Effect of hepatitis C antibody screening in blood donors on post-transfusion hepatitis in Taiwan

Liver diseases in the Asia-Pacific region: a Lancet Gastroenterology & Hepatology Commission

The Asia-Pacific region is home to more than half of the global population and accounted for 62·6% of global deaths due to liver diseases in 2015. 54·3% of global deaths due to cirrhosis, 72·7% of global deaths due to hepatocellular carcinoma, and more than two-thirds of the global burden of acute viral hepatitis occurred in this region in 2015. Chronic hepatitis B virus (HBV) infection caused more than half of the deaths due to cirrhosis in the region, followed by alcohol consumption (20·8%), non-alcoholic fatty liver disease (NAFLD; 12·1%), and chronic infection with hepatitis C virus (HCV; 15·7%). In 2015, HBV accounted for about half the cases of hepatocellular carcinoma in the region. Preventive strategies for viral hepatitis-related liver disease include increasing access to clean drinking water and sanitation. HBV vaccination programmes for neonates have been implemented by all countries, although birth-dose coverage is extremely suboptimal in some. Availability of screening tests for blood and tissue, donor recall policies, and harm reduction strategies are in their initial stages in most countries. Many governments have put HBV and HCV drugs on their essential medicines lists and the availability of generic versions of these drugs has reduced costs. Efforts to eliminate viral hepatitis as a public health threat, together with the rapid increase in per-capita alcohol consumption in countries and the epidemic of obesity, are expected to change the spectrum of liver diseases in the Asia-Pacific region in the near future. The increasing burden of alcohol-related liver diseases can be contained through government policies to limit consumption and promote less harmful patterns of alcohol use, which are in place in some countries but need to be enforced more strictly. Steps are needed to control obesity and NAFLD, including policies to promote healthy lifestyles and regulate the food industry. Inadequate infrastructure and insufficient health-care personnel trained in liver diseases are issues that also need to be addressed in the Asia-Pacific region. The policy response of most governments to liver diseases has thus far been inadequate and poorly funded. There must be a renewed focus on prevention, early detection, timely referral, and research into the best means to introduce and improve health interventions to reduce the burden of liver diseases in the Asia-Pacific region.

Aflatoxin B1 exposure increases the risk of hepatocellular carcinoma associated with hepatitis C virus infection or alcohol consumption

BACKGROUND

Hepatocarcinogenicity of aflatoxin B₁ (AFB₁) has rarely been studied in populations with hepatitis C virus (HCV) infection and those without hepatitis B virus (HBV) and HCV infection (non-B-non-C). This case-control study nested in a community-based cohort aimed to investigate the HCC risk associated with AFB₁ in HCV-infected and non-B-non-C participants.

METHODS

Baseline serum AFB₁-albumin adduct levels were measured in 100 HCC cases and 1767 controls seronegative for anti-HCV and HBsAg (non-B-non-C), and another 103 HCC cases and 176 controls who were anti-HCV-seropositive and HBsAg-seronegative. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were estimated using logistic regression.

RESULTS

In 20 years of follow-up, the follow-up time to newly developed HCC was significantly shorter in participants with higher serum AFB₁-albumin adduct levels in non-B-non-C (p = 0.0162) and HCV-infected participants (p < 0.0001). Within 8 years of follow-up, HCV infection and AFB₁ exposure were independent risk factors for HCC. Elevated serum AFB₁-albumin adduct levels were significantly associated with an increased risk of HCC newly developed within 8 years of follow-up in non-B-non-C participants with habitual alcohol consumption [crude OR (95% CI) for high vs. low/undetectable levels, 4.22 (1.16-15.37)] and HCV-infected participants [3.39 (1.31-8.77)], but not in non-B-non-C participants without alcohol drinking habit. AFB₁ exposure remained an independent risk predictor for HCV-related HCC after adjustment for other HCC predictors (multivariate-adjusted OR [95% CI], 3.65 [1.32-10.10]).

CONCLUSIONS

AFB₁ exposure contributes to the development of HCC in participants with significant risk factors for cirrhosis including alcohol and HCV infection.

Hepatitis C virus infection among injection drug users with and without human immunodeficiency virus co-infection

The aim of this study is to explore the prevalence of hepatitis C virus (HCV) infection among injection drug users (IDUs) with and without human immunodeficiency virus (HIV) infection in southern Taiwan. For 562 IDUs (265 anti-HIV negative, 297 anti-HIV positive), we analyzed liver function, anti-HIV antibody, anti-HCV antibody, HCV viral loads, and hepatitis B surface antigen (HBsAg). HIV RNA viral loads and CD4 cell count for anti-HIV-seropositive IDUs and the HCV genotype for HCV RNA-seropositive IDUs were measured. The seroprevalence rates of anti-HIV, anti-HCV, and HBsAg were 52.8%, 91.3%, and 15.3%, respectively. All the anti-HIV-seropositive IDUs were positive for HIV RNA. Anti-HCV seropositivity was the most important factor associated with HIV infection (odds ratio [OR], 25.06; 95% confidence intervals [CI], 8.97-74.9), followed by male gender (OR, 6.12; 95% CI, 4.05-9.39) and HBsAg seropositivity (OR, 1.90; 95% CI, 1.11-3.34). Among IDUs positive for anti-HCV, 80.7% had detectable HCV RNA. HCV viremia after HCV exposure was strongly related to HIV infection (OR, 6.262; 95% CI, 1.515-18.28), but negatively correlated to HBsAg seropositivity (OR, 0.161; 95% CI, 0.082-0.317). HCV genotype 6 was the most prevalent genotype among all IDUs (41.0%), followed by genotypes 1 (32.3%), 3 (12.8%), and 2 (5.6%). In conclusion, about half IDUs were infected with HIV and >90% with HCV infection. Male and seropositivity for HBsAg and anti-HCV were factors related to HIV infection among our IDUs. HIV was positively correlated, whereas hepatitis B co-infection was negatively correlated with HCV viremia among IDUs with HCV exposure. Different HCV molecular epidemiology was noted among IDUs.

Fighting against viral hepatitis: lessons from Taiwan

Viral hepatitis and its sequelae are important health problems worldwide, including Taiwan. For the last 40 years, Taiwan's scientists and health care providers have worked hard to control these sequelae, and the results have been excellent. The author, Ding-Shinn Chen, had a key role in planning and establishing the control program in Taiwan, and participated in the endeavors from the very beginning. In this perspective, he describes how he became interested in research as a medical student, his encounters with hepatitis B and C, how he and his colleagues started early detection of hepatocellular carcinoma (HCC), how he helped Taiwan's government create and implement the Viral Hepatitis Control Program, and how the effectiveness of the program in the decrease of hepatitis B carriage and HCC was monitored. He also discusses how he pioneered the use of interferon-α plus ribavirin to treat chronic hepatitis C. Hepatitis B viral load as a risk factor for HCC and cirrhosis in hepatitis B surface antigen carriers is reviewed briefly, as is the prevention of sequelae by antiviral therapies. Finally, Dr. Chen discusses unresolved issues that must be addressed and predicts the changes of the patterns of liver disease in Taiwan beyond the mid-21st century, which is in part affected by the fight against viral hepatitis that was initiated in the early 1980s.

CONCLUSION

Dr. Chen's perspective illustrates Taiwan's fight against viral hepatitis over the last 40 years. This experience can be shared by other countries in which the disease is equally prevalent.

Changing aetiology of liver dysfunction in the new generation of a hepatitis B and C-endemic area: cross-sectional studies on adolescents born in the first 10 years after universal hepatitis B vaccination

BACKGROUND/AIM

Geographical variation in viral hepatitis infection complicates various levels of liver diseases. This study elucidates the changing aetiology of alanine transaminase elevation (ALT levels >40 IU/L) in a previously hepatitis-endemic township.

DESIGN/METHODS

Five cross-sectional screenings were performed on teenagers born from 1984 to 1993. We examined hepatitis B surface antigen (HBsAg), anti-hepatitis C virus (anti-HCV), ALT and body mass index, and additionally checked hepatitis B envelope antigen (HBeAg) for positive HBsAg and HCV RNA for positive anti-HCV. Teenagers with ALT elevation underwent an ultrasonography examination.

RESULTS

This study enrolled 1788 (93.7%) of 1909 students, discovering individual prevalence of HBsAg (6.3%), anti-hepatitis B core (anti-HBc) (15.5%), anti-HCV (2.2%), overweight (22.4%), obesity (12.8%) and ALT >40 IU/L (3.7%). HBsAg and anti-HBc prevalence declined with trends, while obesity increased with trends (P<0.001). Among 66 ALT-elevated teenagers, prevalence percentages of risk factors were HBsAg (22.7%), anti-HCV (1.5%), obesity (45.5%), HBsAg with obesity (7.6%) and anti-HCV with obesity (3.0%). Additionally, obesity showed predominance (85.7%) among aetiologies of teenagers with fatty livers (60.9%). The independently associated factors of ALT elevation included being male (odds ratio, 2.18; 95% confidence interval, 1.21-3.93), HBsAg (4.25; 1.06-17.13), HBeAg (7.24; 1.64-31.9), HCV RNA (29.03; 5.8-145.29) and obesity (16.5; 8.79-30.98).

CONCLUSION

In place of viral hepatitis, obesity is becoming the major aetiology of abnormal liver function among the young generation in a previously hepatitis-endemic area.

Seroprevalence of viral hepatitis and sexually transmitted disease among adults with recently diagnosed HIV infection in Southern Taiwan, 2000-2005: upsurge in hepatitis C virus infections among injection drug users

BACKGROUND/PURPOSE

The purpose of this study was to compare the seroprevalence of viral hepatitis and sexually transmitted disease (STD) co-infections among three populations at risk recently diagnosed with HIV infection.

METHODS

A retrospective review of medical records was performed to determine the prevalence of several co-infections among adults recently diagnosed with HIV infection between 2000 and 2005 at National Cheng Kung University Hospital in Tainan, Taiwan.

RESULTS

Among a total of 484 adults, 124 (25.6%) were men having sex with men (MSM), 105 (21.7%) were heterosexual adults, and 255 (52.7%) were injection drug users (IDUs). The case number of adults with recently diagnosed HIV infection increased annually, from 27 in 2000 to 142 in 2005 (p < 0.001). This trend appeared to be attributable to the upsurge in HIV infection among IDUs beginning in 2003. At the time of HIV diagnosis, mean CD4+ counts were significantly higher and plasma HIV-1 RNA loads were lower in the IDU group than the MSM or heterosexual groups. The hepatitis B virus (HBV) carrier rate was similar in all three groups, with an average rate of 16.5%. The prevalence of treponemal antibody and Entamoeba histolytica indirect hemagglutination antibody was higher in MSM (37.5% and 9.4%, respectively) than in heterosexuals (19.6% and 7.3%, respectively) or IDUs (3.2% and 2.1%). The seroprevalence of hepatitis A virus infection increased with age, with 94.2% (97/103) of patients who were older than 40 years. Hepatitis C virus (HCV) or HBV-HCV co-infections were noted more often in IDUs (97.9% and 16.9%, respectively) than in heterosexuals (10.9% and 2.2%, respectively) and MSM (5.3% and 3.6%, respectively).

CONCLUSION

There was a recent upsurge in HIV-HCV co-infected IDUs in southern Taiwan. A higher rate of co-infection with STDs among HIV-infected MSM highlights the need for integrated STD control efforts in current HIV prevention programs.

Screening for viral hepatitis among male non-drug-abuse prisoners

OBJECTIVE

To describe the prevalence of hepatitis B virus (HBV) and hepatitis C virus (HCV) infection and the associated risk factors in a prison population.

MATERIAL AND METHODS

In this cross-sectional study, from November 2004 to February 2005, all 297 newly sentenced prisoners (mean age 37.5+/-11.7 years, age range 16-69 years), who had never used illicit drugs received routine blood check-ups and completed a face-to-face interview. Hepatitis B surface antigen (HBsAg) and anti-HCV antibodies were tested using the t-test, chi-square test, and logistic regression.

RESULTS

Among the 297 subjects, 13.1% were positive for HBsAg, 8.4% were positive for anti-HCV, and 1.7% were positive for combined HBsAg and anti-HCV. Logistic regression analysis demonstrated that tattooing (odds ratio=2.24, 95% CI=1.03-4.88) and an elevated alanine aminotransferase (ALAT) level (odds ratio=4.10, 95% CI=1.61-10.40) were independently related to HCV infection.

CONCLUSIONS

Screening of HBV and HCV infection in prison populations remains necessary. Tattooing and elevated ALAT level are identified as the related factors of HCV infection.

Descriptive epidemiology of hepatitis C virus among male heroin abusers in Taiwan

BACKGROUND

The purpose of this study was to explore the epidemiology of hepatitis C virus (HCV) infection and to determine the risk factors for HCV infection among heroin abusers in Taiwan.

METHODS

This was a cross-sectional study. From November 2004 to February 2005, 577 subjects, including 423 subjects (73.3%) using injectable heroin and 154 subjects (26.7%) using smoked heroin from one male prison located in Taiwan, were enrolled in this study. The mean age was 33.3 +/- 7.9 years (age range 19-65 years). Anti-HCV antibody was tested. A face-to-face interview focusing on sociodemographic information and risk behaviors was addressed. The t test, chi-squared test, and multivariate logistic regression were used.

RESULTS

The overall prevalence of anti-HCV antibody positivity was 74.9%, with 89.8% among injecting heroin abusers and 33.8% among smoking heroin abusers (P < 0.0001). The multivariate logistic regression analysis demonstrated that needle sharing was independently related to HCV infection (odds ratio = 5.25, 95% confidence interval = 2.48-11.12).

CONCLUSIONS

The prevalence of anti-HCV antibody positivity among male injecting drug abusers is high in Taiwan. Needle sharing is identified as a potential risk factor for HCV infection.

Transmission of occult hepatitis B virus by transfusion to adult and pediatric recipients in Taiwan

BACKGROUND/AIMS

The infectivity of occult hepatitis B virus (HBV), defined as HBsAg-negative but HBV DNA-positive, after transfusion has been low but not negligible. To address this, we investigated the incidence of post-transfusion HBV infection after receiving screened blood units in Taiwan.

METHODS

Consecutive HBV-naïve (anti-HBc-negative) recipients with normal ALT were followed for HBV DNA and serologic markers before and after transfusion. Among 4448 blood recipients, 467 (10.5%) were anti-HBc-negative. Post-transfusion 6-month follow-up was completed for 327. We identified 5 (1.5%) who developed hepatitis B viremia 1 week after transfusion. Three were children who later seroconverted to anti-HBc but with normal ALT indicating subclinical acute infection, despite all had anti-HBs from previous vaccination. One had transient transfusion-transmitted HBV without seroconversion to anti-HBc and one possibly had occult HBV infection. Our findings suggested the possibility that occult HBV infection was transmissible by transfusion. The incidence of post-transfusion acute HBV infection was 0.9% (100 per million units) in naïve recipients in Taiwan, a figure 7 approximately 40-fold higher than in developed countries. Moreover, some vaccinated children with anti-HBs were still susceptible.

CONCLUSIONS

Therefore, despite active immunization, sensitive screening assays for occult HBV infection such as nucleic acid amplification test could be considered in endemic areas.

Persistent hyperendemicity of hepatitis C virus infection in Taiwan: the important role of iatrogenic risk factors

The purpose of this study was to investigate determinants of endemic hepatitis C virus (HCV) infection within communities in Taiwan. A two-phase study, including a seroprevalence survey and a prevalent case-control study at the first phase, which has been published previously, and a follow-up seroconversion determination and an incident case-control study during the second phase, was carried out to evaluate correlates of persistent endemic HCV infection. At the first phase, a total of 12,021 men and 1,819 women who were 30-64 years old and living in seven townships in Taiwan were tested for the seroprevalence of antibodies to HCV (anti-HCV). In addition, a prevalent case-control study involving 272 HCV-positive cases and 282 seronegative controls identified from the anti-HCV testing was conducted to investigate risk factors associated with HCV prevalence. During the second phase, a total of 2,728 men and 834 women who were seronegative at recruitment participated in the 1-year prospective study on anti-HCV seroconversion. Subsequently, an incident case-control study based on 39 seroconverters and 81 persistently seronegative controls were carried out to elucidate determinants of HCV seroconvertion. Antibodies to HCV were tested by the second-generation enzyme immunoassay. Information on risk factors of HCV infection was collected from subject interviews. The prevalence of anti-HCV consistently increased with age (range 2.9-5.4%), whereas no apparent age trend was observed for anti-HCV seroconversion rate (range 0.9-1.7%). A striking geographical variation in seroprevalence and seroconversion rates of anti-HCV was observed in the study townships. Furthermore, a significant geographical correlation between HCV seroprevalence and seroconversion rates was noted (r = 0.962, P = 0.001). From the results of both prevalent and incident case-control comparisons, medical injections were found to be the main mode to sustain the persistent endemic state of HCV infection within a community (odds ratios for prevalent and incident case-control studies were 2.5 (95% CI = 1.7-3.6) and 3.1 (95% CI = 1.4-7.1), respectively. The data indicate that the basis for HCV transmission has already been existed in study areas and the iatrogenic risk factor tended to be the major determinant for sustaining persistent endemicity within a community.

Transmission of hepatitis C virus in Asia: past and present perspectives

Hepatitis C virus (HCV) infection is a major public health problem. The epidemiology of HCV infection in different parts of Asia is similar, with an average seroprevalence of hepatitis C antibody (anti-HCV) less than 2.5% in healthy adults. The infection is rarely seen in children. The major routes of HCV transmission in Asia during the past few decades have been through administration of therapeutic blood products and injecting drug use, similar to the pattern observed in other parts of the world. However, obvious parenteral routes of transmission only account for 30-60% of anti-HCV-positive cases, depending on the geographic area. Other inapparent parenteral or per-mucosal exposures, including medical intervention, tattooing, acupuncture, vertical and sexual transmission, accidental needlestick and household contact, are also possible routes of HCV transmission. Although screening of blood donors for anti-HCV and improvements in infection control have significantly decreased the exposure to HCV, it is believed that HCV is still spreading in some areas of Asia because of the lack of routine screening of donated blood, injecting drug usage, traditional medicine practices or medical treatment under suboptimal hygienic conditions that involve blood contamination, and tattooing. Accordingly, until effective and safe immunoprophylaxis is available, interruption of transmission routes, such as implementation of blood donor screening for anti-HCV, adequate sterilization of surgical instruments or the use of disposable medical instruments, especially needles and syringes, and avoidance of sharing personal grooming aids remains the mainstay to prevent HCV infection in Asia today.

Prevention of hepatitis B and C virus infection for prevention of cirrhosis and hepatocellular carcinoma

In Taiwan, cirrhosis and hepatocellular carcinoma (HCC) have been common in medical practice since the 1960s. In 1969, Taiwan was shown to be a hyperendemic area of hepatitis B virus (HBV) infection with a high rate of hepatitis B surface antigen (HBsAg) positivity, 19% of the population being infected before the fourth decade of life. There is evidence indicating that more than 80% of chronic hepatitis, cirrhosis and HCC are the sequelae of chronic HBV infection. In 1984, after 3 years of preparation, a programme to control cirrhosis and HCC began. All neonates born to HBsAg+ mothers were given Pasteur plasma-derived vaccine 5 micrograms i.m. at 1, 5 and 9 weeks with a booster at 12 months. In 1986, all neonates were included in this programme. In addition, beginning in 1987, all non-vaccinated preschool children were also immunized and susceptible medical personnel and people from HBsAg+ households were recommended to receive the vaccine. Using data obtained from the 7-year evaluation study on the efficacy of this vaccine and some historical data, the HBsAg positivity rate in people born in the first few years after 1986 was estimated to be 2.6%. This rate is expected to decrease to 0.2% in those born after around 1990. In July 1992, an anti-hepatitis C virus (HCV) test was included in blood donor screening tests. This was followed by a decrease in the incidence of post-transfusion hepatitis (PTH) from 13 to 2.5% and there have been no anti-HCV+ PTH cases since. However, without immunization, the prevalence of HBsAg decreased among children in Taipei in 1989. This coincided with the widespread use of disposable syringes and needles and an improvement in the sterilization of medical instruments. Therefore, it is likely that HCV infection may also decrease as a result of these practices. Through the use of immunization and improved medical procedures, chronic hepatitis, cirrhosis and HCC may decrease in Taiwan by around 95%.

Heterogeneity of hepatitis C virus

A great deal of information on the molecular heterogeneity of hepatitis C virus (HCV) has been achieved since its discovery in 1989. However, little is known about the clinical significance of these variations. Based on the degree of sequence variation, HCV has been classified into six major groups or types, differing by 31-34% at the nucleotide level over the entire virus genome. Each type is divided into several subtypes that differ by 20-23% in nucleotide sequence. Viruses within the same subtype are up to 10% divergent and, within infected individuals, vary by up to 1.5%. Genotype distributions are not homogeneous around the world and may reflect both historical and recent parenteral routes of transmission. The clinical implication of these genomic variations are not yet fully elucidated: genotype 1b has been associated with end-stage liver disease, including liver cirrhosis and hepatocellular carcinoma, but this finding might rather reflect its earlier introduction to the populations studied. Consistent evidence exists that types 2 and 3 have a higher response rate to interferon treatment than type 1, although the interplay between genotype and viral load in determining the response is still unclear. Immunohistochemical studies indicate a stronger activation of the endogenous interferon system in the liver of patients infected with type 1 compared to those infected with types 2 and 3, explaining, at least in part, its low responsiveness to exogenous interferon treatment. Biological, sequence-dependent variations of genotypes have been poorly investigated to date, but differential efficiency of translation activity of the 5' non-coding region has been reported. The availability of "in vitro" systems for evaluating pathogenetic aspects and neutralization mechanisms will improve the present knowledge on this world-wide infectious disease and on the clinical usefulness of distinguishing between genotypes.

Evaluation of third-generation hepatitis C antibody assay in chronic hepatitis C and chronic non-B, non-C hepatitis

Second-generation hepatitis C virus (HCV) antibody assays are more sensitive and specific than first-generation assays in the detection of HCV infection; such tests are widely used. However, there are still HCV-infected patients who test seronegative for anti-HCV even by second-generation assays. In this study we evaluated the performance of the new third-generation HCV assay (HCV 3.0) in 230 individuals with different second-generation anti-HCV (HCV 2.0) and HCV RNA patterns. Our results showed the followings: only one healthy adult had a discrepant result in 200 subjects negative (group I) or positive (group II) for HCV 2.0 and HCV RNA; 7 of 13 (54%) HCV 2.0-negative but HCV RNA-positive patients (group III) were HCV 3.0-positive; two of 17 (12%) so-called chronic non-B, non-C hepatitis patients (group IV) were positive for HCV 3.0. We conclude that third-generation anti-HCV assays are more sensitive and specific than second-generation assays in the detection of chronic HCV infection; however false-positive results may be observed among low-risk healthy persons.