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 [+ or -] 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 square] 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
Key Words: epidemiology, hepatitis C, heroin abuser, prevalence,
needle sharing, tattoo
In 2002, chronic liver disease
and liver cirrhosis were the sixth leading causes of death in
Taiwan, (1) with hepatitis B and hepatitis C virus (HCV)
infections the leading cause of these diseases. (2-4) In Taiwan,
HCV infection is mainly transmitted by blood transfusion, IV
drug abuse, accidental needle injection, sexual contact,
acupuncture, tattoos, and earlobe piercing. (5-10) Since there
is no effective vaccination to prevent HCV infection,
intervention consists of avoidance techniques only. After
screening for HCV antibodies in blood donors was instituted in
Taiwan in July 1992, the transmission of the HCV virus via blood
transfusion was effectively interrupted. (11,12)
HCV is a common infection among injecting drug abusers. (2,13)
In the study by Chang et al, (8) the prevalence of anti-HCV
antibody positivity was 66.4% among injecting drug abusers.
Policies and programs to prevent HCV infection remain uncertain
in these high risk people.
We hope to make a dent in the rising epidemic of HCV infection
by monitoring HCV infection rates, as a means of showing the
effectiveness of various interventions. This study used data
collected from heroin abusers to explore the following
questions: (1) what are the sociodemographic patterns and the
prevalence of HCV infection in heroin abusers? (2) what are the
risk factors for HCV infection in heroin abusers?
Materials and Methods
This was a cross-sectional study. The study was undertaken at a
male prison in Taiwan from November 2004 to February 2005. All
new sentenced prisoners received a structured questionnaire
interview. A total of 577 men were enrolled in the study. Of
that group, 423 (73.3%) injected heroin and 154 (26.7%) smoked
heroin. The study was approved by the ethics committee. The
subjects' age, employment, years of education, and marital
status were included. A face-to-face interview inquired about
the age of first heroin use, frequency of use, duration of use,
and needle sharing. Other risk factors included the number of
female sexual partners, frequency of condom use, tattoo history,
alcohol use, and blood transfusion history. All study subjects
underwent testing for hepatitis C virus antibody using the third
generation EIA test.
Statistical analysis was performed by SPSS (Chinese Version
10.0, Sinter Information Corp, Taiwan). The t test, [chi square]
test and multivariate logistic regression were used. Relative
risks were estimated by the odds ratio (OR) using a multivariate
logistic regression and were expressed with 95% confidence
interval (CI). A P value less than 0.05 was considered
Sociodemographic characteristics of this study population are
listed in Table 1. The mean age was 33.3 [+ or -] 7.9 years (age
range 19-65 years). Among 68.9% of these abusers, the age of the
first heroin use was less than 30 years old. Eighty percent of
the abusers were employed full time, 60.3% had less than 9 years
of education, and 58.2% were unmarried.
The related factors of HCV infection are listed in Table 2. The
overall prevalence of anti-HCV antibody positivity was 74.9%.
The prevalence of anti-HCV antibody positivity was higher among
injecting heroin abusers than among smoking heroin abusers, with
statistical significance (89.8% versus 33.8%), P < 0.0001). The
subjects with anti-HCV antibody positivity were younger than
those who were anti-HCV antibody negative, with statistical
significance (32.8 versus 34.9 years old, P = 0.005). The
prevalence of anti-HCV positivity did not increase with age (P =
The mean age of first heroin use and history of needle sharing
were significantly associated with anti-HCV positivity. The mean
age of the first heroin use was 26.8 years for the anti-HCV
positive subjects, and 28.7 years for the anti-HCV negative
subjects (P = 0.007). Also, 93.1% of those with a needle sharing
history were anti-HCV positive, compared with 70.8% of those who
did not share needles. (P < 0.0001).
The employment status, years of education, marital status,
frequency of use, duration of use, number of female sex
partners, condom use, tattoo history, alcohol use, and blood
transfusion history were not significantly associated with anti-HCV
The predictors of HCV infection are exhibited in Table 3. In the
final model, multivariate logistic regression revealed that
needle sharing was the only strong risk factor for HCV
infection. That is, the prevalence of anti-HCV positivity
increased 5.25-fold for heroin abusers with a history of needle
sharing (95% confidence interval = 2.48-11.12, P < 0.0001).
Our study revealed that HCV is a common infection among
injecting heroin abusers. The prevalence of anti-HCV positivity
was 89.8% among male injecting heroin abusers. Several studies
have reported similar results. The prevalence of anti-HCV
positivity among injecting drug abusers was 66.4% in southern
Taiwan, (8) 82% in the US, (14) and 75.3% in Australia. (15) In
contrast, the prevalence of anti-HCV positivity among male
smoking heroin abusers was 33.8% in our study and 14.4% among
noninjecting drug abusers in southern Taiwan. (8) The prevalence
of anti-HCV positivity was 3.9% in a hospital-based study of
healthy men. (16) Although there are variations in prevalence,
HCV infection among injecting drug abusers is a critical public
Our study also confirmed that needle sharing was an independent
risk factor for HCV infection (OR = 5.25, 95% CI = 2.48-11.12).
Several studies have consistently observed this association
between needle sharing and HCV infection. (17-20) Hence, risk
reduction programs, including use of sterile needles, is of
We also found the mean age of the first heroin use for the
subjects with anti-HCV positivity was younger than those who
were anti-HCV negative (26.8 versus 28.7 years old, P = 0.007).
We also noted that the cumulative prevalence of anti-HCV
positivity reached an apparently high level (82.2%) before 40
years of age. Due to the fact that the number of heroin users
with anti-HCV positivity was highest among those who began using
before age 30, and among those with less education, risk
reduction counseling must be directed at these specific
Surprisingly, we identified that tattooing was not associated
with anti-HCV positivity in the [chi square] test (P = 0.225).
So far, no consistent data exist for the association between
tattooing and HCV infection. In the study by Alter et al, (21)
no association was found between tattooing and HCV infection. In
contrast, however, several researchers have illustrated a
remarkable association between tattooing and HCV infection.
(5,6,8-10) Ko et al also suspected that unhygienic tattooing
with improperly sterilized needles could obviously introduce an
increased risk for HCV infection in Taiwan. (22)
Due to the small sample size, this is not a thorough
representation of all Taiwanese heroin abusers. However, 70.8%
of those without a needle sharing history were also anti-HCV
positive. Thus, there is un urgent need to investigate the other
routes of transmission of HCV. Hence, a larger detailed study is
necessary for a more accurate description of risk factors.
The prevalence of anti-HCV positivity among male injecting drug
abusers is predominantly high. The parenteral route, mainly by
needle sharing, is the most common transmission route of HCV
infection. Intervention to improve the availability of sterile
needles is a critical public health topic with regard to
reducing HCV infections in Taiwan. Moreover, we sincerely hope
this study could provide the background data for further
decision making in public health care policy.
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Kuan-Fu Liao, MD, Chen-Yuang Peng, MD, PHD, Shih-Wei Lai, MD,
Wu-Long Chang, MS, and Nan-Yung Hsu MD, MS
From the Departments of Internal Medicine, Family Medicine, and
Surgery, China Medical University Hospital, and the Department
of Health, Taichung Prison, Taichung, Taiwan.
Reprint requests to Shih-Wei Lai, Department of Family Medicine,
China Medical University Hospital, No 2, Yuh-Der Road, Taichung,
40447, Taiwan. Email: firstname.lastname@example.org
Accepted January 18, 2006.
ARTICLE: Key Points
* Hepatitis C virus (HCV) infection is the second cause of
chronic liver diseases in Taiwan.
* The prevalence rate of anti-HCV positivity is high among
injecting heroin abusers.
* Needle sharing is identified as a potential risk factor for
Table 1. Sociodemographic characteristics of male heroin abusers
Variable Male heroin abusers (%)
Age (years) (mean [+ or -] SD) 33.3 [+ or -] 7.9
Age of first use (years) (a)
[greater than or equal to]50 7 (1.4)
[less than or equal to]9 years 342 (60.3)
Divorced/separated 95 (16.5)
(a) Imprecise summation of total subjects was due to missing data.
Table 2. Related factors of HCV infection by chi-square test
HCV antibody HCV antibody P value
Variable negative (%) positive (%)
Age (years) (mean [+ or -] SD) 34.9 [+ or -] 32.8 [+ or -] 0.005
Age of first use (years) 28.7 [+ or -] 26.8 [+ or -] 0.007
(mean [+ or -] SD) 7.2 6.8
Smoking 102 (66.2) 52 (33.8)
Injecting 43 (10.2) 380 (89.8)
20-29 48 (21.3) 177 (78.7)
30-39 57 (24.5) 176 (75.5)
40-49 33 (35.1) 61 (64.9)
[greater than or equal to]60 1 (33.3) 2 (66.7)
Employment status (a) 0.491
Unemployed 14 (20.9) 53 (79.1)
Part time 13 (31.0) 29 (69.0)
Full time 106 (24.4) 329 (75.6)
Educational years (a) 0.804
[less than or equal to]9 85 (24.9) 257 (75.1)
>9 years 58 (25.8) 167 (74.2)
Unmarried 77 (23.0) 258 (77.0)
Married 41 (28.1) 105 (71.9)
Divorced/separated 27 (28.4) 68 (71.6)
Non-daily 126 (25.7) 365 (74.3)
Daily 16 (20.8) 61 (79.2)
Duration of use (years) 0.570
[less than or equal to]5 112 (24.8) 339 (75.2)
Female sex partners (a) 0.447
[greater than or equal to]2 92 (25.8) 264 (74.2)
Never 31 (22.1) 109 (77.9)
Sometimes 65 (27.2) 174 (72.8)
Always 23 (22.8) 78 (77.2)
Never 82 (23.6) 265 (76.4)
(a) Imprecise summation of total subjects was due to missing data.
Table 3. Risk factors of HCV infection by multivariate logistic
Variable EP(SE) OR 95% CI
Age (years) -0.02 (0.01) 0.98 0.95-1.00
Needle sharing (never 1.66 (0.38) 5.25 2.48-11.12 (a)
needle sharing as reference)
EP, estimated parameter; SE, standard error; OR, odds ratio; CI,