Human pegivirus (HPgV) is a positive sense, single-stranded RNA virus and a member of the Flaviviridae family [1,2]. HPgV infection, also known as GB virus C or hepatitis G virus, is transmitted vertically (maternal-fetal transmission) or horizontally (sexual exposure or exposure through contaminated blood products) [3] and is associated with an increased risk of leukemia/lymphoma [4,5,6]. The prevalence of HPgV in the general population ranges from 1-4% in high-income countries and is as high as 20% in low- and middle-income countries. HPgV/HIV-1 (human immunodeficiency virus type 1) co-infection is common, especially among at-risk individuals, including those with other chronic viral infections (e.g., hepatitis C virus (HCV)). Several studies suggest that 20-45% of people infected with HIV-1 are co-infected with HPgV [7,8]. HPgV infection may exert beneficial effects in HIV-1 infection [9]; disease severity among HCV-infected individuals is unaffected by HPgV co-infection [10,11]. There are no established antiviral therapies for HPgV although studies have suggested HPgV responses to antivirals used for HCV treatment are variable [12,13].

We investigated the prevalence of HPgV in an established cohort of subjects with HIV/HCV co-infection and DAA regimen effects on HPgV viremia. Our data suggested that HPgV prevalence is high in co-infected patients and that HPgV can be supressed by DAA.