Lack of association between acquisition of TT virus and risk behavior for HIV and HCV infection in Vietnam

Abstract

Background: The search for the cause of chronic; hepatitis among individuals with non-A to G hepatitis has led to the discovery of a post-transfusion hepatitis-related DNA virus, designated TT virus (TTV), which, based on viral sequences, belongs to a new virus family. The principal modes of infection with TTV are poorly understood, and its role in human immunodeficiency virus type 1 (HIV-1) infection is unclear. Objective: To determine if injection drug use (IDU) and high-risk heterosexual activity (HRHA), principal modes of acquiring HIV-1 infection, place individuals at greater risk of acquiring TTV Methods: The authors analyzed DNA, extracted from sera or filter paper-blotted whole blood, obtained during August 1997 and June 1998 from 324 Vietnamese (148 male; 176 female), for TTV sequences by hot-start, heminested polymerase chain reaction. Results: Prevalence of TTV viremia was similar among individuals engaging in IDU or HRHA (23.4% vs. 20.2%; P > 0.5), with no age- or gender-specific differences. No association was found between TTV viremia and co-infection with HIV-1 or hepatitis C virus (HCV). Phylogenetic analysis of 30 TTV sequences revealed two distinct genotypes and four subtypes that did not segregate according to gender, HIV-1 and HCV risk behaviors, or geographic residence. Conclusions: Among HIV-1- or HCV-infected Vietnamese, who presumably acquired their infection by either the parenteral or nonparenteral route, the data indicate no clear association between acquisition of TTV infection and risk behavior for HIV-1 or HCV infection, suggesting that the usual route of TTV transmission in Vietnam is other than parenteral or sexual.