Work

Shuni Virus in Wildlife and Nonequine Domestic Animals, South Africa

Year: 2020

Type: article

Abstract: S huni virus (SHUV) (Peribunyaviridae: Orthobun- yavirus) was isolated in the 1960s from livestock, Culicoides midges, and a febrile child in Nigeria (1,2).In South Africa, SHUV was identified as the causative agent of neurologic disease in horses (3); seropositivity was also demonstrated in 3.0% of veterinarians, suggesting human exposures (4).SHUV was subsequently identified in aborted livestock and cattle with neurologic disease in Israel, suggesting an extended range beyond Africa (5,6).We investigated other potential susceptible species in South Africa. The StudyDuring February 2010-September 2018, a total of 101 whole blood, 71 serum, and 476 tissue specimens from 608 nonequine domestic animals, wildlife, and birds (19 fetuses, 118 juvenile and 471 adults) with unexplained neurologic or febrile disease or sudden unexplained death from across South Africa were submitted to the Zoonotic Arbo and Respiratory Virus Program, Centre for Viral Zoonoses, University of Pretoria (Pretoria, South Africa) as part of a passive zoonotic arbovirus surveillance program.We extracted RNA under Biosafety Level (BSL) 3 conditions using the QIAamp viral RNA mini kit (blood) or the RNeasy mini kit (tissue) (QIA-GEN, https://www.qiagen.com),according to the manufacturer's recommendations.We screened all samples by a SHUV real-time reverse transcription PCR (rRT-PCR) (7) and a newly designed rRT-PCR targeting a conserved area of the S segment of the Simbu serogroup (Appendix, https://wwwnc.cdc.gov/EID/article/26/7/19-0770-App1.pdf).We confirmed PCR-positive samples by Sanger sequencing (Inqaba Biotech, https://www.inqababiotec.co.za) and phylogenetic analyses (Appendix).We also screened all specimens for West Nile (WNV), Wesselsbron (8), Middelburg (MIDV), Sindbis (9), and equine encephalosis viruses (10).In addition, serum samples from African buffalo (Syncerus caffer) (n = 45) and white rhinoceros (Ceratotherium simum) (n = 48) from Kruger National Park were collected in March 2014 and June 2016, respectively, by South African National Parks and from wild Nile crocodiles (Crocodylus niloticus) (n = 34) from northern KwaZulu-Natal collected during 2009-2012 by the Faculty of Veterinary Sciences, University of Pretoria, as part of surveillance studies.We examined tissue samples from a SHUV PCR-confirmed positive buffalo (MVA43/10) microscopically under a light microscope using routinely prepared hematoxylin and eosin stained (11) histological sections at the Section of Pathology, Department of Paraclinical Sciences, Faculty of Veterinary Science, University of Pretoria.We subjected serum samples to an epitope-blocking ELISA (eb-ELISA) (12,13) with modifications to detect antibodies to SHUV (Appendix).

Source: Emerging infectious diseases

DOI: 10.3201/eid2607.190770