No Evidence of Hepatitis C Virus Recombination in Superinfected Patients

Some pathogens are able to recombine, or exchange genetic material, within the body of a host, which can potentially result in more aggressive or drug-resistant strains. It is unclear whether hepatitis C virus (HCV) is able to recombine in patients infected with more than one strain.

To address this question, researchers with the Blood Systems Research Institute in San Francisco performed PCR testing to look for evidence of viral recombination in 5 young injection drug users recently infected with HCV who subsequently became superinfected with a distinguishable new strain.

Results

In 2 cases of superinfection with HCV of the same subtype (1a), the initial and subsequent strains were both sequenced and compared for evidence of recombination.

In 3 cases of superinfection with strains of different genotypes or subtypes (3a/1a, 1a/3a, 1b/1a), the later time-point HCV genomes were sequenced and compared with representative genomes of the initial genotype/subtype.

No evidence of recombination within or between genotypes or subtypes was found using 6 different programs for detecting recombination.

Conclusion

"We conclude that the generation of viable recombinant HCV genomes able to dominate in the viral quasispecies is a rare event," the authors wrote.

Because the number of patients was small, however, this study does not prove that recombination cannot or does not sometimes occur.

08/29/06

Reference
F Bernardin, B Herring, K Page-Shafer, and others. Absence of HCV viral recombination following superinfection. Journal of Viral Hepatitis. 13(8): 532-537. August 2006.