Tottorivirus asuscro (Tottorivirus A)
LEVELS: NOT ASSIGNED; NOT ASSIGNED; NOT ASSIGNED; NOT ASSIGNED; NOT ASSIGNED; NOT ASSIGNED; NOT ASSIGNED; NOT ASSIGNED
| Register id | porcine_tottorivirus |
| Type | virus |
| Scientific name | Tottorivirus asuscro |
| NCBI taxid | 3432973 |
| Evidence | 1 document(s) |
| Assigned | 2026-09-04, against criteria version 093366e352a2 |
Overview
Porcine tottorivirus, also known as swine picornavirus Japan, was found in the faeces of healthy pigs in Japan in 2015 and detected on seven of the twelve farms examined; it has since turned up in the United States, China and South Africa, and preliminary sequence analysis suggests at least seven genetic types exist. Beyond that the reference chapter states the position in a single sentence: nothing is known concerning its potential to cause disease in pigs. Attempts to grow it in porcine kidney and Vero cells failed, so detection rests on a laboratory-built RT-PCR and on metagenomic sequencing. No human infection is described, and none of its close relatives is associated with people. All eight of this entry's criteria were left unscored, because there is no evidence on which to base any of them — the entry records a virus that exists in pigs and about which nothing else can honestly be said.
C1 Zoonotic potential
Likelihood of transmission from pigs to humans
NOT ASSESSED — no evidence in folder. No level was assigned on this criterion. This is a statement about what the evidence folder holds, not a finding about the agent.
Corrected by Eric from L1 Highly unlikely. Reason: CONFIRMED AS NOT ASSESSABLE, reaffirmed 2026-08-31. "not assignable, this virus seems to have been detected only as a random finding related to sequence based pig biome projects. No real evidence it causes human or animal disease but fundamentally, there is an absence of evidence. All criteria should be set to not assignable, then send it to KISS." He first ruled all eight null on 2026-08-29 and has restated it after the C4 rework moved the machine level on this entry. His phrase is the distinction the register turns on: not evidence of absence, but absence of evidence.
Basis. ch36 36.11 covers porcine tottorivirus in full and makes no mention of human infection. Its named relatives are the genera Teschovirus, Hunnivirus and Malagasivirus, none of which the chapter associates with people.
How this level was decided
INFERRED from the chapter structured silence. Level 1, and it is the weakest kind of inference -- the section is eight sentences long and may simply not have reached the question rather than answered it.
C2 Zoonotic impact
Severity of human illness caused by the agent
NOT ASSESSED — no evidence in folder. No level was assigned on this criterion. This is a statement about what the evidence folder holds, not a finding about the agent.
Corrected by Eric from L1 No human illness. Reason: CONFIRMED AS NOT ASSESSABLE, reaffirmed 2026-08-31. "not assignable, this virus seems to have been detected only as a random finding related to sequence based pig biome projects. No real evidence it causes human or animal disease but fundamentally, there is an absence of evidence. All criteria should be set to not assignable, then send it to KISS." He first ruled all eight null on 2026-08-29 and has restated it after the C4 rework moved the machine level on this entry. His phrase is the distinction the register turns on: not evidence of absence, but absence of evidence.
Basis. No human disease is described in ch36 36.11.
How this level was decided
INFERRED, on the same thin silence, and carrying the same caveat. C2 scores level 1 whenever the agent does not cause disease in people.
C3 Herd introduction risk
Effort required to keep the agent out of the herd
NOT ASSESSED — no evidence in folder. No level was assigned on this criterion. This is a statement about what the evidence folder holds, not a finding about the agent.
Corrected by Eric from L1 Already in the herd. Reason: CONFIRMED AS NOT ASSESSABLE, reaffirmed 2026-08-31. "not assignable, this virus seems to have been detected only as a random finding related to sequence based pig biome projects. No real evidence it causes human or animal disease but fundamentally, there is an absence of evidence. All criteria should be set to not assignable, then send it to KISS." He first ruled all eight null on 2026-08-29 and has restated it after the C4 rework moved the machine level on this entry. His phrase is the distinction the register turns on: not evidence of absence, but absence of evidence.
Basis. ch36 36.11: porcine tottorivirus "was found in the feces of healthy pigs in Japan in 2015", was detected "in pigs on seven out of 12 farms examined", and has since been found in the United States, China and South Africa.
How this level was decided
INFERRED. Present in the faeces of healthy pigs on more than half the farms surveyed and on four continents, which is the pattern of an agent already carried by the pigs rather than one arriving. No introduction event to prevent. Level 1.
C4 Detection difficulty
Difficulty of recognizing and confirming infection
NOT ASSESSED — no evidence in folder. No level was assigned on this criterion. This is a statement about what the evidence folder holds, not a finding about the agent.
Corrected by Eric from L4 No validated assay. Reason: CONFIRMED AS NOT ASSESSABLE, reaffirmed 2026-08-31. "not assignable, this virus seems to have been detected only as a random finding related to sequence based pig biome projects. No real evidence it causes human or animal disease but fundamentally, there is an absence of evidence. All criteria should be set to not assignable, then send it to KISS." He first ruled all eight null on 2026-08-29 and has restated it after the C4 rework moved the machine level on this entry. His phrase is the distinction the register turns on: not evidence of absence, but absence of evidence.
Basis. ch36 36.11: "Naoi et al. (2016) were not able to isolate the virus using a porcine kidney cell line (CPK) or Vero cells, but detected the virus in pigs on seven out of 12 farms examined using a conventional RT-PCR targeting the 3D-coding region." Subsequent detections were by metagenomic studies. "Preliminary analyses of the VP1 region of these sequences suggest that at least seven genetic types exist."
How this level was decided
MOVED L3 -> L4 under the rewording. Culture failed, detection rests on one conventional RT-PCR from a single publication plus metagenomics, and nobody has evaluated either. The seven genetic types make it worse rather than better -- a primer set designed against one is not known to find the others. No test of known reliability exists anywhere. NOTE: Eric ruled all eight criteria of this entry unassessable on 2026-08-29, so the published cell is empty regardless.
C5 Production cost
Financial impact on the infected farm's cost of production
CONFIRMED NOT ASSESSABLE. No level was assigned on this criterion, and Eric has reviewed that and ruled it correct — the folder holds nothing bearing on it. This is a statement about what the evidence supports, not a finding about the agent.
Confirmed by Eric. CONFIRMED AS NOT ASSESSABLE, reaffirmed 2026-08-31. "not assignable, this virus seems to have been detected only as a random finding related to sequence based pig biome projects. No real evidence it causes human or animal disease but fundamentally, there is an absence of evidence. All criteria should be set to not assignable, then send it to KISS." He first ruled all eight null on 2026-08-29 and has restated it after the C4 rework moved the machine level on this entry. His phrase is the distinction the register turns on: not evidence of absence, but absence of evidence.
Basis. ch36 36.11 states in full: "Nothing is known concerning the potential for porcine tottorivirus to cause disease in pigs." The section records the discovery, the taxonomic placement, the failed culture attempts, the detection method, the geographic spread and the existence of at least seven genetic types.
How this level was decided
NOT ASSESSED. No level assigned, and the chapter could not be more explicit -- nothing is known about whether this virus causes disease at all. Every C5 level is a claim about magnitude of cost, including level 1, and the folder supports none of them. THIS MAKES THE ENTRY UNEXPORTABLE, which is the correct signal for a virus discovered in 2015 in healthy pigs and never studied for pathogenicity.
C6 Market impact
Duration of material disruption to pork and pig markets
NOT ASSESSED — no evidence in folder. No level was assigned on this criterion. This is a statement about what the evidence folder holds, not a finding about the agent.
Corrected by Eric from L1 Negligible. Reason: CONFIRMED AS NOT ASSESSABLE, reaffirmed 2026-08-31. "not assignable, this virus seems to have been detected only as a random finding related to sequence based pig biome projects. No real evidence it causes human or animal disease but fundamentally, there is an absence of evidence. All criteria should be set to not assignable, then send it to KISS." He first ruled all eight null on 2026-08-29 and has restated it after the C4 rework moved the machine level on this entry. His phrase is the distinction the register turns on: not evidence of absence, but absence of evidence.
Basis. Section 36.11 records no trade measure, movement control or consumer response. The virus has no regulatory status.
How this level was decided
INFERRED. A virus with no known disease potential and no regulatory status has no mechanism to move pork supply or demand. Level 1 rests on the absence of any pathway.
C7 Treatment potential
Potential for treatment to improve outcomes
CONFIRMED NOT ASSESSABLE. No level was assigned on this criterion, and Eric has reviewed that and ruled it correct — the folder holds nothing bearing on it. This is a statement about what the evidence supports, not a finding about the agent.
Confirmed by Eric. CONFIRMED AS NOT ASSESSABLE, reaffirmed 2026-08-31. "not assignable, this virus seems to have been detected only as a random finding related to sequence based pig biome projects. No real evidence it causes human or animal disease but fundamentally, there is an absence of evidence. All criteria should be set to not assignable, then send it to KISS." He first ruled all eight null on 2026-08-29 and has restated it after the C4 rework moved the machine level on this entry. His phrase is the distinction the register turns on: not evidence of absence, but absence of evidence.
Basis. ch36 36.11: "Nothing is known concerning the potential for porcine tottorivirus to cause disease in pigs."
How this level was decided
NOT ASSESSED. No level assigned. C7 asks the size of the opportunity a treatment would create, which cannot be answered where nothing is known about whether the agent causes harm. Level 1 would assert animals do acceptably without treatment; level 3 would assert outcomes would improve with one. The folder supports neither.
C8 Vaccine availability
Availability of effective vaccines or bacterins
NOT ASSESSED — no evidence in folder. No level was assigned on this criterion. This is a statement about what the evidence folder holds, not a finding about the agent.
Corrected by Eric from L1 Available, or not needed. Reason: CONFIRMED AS NOT ASSESSABLE, reaffirmed 2026-08-31. "not assignable, this virus seems to have been detected only as a random finding related to sequence based pig biome projects. No real evidence it causes human or animal disease but fundamentally, there is an absence of evidence. All criteria should be set to not assignable, then send it to KISS." He first ruled all eight null on 2026-08-29 and has restated it after the C4 rework moved the machine level on this entry. His phrase is the distinction the register turns on: not evidence of absence, but absence of evidence.
Basis. No vaccine is described for porcine tottorivirus in ch36 36.11.
How this level was decided
INFERRED. No vaccine exists and none is warranted for a virus with no known disease potential. Level 1 on the second clause, scored where C5 and C7 were not for the same reason as on pasivirus_a -- it asserts only that no product exists and none is called for.
Levels and evidence are generated from data/assignments/porcine_tottorivirus.yml; the overview is authored in data/overviews/porcine_tottorivirus.md. Do not hand-edit this page — corrections go in data/assignments/CORRECTIONS.yml.
Quoted material marked Basis is from Zimmerman JJ, Karriker LA, Ramirez A, Schwartz KJ, Stevenson GW, Zhang J, eds. Diseases of Swine, 12th edition. Hoboken: Wiley Blackwell, 2025 — except where another source is named in the quotation itself.