Seroprevalence of hepatitis B markers among incarcerated intravenous drug users.

BACKGROUND: Drug injection is one of the most prominent risk factors for transmission of viral hepatitis. Prevalence of hepatitis B virus (HBV) is generally higher in prisoners compared with the general population. The object of this study was to assess the markers of HBV and related risk factors among intravenous drug users (IVDU) in prisoners.
MATERIALS AND METHODS: Through a cross-sectional study in 2012 HBV infection and its risk factors were assessed in prisoners with a history of intravenous drug use in Isfahan, Iran. A checklist was fulfilled for each participant and 5 ml blood was taken from each subject. Sera were analyzed for markers of the hepatitis B: Hepatitis B virus surface antigen (HBsAg), antibody to hepatitis B virus surface antigen (HBsAb) and hepatitis B virus core antibody (HBcAb) by ELISA. We used Chi-square test and logistic regression model to analyze data and P < 0.05 was considered to be significant.
RESULTS: All of the studied participants (n = 970) were men. The mean ± standard deviation of the age of the subjects was 32.61 ± 8.1 years and the majority of them had less than high school education. More than 40% of these men had a history of injection drug inside prison and 2.27% of them self-reported history of HBV infection. Of the 970 IVDU, 32 (3.3%) were positive for HBsAg. Among HBsAg + subjects, 23 (71.88%) were HBcAb+. 120 (12.37%) were found positive for isolated HBsAb, 45 (4.64%) for isolated HBcAb and 67 (6.9%) for both HBsAb and HBcAb. History of sharing needle (odds ratio: 2.25, 95% confidence interval: 1.09-4.65) had a significant association with HBsAg positivity.
CONCLUSION: The results suggest that history of sharing needle had a significant association with HBsAg positivity. It seems that educational programs for injecting drug related behaviors, especially syringe sharing, are needed for IVDU.

INTRODUCTION

Injecting drug use is a worldwide public health problem with 16 million people injected drugs in 2007.[1] Drug injection is one of the most important risk factors for transmission of viral hepatitis.[2] The transmission of these diseases in intravenous drug users (IVDU) is caused by using sharing injection equipment such as needle, syringes and other paraphernalia.[34] Studies have documented that the prevalence rate of hepatitis B virus (HBV) infection is higher among IVDU.[56] 16% of acute viral hepatitis subjects reported to the Center for Disease Control and prevention had recent use of injected drugs as a risk factor.[7]

Hepatitis B virus is a health problem and the main cause of chronic hepatitis, hepatocellular carcinoma, and cirrhosis.[8] It is estimated that 2 billion people have been exposed to this virus at some time in their lives and between 350 and 400 million are chronic carriers of HBV.[9] Chronic viral hepatitis B infection causes about 1 million deaths annually.[8] HBV infection may be transmitted vertically from mothers to their newborn infants or horizontally by means of body secretions and blood products. The researches showed that needle-stick injuries in health personnel, shared needles in drug abusers, tattooing, ear and nose piercing practices, and hemodialysis have been associated with increased risk of transmission.[10]

HBV infection is considered as ‘desmoteric’ infections, which mean its prevalence is generally higher in prisoners than in nonprisoners. Many studies showed that incarceration is a significant predictor of HBV infection.[111213] According to limited studies in Iran, the HBV infection prevalence varies among incarcerated injection drug users from 3% to 4.5% in different parts of the country.[131415] The risk factors before arrest such as injection drug use, high-risk sexual behaviors and poor access to health care and also factors after capture such as sexual harassment, body piercing and nonprofessional tattooing may play important roles in the higher prevalence of HBV among prisoners in comparison with the general population.[16]

Hepatitis B infection puts a heavy burden on the health care system because of the cost of treatment of liver diseases. Exact data on the prevalence of this infection is required for suitable prevention and control of this disease. A large number of prisoners are drug addicts;[1718] thus, we assess HBV markers and the related risk behaviors among IVDU prisoners in Isfahan, Iran.

MATERIALS AND METHODS

This cross-sectional study was performed at March 2012 in two prisons in Isfahan province, Iran. There were a total of 11 prisons in Isfahan province; we selected two prisons, the central prison and Asadabad Camp, because the most of IVDU prisoners were resident in these prisons. Prisoners were enrolled if they had intravenous drug history. We defined, an IVDU as ‘a person using any kind of injectable drug for at least 1 time.’[19] The purpose of the study was fully explained to inmates and participation in the study was voluntary. It was emphasized that the study information would remain confidential and an informed consent was obtained from each subject. A checklist was completed to assess prisoners’ demographic characteristics (such as age, level of education, and nationality) and HBV-related risk behavior like marital status, sexual behaviors, use of shared injecting equipment, dental procedures, and history of blood transfusion,[102021] by a trained staff with a face-to-face interview. Interviews were individually done. The research protocol was approved by the Ethics Committee of the Isfahan University of Medical Sciences (Project No: 291072).

A volume of 5 ml of blood was drawn from each subject. The blood samples were transported to the laboratory of Infectious Diseases Research Center, Isfahan, during 2-5 h in the cold box and were then centrifuged and serum was separated. The separated serum was transferred to a sterile tube and then stored at −70°C until processing.[17] Markers of the HBV: Hepatitis B virus surface antigen (HBsAg), antibody to hepatitis B virus surface antigen (HBsAb) and hepatitis B virus core antibody (HBcAb) were tested using fourth generation enzyme immunoassays (Acon, USA).

The data was analyzed using SPSS software (version 16.0, 2007, SPSS Inc., Chicago, IL, USA). Bivariate analysis was performed using Chi-square test to assess the association between risk factors and HBV markers. Multiple logistic regression was used for the significant variables in the bivariate analysis as explanatory variables to calculate adjusted odds ratio and 95% confidence intervals (CI). P < 0.05 was considered as statistically significant.

RESULTS

All of the study participants (n = 970) were male with a mean age of 32.61 ± 8.14; the youngest and oldest were 18 and 67 years old, respectively. 3.6% of the subjects had never attended school, 38.3% had attended primary school, 40% had attended guidance school, and 15.7% had reached high school and only 2.4% had more than a high school education. The majority of prisoners were Iranian (Iranian: 98.8%, Afghan: 1.1%, Indian: 0.1%). Overall, 521 (55.4%) had ever been married. Among the married persons, 460 (92.2%) had been married once, 34 (6.8%) had been married twice and 5 (1%) had been married more. Of those interviewed 43.1% had sex with men and 64.4% had more than one heterosexual partner, among whom 30.9% mentioned to use a condom during sex. The mean of frequency of intravenous injections was 54 times/month. 40.3% of the cases had a history of injection drug inside prison. 762 prisoners reported a history of alcohol consumption. 22 out of 970 inmates self-reported a history of HBV infection.

Of the 970 incarcerated injection drug users, 32 (3.3%) were found positive for HBsAg. 23 (2.37%) HBsAg-positive subjects had positive HBcAb results that were compatible with chronic HBV, 144 (14.85%) were HBsAg-positive and/or HBcAb positive that were compatible with past or current infection.[22] Only one prisoner was positive for all markers of HBV infection. Among the studied subjects, 120 (12.37%) and 45 (4.64%) were positive for isolated HBsAb and isolated HBcAb, respectively. Sixty-seven were positive for both HBsAb and HBcAb that were compatible with previously cured infection. There was a significant association between HBsAg positivity and history of sharing needle (P = 0.04) [Table 1]. The logistic regression model also showed statistically significant relationships between the HBsAg and positive history of sharing needle (odds ratio: 2.25, 95% CI: 1.09-4.65).

Table 1

Bivariate analysis of HBV markers

DISCUSSION

In this study, prevalence of HBV markers was assessed among IVDU in prisons in Isfahan province. Our results indicated that the prevalence of HBsAg seropositivity was 3.3% among these inmates. Other similar studies in Iran have shown similar results. The prevalence of HBsAg in incarcerated IVDU in Mashhad, a province in the north of Iran, was reported to be 2.9% by Rowhani-Rahbar et al.[14] In a study of four prisons in Iran from 401 IVDU, 17 persons (4%) were HBsAg-positive.[18] In a prison in Gorgan, Iran, 4.1% of prisoners were positive for HBsAg.[23] The prevalence of HBsAg in drug addicts’ prisoners was reported to be 3.8% in Zanjan, a province in the west of Iran.[24] In Mir-Nasseri et al. study, the HBsAg positivity among IVDU prisoners in Tehran, Iran was 4.5%.[13]

Although the HBsAg prevalence is still low in the IVDU in prisons of Iran, taking into account the similarity in transmission routes of this virus with HCV, the high rate of infection with HCV in IVDU and also the increasing number of injection drug users, it can be predicted that there is a high chance of increase in the incidence of HBV infection in the near future.

Since the high-risky behaviors in IVDU frequently happen, we assessed some risk factors associated with HBV positivity. The results of this study showed participants who had a history of shared drug injection were more likely to be positive for HBsAg. There are enough evidences to support that injecting drug use and syringe sharing are common among IVDU in prison.[2526] The risk of syringe contamination by this virus is higher in prisons than outside where syringes are commonly shared with only one or two other subjects.[27] In most of the prisons, the lack of access to new syringes or other injecting equipment results in prisons acting as an incubator for HBV epidemic. Some countries intend to control this risk factor in prisons and have managed prison-based needle exchange programs. A few studies documented that the provision of syringes for IVDU in prisons may contribute to a considerable reduction of syringe sharing.[28]

Results showed that more than 80% of these men had no immunity against hepatitis B. Unfortunately, we did not ask about their vaccination program. Prisons are not separated places from the community. Many inmates spend short periods in prison and some prisoners contact with their families during their vacation, or after completion of their incarceration, therefore this population can transfer infections to the community. On the other hand, in prisons there are suitable opportunities to contact large numbers of IVDU for long periods and it is possible that they transfer this infection to each other. Therefore, antibody testing for immunity against HBV and implementation program on immunization of this high-risk group should be considered.

In our study, the HBcAb could be detected in 35.83% of the HBsAb positive population, demonstrating that the immunity against hepatitis B has still been acquired through virus exposure in a substantial portion of subjects.

Prevalence of different markers of HBV infection among men in the general population in Isfahan province were reported 1.8%, 13.7%, and 4.4% for HBsAg, HBsAb, and HBcAb, respectively.[29] Comparison of the results of the general population with our data shows that these markers are more prevalent among incarcerated IVDU than the general population. These findings indicate that prisons in Iran could be also high-risk places for infection transmission and they can have an important effect on the rate of infection.

This study has some limitations. The vertical transmission of HBV from HBsAg-positive mothers to their infants at birth or in early infancy has been considered a possible route for the spread of infection that might explain the maintenance of the virus in populations before the use of needles. Unfortunately, we did not ask prisoners about it. In addition, in our check list there was no question about intra-familial transmission and liver diseases. Furthermore, we did not measure variables such as knowledge, attitudes and perception of risks which might have an important impact on the risk of this infection.

CONCLUSION

The results suggest that sharing needle had a significant association with HBsAg positivity. It seems that educational programs for injecting drug related behaviors, especially syringe sharing are needed for IDUs. This finding could be an important evidence for harm-reduction policies in Iran.

AUTHORS’ CONTRIBUTION

All authors have contributed in designing and conducting the study. ZN, MY, NK and MM collected the data and PA, BA, and ZN did the analysis. All authors have assisted in preparation of the first draft of the manuscript or revising it critically for important intellectual content. All authors have read and approved the content of the manuscript and are accountable for all aspects of the work.