Introduction

It is estimated that the number of cannabis and opioid users worldwide are 161 million and 16 million, respectively. Cannabis is the most consumed drug in the world (1). Cannabis or marijuana contains the psychoactive chemical delta-9-tetrahydrocannabinol, which is believed to be the main chemical component that produces the psychoactive effect. Cannabis is often used through smoking in hand-rolled cigarettes, pipes, or water pipes (2). Opioids contain hydrocodone, oxycodone, morphine, and codeine, and the illegal opioid, heroin. Heroin is a powerful opiate drug, and used through injecting, smoking, or snorting (3). Hepatitis B virus (HBV), hepatitis C virus (HCV) and HIV prevalence in the world varies depending on geographical location. Turkey is a medium endemic country for both HBV (2%-8%) and HCV (1%-2%). The prevalence of HIV infection in Turkey varies from region to region but still seems low (1,4). On the other hand, since drug addicts show risky behaviors, including unsafe sex and risky injection practices, it is believed that there is a strong link between the spread of infectious diseases and drug abuse. The most important factor increasing their risk of HBV, HCV and HIV transmission is sharing drug preparation or injecting equipment (5). 50%-80% of HCV infection in the developed countries occurs among injection drug users (6). HCV infection is the most common blood-borne infection among drug addicts in the developed countries. HIV, less common than HCV, can also be transmitted during unprotected sex. In several studies, high HBV, HCV and HIV prevalence was described among drug users in the several countries (7,8,9,10). However, there is not enough knowledge about the epidemiology of these infections in drug addicts in Turkey, whereas several countries have a developed surveillance systems to monitor the spread of HBV, HCV and HIV infections in drug users. Therefore, in this study, it was aimed to investigate the frequency of HBV, HCV and HIV infections in cannabis and opioid addicts admitted to the drug addiction treatment center at Elazığ Mental Health Hospital.

Materials and Methods

Subjects

This retrospective study included 276 drug addicts in Drug Addiction Treatment Centre at Elazığ Mental Health Hospital in 2015. There is a drug addiction treatment center providing medical care and social support for drug addicts in the hospital. This study was approved by Fırat University Ethics Committee (08/11/26.04.2016).

Serological Analysis

Blood samples collected from the drug users were analyzed in the center clinical laboratory of the hospital. Hepatitis B surface antigen (HBsAg), anti-HBs, anti-HCV (GBC, Taiwan, ROC) and anti-HIV (DIA.PRO, Milano, Italy) tests were performed by enzyme-linked immunosorbent assay using the Triturus analyzer (Grifols, Parets del Valles, Spain). Each study included both positive and negative controls. For HBsAg, anti-HCV and anti-HIV parameters, samples with a cut-off value of <1 were considered negative and samples with a cut-off value of ≥1 were considered positive. For anti-HBs, samples with <10 mlU/mL were considered negative and samples with ≥10 mlU/mL were considered positive. The samples detected to be positive in the first run were tested again. For samples which were repeatedly positive for HIV, the results were confirmed by the Western blot test.

Drug Analysis

The cannabis and opioid metabolites in urine samples of drug addicts were analyzed in the center clinical laboratory of the hospital. All tests for drug detection (CEDIA, Fremont, USA) were performed by cloned enzyme donor immunoassay, using the Roche Hitachi Modular P800 analyzer (Diamond Diagnostics, Holliston, USA).

Statistical Analysis

Statistical analyses were performed by SPSS 20 (SPSS Inc, Chicago, USA). The differences in results between two groups were assessed by the chi-square test. The Kruskal-Wallis test was performed to compare hepatitis parameters between cannabis, opioid and mixed drug users. A p value of less than 0.05 was considered statistically significant.

Results

All the 276 drug addicts in the study were male and the mean age of the subjects was 28.89±10.49 years (range: 18-68 years). As shown in Table 1, 34 and 173 drug addicts who were admitted drug addiction treatment center have used only cannabis and only opioid, respectively. The number of mixed drugs users in whom both cannabis and opioid metabolites were detected in the urine samples was 69. 55.9% of cannabis users, 53.8% of opioid users and 47.8% of both cannabis and opioid users were in the 20-29 age group (Figure 1).

In drug addicts, HBsAg, anti-HBs and anti-HCV rates were 4%, 52.3% and 7.9%, respectively. Anti-HIV test was negative in all the drug addicts. HBV and HCV rates among cannabis, opioid and mixed drugs users are shown in Table 2. Whereas the rate of HBsAg among cannabis users (8.8%) was higher than opioid (4.1%) and mixed drugs users (1.4%), this difference was not statistically significant. The rate of anti-HBs among cannabis, opioid and mixed drugs users was similar (52.9%, 52.6% and 52.2%, respectively). Whereas cannabis users were anti-HCV-negative, 6.4% of opioid users and 15.9% of mixed drugs users were anti-HCV positive (p=0.009).

The highest HBsAg seropositivity was detected in the 40-49 age group while the highest anti-HCV seropositivity was determined in the 40-49 group and in those older than 50 years of age. Seropositivity of HBsAg and anti-HCV was not detected in the <20 age group (Figure 2). The frequency of anti-HBs was found to be 80.4% in the <20 age group (Figure 3).

Discussion

HBV, HCV and HIV infections are a serious problem among drug addicts and remain an important public health issue. The high HBV, HCV and HIV prevalence among drug users in various parts of the world is still at the alarming rate. Unfortunately, there is limited data about HBV, HCV and HIV prevalence in drug addicts in Turkey. In our previous study performed between September 2011 and October 2012, HBsAg, anti-HBs and anti-HCV frequency in drug addicts were found to be 2.6%, 38.3% and 9.4%, respectively. Additionally, anti-HIV positivity was not detected (1). The present study showed that the frequency rate of HBsAg, anti-HBs and anti-HCV in drug addicts was 4%, 52.3% and 7.9%, respectively. All the drug addicts in this study were HIV-negative, and this result might be related to the size of the HIV reservoir in Turkey. HBV and HCV are more stable in environmental conditions and transmitted more easily than HIV. The incidence rates for HBV and HCV infections are also typically much higher than HIV infection (11).

HBV and HCV prevalence in injecting drug users varies between regions in Europe over 40% and 40-90%, respectively. In a study carried out in Luxembourg, it was detected that the prevalence of HCV was 81.3% in injecting drug users and 19.1% in non-injecting drug users. The authors claimed that these results put Luxembourg in the upper range of the prevalence of HCV among injecting drug users in Europe (7). In the European Economic Area and the European Union, the estimated HIV prevalence among injecting drug users ranges from less than 1% to more than 60%. A significant increase in HIV infection among injecting drug users in Greece and Romania in 2011 has been reported (8). A serious increase in the number of newly diagnosed HIV infection among injecting drug users, more than 10-fold, was reported in Greece during the first seven months of 2011 (9). In the United States, HCV seroprevalence has been reported in 18%-38% of shorter duration injection drug users and 75%-90% of long-term injection drug users (10).

The high HBV, HCV and HIV prevalence in drug addicts depends on multiple factors, including the number of needle-sharing partners, the frequency of needle sharing and the social network structures among drug addicts. Additionally, the types of drugs, risky sexual behaviors, the size of the drug addicts population, and awareness of risks and prevention measures are other important factors. In a study conducted among drug users in St. Petersburg, Russia, it was shown that the type of the injected drug was associated with the prevalence and incidence of HIV infection (12). In the present study, whereas anti-HCV was not detected among cannabis users, 6.4% of opioid users and 15.9% of mixed drugs users were anti-HCV positive. This study showed that the type of drug has an effect on the rate of anti-HCV.

This study showed that the highest rate of drug use was in the 20-29 age group. Therefore, effective programs preventing HBV and HCV infection among drug addicts should target young persons. Additionally, our results were consistent with previous studies (10,13) which demonstrated that frequency of anti-HCV increases with age. This status may be related to the duration of drug use. Longer duration of drug use may lead to more sharing of needles and other equipment, resulting in a greater likelihood of transmission. On the other hand, this study showed that the rate of anti-HBs positivity was 80.4% in those younger than 20 years of age. In Turkey, hepatitis B vaccine was included in the national vaccination program in 1998. While the vaccine is given to any adult in the risk groups who desires protection, all infants are vaccinated with three doses (14,15).

Study Limitations

This study had several limitations. The tests showing acute or chronic infection could not be performed. Tests distinguishing HBV vaccine from past HBV infection could not be performed in anti-HBs positive patients. Lastly, the risk factors for transmission of HBV and HCV transmission could not be determined among the drug addicts due to the retrospective design of the study.

Conclusion

This study demonstrated that HBV and HIV prevalence among drug addicts was not higher than in the general population in Turkey. However, it may be said that HCV infection among especially opioid users and mixed drugs users was a problem. Reducing HBV, HCV and HIV transmission among drug users should be an important public health objective. Understanding of local status in HBV, HCV and HIV infections is important for developing prevention strategies.

Ethics

Ethics Committee Approval: This study was appoved by the Fırat University Ethical Committee, 08/11/26.04.2016, Informed Consent: This study was a retrospective and no informed consent was obtained.

Peer-review: Internally peer-reviewed.

Authorship Contributions

Surgical and Medical Practices: N.K., Concept: N.K., Design: N.K., Data Collection or Processing: N.K., Z.Ç., Analysis or Interpretation: N.K., Z.Ç., Literature Search: N.K., Z.Ç., Writing: N.K.

Conflict of Interest: No conflict of interest was declared by the authors.

Financial Disclosure: The authors declared that this study received no financial support.