|
Descriptive epidemiology of
hepatitis C virus among male heroin abusers in Taiwan.
http://www.thefreelibrary.com/Descriptive+epidemiology+of+hepatitis+C+virus+among+male+heroin+...-a0145561557
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
infection.
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
Study Population
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
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
statistically significant.
Results
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 =
0.169).
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
positivity.
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).
Discussion
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
health threat.
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
great concern.
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
sociodemographic groups.
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)
Limitations
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.
Conclusion
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.
References
1. Main Causes of Deaths in Taiwan in 2002, Department of
Health, Taiwan. Available at: http://www.doh.gov.tw/ufile/Doc/S02/9101-eng.xls.
Accessed February 23, 2006.
2. Chen DS, Wang JT, Chen PJ, et al. Hepatitis C virus infection
in Taiwan. Gastroenterol Jpn 1991; 26(suppl 3):164-166.
3. Tsai JF, Chang WY, Jeng JE, et al. Hepatitis C virus
infection as a risk factor for non-alcoholic liver cirrhosis in
Taiwan. J Med Virol 1993; 41:296-300.
4. Tai DI, Chen CH, Chang TT, et al. Eight-year nationwide
survival analysis in relatives of patients with hepatocellular
carcinoma: role of viral infection. J Gastroenterol Hepatol
2002;17:682-689.
5. Chen TZ, Wu JC, Yen FS, et al. Injection with nondisposable
needles as an important route for transmission of acute
community-acquired hepatitis C virus infection in Taiwan. J Med
Virol 1995;46:247-251.
6. Li CP, Hwang SJ, Lu CL, et al. Risk factor analysis of
patients with chronic hepatitis C in Taiwan. Zhonghua Yi Xue Za
Zhi (Taipei) 1996;58:275-280.
7. Wang CS, Chang TT, Chou P. Differences in risk factors for
being either a hepatitis B carrier or anti-hepatitis C+ in a
hepatoma-hyperendemic area in rural Taiwan. J Clin Epidemiol
1998;51:733-738.
8. Chang CJ, Ko YC, Liu HW. Seroepidemiology of hepatitis C
virus infection among drug abusers in southern Taiwan. J Formos
Med Assoc 1998;97:826-829.
9. Sun CA, Chen HC, Lu CF, et al. Transmission of hepatitis C
virus in Taiwan: prevalence and risk factors based on a
nationwide survey. J Med Virol 1999;59:290-296.
10. Lee PL, Wang JH, Tung HD, et al. A higher than expected
recovery rate from hepatitis C infection amongst adolescents: a
community study in a hepatitis C-endemic township in Taiwan.
Trans R Soc Trop Med Hyg 2004;98:367-372.
11. Wang JT, Wang TH, Lin JT, et al. Effect of hepatitis C
antibody screening in blood donors on post-transfusion hepatitis
in Taiwan. J Gastroenterol Hepatol 1995;10:454-458.
12. Chang TT, Young KC, Yang YJ, et al. Incidence of
post-transfusion hepatitis in Taiwan before and after
introduction of anti-HCV testing. Liver 1996;16:201-206.
13. Lee SD, Chan CY, Wang YJ, et al. Seroepidemiology of
hepatitis C virus infection in Taiwan. Hepatology
1991;13:830-833.
14. Samuel MC, Doherty PM, Bulterys M, et al. Association
between heroin use, needle sharing and tattoos received in
prison with hepatitis B and C positivity among street-recruited
injecting drug users in New Mexico, USA. Epidemiol Infect
2001;127:475-484.
15. Hallinan R, Byrne A, Amin J, et al. Hepatitis C virus
prevalence and outcomes among injecting drug users on opioid
replacement therapy. J Gastroenterol Hepatol 2005;20:1082-1086.
16. Lai SW, Ng KC, Li CI. Descriptive analysis of HBsAg and HCV
antibody prevalence in patients receiving health checkups: a
hospital-based study. Mid Taiwan J Med 2004;9(suppl 1):s64-s69.
17. Abraham HD, Degli-Esposti S, Marino L. Seroprevalence of
hepatitis C in a sample of middle class substance abusers. J
Addict Dis 1999;18:77-87.
18. Wada K, Greberman SB, Konuma K, et al. HIV and HCV infection
among drug users in Japan. Addiction 1999;94:1063-1069.
19. Habib SE, Lovejoy FH, Aspin C. Hepatitis C prevalence and
risk behavior of injecting drug users in Sydney: a continuing
concern. Southeast Asian J Trop Med Public Health
2001;32:823-834.
20. Herring BL, Tsui R, Peddada L, et al. Wide range of
quasispecies diversity during primary hepatitis C virus
infection. J Virol 2005;79:4340-4346.
21. Alter MJ, Coleman PJ, Alexander WJ, et al. Importance of
heterosexual activity in the transmission of hepatitis B and
non-A, non-B hepatitis. JAMA 1989;262:1201-1205.
22. Ko YC, Ho MS, Chiang TA, et al. Tattooing as a risk of
hepatitis C virus infection. J Med Virol 1992;38:288-291.
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: wei@www.cmuh.org.tw
Accepted January 18, 2006.
RELATED
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
HCV infection.
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,
|
