摘要：Objectives. We investigated a cluster of new hepatitis C cases in rural New York among a cohort of young people who inject drugs (PWID) and misuse prescription opioid analgesics (POA). Methods. We recruited a purposive sample of PWID from Cortland County for an in-person survey and HCV rapid antibody test (March–July 2012). We examined sociodemographics, drugs currently injected, and lifetime and recent injection behaviors to ascertain associations with HCV antibody (anti-HCV) positivity. Results. Of 123 PWID, 76 (61.8%) were younger than 30 years, and 100 (81.3%) received HCV rapid testing. Of those tested, 34 (34.0%) were positive. Participants who reported injecting POA in the past 12 months were 5 times more likely to be anti-HCV positive than those who injected drugs other than POA, and participants who reported sharing injection equipment in the past 12 months were roughly 4 times more likely to be anti-HCV positive than those who did not. Conclusions. Our analysis suggests people injecting POA may be at higher risk for HCV infection than people who inject heroin or other drugs but not POA. Hepatitis C virus is the most common blood-borne infection in the United States, with an estimated 4.1 million people HCV antibody (anti-HCV) positive and 3.2 million living with chronic infection. 1 Infection with hepatitis C is the leading cause of chronic liver disease, and mortality rates associated with HCV infection now surpass those associated with HIV disease. 2 HCV infection prevalence has reached epidemic proportions and is endemic among people who inject drugs (PWID). 3 HCV is transmitted primarily by percutaneous exposure to contaminated blood, with injection drug use being the most common risk factor and the leading cause of incidence in the United States. 4 Estimated seroprevalence among PWID ranges from 30% to 70%, depending on frequency and duration of use, 3,5 and HCV incidence among PWID is high (≤ 40 per 100 person-years), especially among younger PWID (aged 18–29 years). 6 Anti-HCV prevalence among the population of young PWID has historically been lower than among older PWID, between 10% and 36%. 7,8 Over the past decade, however, state-level and national reporting staff have identified the largest increase in newly reported HCV cases to be among adolescents and young adults (aged 15–29 years). 9 This increase is occurring predominantly in rural and suburban regions of the country, with clusters reported in Massachusetts, 10 Pennsylvania, 10 Wisconsin, 11 Washington, 12 and Upstate New York, 13 and similar findings have recently been reported in the Appalachia region. 14,15 Taken together, these reports suggest a significant change in the demographics of newly infected PWID. In contrast to the late 1990s, when national surveys identified anti-HCV cases among PWID as highest among men, African Americans, urban residents, and people aged 40 to 49 years, 1 the more recent, cluster-associated cases are more likely to be young adults (aged 20–29 years), most of whom are White and reside in rural and suburban areas. In addition to the change in both age distribution and geographic location, another distinguishing feature of these newly reported cases is the relatively high proportion of adolescents and young adults who report the nonmedical use of prescription opioid analgesics (POA) before initiating injecting. 16,17 Correspondingly, an increase in the number of young adults from rural areas who are injecting POA has also been reported. In a study of PWID from rural Appalachia, for example, two thirds of young PWID report injecting POA, 18 and these people are young, White, and aged 18 to 29 years and report injecting drugs that differ significantly from those injected by their urban counterparts, most of whom inject heroin and cocaine or crack. 19 Similar reports of POA injection among this age cohort have been reported in Massachusetts, Wisconsin, and Tennessee. 10,20,21 In all, these recent reports and data portend a nascent intersection between the United States’ prescription drug epidemic 22 and what has been described as an emerging HCV epidemic. 23 Consistent with this developing trend was a recent cluster of newly reported HCV cases among a cohort of young PWID in Cortland County, New York (Cortland County Health Department, oral communication, 2011). Cortland is a rural county in central New York just south of Syracuse, with an estimated population of 49 000. In 2011, the Cortland County Health Department reported 18 new HCV cases among people aged younger than 35 years (New York State Department of Health, Bureau of Communicable Disease Control, unpublished statistics, 2012), whereas only 1 case was reported in this age group in 2010 (New York State Department of Health, Bureau of Communicable Disease Control, unpublished statistics, 2012). In response, the New York State Regional Health Department, in conjunction with the Cortland County Health Department, launched an investigation into the 18 new cases and discovered, through targeted interviews, a correlation among age, injection drug use, POA misuse, and anti-HCV positivity. The pressing need to further comprehend the behavioral risk factors associated with this increase—beyond the original 18 cases—was the motivation for conducting this follow-up survey investigation.
