Contact: Dr. Lia Rotherham or  Dr. Antoinette van Schalkwyk

Investigations into the epidemiology of a disease are closely associated with the Diagnostic program. Samples submitted to the ARC-OVI that test positive for a specific disease are send for subsequent molecular epidemiology. In addition to this, a couple of disease surveillance project are underway. Molecular epidemiology for the following disease are performed in VDD:


  • African horse sickness

    The prevalence of each serotype of AHSV is determined for each season (ranging from September till August the following year). This is based on sequence analysis of an in-house serotype specific RT-PCR, using segment 2 as template.


  • African swine fever
    The genotype of each isolate of ASFV is determined based on sequence analysis of partial P72, P45 and P30 genes.
  • Avian influenza 

    Each isolate that test positive using molecular diagnostic test for AI, is submitted for additional testing to determine its specific Hemagglutinin (H1 to H18) and Neuraminidase (N1 to N11) antigen. Sequences of partial HA and NA genes are used in subsequent epidemiology of the disease.

  • Newcastle disease

Samples received for Newcastle disease testing are pathotyped into virulent and avirulent strains based on partial sequences of the Fusion-matrix gene.

  • Heartwater

We test for heartwater infection with qRT-PCR targeting the conserved pCS20 gene region of Ehrlichia ruminantium. Positive samples are sequenced for further analysis.

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