Hepatitis C Virus Subtypes Novel 6g-Related Subtype and 6w Could Be Indigenous in Southern Taiwan with Characteristic Geographic Distribution

• Main Authors: Hung-Da Tung, Pei-Lun Lee, Jyh-Jou Chen, Hsing-Tao Kuo, Ming-Jen Sheu, Chun-Ta Cheng, Tang-Wei Chuang, Hsu-Ju Kao, Yu-Hsun Wu, Mai-Gio Pang, Cheng-Heng Lin, Chia-Yi Hou, Hsin-Hua Tsai, Li-Ching Wu, Chuan Lee
• Format: Article
• Language: English
• Published: MDPI AG 2021-07-01
• Series: Viruses
• Subjects: hepatitis C virus; genotype; injection drug user; phylogenetic analysis
• Online Access: https://www.mdpi.com/1999-4915/13/7/1316

Hepatitis C virus (HCV) genotype (GT) 6 is the most genetically diverse GT and mainly distributed in Southeast Asia and south China but not Taiwan. Earlier studies showed the major HCV GTs in Taiwan were GT 1b and 2 with very rare GT 6 except in injection drug users (IDUs), and subtype 6a is the main GT 6 subtype among IDUs. Recently, we reported a much higher prevalence (18.3%) of GT 6 in Tainan City, southern Taiwan. This study was designed to clarify the subtypes of GT 6 in this endemic area. A total of 3022 (1343 men and 1679 women) HCV viremic patients were enrolled. Subtypes of GT 6 were determined by sequencing of core/E1 and nonstructural protein 5B in 322 of 518 GT 6 patients. The overall GT 6 prevalence rate was 17.1% (518/3022), with higher prevalence districts (>25%) located in northern Tainan. A novel 6g-related subtype is the most prevalent subtype (81.0%), followed by 6w (10.8%), 6a (7.5%), and 6n (0.7%). The high GT 6 prevalence in Tainan was mainly due to a novel 6g-related subtype and 6w. These two subtypes could be indigenous in Tainan with characteristic geographic distribution.