Genotypic variations around the world: Is hepatitis C virus evolving?

Distribution of Hepatitis C virus genotypes in city of Mashhad, North-east of Iran

PURPOSE

Six major hepatitis C virus genotypes have been characterised, which vary in their geographical distribution. The prevalence of hepatitis C virus (HCV) in an area is not constant, and depends on the changes in route of infection, which may change over time. In this study, the distribution of HCV genotypes in Mashhad, the capital of Razavi Khorasan province in north-east of Iran was investigated. Mashhad is a holy city of Shiate Moslems, which attracts more than 20 million tourists and pilgrims every year.

MATERIALS AND METHODS

Two hundred and seventy-eight HCV infected subjects (227 males and 51 females) were included in this study. HCV genotypes were analysed by type specific reverse transcriptase polymerase chain reaction (RT-PCR).

RESULTS

Genotype 3a was detected in 49.6%, 1a in 36.3%, 1b in 12.6% and 2a in 0.4%. Two HCV genotypes were detected in 1.1% cases; 1a +3a in 1%, 3a + 1b in 0.4%. Genotypes 2b and 3b were not detected in any samples.

CONCLUSION

We demonstrated that despite the previous reports on the frequency of HCV genotypes in Iran, 3a is the predominant genotype in Mashhad.

Distribution of hepatitis C virus genotypes in a diverse US integrated health care population

Hepatitis C virus (HCV) genotypes influence response to therapy, and recently approved direct-acting antivirals are genotype-specific. Genotype distribution information can help to guide antiviral development and elucidate infection patterns. HCV genotype distributions were studied in a diverse cross-section of patients in the Northern California Kaiser Permanente health plan. Associations between genotype and race/ethnicity, age, and sex were assessed with multivariate logistic regression models. The 10,256 patients studied were median age 56 years, 62% male, 55% White non-Hispanic. Overall, 70% were genotype 1, 16% genotype 2, 12% genotype 3, 1% genotype 4, <1% genotype 5, and 1% genotype 6. Blacks (OR 4.5 [3.8-5.5]) and Asians (OR 1.2 [1.0-1.4]) were more likely to have genotype 1 than 2/3 versus non-Hispanic Whites. Women less likely had genotype 1 versus 2/3 than did men (OR 0.86 [0.78-0.94]). Versus non-Hispanic Whites, Asians (OR 0.38 [0.31-0.46]) and Blacks (OR 0.73 [0.63-0.84]) were less likely genotype1a than 1b; Hispanics (OR 1.3 [1.1-1.5]) and Native Americans (OR 1.9 [1.2-2.8]) more likely had genotype 1a than 1b. Patients age ≥65 years less likely had genotype 1a than 1b versus those age 45-64 (OR 0.34 [0.29-0.41]). The predominance of genotype 1 among all groups studied reinforces the need for new therapies targeting this genotype. Racial/ethnic variations in HCV genotype and subtype distribution must be considered in formulating new agents and novel strategies to successfully treat the diversity of hepatitis C patients.

In vitro activity of daclatasvir on hepatitis C virus genotype 3 NS5A

The NS5A replication complex inhibitor daclatasvir (DCV; BMS-790052) inhibits hybrid replicons containing hepatitis C virus (HCV) genotype 3a (HCV3a) NS5A genes with 50% effective concentrations (EC(50)s) ranging from 120 to 870 pM. Selection studies with a hybrid HCV3a replicon identified NS5A residues 31 and 93 as sites for DCV-selected resistance. Our results support the potential use of DCV as a component in combination therapies for HCV3a chronic infection.