Epidemiology of hepatitis C virus infection in an area of Southern Italy

Hepatitis C: a review and update

The hepatitis C virus is an RNA virus that is a major cause of acute and chronic hepatitis. It is contracted chiefly through parenteral exposure to infected material such as blood transfusions or injections with dirty needles. Those at highest risk for development of hepatitis C are injection-drug users, people who snort cocaine with shared straws, and health care workers who are at risk for needle-stick and other exposures. Although the incidence of acute hepatitis C infection has fallen dramatically in the United States during the past decade, the prevalence of infection remains high (approximately 2.7 million Americans) because chronic hepatitis C develops in about 75% of those infected. Both acute and chronic hepatitis C are asymptomatic in most patients. However, chronic hepatitis C is a slowly progressive disease and results in severe morbidity in 20% to 30% of infected persons. Chronic hepatitis C is associated with a host of extrahepatic manifestations, many of which may be seen by dermatologists. The most frequent of these are mixed cryoglobulinemia with leukocytoclastic vasculitis and porphyria cutanea tarda. (J Am Acad Dermatol 2001;44:159-79.)

LEARNING OBJECTIVE

At the conclusion of this learning activity, participants should be familiar with the essentials of the virology of the hepatitis C virus and the major features of the human diseases caused by hepatitis C viral infection; the extrahepatic manifestations of hepatitis C viral infection, with particular emphasis upon dermatologic manifestations, including leukocytoclastic vasculitis, porphyria cutanea tarda, and lichen planus; and the current methods of management of hepatitis C and its extrahepatic manifestations.

Epidemiology of hepatitis C virus infection in Italy: the slowly unraveling mystery

In spite of the large diffusion of hepatitis C virus (HCV) infection and its high association with liver disease, the epidemiology of HCV in Italy is still unclear. This review collects all the data available on the prevalence and incidence of HCV infection in Italy and compares them with those reported in other countries.

Hepatitis C virus (HCV) infection and liver-related mortality: a population-based cohort study in southern Italy. The Association for the Study of Liver Disease in Puglia

BACKGROUND

Hepatitis C virus (HCV) is a common cause of chronic liver diseases but the degree to which these diseases contribute to liver-related mortality is not well established. The aim of this study was to estimate the absolute and relative effects of HCV infection on liver-related mortality.

METHODS

A population random sample of 2472 subjects aged > or = 30 years was enrolled and followed up from 1985 to 1996. At enrollment, a structured interview and a clinical evaluation were performed. Serum samples were tested using HCV ELISA and RIBA HCV. Outcomes were overall and liver-related mortality and tracing procedures included review of office and hospital records, death certificates, and interviews with general practitioners, attending hospital and next of kin. Statistical analysis was performed using Poisson and binomial prospective data regression.

RESULTS

Crude overall and liver-related mortality rates were 7.66 (95% CI : 6.68-8.79) and 0.9 (95% CI : 0.3-2.2) per 10(3) person-years, respectively. For HCV infection effect, incidence rate ratio and difference (per 10(3) person-year), risk ratio and difference were 27.5 (95% CI : 6.5-115.6), 4 (95% CI : 3-7), 33.1 (95% CI : 7.8- 139.3) and 0.06 (95% CI : 0.04-0.08), respectively; all measures were adjusted for age at death, sex and daily alcohol intake.

CONCLUSIONS

The results show a strong relative but weak absolute effect of HCV infection on liver-related mortality in the 10-year period considered. Poisson and binomial models are virtually equivalent, but the choice of the summarizing measure of effect may have a different impact on health policy.

Hepatitis C virus infection and alanine transaminase levels in the general population: a survey in a southern Italian town

BACKGROUND/AIM

The aim of the study was to estimate the prevalence, risk factors and genotype distribution of hepatitis C virus (HCV) in the general population older than 5 years of age in a southern Italian town. The positive predictive value of alanine transaminase (ALT) screening in identifying HCV positive subjects was also assessed.

METHODS

Cluster random sampling from the census of the general population was used. ELISA and RIBA tests assessed the presence of anti-HCV; nested reverse transcription polymerase chain reaction (RT-PCR) was used to identify HCV-RNA; genotyping was performed by INNO-LIPA III. The association linking anti-HCV seropositivity with potential risk factors was assessed by multiple logistic regression analysis.

RESULTS

Among the 488 subjects enrolled, 79 (16.2%) were anti-HCV positive. The prevalence increased from 1.2% in subjects 6-29 years of age to 42.1% in those > or = 60 years. Forty percent of these positive subjects also had abnormal ALT level and 54.4% were HCV RNA positive by PCR. The positive predictive value of the ALT test in identifying anti-HCV positive subjects was 65%; however, it was 46.7% in subjects younger than 60 years of age and 90.5% in those 60 or older. Genotype 1b was detected in 74% of subjects, type 2c in 23.3%, and type 1a in 2.3%. The only two variables significantly associated with HCV seropositivity in multivariate analysis were age older than 45 years (O.R. 8.5; CI 95%=3.0-24.1) and past use of glass syringes (O.R. 3.4; CI 95%=1.5-7.6).

CONCLUSIONS

These findings confirm that HCV infection is endemic in southern Italy, particularly among the elderly. Percutaneous exposure, such as injections with nondisposable, multiple-use, glass syringes used in the past for medical purposes may have played a major role in the spread of HCV infection. ALT screening is not useful in detecting HCV positive subjects in the general population, particularly among subjects who could benefit from antiviral therapy.

HCV: epidemiology, modes of transmission and prevention of spread

Approximately 3% of the world's population has been infected with the hepatitis C virus (HCV), which represents about 170 million chronic carriers at risk of developing serious complications. Following the introduction of screening of blood donors for infection the risk of transmitting HCV by blood products is presently at 1/200,000 units distributed. Intravenous (i.v.) drug users are currently the main risk group with a prevalence rate of about 80% and a yearly incidence varying between 4 and 6%. Vertical and sexual transmissions have also been implicated but data are limited and sometimes controversial. The source of infection for the 30% of cases without an identifiable risk factor remains to be clarified. Prevention of spread includes detailed information of persons at risk of being infected, screening of high-risk populations, strengthening of syringe exchanges among i.v. drug users and strict application of disinfection procedures for all invasive medical equipment.

Hepatitis C virus infection in Western Europe

Hepatitis C virus (HCV) infection is now recognised as the most common infection causing chronic liver disease in Europe. Approximately 3% of the world population has been infected with HCV, which represents about 170 million chronic carriers at risk of developing serious complications with more than 5 million in Europe alone. In the general population, the prevalence varies geographically from about 0.5% in northern countries to 2% in Mediterranean countries. Among newly detected HCV cases, 40-60% have normal ALT levels, 80% are viraemic, while about 70% of newly detected HCV carriers present histologic liver disease. More than 75% of the cases remain to be identified. The residual risk for transmitting HCV by blood products is at present 1/200 000 units distributed. Intravenous drug users are currently the main risk group. The prevalence rate is about 80% and the yearly incidence varies between 4 and 6%. In haemodialysis patients, the prevalence ranges from 10% to 30% and the incidence from 3% to 7%. The source of infection for the 30% of cases without identifiable risk factor remains to be clarified and appropriate well-controlled case-control studies on large samples are necessary. Further training and information campaigns remain desirable to improve knowledge and awareness among health care professionals.

Hepatitis C epidemiology

Hepatitis C virus infection occurs in all parts of the world. Infection is generally due to percutaneous exposures, though sexual and perinatal transmission may occur. While further study is needed to elucidate the biology of HCV transmission and develop vaccines for prevention, new HCV infections can be reduced by economic development and education regarding blood-borne infections.

Viral hepatitis

Hepatitis A is still the most frequently reported vaccine preventable disease. A reduction in the incidence will only be achieved by routine childhood vaccination rather than by targeted vaccination of high-risk groups. A larger vaccine program is warranted. Hepatitis B remains a large public health problem. Vaccination targeted to high-risk adults failed to decrease the incidence of hepatitis B virus (HBV) infection. Sexual as well as nosocomial transmission remain serious problems. Vaccine escape variants have also been identified in newborns from infected mothers who had been vaccinated at birth. Clearance of HBV infection results from complex immune mechanisms including TH1 cytokines significantly associated with HLA class II alleles. Escape HBV mutants, especially precore mutants, influence the outcome. The sequences of the promoter and other critical regions were associated with severe activity. Lamivudine is a major advance in therapy of chronic hepatitis B which was recently approved in many countries. Although drug resistant mutants may be selected during therapy, additional nucleoside analogues including adefovir are promising. Optimal combination strategies of different active compounds need to be researched. Three per cent of the world population has been infected with hepatitis C virus (HCV). Epidemiology has shifted from transfusion to non-transfusion settings. Intravenous drug abuse is currently the main risk but nosocomial infection is also of concern. Three independent factors seem associated with fibrosis progression: age, daily alcohol consumption of 50 g or more and male gender. Median duration of progression to cirrhosis is about 30 years. At the cirrhotic stage, about 3-5% of patients per year develop hepatocellular carcinoma. There is little evidence that direct cytopathicity plays a significant role in liver cell injury. HCV also infects extrahepatic cells which seems critical in the pathogenesis of the many extrahepatic manifestations. The recent identification of CD81 protein as one of the HCV receptor candidates may help us to understand how chronic HCV infection may trigger a wide spectrum of clinical manifestations, autoimmune or even lymphoproliferative, through potent continuous B cell activation in the context of various host and/or environmental cofactors. Direct measurement of HCV RNA has clarified HCV replication kinetics and variability. Among patients with chronic hepatitis C, 48 weeks of treatment with interferon/ribavirin therapy produced a response rate of 28% among those with genotype 1 and 66% with other genotypes. Similar differences were found for combination therapy among patients who had relapsed following previous interferon (IFN) therapy. Viral load prior to treatment has been clearly shown to be predictive of response to interferon treatment, with increased viral load associated with decrease rates of response. In patients non-responsive to interferon, a second course of interferon alone has no beneficial effect whereas combination therapy may induce response in 25%. In conclusion, combination therapy should be given in all situations. Viral eradication should not be the only objective of the treatment since histological improvement may be obtained despite persisting viral replication with prolonged maintenance of antiviral therapy.

Hepatitis C infection in an Italian population not selected for risk factors

AIMS/BACKGROUND

This study estimated the prevalence of HCV infection and relationship with viremia in a general population. The inhabitants of Albavilla town were personally invited to participate.

METHODS

Out of 3997 inhabitants falling within the age range 18-85 years, 2403 (participation rate 60.1%) were examined for transaminases, HCVAb, HCVRNA, genotype and immunoblot assay. The following information was collected: sex, age, blood transfusions, surgery, use of glass syringes, drug addiction, alcohol consumption, tattoos and body mass index.

RESULTS

115 (4.8%) were HCVAb+, the prevalence being 1.2% under 40 years. Transfusion in the past was the only risk factor for HCV infection. Among the HCVAb+ subjects, 71 (61.7%) were HCVRNA+. 40.8% of the HCVAb+/HCVRNA+ group had normal ALT, compared with 68% of those with HCVAb+/HCVRNA-. The HCV genotypes in the 71 HCVRNA+ subjects were: 2a/2c in 58 (81.7%), 40% of them with normal ALT;1b in 11 (15.5%), none with normal ALT; genotype 3 in two (2.8%).

CONCLUSION

The prevalence of HCVAb in this general population was 4.8%. About 3% were HCVRNA positive and of these genotype 2a/ 2c was present in 81.6%.

Molecular epidemiology of hepatitis C virus infection in an area of hyperendemicity in southern Italy: a population-based study

In a cohort of subjects from Italy, anti-hepatitis C virus (HCV) and HCV RNA [HCV(+) subgroup] prevalences were 24.6 and 79.6%, respectively. HCV types 1b and 2a/c accounted for 95% of infections. Adjusted alanine aminotransferase levels were higher in males than in females and in RNA-positive subjects than in RNA-negative subjects regardless of HCV type. Genotype distribution was unrelated to demographic variables.

Characteristics of hepatocellular carcinoma in Italy

BACKGROUND/AIMS

This study aimed to assess the main features of hepatocellular carcinoma at the time of diagnosis in Italy, particularly in relation to the presence or absence of underlying cirrhosis, hepatitis virus marker patterns, age of the subjects and alpha-foetoprotein values.

METHODS

A total of 1148 patients with hepatocellular carcinoma seen at 14 Italian hospitals in the 1-year period from May 1996 to May 1997 were the subjects of this prevalence study. Both newly diagnosed cases (incident cases) and cases diagnosed before May 1996 but still attending the hospitals during the study period (prevalent cases) were included.

RESULTS

We found that 71.1% of cases were positive for hepatitis C virus antibodies but negative for HBsAg; in contrast, 11.5% were negative for anti-HCV but positive for HBsAg; 5.3% were positive for both markers; and 12.1% were negative for both viruses. The mean age of detection was over 60 years, with a younger mean age in HBsAg-positive compared to anti-HCV-positive patients (59.3 years vs. 65.6 years, p<0.01). The male-to-female ratio among HBsAg-positive patients was 10.4:1, in contrast to 2.8:1 among anti-HCV-positive patients (p<0.01). The majority of cases (93.1%) had underlying cirrhosis. Cirrhotic patients were more likely to be anti-HCV positive than non-cirrhotic cases (73.2% vs 43.9%; p<0.01); conversely, absence of hepatitis virus markers was more frequently observed in the non-cirrhotic than in the cirrhotic population (40.9% vs. 10.0%; p<0.01). Overall, the alpha-foetoprotein level was altered (>20 ng/ml) in 57.9% of patients; only 18% of cases presented diagnostic (>400 ng/ml) values. Anti-HCV positivity (O.R. 2.0; CI 95%=1.3-3.1) but not HBsAg positivity (O.R. 1.0; CI 95%=0.6-1.8) was shown to be an independent predictor of the likelihood of altered alpha-foetoprotein values by multivariate analysis.

CONCLUSIONS

These findings point to differences in the characteristics of the populations infected by hepatitis B and hepatitis C. Factors other than the hepatitis viruses are important in non-cirrhotic patients. A change in the relative prevalence of hepatitis virus markers among hepatocellular carcinoma cases was demonstrated, reflecting a significant change in the rate of HBV endemicity in the Italian population. Finally, the increased trend in the mortality rate from liver cancer in Italy from 4.8 per 100,000 in 1969 to 10.9 in 1994 may reflect the large cohort of subjects infected with HCV via the iatrogenic route during 1950s and 1960s when glass syringes were commonly used for medical treatment.

Hepatitis B and C virus sexual transmission among homosexual men

OBJECTIVE

We estimated hepatitis B virus (HBV) and hepatitis C virus (HCV) sexual transmission among homosexual men.

METHODS

Two hundred twenty-eight homosexually active men attending two clinical centers and presenting no risk factors except for sexual exposure were interviewed, and a blood sample was drawn. HBV marker test was performed using enzyme-linked immunosorbent assay (ELISA) and radioimmunoassay, and HCV was tested using ELISA-2 and recombinant immunoblot assay-2.

RESULTS

HBV and HCV infection prevalence rates were 34.4% and 12.7%, respectively. Using logistic regression analysis including sexual exposure and controlling for confounders, we found that anal receptive intercourse (odds ratio [OR] = 4.01; 95% confidence interval [CI] = 1.34-11.94), duration of homosexuality (OR = 3.43; 95% CI = 1.29-9.12), insertive anilingus (OR = 2.02; 95% CI = 1.06-3.87), and sexually transmitted diseases (OR = 1.87; 95% CI = 1.00-3.47) were independently associated with the risk of HBV sexual transmission. We did not find any association between sexual behavior and HCV transmission.

CONCLUSIONS

Sexual behavior is a plausible explanatory factor of HBV sexual transmission among homosexual men. Further evidence is needed to elucidate the occurrence and the efficiency of HCV sexual transmission in the absence of other risk factors.