GENOTYPE DISTRIBUTION OF HCV IN GALVESTON, TEXAS

Zhen Yang M.S.¹, C. Clement M.D.¹, and J. Dong, M.D., Ph.D.¹

¹Department of Pathology, UTMB

Background: Six genotypes of HCV, each comprising multiple subtypes, have been identified worldwide. Substantial regional differences appear to exist in the distribution of HCV genotypes and subtypes. HCV 1a and 1b are the most common in the United States. However, there is limited information about the distribution of HCV genotypes/subtypes in distinct geographic regions of the United States. Objective: The purpose of this study was to evaluate the distribution of HCV genotypes/subtypes in Galveston, Texas, and to correlate with patient demographic characteristics. Methods: HCV genotyping results performed in the UTMB Molecular Diagnostics Laboratory between September 2007 to February 2009 were evaluated. Genotyping method was INNO-LiPA HCV 2.0 (Siemens). Results: Of the 1342 genotype tests performed, the great majority (63.26%, 849/1342) were subtype 1a. Subtypes 1b, 2b, and 3a were identified in 144 (10.73%), 110 (8.20%) and 164 (12.22%) patients, respectively. Subtypes 3b, 4, and 6 were each positive in 1 (0.07%), 7 (0.52%), and 2 (0.15%) of the patients. There were rare cases of mixed infection including 9 (0.67%) of 2a/2c, 6 (0.45%) of types 1 and 2, and 1 (0.07%) of types 1 and 3. Overall, male to female ratio was 4.39:1, and 74.59% of patients were between ages 40-60 years. However, there was no difference in gender or the mean age among patients with different HCV genotypes/subtypes. Caucasian, Black, and Spanish patients constituted, respectively, 46.27%, 26.45%, and 23.62% of the test population, and subtype 1a was the predominant type in all the three groups. Conclusions: HCV genotypes 1a, 3a, 1b and 2b are the predominant genotypes in Galveston, TX.