Abstract:
Rift Valley fever (RVF) is a vector-borne viral disease of ruminants mainly, and man,
characterized by abortions and neonatal deaths in animals and flu-like to more severe symptoms
that can result in death in humans. The disease is endemic in Africa, Saudi Arabia and Yemen,
and outbreaks occur following proliferation of RVF virus (RVFV) infected mosquito vectors.
Vertebrate animal maintenance hosts of RVFV, which serve as a source of virus during inter-epidemic
periods remain unknown, with wild and domestic suids being largely overlooked. To address this,
we evaluated the virus neutralization test (VNT) for RVF antibody detection in suid sera, as a first step
in assessing the role of suids in the epidemiology of RVF in Africa. Testing of experimental and field
sera from domestic pigs and warthogs with a commercial RVF competitive antibody ELISA, served as
a reference standard against which the VNT results were compared. Results indicate that VNT can
detect anti-RVFV antibodies within three days post-infection, has an analytical specificity of 100%
and diagnostic sensitivity and specificity of 80% and 97%, respectively. Although labour-intensive
and time-consuming, the VNT proved suitable for screening suid sera and plasma for presence of
RVFV antibodies in viraemic and recovered animals.
