The prevalence of ovine herpesvirus-2 in 4 sheep breeds from different regions in South Africa

C.W Bremer

doi:10.4102/jsava.v81i2.112

Abstract

About 90% of bovine malignant catarrhal fever (BMCF) PCR-positive cases in South Africa are caused by alcelaphine herpesvirus-1 (AlHV-1) and the other 10% by ovine herpesvirus-2 (OvHV-2). The prevalence of OvHV-2 in different sheep breeds in South Africa was determined in order to investigate whether the lower incidence of BMCF caused by OvHV-2 in comparison with AlHV-1 can be ascribed to a low incidence of the virus in sheep. A single-tube hemi-nested PCR was developed, evaluated and applied to detect OvHV-2 DNA. The prevalence of the virus in 4 sheep breeds from various regions in South Africa was shown to be 77%. No statistically significant difference was found amongst the sheep breeds tested.

Highlights

Malignant catarrhal fever (MCF) is a lymphoproliferative disease of cattle, pigs and certain species of captive and wild ruminants and has worldwide distribution
In South Africa, approximately 90 % of MCF polymerase chain reaction (PCR)-positive cases are associated with Alcelaphine herpesvirus-1 (AlHV-1) and only 10 % with ovine herpesvirus-2 (OvHV-2)
Cell cultures Bovine herpesvirus-1 (BHV-1) and bovine herpesvirus-2 (BHV-2) were cultivated in VERO cells and bovine herpesvirus-4 was cultivated in foetal bovine testes cells

Summary

Introduction

Malignant catarrhal fever (MCF) is a lymphoproliferative disease of cattle, pigs and certain species of captive and wild ruminants and has worldwide distribution. Alcelaphine herpesvirus-1 (AlHV-1) is carried asymptomatically by wildebeest (Connochaetes taurinus and C. gnou)[15,17] and ovine herpesvirus-2 (OvHV-2) by sheep[4]. Both AlHV-1 and OvHV-2 cause disease in cattle. OvHV-2 causes disease in various other ruminant species as well as in pigs[12]. In South Africa, approximately 90 % of MCF PCR-positive cases are associated with AlHV-1 and only 10 % with OvHV-2 One study indicated the presence of AlHV-1 in 100 % of wildebeest calves by using a nucleic acid probe[13] while in another study AlHV-1 was isolated from 65 % of wildebeest calves[1]

Methods

Results

Conclusion