Typing hepatitis C virus by polymerase chain reaction with type-specific primers: application to clinical surveys and tracing infectious sources

TLDR

Hepatitis C virus can be divided into four types (I–IV) based on nucleotide variation in the core gene. The authors developed a PCR assay that amplifies a core gene fragment with a universal sense primer and a mixture of four type‑specific antisense primers, allowing typing by the size of the resulting products. In a survey of 159 blood donors, 82 % were type II, higher than the 60 % seen in 80 patients with non‑A, non‑B liver disease; type I was detected in 5 of 11 haemophiliacs, double infections occurred in four patients, and identical types were observed in mother‑baby and donor‑recipient pairs.

Abstract

Based on variation in nucleotide sequence within restricted regions in the putative C (core) gene of hepatitis C virus (HCV), four groups of HCV have been postulated in a panel of 44 HCV isolates. They were provisionally designated types I, II, III and IV. A method for typing HCV was developed, depending on the amplification of a C gene sequence by polymerase chain reaction using a universal primer (sense) and a mixture of four type-specific primers (antisense). HCV types were determined by the size of the products specific to each of them. Type II was found in HCV samples from 131 (82%) of 159 blood donors, more often than in those from 48 (60%) of 80 patients with non-A, non-B (NANB) liver disease in Japan (P less than 0.01). In 11 haemophiliacs who had received imported coagulation factor concentrates, type I was found in five, as against type II in four. Double infection with two different HCV types was found in two patients with chronic NANB liver disease (types I and II; II and III) and two haemophiliacs (types I and II; I and III). HCV types were identical in mother and baby in each of two examples of perinatal transmission, and were also identical in donor and recipient in a case of accidental needle exposure.