Hepatitis C virus transmission in the prison/inmate population

Transmission

HCV is transmitted through contact with blood, blood products, or bodily fluids contaminated with the virus either directly or through an exposed object(8,11-14). The majority of HCV transmission occurs through direct and indirect exposure to infected blood(12). Risk factors associated with HCV in Canada include injection drug use (IDU)(8,11) when drug injection paraphernalia is shared(8,13,15) without adequate sterilization(16); receipt of unscreened blood or blood products(11,13) as a consequence of unproven blood screening practices before 1992(17); vertical and sexual transmission(13) either at birth or from engaging in high risk sexual practices; and parenteral exposure from tattooing, body piercing, or sharing of personal hygiene items contaminated with HCV(13).

Incidence and prevalence in correctional facilities

Worldwide estimates of the prevalence of HCV have been reported to range from between 19.2% and 84.0%^{(10,15,17-33)}.

Women are reported to have greater variability than men in the prevalence rate. Studies done in Canada, the United States and Australia, have shown that the prevalence of HCV among females ranges from 25.3% to 67.0%^{(18,28,30,34)}, as compared with 4.0% to 39.4% among men^(18,28,34). Butler et al. reported that the higher rate among females was the result of a higher concentration of females in prison for drug-related offences⁽¹⁸⁾. Overall, the prevalence of HCV in the Canadian correctional population seems less variable, ranging from 19.2% to 39.8%^{(19,24-26,29,30,32,33)}.

A number of studies have reported that the inmate population engages in risk behaviours that place them at greater risk of HCV infection than that observed in the general population. Prevalence data indicate that serving time in prison increases the likelihood that an inmate will become infected with HCV. Many offenders are confined together for long durations, which increases risk exposures⁽⁵⁾, and in the United States inmates typically have poorer health than the general population because of poverty, poor access to health care, and high rates of self-abuse outside of prison⁽³⁵⁾. The types of risk factors identified and described in this review are injection drug use, previous imprisonment, tattooing, and sexual activity.

Injection drug use and sharing drug injection paraphernalia

IDU, improper sterilization and sharing of IDU paraphernalia, and other associated behaviours are often referred to as proxy risk behaviours known to lead to HCV infection in non-infected IDUs⁽²¹⁾. The prevalence of inmates reporting injection drug use in Canadian prisons has doubled, from 12.0% in 1995 to 24.0% in 1998^(24,31). The increasing numbers of injection drug users being incarcerated and bringing their habits with them into the prison system correlates with an increase in incident cases in prison^(24,29,36).

Prospective, longitudinal and cross-sectional studies from Canada, the United States, the United Kingdom, Ireland and Denmark indicate a prison inmate odds ratio of 5.5⁽²¹⁾ for IDU and a prevalence of HCV infection ranging between 46.0% and 89.9%^{(16,19-21,28,29,36,37)}. Injection drug users, especially males⁽³⁸⁾, have a much higher risk of becoming infected with HCV, and the risk grows exponentially with each year that they inject drugs^{(15,17,18,23)}. Multivariate analysis shows that injection drug users who inject both inside and outside of prison have a higher prevalence of HCV infection than those who inject only inside or outside prison^(24,29). One explanation for this is that inmates in prison inject less overall but share needles more frequently⁽³⁹⁾, since drugs are readily available and injecting apparatus is scarce in the prison system⁽²⁷⁾. These circumstances favour repeated use of a limited number of syringes by many prisoners⁽²⁷⁾.

Malliori et al. conducted a cross-sectional study of 544 drug users imprisoned for drug-related offences and found that 39% of IDUs who were aware of their own or a fellow inmate?s positive hepatitis infection status continued to share syringes with fellow inmates; 40% had injected drugs in the previous 30 days(21). Thus, non-infected injection drug users who continue to engage in high-risk behaviours are unknowingly being infected with HCV as a result of fellow inmates not disclosing their hepatitis status.

Drug sniffing and/or snorting is cited as a major risk factor for the acquisition of HCV infection. Cocaine and heroin can cause bleeding in the nose as a result of nasal irritation and trauma to the nasal cavity⁽³⁷⁾. The blood from the nose can remain on the surface of sniffing and snorting equipment, such as straws or rolled money, which can be passed on to the next person. Individuals who sniff or snort heroin and cocaine at the same time are more likely to be infected with HCV because of the damaging effects of the combination on the delicate nasal mucosal lining⁽³⁷⁾. Ironically, many individuals sniff or snort drugs in an attempt to avoid acquiring HCV and other infectious viruses through injection. Regardless of the method used, inmates who share equipment contaminated with HCV place themselves and others at risk of HCV infection.

Previous imprisonment

Previous imprisonment has been reported as a risk factor for HCV infection^{(17,18,21,23,38)}. The odds of HCV infection increase with increasing frequency of incarceration, increased duration of each imprisonment, and an increase in the time between release and re-incarceration^{(17,18,21,23,38)}. In one study, individuals who were incarcerated more than five times were significantly more likely to become HCV positive (odds ratio of 21.7)⁽²¹⁾. The chance of HCV positivity gradually increases with each additional month spent in prison⁽³⁸⁾.

Inmates re-incarcerated < 5 years after their release show an odds ratio of 23 and a positivity value of 76.7% for HCV infection⁽¹⁷⁾. This increased risk is primarily the function of inmates continuing to engage in high-risk injecting practices, such as sharing IDU paraphernalia with a large and homogeneous cohort of inmates.

Tattooing

Various studies have reported an association between tattooing and transmission of HCV in the inmate population whereas others have not⁽³⁵⁾. In voluntary, cross-sectional seroprevalence studies of over 3000 prison inmates from Canada, the United States and Australia, 18.0% to 93.2% of inmates with tattoos were HCV positive^{(15,18,19,24,31)}. In addition, the odds of being infected with HCV increase with multiple tattoos as compared with only single tattoos. One study found that inmates with a single tattoo had an odds ratio of 5.4 with an 11.6% HCV positivity rate, and among those with multiple tattoos the odds ratio was 9.2 with a 16.7% positivity rate⁽⁴⁰⁾.

For the most part correctional facilities lack appropriate protocols for the safe administration of tattoos such as proper use of equipment, sterilization facilities^(41,42), and licensed tattooists (or trained prisoners)⁽³⁵⁾. Also, IDUs have a high number of tattoos, which at times are used to cover injection drug use track marks⁽³⁵⁾. The motivation for tattooing in the prison system is commonly reported by inmates to be boredom⁽⁴³⁾. These unsafe and unhygienic practices make tattooing a proxy risk behaviour for the sharing of tattoo devices and subsequent HCV infection.