Multiple hepatitis virus infections in chronic HBsAg carriers in Naples

Summary.  In order to determine the prevalence of multiple infections with hepatitis viruses in chronic HBsAg carriers in Naples, to assess the interaction between HBV, HDV and HCV infections and to evaluate the influence of multiple virus hepatitis infections on the clinical presentation, we studied 198 HBsAg chronic carriers observed consecutively from 1971 to 1988 at our Liver Unit. Of the 198 HBsAg chronic carriers, 171 had undergone percutaneous liver biopsy. The presence of HBcAg or HDAg in the liver biopsy was considered a marker of HBV or HDV replication, respectively; the presence of anti-HCV was considered a marker of HCV infection. Anti-HCV was observed in 13.6% of the 22 subjects with normal liver, in 27.7% of the 47 patients with minimal chronic hepatitis, in 40% of the 50 with mild chronic hepatitis, in 70.6% of the 17 with moderate hepatitis, in 66.7% of the 3 with severe chronic hepatitis and in 65.6% of the 32 with active cirrhosis. Anti-HCV positive cases were antiHD positive more frequently than the anti-HCV negative (59.2% vs. 43%, p=0.05). HDV infection exerted a clear inhibition on the HBV genome. Among the 171 HBsAg chronic carriers, the finding of an active chronic hepatitis (moderate chronic hepatitis+severe chronic hepatitis+active cirrhosis) is less frequent in subjects with HBV replication alone than in those with HDV replication or HCV infection. Patients with both HBV replication and HCV infection and those with both HDV replication and HCV infection showed a very high prevelance of active chronic hepatitis.     

Virological and clinical aspects of multiple hepatitis virus infections: preliminary data of an italian multicentre study

To evaluate the interference between HBV, HCV and HDV and the clinical impact of coinfection as compared with single HBV or HCV infection, we unrolled 618 HBsAg and/or anti-HCV positive subjects (337 with liver biopsy and 281 without liver biopsy) at their first observation at one of the seven Italian Liver Units from 1993 to 1997 (Padova, Rome, Sassari, Naples, Bari, Messina, Palermo). Serum HBV-DNA by dot-blot was found more frequently in patients with HBV infection alone (52% of 133 cases) than in those with HBV-HCV coinfection (28% of 64 cases, p<0.005) or in those with HBV-HDV-HCV coinfection (12% of 25 cases, p<0.0005) or with HBV-HDV coinfection (13% of 8 cases, p<0.05). We observed a higher prevalence of HCV-RNA positive cases in the patients with HCV infection alone (91.2% of 114 cases) than in those with HBV-HCV coinfection (64.5% of 62 cases, p<0.0001) or with HBV-HDV-HCV infection (19% of 21 cases, p<0.0001). These observations suggest a reciprocal inhibition of HBV and HCV genome in multiple hepatitis viral infection. A severe liver disease was more frequently observed in patients with HBV-HCV coinfection (66%) than in those with a single HBV infection (43%, p<0.05) or HCV infection (46%, p<0.05). Anti-HCV positive/anti-HBc positive patients, lacking both HBsAg and anti-HBs, compared with the anti-HCV positive/anti HBc negative ones, more frequently showed severe clinical presentation and less frequently had a sustained response to a-IFN treatment.     

Molecular epidemiological and clinical aspects of hepatitis D virus in a unique triple hepatitis viruses (B,C, D) endemic community in Taiwan

The molecular epidemiological and clinical aspects of hepatitis D virus (HDV) in a unique HBV, HCV, and HDV triple virus endemic community in southern Taiwan were investigated. A total of 2,909 residents aged 45 or older were screened for hepatitis B surface antigen (HBsAg), anti-HCV antibody, and anti-HDV antibody (specifically for HBsAg-positive carriers). Factors that might be associated with HDV infection, viral nucleic acid detection, and genotyping of HBV, HCV, and HDV were investigated. The prevalence of HBsAg and anti-HCV were 12.6% (366/2,909) and 41.6% (1,227/2,909), respectively. For HBsAg carriers, 15.3% (56/366) were positive for anti-HDV assay. Living in a higher endemic district of HCV infection (odds ratio [OR] = 3.2; 95% confidence interval [CI] = 1.7-6.3), male gender (OR = 1.9; 95% CI = 1.1-3.6) and co-infection with HCV (OR = 1.8; 95% CI = 1.0-3.3) were significantly independent factors associated with HDV infection. The detection rate of HDV RNA among anti-HDV-positive patients was only 12.7% (7/55). The mean HBV titer of triple infection group was significantly lower than in the HBV/HDV co-infection group (2.23 vs 3.05 in log(10), copies/ml, P = 0.046). HCV RNA detection among the triple infection group showed 47.4% (9/19) viremia rate and viral loads of 579,121 IU/ml in median (16,803-1,551,190 IU/ml). The prevalent genotype of HBV was type B (23/25); HCV was 1b (7/9) and HDV was IIa/IIb (4/4). Only the presence of HCV RNA predicted the presence of elevated ALT significantly (OR = 25.0; 95% CI = 3.39-184.6). In conclusion, the geographical aggregation of HDV infection paralleled that of HCV infection in this community. HCV suppressed the replication of HBV among triple vital infection patients. HBV and HDV lapsed into a remission or nonreplicative phase in most cases, and HCV acted as a dominant factor in triple viral-infected individuals. Only the presence of HCV RNA was associated with elevated ALT values, but not HBV or HDV.     

Familial clustering of hepatitis B and C viruses in Korea.

In order to evaluate the familial clustering of hepatitis B virus(HBV) and hepatitis C virus(HCV) infections and to elucidate the possible routes of HCV transmission among Korean adults with chronic liver disease, 137 household contacts of 51 chronic carriers of HBsAg and 111 household contacts of 38 controls, and 181 household contacts of 96 anti-HCV positives and 102 household contacts of 76 anti-HCV negatives were tested from July 1990 to March 1994. Of 71 non-vaccinated household contacts of HBsAg carriers, 10 gave positive result for HBsAg(14.1%), but none of the household contacts of the controls were positive for HBsAg(p < 0.05). Familial clustering of HBV infection was found, when the offspring of carriers and controls were compared. A significantly higher percentage of the offspring of carriers were positive for HBV infection(54.6% vs 15.4%, p < 0.05) with OR of 6.6(95% Cl; 1.3-34.5). No evidence of familial clustering of HCV infection was found with 2.2%(4/181) anti-HCV positivity among the household contacts of index cases, similar to 1.0%(1/102) among those of controls. History of acute hepatitis(OR 3.2), transfusion(OR 3.2), and acupuncture(OR 2.5) were associated with an increased risk of HCV infection. In conclusion, HBV has strong familial clustering whereas HCV does not in Korea.     

Prevalence of parenterally transmitted hepatitis viruses in clinically diagnosed cases of hepatitis

Hepatitis B virus (HBV) is the most important causative agent of blood borne hepatitis in humans. Hepatitis D Virus (HDV) infection occurs either as a coinfection or superinfection in HBV carriers. Hepatitis C virus (HCV) is the major cause of transfusion non-A, non-B hepatitis and continues to be a major cause of human liver disease throughout the world. The present study was conducted on 70 clinically diagnosed cases of viral hepatitis to study the prevalence of parenterally transmitted viral hepatitis. The serum samples were tested for HBsAg, HBeAg, IgM anti-HBc, anti-HBe, anti-HCV and anti-HDV using separate ELISA kits. Of the 70 serum samples tested, 28 (40%) were positive for HBsAg out of which 3 (4.28%) were positive for HBeAg also. Five (7.1%) of the HBsAg positive cases tested positive for IgM anti-HBc also. HBsAg alone was found in 17 (24.28%) cases. The prevalence of anti-HCV was 3 (4.28%) in 70 cases. Thus early screening of clinically diagnosed cases of viral hepatitis is essential for establishing diagnosis and treatment to prevent long term sequelae.     

An epidemiological study of hepatitis C virus infection in a local district in Japan

Mass screening of anti-HCV in Iyo city, Japan was performed. Sera from 136 subjects were tested for anti-HCV by ELISA (Ortho Diagnostic Inc.). Anti-HCV was positive in 13 subjects (9.6%). The familial study for anti-HCV revealed 2 persons positive for anti-HCV in 2 families each, while only 1 person was positive in each of the 8 other families. Two females were positive for both anti-HCV and HBsAg, and all of their 3 children were negative for anti-HCV and positive for HBsAg. Positive rate of anti-HCV was higher in subjects who had a history of blood transfusion or "Chinese acupuncture" than that in those who did not. These results indicate that not only blood transfusion but also "Chinese acupuncture" and intrafamilial transmission are possible routes of HCV infection. The rate of vertical transmission of HCV is definitely lower than that of HBV.     

Low-Level Viremia and Intracellular Expression of Hepatitis B Surface Antigen (HBsAg) in HBsAg Carriers with Concurrent Hepatitis C Virus Infection

Assays of hepatitis B virus (HBV) replication and antigen expression in HBV surface antigen (HBsAg) carriers with concurrent hepatitis C or D virus (HCV or HDV) infection revealed that HCV and HDV can suppress HBV replication but that HCV also substantially suppresses HBV surface protein expression. HBsAg carriers with concurrent HCV infection thus have low-level viremia and intracellular HBsAg.     

Epidemiology of hepatitis B and C in Croatia

The incidence of HBV and HCV infection is hard to determine because of the high number of asymptomatic infections. According to data of the Croatian Institute of Public Health, there are 200 newly infected persons with hepatitis B and approximately the same number of newly identified HBsAg carriers occur each year. Accordingly, Croatia is among the countries with less than 2% of HBsAg carriers in the general population. In these circumstances, HBV infection is most often spread among adolescents and younger adults. The route of transmission is most often sexual (semen) or through the skin in high-risk groups. An increased risk of infection is found in newborns of HBsAg positive mothers, i.v. addicts, promiscuous individuals, male homosexuals, person in close contact with acutely ill or chronic HBsAg carriers, persons that come in contact with blood and other potentially contaminated body fluids, dialysis patients, patients with multiple blood transfusions, patients with transplanted organ or tissue, patients treated for hematologic malignancies and hemophilia, and persons who undergo acupuncture, tattooing or piercing, or travel to areas with a high prevalence of HBV infection. The estimated prevalence of HCV infection marker (anti-HCV) in the Croatian general population is more than 1% and the number of yearly infected with hepatitis C reported to the Croatian Institute of Public Health is around 200 cases. The highest incidence is found in the 20-40 age groups at a high risk of infection by the use of drug injection. At risk are persons who received transfusion of blood or blood products prior to the availability of blood screening of voluntary blood donors.     

Tattooing as a risk of hepatitis C virus infection.

The association of hepatitis C virus (HCV) infection and tattooing was studied in 87 tattooed and 126 tattoo free healthy young men who did not engage in intravenous drug use or multiple sexual activity. Antibody against HCV (anti-HCV) was tested in serum specimens by enzyme immunoassay with C100-3, NS3, and core antigens; 11 of the 87 (12.6%) tattooed and 3 of the 126 (2.4%) tattoo free subjects were positive for anti-HCV (odds ratio = 5.9, 95% CI = 1.6-22.0). A relationship was demonstrated by an increased risk for HCV infection with an increasing number of tattooed site (P(trend) = 0.002). All but one of the 87 tattooed subjects had been infected by hepatitis B virus (HBV) and 25 were carriers of hepatitis B surface antigen (HBsAg). None of the 25 HBsAg carriers was positive for anti-HCV whereas 11 of the 62 HBsAg non-carriers had anti-HCV, suggesting a negative association between the HBsAg carriage and the long lasting anti-HCV (P = 0.02, Fisher's exact). The status of the tattooer was also an important determinant for HCV infection; the risk was higher if tattooing was done by a non-professional friend than by a professional tattooist. Tattooing, probably with improperly sterilized needles, can clearly pose an increased risk for HCV infection in Taiwan. This study indicates the need for legal standards for hygienic tattooing as part of preventive measures for the control of parenterally transmitted infections.     

Endemic hepatitis C virus infection in a Sicilian town: further evidence for iatrogenic transmission

The prevalence of and risk factors for HCV and HBV infections in the general population and the predictive value of ALT screening in identifying anti-HCV positive subjects have been evaluated in a small Sicilian town. A random 1:4 sampling from the census of the general population was performed. Anti-HCV, HCV-RNA, HCV genotype, HBsAg, and anti-HBc were tested. The linkage between HCV infection and potential risk factors was evaluated by multiple logistic regression analysis. Among 721 subjects studied, 75 (10.4%) were anti-HCV positive. The HCV infection rate increased from 0.4% in subjects 10-29 years of age to 34% in those > 60 years of age. Among the 75 anti-HCV positive subjects, 66.7% were HCV-RNA positive and 36% had abnormal ALT, in contrast abnormal ALT levels were found in 4.3% of the 646 anti-HCV negative subjects (P < 0.01). HCV genotype 1b infected the majority (88.0%) of viremic subjects. Exposure to HBV infection (anti-HBc positivity) was found in 11.2% of subjects; HBsAg positivity was 0.7%. At multivariate analysis, two variables were associated with HCV infection: age > or = 45 years (OR 27.8; CI 95% = 11.0-70.2) and previous hospitalization (OR 2.5; CI 95% = 1.3-4.7). ALT testing had low positive predictive value (PPV = 49.1%) for HCV infection. The positive predictive value was good (88%) in people > or = 60 years of age, but minimal (16.7%) in those below 60. These findings indicate that HCV infection is common in the elderly, perhaps as a result of past iatrogenic transmission. The present low rate of HCV infection among the younger generations coupled with the low progression of the viral related liver damage does not support the projection of a future increasing incidence in the next decades of the burden of HCV-related chronic disease. HBV infection, formerly common in this area, is already in sharp decline. In an area of high HCV endemicity, screening of the general population by ALT cannot be used a surrogate marker to detect HCV infection in those susceptible to treatment.     

Changing seroepidemiology of hepatitis B, C, and D virus infections in high-risk populations

Needle-sharing and sexual contact are important transmission routes of hepatitis B, C, and D virus (HBV, HCV, HDV) infection. This study aimed to investigate the current status of these viral infections among high-risk populations including prostitutes and intravenous (i.v.) drug users, compared with the prevalence rate reported previously to examine the changing seroepidemiology. Of the 916 female prostitutes, 79 (9%) were positive for antibody to HCV (anti-HCV), 111 (12%) were positive for HBV surface antigen (HBsAg), and 5 (5%) had antibody to HDV (anti-HDV). The prevalence rate was significantly lower compared to that in 1989-1991 (12%, P = 0.037) for HCV infection, and to that in 1988 (59%) and 1996 (40%) (P < 0.0001) for HDV infection. Of the 494 i.v. drug users, 87 (18%) patients were HBsAg carriers and 12 (14%) were anti-HDV-positive. The prevalence rate of HDV infection was significantly lower than that reported in 1985 (79%, P < 0.0001). Among the 443 tested i.v. drug users, 182 (41%) were anti-HCV-positive, significantly lower than that in 1985 (53%, P = 0.026). Of the 263 male prostitutes, 11 (4%) were anti-HCV-positive, 45 (17%) were HBsAg-positive, and 7 (16%) were anti-HDV-positive. Of the 129 illegal immigrant prostitutes, 7 (5%) were anti-HCV-positive, 15 (12%) were HBsAg-positive and none were positive for anti-HDV. In conclusion, the findings indicate a declining prevalence of HCV and HDV infections among drug users and prostitutes over the past 16 years. Male prostitutes and immigrant prostitutes are new "high-risk" populations and may become a reservoir for disease transmission.     

Antibodies to hepatitis delta virus in intravenous drug addicts and male homosexuals in Spain

In a study to determine the incidence of infection with hepatitis delta virus (HDV) in high-risk groups in Spain, tests to detect serological markers of infection with hepatitis B virus (HBV) and total antibodies against HDV (anti-HDV) were performed in serum samples from 451 unselected intravenous drug addicts and 168 homosexual or bisexual men. Most samples were obtained from primary health care units in Madrid. In drug addicts 87.4% of samples were positive for HBV markers and 15.1% were positive for anti-HDV. However, the incidence of anti-HD was much higher in HBsAg carriers (70.7%) than in individuals positive for anti-HBs (10.4%). Ninety-two samples (54.8%) from homosexual men were positive for HBV markers, but all were negative for anti-HD. Thus, parenteral transmission seems to play a major role in the spread of HDV in Spain, the sexual route being of minor relevance.     

Hepatitis C virus in the etiology of chronic hepatitis and liver cirrhosis: possibility of mixed viral infections due to parenteral transmission.

Sera obtained from 381 patients with chronic liver disease from four cities within the USSR were studied for HBV, HDV, and HCV markers of infection. Anti-HCV activity was detected in 41.2% of non-A, non-B cases. The etiological distribution of chronic hepatitis in Moscow and Dushanbe was similar with an approximate 20% prevalence for HBV, HDV, and HCV infections, whereas in Yakutsk 40% of cases were caused by HDV infections. The etiology of disease remained unrecognized in approximately 40% of patients with chronic liver disease in Moscow and Dushanbe and in 15% in Yakutsk. Anti-HCV activity was detected in 18.8% of patients with chronic HBV infections and in 8.3% of patients with chronic HDV infections. Anti-HCV activity was detected in 41% of patients without markers of HBV or HDV infections. The reasons for the observed differences in HCV prevalence among patients chronically infected with HDV are discussed.     

Hepatitis D virus infection among intravenous drug abusers in Taiwan: analysis of risk factors and liver function tests

To investigate the prevalence of hepatitis D virus (HDV) and hepatitis B virus (HBV) infection among intravenous drug abusers in Taiwan, a total of 761 male prisoners, including 680 intravenous drug abusers, were studied for serological markers of HBV and HDV. Questionnaires were distributed to evaluate the risk factors for HDV infection and also to estimate the strength of association among HDV infection and the risk factors. HBV infection was common, and the positive rates of HBV markers between intravenous drug abusers and non-drug abusers were not statistically different. However, the positive rate of the antibody to HDV was significantly higher among intravenous drug abusers than among non-drug abusers (21.3% vs. 8.6%). Of 131 chronic HBV carriers with intravenous drug abuse, 119 (91%) were anti-HD positive. Using multiple logistic regression models, we found that the most important risk factor for HDV infection was hepatitis B surface antigen (HBsAg) carriage, and intravenous drug addiction the next. A matched case-control study also was conducted to compare liver function tests among both anti-HD- and HBsAg-positive group anti-HD-negative, and HBs-AG-positive group as well as those with neither positive. Statistically significant difference in liver function tests was not found. It is concluded that the HBsAg carriers with intravenous drug abuse in Taiwan are commonly HDV infected with and that the infection does not seem to affect the liver as assessed by liver function tests.     

Prevalence of hepatitis B, C, and delta virus infections among children in Mongolia: progress in childhood immunization

Mongolia is highly endemic for hepatitis B virus (HBV), hepatitis C virus (HCV), and hepatitis delta virus (HDV) infections among apparently healthy adults. However, the age-specific prevalence of ongoing HBV, HCV, and HDV infections among children in Mongolia remains unknown. Therefore, samples obtained from a total of 655 apparently healthy children of 0.3-15 years of age (307 boys and 348 girls; age, mean +/- standard deviation [SD], 8.4 +/- 4.2 years) living in Mongolia, between October 2005 and January 2006, were tested for serological and molecular markers of HBV, HCV, and HDV infections. Although 88.7% of the 655 children studied were immunized against hepatitis B, 64 (9.8%) tested positive for hepatitis B surface antigen (HBsAg) and/or HBV DNA and 13 (2.0%) for HDV RNA. Twenty-seven children (4.1%) had detectable HCV RNA. Collectively, 82 (12.5%) were viremic for one or more of these viruses, including eight children with dual viremia of HBV/HCV and one child with triple HBV/HCV/HDV viremia. When children without anti-HBc, anti-HCV and anti-HDV IgG (n = 510) served as a control, a history of hospitalization was significantly associated with HBV viremia (P < 0.0001), anti-HBc positivity (P < 0.0001), and HCV viremia (P = 0.0001). HBsAg mutation was found in 18 (31.6%) of the 57 children with viremia, including those at amino acid position 126, 127, 129, 131, 134, 143 or 144. There were no significant differences in the frequency of HBsAg mutation in relation to age, sex, and hepatitis B vaccination status of the children, suggesting that HBsAg mutation plays a limited role in failure of vaccination in Mongolia.     

Seroepidemiological survey of hepatitis B and C virus infections in Ghanaian children

The seroprevalences of hepatitis B virus (HBV) and hepatitis C virus (HCV) markers were evaluated in a random sample of 803 children attending school in Ashanti-Akim North district in Ghana in order to gain a better understanding of transmission patterns of these viruses, particularly horizontal transmission of HBV. This rural district is typical of 70% of the Ghanaian population. The overall seroprevalence of at least one marker of HBV infection was 61.2%, with rates increasing from 48% to 80% between the ages of 6–18 years (P < 0.001). The overall HBsAg seroprevalence was 15.8%, with the proportion of HBsAg positives amongst those with anti-HBc increasing from 39.3% in 6–7-year-olds to 51.8% in 12–13-year-old. It appears that horizontal transmission during this age period was accompanied by a high rate of HBsAg carriage. Among those infected but not carriers, i.e., those HBsAg negative and anti-HBc positive, >50% lacked detectable levels of anti-HBs, an unusual pattern of convalescent immune response to HBV. The overall seroprevalence of anti-HCV was 5.4% and did not differ significantly by age or gender. Anti-HCV seroprevalence was not associated with the presence of any HBV marker. A better understanding of the unusually high prevalences of HBV and HCV infections demonstrated in this population is likely to influence vaccination and blood transfusion policies and to stimulate further evaluations of these infections and their vehicles of spread in highly endemic regions such as sub-Saharan Africa. © 1996 Wiley-Liss, Inc.     

IgM- and IgG-class antibodies to the hepatitis C virus]

The test system widely used currently for the determination of anti-HCV permits the detection of anti-HCV IgG alone. The data recently published by T. G. Wreghitt et al. confirm the probability of the presence of anti-HCV of both IgG and IgM classes in sera from hepatitis C patients. Anti-HCV IgM was detected by Ortho test with some modifications using an anti-M conjugate in the last stage of the experiment. Anti-HCV IgG were detected by regular Ortho test. A total of 46 patients with different forms of HCV infection and a control group were examined. According to the preliminary data, 18 patients were positive in the routine anti-HCV Ortho test. Among 18 anti-HCV-positive patients, nine had chronic HCV infection and the other 9 acute HCV infection. The distribution of IgM and IgG anti-HCV in the acute patients was as follows: 4 patients (44.5%) had approximately equal titres of IgG and IgM, 3 (33.5%) had predominantly IgG, 2 (22.2%) mainly IgM. A similar pattern was observed in the group with chronic HCV infection. Thus, 5 subjects (55.6%) showed approximately equal ratio of IgM and IgG anti-HCV, 2 (22.2%) had mostly IgM and the rest 2 mainly IgG. No anti-HCV in the control group was found. The control group consisted of 18 patients with chronic liver diseases without markers of HBV or HDV infection, 3 with HAV infection, 2 with HBV infection and 5 healthy subjects. The specificity of anti-HCV IgM test was confirmed by Chiron Western blot analysis using the same modification.(ABSTRACT TRUNCATED AT 250 WORDS)     

High prevalence of hepatitis B,C and delta virus infections among blood donors in Mongolia

Summary. Serum samples obtained from 289 first-time and 114 repeat donors at the Blood Center of Mongolia (MBC) were tested for serological and molecular markers of hepatitis B virus (HBV), hepatitis C virus (HCV), and hepatitis delta virus (HDV) infections. Among the 403 blood donors, 33 (8.2%), 21 (5.2%), and 27 (6.7%) tested positive for hepatitis B surface antigen (HBsAg) and/or HBV DNA, HCV RNA, and HDV RNA, respectively. Collectively, 55 donors were viremic for one or more of these viruses, and included 54 first-time donors (18.7%) and 1 repeat donor (0.9%) (P < 0.0001). One discrepant case with HBsAg detectable only at MBC was negative for HBsAg, HBV DNA and anti-HBc in this study. Four donors who were HCV-viremic in this study were negative for anti-HCV by the MBC method. Further efforts to increase the sensitivity and specificity of the currently-used tests are urgently required in Mongolia. Three donors who were positive for anti-HBc and anti-HDV but negative for HBsAg, had both HBV DNA and HDV RNA. This suggests that introduction of a new anti-HDV serological test is useful for not only HDV screening but also HBV screening of anti-HBc-positive, HBsAg negative donors, considering a possibility of viral interference by coexisting HDV.     

Hepatitis B and D virus infection among drug abusers in Taiwan

Approximately 15 to 20% of the general population in Taiwan are chronic hepatitis B surface antigen (HBsAg) carriers. However, the incidence of hepatitis D virus (HDV) infection is low (5-8%) in patients with HBsAg-positive chronic liver diseases in this area. To evaluate the prevalence of hepatitis B virus (HBV) and HDV infection among drug abusers in Taiwan, serum samples were collected from 152 drug abusers at the Taipei Municipal Anti-Narcotic Institute and test for HBV and HDV markers. Of these, 24 (15.8%) were HBsAg positive, and only 15 (9.9%) were seronegative for all HBV markers. Of the 115 intravenous drug abusers, serum antibody to hepatitis D antigen (anti-HD) was positive in 78.9% of 19 persons who were HBsAg positive, and in 7.5% of 80 persons who were positive for antibody to HBsAg (anti-HBs). Anti-HD was not detected in the sera from all 37 nonintravenous drug abusers regardless of the status of their HBV markers. Also, none of 63 asymptomatic HBsAg carrier pregnant women or 23 patients with acute type B viral hepatitis had measurable anti-HD in their sera. Thus, the high frequency of HDV detected among Chinese HBsAg carrier intravenous drug abusers in Taiwan is similar to that reported in Western countries.