Aim: To investigate the genetic type of 20 pestiviruses collected from New Zealand over the period 1967-97.
Methods: The pestiviruses were genetically typed by the sequencing of polymerase chain reaction (PCR) products. The primers selected were from the 5'-untranslated region (5'-UTR) of the pestivirus genome and consistently amplified a 288 bp fragment from all samples tested.
Results: Sequencing and phylogenetic analysis of PCR products revealed that all samples obtained from cattle represented bovine viral diarrhoea (BVDV) type I. Two sheep isolates were characterised as border disease virus (BDV). A pestivirus isolated from foetal calf serum of USA origin was typed as BVDV type II.
Conclusions: The findings show that the evolution of pestiviruses in New Zealand has been similar to Europe and North America, indicating the occurrence of a conservative phylogenetic branch of BVDV type I in cattle and the presence of BDV in the sheep population.