Prevalence of Hepatitis C virus in intravenous drug users

INTRODUCTION

Drug addiction has become a global epidemic, spreading at an alarming rate. According to the United Nations Office on Drugs and Crime World Drug Report 2025, 316 million people used a drug (excluding alcohol and tobacco) in 2023, accounting for 6% of the global population aged 15–64, compared to 5.2% in 2013. Cannabis remains the most widely used drug (244 million users), followed by opioids (61 million), amphetamines (30.7 million), cocaine (25 million), and ecstasy (21 million).^[1] The situation in India is equally concerning, as 95% of the world’s opium is produced in countries surrounding India.^[1] Due to easy access, India has been significantly affected by the opium epidemic. Approximately 2 million people in our nation use opiates. According to the 2019 National Survey on the Extent and Pattern of Substance Use in India, there are 8.5 Latin America and the Caribbean persons who inject drugs (PWIDs) in India.^[2] The International Narcotics Control Board found that heroin is becoming the drug of choice for opium addicts in India, primarily used intravenously, putting them at risk for blood-borne infections. Other high-risk behaviors of PWIDs include sharing needles and syringes, as well as engaging in perilous sexual behavior.^[3] Injection drug use (IDU) is quickly becoming the leading cause of new Hepatitis C virus (HCV) infections in many developed and developing nations. Among Indian states, Mizoram, Punjab, and Manipur are the most affected. Punjab ranks second among India’s top ten states with the highest proportion of PWID.^[4] However, this may only represent the tip of the iceberg, as estimates suggest that <15% of individuals with chronic HCV infection are aware of their diagnosis and struggle to identify themselves due to the associated stigma.^[5] Approximately 75–85% of infected individuals have chronic HCV infections. In India, the prevalence of chronic HCV infection ranges from 0.9% to 1.9%; however, in Punjab, a northern state, the prevalence is 3.6%.^[4]

MATERIAL AND METHODS

This prospective observational study was conducted over a period of 6 months, from September 2023 to February 2024, in the Serology section of the Microbiology laboratory within the Microbiology department, Adesh Institute of Medical Sciences and Research (AIMSR), Bathinda, after taking due ethical clearance by the AIMSR Research and the Ethics Committee for Biomedical and Health Research at Adesh University, Bathinda.

The sample size for the study was determined using the formula:

n = (Z² × P × (1 - P)) / L²

where Z represents the standard normal deviate at a 95% confidence level (1.96), P denotes the estimated prevalence of disease, and L indicates the allowable error. A 10% absolute precision and 95% confidence level were considered for the calculation. The prevalence of HCV infection among intravenous (IV) drug users was assumed to be 32% (P = 0.32), based on the findings of Burt et al. (2007), who reported a 32% prevalence of anti-HCV antibodies among young injection drug users (aged 18–30 years) in Seattle during 2004, following a decline from 68% in 1994.^[6]

Substituting these values into the formula:

n = (1.96)² × 0.32 × (1 - 0.32) / (0.10)² = 83.6

Hence, the minimum required sample size was calculated as 84, which was rounded up to the next whole number. To account for potential non-response or data loss, a few additional participants were included.

Clinical data and patient histories were collected from patient files, test requisition forms, and relatives. Comorbidities were confirmed either from clinical records or by diagnostic tests performed within the hospital. Human Immunodeficiency Virus (HIV) and Hepatitis B Virus (HBV) were detected using an Enzyme-Linked Immunosorbent Assay (ELISA), while HCV infection was considered the primary outcome of the study. Other infections were recorded and analyzed as co-infections.

Inclusion criteria: Patients aged above 16 years with a confirmed history of IV drug use.

Exclusion criteria: Patients with a history of only oral or smoked drug use.

Samples with co-infections such as HIV, HBV, tuberculosis (TB), and diabetes mellitus (DM) were not excluded. These comorbidities were documented and analyzed descriptively to assess their relationship with HCV infection. To minimize confounding bias, stratified analysis was performed to evaluate the association of HCV with individual comorbidities, ensuring a more accurate interpretation of results.

The study protocol, including the consent procedure, was reviewed and approved by the Institutional Ethics Committee for Biomedical and Health Research, Adesh University, Bathinda.

Indirect ELISA was performed on serum samples separated from the collected whole blood. All reagents and materials were equilibrated to room temperature (20–25°C) prior to testing. A commercial third-generation HCV ELISA kit (HCV Microlisa 3rd Generation, containing core, E1, E2, NS3, NS4, and NS5 antigens; J. Mitra & Co. Pvt. Ltd., New Delhi, India) was used for the detection of anti-HCV antibodies. The absorbance (optical density) of each processed serum sample was measured at 450 nm using an ELISA microplate reader (Robonik Absorbance Microplate Reader). The cutoff value for interpretation of results was determined according to the HCV Microlisa 3rd Generation ELISA Test Instruction Manual (J. Mitra & Co. Pvt. Ltd., 2021). The procedure is summarized in the flowchart presented in Figure 1.

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Figure 1:

Flowchart showing the processing of samples.

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Quality control measures included: Running both positive and negative controls in each batch, maintaining internal quality checks as per manufacturer instructions, and calibrating the ELISA reader weekly. HIV and HBV were also detected using commercial ELISA kits (J. Mitra and Co.), and HCV was treated as a primary infection, while co-infections were recorded separately. The overall testing workflow and infection categorization process are shown in Figure 2.

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Figure 2:

Enzyme-linked immunosorbent assay microtiter plate displaying NC as the negative control, PC as the positive control run in triplicate and test samples T1 to T23. Color development occurs after the addition of the stop solution. (1) NC <0.150 was considered valid, (2) PC more than 0.500 was considered valid, (3) if neither was true, the run was considered invalid, (4) cutoff absorbance = PCx × 0.23, (5) for example, if PCx = 1.87, the cutoff value would be 1.87 × 0.23 = 0.430, (6) test absorbance value <0.430 is considered negative, and (7) test absorbance value of ≥0.430 is considered positive.

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False Positive:

• Incorrect interpretation and calculation of results

• A highly reactive sample was compromised due to pipette tip contamination

• Substrate contamination

• Insufficient washing or aspiration during the washing process.

False Negative:

• Insufficient addition of substrate/conjugate solution.

• Deterioration of the enzyme conjugate.

• Presence of white particles in the working substrate solution.

• Incorrectly low incubator temperature, timing, or pipetting.

RESULTS

This prospective observational study was conducted in the serology section of the Central Laboratory, Microbiology Department, AIMSR, Bathinda, Punjab. A total of 90 blood samples were collected from patients receiving IV drugs and hospitalized in the psychiatric unit. The most common presenting complaint among injecting drug users (IDUs) was loss of appetite (33.34%), followed by weight loss (28.89%) and vomiting (25.56%). Anxiety and depression were reported in 24.45% and 22.23% of cases, respectively. Approximately 13.34% of patients presented with a pseudoaneurysm, while 3.34% had a documented history of schizophrenia. This clinical profile highlights the combined physical and psychological burden among IDUs, many of which overlap with complications associated with HCV infection, emphasizing the need for timely diagnosis in hospital-based settings.

Out of the 90 samples, 39 (43.33%) were positive and 51 (56.66%) were negative for HCV ELISA. Among the 39 (43.33%) HCV-positive samples, 38 (97.43%) were male, and only one was female. The highest positivity rate of HCV infection was found among patients in the 26–35 years age group, while the lowest rate was observed in those aged between 46 and 55 years. Observation of patients by locality revealed that the majority of HCV-positive individuals (71.80%) resided in rural areas. Most patients fell under the work profile of the educated sector, followed by laborers. Most of the HCV-positive patients belonged to the laborer category at 35.90% followed by agriculture at 30.77%. Associated comorbidities in HCV-positive patients included TB (61.53%), diabetes mellitus (48.71%), HIV co-infection (12.82%), Hepatitis B co-infection (7.69%), and bacterial endocarditis (2.56%). The most common IV drug used by HCV-positive patients was heroin (97.44%), followed by cannabis. The prevalence of HCV was considerably higher among those who had previously injected drugs for an extended period; among recent initiates, the prevalence was low at 7.69% for injecting for <3 years and higher at 56.41% for injecting for more than 8 years. This study focused on finding the prevalence of HCV in IDUs.

IDUs presented with chief complaints of loss of appetite (33.34%), followed by weight loss (28.89%) and vomiting (25.56%). Anxiety and depression accounted for 24.45% and 22.23%, respectively. In addition, 13.34% of patients presented with pseudoaneurysm, while 3.34% had a history of schizophrenia, as illustrated in Figure 3.

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Figure 3:

Distribution of presenting complaints among intravenous drug users (n = 90).

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Out of 90 samples, 39 (43.34%) showed a positive result for HCV ELISA, while 51 (56.66%) displayed a negative result. Our study found the prevalence of HCV to be 43.34%, as illustrated in Figure 4.

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Figure 4:

Total samples processed and positivity rate.

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A total of 39 patients who tested positive for HCV were categorized by gender, with 38 (97.44%) identifying as male and 1 (2.56%) as female, as illustrated in Figure 5.

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Figure 5:

Gender-wise distribution of Hepatitis C virus-positive patients (n = 39).

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The age-wise distribution of positive HCV patients showed that the maximum number of patients belonged to the 26–35 years age group, followed by the 36–45 years age group, while the minimum positivity rate was observed in the 46–55 years age group. These results are shown in Table 1.

The locality-wise distribution of positive HCV patients showed that the majority of them resided in rural areas, accounting for 71.80%, as illustrated in Figure 6.

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Figure 6:

Locality-wise distribution of Hepatitis C virus-positive patients (n = 39).

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Most of the HCV-positive patients were laborers, accounting for 35.90%, followed by those in agriculture at 30.77%, as illustrated in Figure 7.

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Figure 7:

Distribution of Hepatitis C virus-positive patients based on work profile (n = 39).

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Associated comorbidities in HCV-positive patients included TB (61.53%), diabetes mellitus (48.71%), HIV co-infection (12.82%), and Hepatitis B co-infection (7.69%), while bacterial endocarditis accounts for 2.56%, as illustrated in Figure 8.

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Figure 8:

Associated comorbidities among Hepatitis C virus-positive patients (n = 39).

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The most common IV drug used by HCV-positive patients was heroin at 97.44%, followed by cannabis. The corresponding data are presented in Table 2.

A maximum HCV positivity rate of 56.41% was observed in patients who had been chronic drug injectors (≥8 years). The distribution pattern of HCV-positive patients in relation to duration of drug use (n = 39) is shown in Table 3.

DISCUSSION

In this prospective observational study, a total of 90 suspected IDUs were included. We found that the IDUs presented with various types of symptoms and complaints. The majority of individuals had chief complaints of loss of appetite, weight loss, vomiting, anxiety, and depression; the least common symptoms were pseudoaneurysm at the injection site and schizophrenia [Figure 3]. This could be because substance abuse and mental health issues such as depression and anxiety frequently coexists. Depression itself can impact appetite, and many antidepressants are linked to a decrease in weight as a side effect. In addition, many brain stimulants can suppress hunger.

We found that the prevalence of HCV among IDUs was 43.34% [Figure 4], which is higher than the 27.87% prevalence reported by Shivaprakash et al. (2023) in Karnataka, where 109 out of 391 participants were HCV-positive,^[7] whereas a similar prevalence of 38.12% reported by Mahajan et al. (2016) in a study conducted in Amritsar, Punjab.^[8] The higher prevalence of HCV in IDUs may stem from the usage of shared contaminated needles and multiple injection exposures.

According to various studies, HCV prevalence is higher in males than in females. This may be due to men having easier access to drugs due to peer pressure and cultural norms, as well as stress, which increases the likelihood of drug use among men. The gender distribution of the total 39 positive patients in our study showed that 97.40% were male and 2.60% were female [Figure 5], based on the results of Mahajan et al. (2016) who also stated that males (98.6%) have a higher prevalence of HCV.^[8]

In our study, the prevalence of HCV was found to be higher, at 17 (43.58%), in the 26–35 age group [Table 1], while the lowest prevalence was observed in the 16–25 age category followed by the 46–55 age category. This study also showed a higher incidence within the specified mean age of 33.3 years. These findings align with Verma et al. (2020), who found that the majority of drug users were in the 20–29 years age range (47.7%), while the highest HCV prevalence was seen in the 30–39 years age range (31.8%).^[9] This may be due to men in the age group of 25–36 years often engaging in higher rates of IV drug use, which significantly increases the risk factor for HCV transmission. Exposure to contaminated blood may result from sharing needles or other drug paraphernalia. Adults may be more prone to experimenting with drugs, which raises their risk of HCV infection, including injectable drug use. Friends or acquaintances who participate in risky behaviors can influence adults. In addition, stress in relationships and work contributes to a higher prevalence rate.

In the present study, we found that the prevalence of HCV is higher in rural areas than in urban areas. Out of the 39 HCV-positive samples, 11 (or 28.20%) were from the metropolitan area, and 28 (or 71.80%) were from the rural area [Figure 6]. This finding aligns with the results of Ullah and Kaur (2019), which showed that 70% of drug abusers were from a rural background.^[10] Several factors may contribute to this scenario, including the fact that rural areas often have fewer healthcare resources and limited access to harm reduction programs, such as needle exchange services, which increases the likelihood of needle-sharing. Economic hardships and social isolation in rural communities can also lead to higher rates of drug use and hinder access to addiction treatment. In addition, the stigma surrounding drug use in rural areas may prevent individuals from seeking help, resulting in higher rates of undiagnosed and untreated HCV infections. Improving healthcare access and implementing harm reduction strategies are crucial in addressing these disparities.

In our study, IDUs came from various backgrounds. Based on their work profiles, we identified certain patient types with the highest numbers: 14 (35.90%) and 12 (30.77%) were in the laborer work profile followed by agriculture [Figure 7]. Laborers and agricultural workers might be more prone to IV drug use due to several factors, including high levels of physical stress and injury, which can drive individuals to seek pain relief or escape from hardship. The demanding nature of their work often leads to poor access to healthcare, making self-medication more common. In addition, economic instability and social isolation can exacerbate mental health issues, prompting some to turn to drugs as a coping mechanism. Initiating and maintaining drug use behaviors can be significantly influenced by peer pressure and social influences.

In our study, we observed a spectrum of comorbid infections among patients, including TB (45, 61.53%), diabetes mellitus (48.71%), HIV co-infection (12.82%), Hepatitis B co-infection (7.69%), and bacterial endocarditis (2.56%) [Figure 8]. Similar studies have shown that HCV has associated co-morbidities such as TB, diabetes, and blood-borne diseases. Frequent use of IV drugs carries a higher risk of blood-borne diseases and related conditions such as HIV, Hepatitis B, and infective endocarditis. One study conducted by Wu et al. (2015) indicated that TB was a critical comorbid illness in patients. This is in line with our study, where we found that TB prevalence was higher in HCV-positive patients.^[11] Earlier research indicates that HIV impairs the body’s ability to combat Hepatitis C, suggesting that when HIV and HCV coexist, liver damage from Hepatitis C may occur sooner.^[12] Therefore, if hepatitis C and HIV coexist, cirrhosis and liver diseases may develop at an earlier age. In addition, some research has shown that acute Hepatitis caused by the co-infection of HBV and HCV will eventually lead to chronic Hepatitis due to HCV.^[13] Some studies have indicated that the incidence of diabetes mellitus increases with HCV infection compared to non-infected individuals.^[14,15]

Various studies have suggested that IDUs are more likely to use heroin than other drugs. In the present study, all HCV-positive patients, except one, used heroin [Table 2], which aligns with findings from a survey conducted by Chowhan and Sakral (2019).^[3] Heroin remains the most commonly injected drug due to its easy availability and relatively lower cost compared to other narcotics. Its wide availability in nature and its relatively low cost make it easier to utilize. Heroin gives an immediate effect when injected. People frequently use heroin to cope with stress, trauma, or physical or psychological suffering.

In the present study, we found that the prevalence of HCV in patients taking drugs for <3 years was (7.69%), 3–5 years was (12.82%), 5–8 years was (23.08%), and ≥8 years was (56.41%) [Table 3], which is in line with earlier studies, which stated that HCV prevalence was significantly higher among those who had a history of longer duration of injecting drugs. Long-term drug usage can impair immunity and make a person more vulnerable to illnesses.^[16-18]

CONCLUSION

Our study sheds light on the prevalence, distribution, socio-demographic factors, and comorbidities associated that our study demonstrates that HCV prevalence among hospitalized IDUs was 43.34%, with the highest burden in males aged 26–35 years. Chronic drug use (>8 years) and heroin injection were strongly associated with infection. Comorbidities such as TB, HIV, HBV, and diabetes were common and significantly complicated the clinical profile of patients.

Key challenges include high rates of co-infections, poor awareness, and delayed diagnosis. Strengthening early screening, harm-reduction programs (needle exchange and opioid substitution therapy), and integration of HCV testing with TB/HIV services are potential solutions to reduce transmission and improve outcomes in this high-risk population.