Volume 25, Number 5—May 2019
Dispatch
Novel Picornavirus in Lambs with Severe Encephalomyelitis
Table 2
Clinical history of lambs in England with nonsuppurative encephalomyelitis and results of testing of archived samples for presence of OvPV in spinal cord and brain*
| Year | Signalment (case reference) | Case information | RT-PCR† | OvPV reads, no. (%)‡ | Reference coverage§ | Nucl. seq. identity§ |
|---|---|---|---|---|---|---|
| 1998 |
3-week-old mule lamb (1454/98) |
Clinical signs of head tilt, rolling eyes and star gazing, and rapid onset of ataxia, recumbency, and paddling; no response to antimicrobial drugs, multivitamins including B1. Negative for Louping ill virus antibodies in cerebrospinal fluid and serum. |
Positive |
570 (0.003) |
92% |
90%–96% |
| 2000 |
2–4-week-old milking breed lamb (960/00) |
One of ≈12 lambs fed artificial colostrum (snatched at birth to prevent transmission of maedi-visna virus) that developed neurologic signs at ≈2 weeks of age, first weak in forelimbs, then hindlimbs, and by the second day, tremor and incoordination. |
Cq 35 |
1061 (0.01) |
98% |
95%–96% |
| 2004 |
Two 7–8-day-old triplet lambs (E1028/04 and E1029/04) |
Triplets fed proprietary powdered colostrum because the ewe had insufficient milk. Signs of fine tremor progressing to recumbency; the third triplet developed similar neurologic signs at 3 weeks of age (not submitted for investigation). |
Cq 32; positive |
747,777 (3.02); 238,627 (1.11) |
Full; full |
95%; 95% |
| 2008 |
2-week-old Texel X Swaledale (S313-04-08-1) |
Neurologic signs not otherwise specified. |
Cq 36 |
242 (0.0006) |
89% |
93%–95% |
| 2010 |
1-week-old mule X female lamb (S78-04-10-1) |
Approximately 25 lambs have been similarly affected. Portions of fixed juvenile ovine brain were submitted from field postmortem examination with history of suspected neurologic disease before euthanasia. |
Cq 24 |
18,572 (0.07) |
Full |
95% |
| 2014 | Breed and age not known (S247-04-14) | Preweaned lamb with neurologic signs. Field postmortem samples submitted with clinical history of “suspect swayback,” thus likely clinical signs of ataxia and paresis. | Cq 34 | NP | NP | NP |
*Cq, PCR quantification cycle; NP, not performed; nucl. seq., nucleotide sequence; OvPV, ovine picornavirus; RT-PCR, reverse transcription PCR; qRT-PCR, quantitative RT-PCR.
†RT-PCR was performed as prescreening for sample selection for high-throughput sequencing. Where feasible, Cq values of the qRT-PCR are indicated; positive means positive in semi-nested PCR.
‡Number (proportion) of OvPV reads in the complete high-throughput sequencing dataset.
§Genome coverage and nucleotide sequence identity of the full genome or several contigs in relation to the OvPV reference genome strain OvPV/Wales/2017/S014175 (International Nucleotide Sequence Data Collaboration accession no. LR216008).