Grantz Kyra H, Cepeda Javier, Astemborski Jacqueline, Kirk Gregory D, Thomas David L, Mehta Shruti H, Wesolowski Amy
Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA.
Division of Infectious Diseases, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
J Viral Hepat. 2025 Apr;32(4):e13999. doi: 10.1111/jvh.13999. Epub 2024 Sep 5.
Hepatitis C virus (HCV) causes substantial morbidity and mortality, particularly among people who inject drugs (PWID). While elimination of HCV as a public health problem may be possible through treatment-as-prevention, reinfection can attenuate the impact of treatment scale-up. There is a need to better understand the distribution and temporal trends in HCV infection risk, including among HCV-seropositive individuals who will be eligible for treatment and at risk for subsequent reinfection. In this analysis of 840 seronegative and seropositive PWID in Baltimore, MD USA, we used random forest methods to develop a composite risk score of HCV infection from sociodemographic and behavioural risk factors. We characterised the individual heterogeneity and temporal trajectories in this composite risk score using latent class methods and compared that index with a simpler, conventional measure, injection drug use frequency. We found that 15% of the population remained at high risk of HCV infection and reinfection by the composite metric for at least 10 years from study enrolment, while others experienced transient periods of moderate and low risk. Membership in this high-risk group was strongly associated with higher rates of HCV seroconversion and post-treatment viraemia, as a proxy of reinfection risk. Injection frequency alone was a poor measure of risk, evidenced by the weak associations between injection frequency classes and HCV-associated outcomes. Together, our results indicate HCV infection risk is not equally distributed among PWID nor well captured by injection frequency alone. HCV elimination programmes should consider targeted, multifaceted interventions among high-risk individuals to reduce reinfection.
丙型肝炎病毒（HCV）会导致严重的发病和死亡，尤其是在注射毒品者（PWID）中。虽然通过治疗即预防可能消除作为公共卫生问题的HCV，但再感染会削弱扩大治疗规模的影响。有必要更好地了解HCV感染风险的分布和时间趋势，包括在符合治疗条件且有后续再感染风险的HCV血清阳性个体中。在美国马里兰州巴尔的摩对840名血清阴性和血清阳性的注射毒品者进行的这项分析中，我们使用随机森林方法从社会人口统计学和行为风险因素中得出HCV感染的综合风险评分。我们使用潜在类别方法对该综合风险评分中的个体异质性和时间轨迹进行了特征描述，并将该指数与一种更简单的传统指标——注射毒品使用频率进行了比较。我们发现，从研究入组起，15%的人群至少10年一直处于通过综合指标衡量的HCV感染和再感染的高风险中，而其他人经历了中度和低度风险的短暂时期。这个高风险组的成员与HCV血清转化和治疗后病毒血症的较高发生率密切相关，后者可作为再感染风险的指标。仅注射频率是一个较差的风险衡量指标，注射频率类别与HCV相关结果之间的弱关联就证明了这一点。总之，我们的结果表明，HCV感染风险在注射毒品者中分布不均，仅靠注射频率也无法很好地体现。HCV消除计划应考虑对高风险个体采取有针对性的多方面干预措施，以减少再感染。
