Gordon SC, et al. - Because hepatitis C virus (HCV) genotype impacts disease course and response to treatment, researchers investigated how geography and patient characteristics influence HCV genotype and determined subtype distribution in a large sample of patients under routine clinical care. Upon analysis of data from the Chronic Hepatitis Cohort Study of over 8,000 HCV-infected patients from 4 large US health systems, researchers noted a significant variation in genotype distribution by geographic and demographic factors. In age-adjusted analyses, genotype (GT)1 was significantly more prevalent among African American patients (85%) than other racial categories; this was largely driven by a markedly higher proportion of GT1 subtype b (∼34%) than in Asian/other (24%) and white (21%) patients. As birth decade progressed, GT3 represented an increasing proportion of infections; it increased from 4% in patients born before 1946 to 18% of those born after 1976. Within the cohort of “living/uncured” patients, GT3 patients displayed high elevated alanine aminotransferase (> 2 times the upper limit of normal) levels, whereas the combined group of GT4&6 patients had Fibrosis-4 Index scores indicative of cirrhosis. Observations thereby suggested a more variable distribution of HCV genotypes and subtypes in the United States than indicated by previous national-level estimates and single-center studies.