Experimental Infection of Domestic Pigs (Sus scrofa) with Rift Valley Fever Virus

Baratang Alison Lubisi; Paidamwoyo Barry Mutowembwa; Phumudzo Nomicia Ndouvhada; Lieza Odendaal; Armanda D S Bastos; Mary-Louise Penrith

doi:10.3390/v15020545

Experimental Infection of Domestic Pigs (Sus scrofa) with Rift Valley Fever Virus

Viruses. 2023 Feb 16;15(2):545. doi: 10.3390/v15020545.

Authors

Baratang Alison Lubisi^{1

2}, Paidamwoyo Barry Mutowembwa¹, Phumudzo Nomicia Ndouvhada¹, Lieza Odendaal³, Armanda D S Bastos², Mary-Louise Penrith⁴

Affiliations

¹ Agricultural Research Council-Onderstepoort Veterinary Research, Onderstepoort, Pretoria 0110, South Africa.
² Department of Zoology and Entomology, Faculty of Natural and Agricultural Sciences, University of Pretoria, Hatfield, Pretoria 0028, South Africa.
³ Department of Paraclinical Sciences, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, Pretoria 0110, South Africa.
⁴ Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, Pretoria 0110, South Africa.

Abstract

Rift valley fever (RVF), caused by the RVF virus (RVFV), is a vector-borne zoonotic disease that primarily affects domestic ruminants. Abortion storms and neonatal deaths characterise the disease in animals. Humans develop flu-like symptoms, which can progress to severe disease. The susceptibility of domestic pigs (Sus scrofa domesticus) to RVFV remains unresolved due to conflicting experimental infection results. To address this, we infected two groups of pregnant sows, neonates and weaners, each with a different RVFV isolate, and a third group of weaners with a mixture of the two viruses. Serum, blood and oral, nasal and rectal swabs were collected periodically, and two neonates and a weaner from group 1 and 2 euthanised from 2 days post infection (DPI), with necropsy and histopathology specimens collected. Sera and organ pools, blood and oronasorectal swabs were tested for RVFV antibodies and RNA. Results confirmed that pigs can be experimentally infected with RVFV, although subclinically, and that pregnant sows can abort following infection. Presence of viral RNA in oronasorectal swab pools on 28 DPI suggest that pigs may shed RVFV for at least one month. It is concluded that precautions should be applied when handling pig body fluids and carcasses during RVF outbreaks.

Keywords: pathology; phylogenetics; polymerase chain reaction; sequencing; serology.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Antibodies
Female
Humans
Pregnancy
RNA, Viral
Rift Valley Fever*
Rift Valley fever virus*
Sus scrofa
Swine

Substances

Antibodies
RNA, Viral

Grants and funding

This research was funded by the Joy Liebenberg Trust, the South African Government Treasury’s Economic Competitive Support Programme and Gauteng Department of Agriculture and Rural Development (GDARD). The APC was funded by Prof. M.-L.P. of the University of Pretoria, Faculty of Veterinary Science, South Africa.