Supplementary Material for: No Difference in Prevalence of Transmitted Drug Resistance between Injection Drug Users and Non-Injection Drug Users: A Cross-Sectional Study among Antiretroviral Treatment-Naïve HIV Patients

Objectives: The epidemiological evidence is inconsistent about whether HIV-positive injection drug users (IDUs) are at higher risk of developing antiretroviral resistance than any other HIV-positive populations. This study aims to investigate and compare transmitted drug resistance (TDR) between IDUs and non-IDUs in Lingshan County, an HIV-hit region in Guangxi, China, where IDU and heterosexual transmission were the two dominant transmission routes and roughly equally contributed to the local HIV transmission. Methods: A cross-sectional study was conducted among newly diagnosed and antiretroviral-treatment (ART)-naïve HIV-1 patients from Lingshan County. The pol gene of HIV-1 from the individuals was sequenced followed by genotyping and TDR analysis. Results: Two dominant transmission routes, heterosexual contact and IDU, accounted for 49.2 and 45.9% of 183 HIV-1 infection cases, respectively. Three genotypes, including CRF08_BC (70.6%), CRF01_AE (24.4%), and CRF07_BC (5.0%), and three unique recombinant forms (1.6%), were identified. There was a significant difference in genotype distribution among the different transmission routes (F = 21.814, p < 0.001). The overall TDR prevalence was 5.5%. There were no significant differences in TDR prevalence among the different transmission routes (F = 1.420, p = 0.439). Conclusions: Injection drug use has little impact on TDR prevalence compared with other routes of transmission.