Volume 15, Number 6—June 2009
Research
Lineage 2 West Nile Virus as Cause of Fatal Neurologic Disease in Horses, South Africa
Marietjie Venter
, Stacey Human, Dewald Zaayman, Gertruida H. Gerdes, June Williams, Johan Steyl, Patricia A. Leman, Janusz Tadeusz Paweska, Hildegard Setzkorn, Gavin Rous, Sue Murray, Rissa Parker, Cynthia Donnellan, and Robert Swanepoel
, Stacey Human, Dewald Zaayman, Gertruida H. Gerdes, June Williams, Johan Steyl, Patricia A. Leman, Janusz Tadeusz Paweska, Hildegard Setzkorn, Gavin Rous, Sue Murray, Rissa Parker, Cynthia Donnellan, and Robert SwanepoelTable 1
Viral diagnostic findings, West Nile virus–infected horses, South Africa*
| Case no. | Date sample received | Location | Specimen | Final diagnosis | Results of tests for other viruses |
|---|---|---|---|---|---|
| SAE12/07 | 2007 Apr 23 | Johannesburg, Sandton, Gauteng | Plasma | WNV IgM+ | AHSV–, EEV– |
| SAE89/08 | 2008 Mar 3 | Colesburg North Cape | Plasma | WNV IgM+ | AHSV–, EEV– |
| HS101/08 | 2008 Apr 15 | Tiegerpoort Pretoria, Gauteng | Brain | WNV PCR+, DNA sequencing L2, virus isolae WNV PCR+ | Rabies–, AHSV–, EEV–, EHV–, flavivirus antigen in lumbar spinal cord section and in some gray matter axons (Figure 1) |
| M123/08 | 2008 May 8 | Midrand, Gauteng | Brain | WNV PCR+, DNA sequencing L2 | AHSV–, EEV–, EHV– |
| HS125/08 | 2008 May 26 | Pretoria, Hammans-kraal, Gauteng | Brain | WNV PCR+, DNA sequencing L2 | AHSV from spleen PCR+; AHSV from lung IHC+, lymph node IHC–, liver IHC– |
| SAE126/08 | 2008 Mar 7 | Midrand, Gauteng | Brain | WNV PCR+, DNA sequencing L2 | AHSV RT-PCR+, AHSV type 7; IHC EEV–, AHSV+, AHSV IHC+ (lung liver, heart) |
| SAE134/09 | 2008 Jul 18 | Potchef-stroom, North-Western Province | Serum | WNV PCR+, DNA sequencing L2 | AHSV–, EEV–, EHV-1 weak sero+ |
*WNV, West Nile virus, Ig, immunoglobuliln; AHSV, African horse sickness virus; EEV, equine encephalosis virus; EHV, equine herpesvirus; L2, lineage 2; –, negative; +, positive; RT-PCR, reverse transcription–PCR; IHC, immunohistochemistry.
