prevalences of anti-HIV, anti-HCV and both antibodies were found in studied patients aged 20 years or less. Patients with primary education, or lower, had relatively higher prevalence of anti-HIV and/or anti-HCV than those with higher level education. A relatively higher prevalence was found among commercial sex workers and labourers. Among 13 HIV and HCV co-infected individuals, there were four cases who had histories of sexual contact without condom use, but no history of parenteral contact. The rest (9/13) had histories of both parenteral contact and sexual contact without condom use.     

Prevalence and associated factors to hepatitis C in hemodialysis patients in Brazil

OBJECTIVE: The prevalence of hepatitis C virus (HCV) is higher in patients on hemodialysis than in the general population, probably due to greater exposure to risk situations. The purposes of the study were to determine anti-HCV antibodies prevalence among hemodialysis patients and dialysis clinics and patients factors associated with HCV transmission. METHODS: A cross-sectional study was conducted in 752 hemodialysis patients in all 12 dialysis clinics of Fortaleza, Brazil, and were screened using third generation ELISA. Sociodemographic, clinical, and epidemiological data of 663 patients were collected through interviews. Nosocomial factors were assessed using a specific questionnaire tool. Statistical analysis was conducted using Student's t test, odds ratio and multivariate analysis. RESULTS: The prevalence of anti-HCV was 52% (390/746; ranged from 6% to 72%). The anti-HCV positivity was higher in patients who had previous peritoneal dialysis (OR=1.76; 95% CI 1.12-2.76) and blood transfusion (OR=2.75; 95% CI 1.25-6.03). Dialysis age has been associated with anti-HCV positivity (OR=1.47; 95% CI 1.35-1.61). Clinics practices associated with anti-HCV positivity were: previous preparing of heparin (OR=2.92; 95% CI 1.23-6.92), failure in gloves use or change (OR=5.73; 95% CI 1.75-18.72), unsatisfactory dialysis machine disinfection (OR=2.79; 95% CI 1.57-4.96), and patient isolation in dialysis room (OR=0.18; 95% CI 0.05-0.61). CONCLUSIONS: The results show high anti-HCV prevalence among hemodialysis patients and the association of nosocomial factors with new HCV infection cases.     

Measures to reduce HIV infection have not been successful to reduce the prevalence of HCV in intravenous drug users

The objective of the study was to determine whether measures taken to prevent human immunodeficiency virus (HIV) infection also lead to a reduction in the prevalence of hepatitis C virus (HCV) infection among intravenous drug users (IDU). Antibodies to HCV, HIV and hepatitis B virus (HBV) were determined in IDU who voluntarily attended AIDS prevention and information centres for the first time between 1990 and 1996. Of the 5473 IDU studied, determination of HCV was done in 3238 cases. The prevalence of antibodies to HCV was 85%. During the first period studied (1990–1992), the prevalence of antibodies to HCV was 84.5%, during the second (1993–1994) 84.1% and during the third (1995–1996) 87%; in the case of HBV the prevalence during the three periods was 74.5, 67.6 and 66.8% respectively, and for HIV it was 41.9, 38.8 and 36.6% respectively (RR: 0.72; 95% confidence interval (CI): 0.65–0.81). Among drug users addicted for less than 2 years, the trend of the prevalence of antibodies to HCV and HBV remained constant, while the prevalence of HIV infection decreased (RR: 0.61; 95% CI: 0.42–0.89). Measures to prevent transmission of HIV in drug users do not lead to a reduction in the prevalence of HCV infection. Further study is necessary to obtain a better understanding of how HCV is transmitted among drug users in order to apply measures which are effective in preventing HCV infection.     

Parenteral and sexual transmission of human immunodeficiency virus in intravenous drug users: a study of seroconversion. The Northern Italian Seronegative Drug Addicts (NISDA) Study.

To evaluate the role of parenteral and sexual transmission of human immunodeficiency virus, we studied seronegative intravenous drug users recruited from 25 drug dependence treatment centers in northern Italy. All attending intravenous drug users were asked for their consent and screened for antibodies to human immunodeficiency virus; those who were seronegative were enrolled, interviewed about their habits, and invited to follow-up visits. Between 1987 and 1989, 1,195 seronegative intravenous drug users were enrolled, 635 were followed up (mean duration, 11.9 months), and 35 seroconversions were observed. The incidence rate ratios were 3.3 (95% confidence interval (CI) 1.4-7.5) for subjects aged less than 20 years, 2.4 (95% CI 1.2-4.7) for less than 2 years of intravenous drug use, 2.2 (95% CI 0.9-5.5) for syringe sharing, and 1.0 for subjects with a sexual partner who had tested positive for human immunodeficiency virus. A case-control approach, using logistic regression and adjusting for sex, age, area, and prevalence, showed odds ratios of 13.2 (95% CI 3.1-56.8) for frequent syringe sharing and 4.0 (95% CI 1.5-10.4) for sexual contacts with seropositive partners; frequent use of condoms was associated with a reduction in risk that did not reach statistical significance. Parenteral transmission is the most important route of infection with the human immunodeficiency virus among intravenous drug users, and sexual transmission plays a relevant, additive role.