Overrepresentation of injection drug use route of infection among human immunodeficiency virus long-term nonprogressors: A nationwide, retrospective cohort study in China, 1989–2016

Abstract

Background. Why some persons living with human immunodeficiency virus (HIV) (PLWH) progress quickly and others remain “healthy” for a decade or more without treatment remains a fundamental question of HIV pathology. We aimed to assess the epidemiological characteristics of HIV long-term nonprogressors (LTNPs) based on a cohort of PLWH in China observed between 1989 and 2016. Methods. We conducted a nationwide, retrospective cohort study among Chinese PLWH with HIV diagnosed before 1 January 2008. Records were extracted from China’s national HIV/AIDS database on 30 June 2016. LTNPs were defined as those with AIDS-free, antiretroviral therapy–naive survival, with CD4 cell counts consistently ≥500/μL for ≥8 years after diagnosis. Prevalence was calculated, characteristics were described, and determinants were assessed by means of logistic regression. Potential sources of bias were also investigated. Results. Our cohort included 89 201 participants, of whom 1749 (2.0%) were categorized as LTNPs. The injection drug use (IDU) route of infection was reported by 70.7% of LTNPs, compared with only 37.1% of non-LTNPs. The odds of LTNP status were greater among those infected via IDU (adjusted odds ratio [95% confidence interval], 2.28 [1.94–2.68]) and with HIV diagnosed in settings with large populations of persons who inject drugs (1.75 [1.51–2.02] for detention centers, 1.61 [1.39–1.87] for Yunnan, 1.94 [1.62–2.31] for Guangdong, and 2.90 [2.09–4.02] for Xinjiang). Conclusions. Overrepresentation of the IDU route of infection among LTNPs is a surprising finding worthy of further study, and this newly defined cohort may be particularly well suited to exploration of the molecular biological mechanisms underlying HIV long-term nonprogression.