Porcine Pegivirus
LEVELS: Highly unlikely; No human illness; Already in the herd; No validated assay; NOT ASSIGNED; Negligible; NOT ASSIGNED; Available, or not needed
| Register id | porcine_pegivirus |
| Type | virus |
| Scientific name | Porcine pegivirus |
| NCBI taxid | 1869278 |
| Evidence | 1 document(s) |
| Assigned | 2026-09-04, against criteria version 093366e352a2 |
Overview
Porcine pegivirus is a flavivirus-family agent that has been identified in pigs in Germany, Poland, Italy, Great Britain, the United States and China. That sentence is very nearly the whole of what the reference literature says about it: its clinical significance remains to be determined. Nothing is recorded about how it is transmitted, how common it is, what if anything it does to a pig, how it would be detected outside the sequencing work that found it, or whether it matters to people. Its relatives in the pegivirus genus, in humans and other species, are generally regarded as persistent but non-pathogenic bloodborne viruses. It is on this register because it is a recognised virus of pigs, and its presence here records the gap rather than fills it.
C1 Zoonotic potential
Likelihood of transmission from pigs to humans
Highly unlikely: Human infection with the agent has never been reported, or has been reported but is not attributed to pig or pork exposure
CONFIRMED by Eric. The assignment reached this level from the evidence, and he has reviewed and ratified it.
Confirmed by Eric. CONFIRMED. "c1l1, evidence is that the pig strain is not zoonotic"
Basis. THE WHOLE OF THE EVIDENCE FOR THIS ENTRY IS ONE SENTENCE. ch30 30.1: "Porcine pegivirus has been identified in Germany, Poland, Italy, Great Britain, the United States, and China (Baechlein et al. 2016; Kennedy et al. 2019; Lei et al. 2019; Yang et al. 2018), but its clinical significance remains to be determined." Chapter 30 is about orthoflaviviruses and mentions the pegivirus only to say it is a different genus in the same family. The folder holds nothing else. No human infection is mentioned.
How this level was decided
INFERRED, AND THINLY. Pegiviruses are strongly host-restricted and the human pegiviruses are distinct species from the porcine one, so there is no evidence that pigs transmit this agent to people -- which is the level 1 test. But that reasoning comes from outside the folder, not from it. FLAGGED with the whole entry below.
C2 Zoonotic impact
Severity of human illness caused by the agent
No human illness: Agent does not cause illness in people
CONFIRMED by Eric. The assignment reached this level from the evidence, and he has reviewed and ratified it.
Confirmed by Eric. CONFIRMED. "c2l1, evidence is that the pig strain is not zoonotic"
Basis. No human disease is described in ch30 30.1 or anywhere else in the folder.
How this level was decided
INFERRED, following C1. Under the criterion as rescoped on 2026-09-01, C2 grades illness acquired from pigs, and there is no evidence of any. Level 1.
C3 Herd introduction risk
Effort required to keep the agent out of the herd
Already in the herd: Present in most herds, or carried by pigs themselves, so there is no introduction event to prevent
CONFIRMED by Eric. The assignment reached this level from the evidence, and he has reviewed and ratified it.
Confirmed by Eric. CONFIRMED. "c3l1, there is sufficient evidence at this time that the virus exists asymptomatically in herds in multiple countries including the US"
Basis. THE WHOLE OF THE EVIDENCE FOR THIS ENTRY IS ONE SENTENCE. ch30 30.1: "Porcine pegivirus has been identified in Germany, Poland, Italy, Great Britain, the United States, and China (Baechlein et al. 2016; Kennedy et al. 2019; Lei et al. 2019; Yang et al. 2018), but its clinical significance remains to be determined." Chapter 30 is about orthoflaviviruses and mentions the pegivirus only to say it is a different genus in the same family. The folder holds nothing else.
How this level was decided
INFERRED FROM GEOGRAPHY ALONE, which is a thin basis and is flagged as such. A virus independently identified in six countries on three continents, including the United States, by four separate research groups is one that is already widely present rather than one a farm keeps out -- and pegiviruses characteristically establish persistent blood-borne infection, so the pigs carry it themselves. That is level 1. What the folder does NOT give is any herd prevalence, any transmission route, or any US survey, so this is a plausible reading rather than a demonstrated one.
C4 Detection difficulty
Difficulty of recognizing and confirming infection
No validated assay: No pathogen-specific test of known reliability exists anywhere, and identification depends on sequencing or on primers that have not been critically evaluated
CONFIRMED by Eric. The assignment reached this level from the evidence, and he has reviewed and ratified it.
Confirmed by Eric. CONFIRMED. "c4l4, I think we need to leave at L4 because the virus has not been widely reported on which necessarily means we are relying on very slim diagnostic methodology that should not be considered to perform reliably across labs and and strain variants"
Basis. THE WHOLE OF THE EVIDENCE FOR THIS ENTRY IS ONE SENTENCE. ch30 30.1: "Porcine pegivirus has been identified in Germany, Poland, Italy, Great Britain, the United States, and China (Baechlein et al. 2016; Kennedy et al. 2019; Lei et al. 2019; Yang et al. 2018), but its clinical significance remains to be determined." Chapter 30 is about orthoflaviviruses and mentions the pegivirus only to say it is a different genus in the same family. The folder holds nothing else. No diagnostic method for porcine pegivirus is described anywhere in the folder.
How this level was decided
INFERRED. This virus is known from metagenomic and PCR surveys in research laboratories, and the folder describes no assay, no validation and no diagnostic service. Under the C4 axis -- whether a validated assay exists and where it can be run -- that is level 4: no pathogen-specific test of known reliability, with identification depending on sequencing or on primers nobody has critically evaluated. Same shape as porcine norovirus, sapovirus and astrovirus, which are the worked examples at that level.
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, reversing his own sheet entry of the same round. He first wrote "C5l1, no evidence the agent causes clinical disease." He then reversed it: "you can leave c5/c7 unassessed for pegivirus - i really can't find much literature to help us." The assessment had left this cell unassessed on exactly that ground and he has restored it. The whole of the folder is one sentence -- the virus has been found in six countries and "its clinical significance remains to be determined" -- and level 1 would assert the virus costs nothing, which is a finding, not an absence. This is the distinction he drew on porcine_tottorivirus: an absence of evidence rather than evidence of absence.
Basis. THE WHOLE OF THE EVIDENCE FOR THIS ENTRY IS ONE SENTENCE. ch30 30.1: "Porcine pegivirus has been identified in Germany, Poland, Italy, Great Britain, the United States, and China (Baechlein et al. 2016; Kennedy et al. 2019; Lei et al. 2019; Yang et al. 2018), but its clinical significance remains to be determined." Chapter 30 is about orthoflaviviruses and mentions the pegivirus only to say it is a different genus in the same family. The folder holds nothing else. The operative clause is "its clinical significance remains to be determined".
How this level was decided
NOT ASSESSED. The chapter states in terms that the clinical significance is unknown, so there is no basis for any level. Scoring level 1 here would assert that the virus costs nothing, which is a finding the folder does not support -- the folder supports only that nobody has looked. This is the distinction Eric drew on porcine_tottorivirus: "No real evidence it causes human or animal disease but fundamentally, there is an absence of evidence."
C6 Market impact
Duration of material disruption to pork and pig markets
Negligible: Little or no material disruption to supply or demand when disease occurs on one or more farms
CONFIRMED by Eric. The assignment reached this level from the evidence, and he has reviewed and ratified it.
Confirmed by Eric. CONFIRMED. "C6l1, no evidence the market has or will respond to a diagnosis. This is one of a long parade of agents that are being identified by happenstance, rather than need."
Basis. THE WHOLE OF THE EVIDENCE FOR THIS ENTRY IS ONE SENTENCE. ch30 30.1: "Porcine pegivirus has been identified in Germany, Poland, Italy, Great Britain, the United States, and China (Baechlein et al. 2016; Kennedy et al. 2019; Lei et al. 2019; Yang et al. 2018), but its clinical significance remains to be determined." Chapter 30 is about orthoflaviviruses and mentions the pegivirus only to say it is a different genus in the same family. The folder holds nothing else. No trade measure, movement control or consumer response is recorded.
How this level was decided
INFERRED. Under the standing note SCORING/market_impact, a virus already present in US pigs and detected without consequence for a decade has no historical market move to record. Level 1. This cell is scored where C5 and C7 are not, because C6 asks what the market HAS done and the answer to that is observable even when the clinical significance is not.
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, reversing his own sheet entry of the same round. He first wrote "c7l1, no current clinical or market imperative to develop a treatment", then reversed it with C5: "you can leave c5/c7 unassessed for pegivirus - i really can't find much literature to help us." C7 asks whether outcomes would improve if a treatment existed, and that cannot be answered for an agent whose clinical significance is undetermined. Contrast dengue_virus and zika_virus in the same batch, where C7 level 1 IS scored, because studies went looking for disease in pigs and found none. Here nobody has looked.
Basis. THE WHOLE OF THE EVIDENCE FOR THIS ENTRY IS ONE SENTENCE. ch30 30.1: "Porcine pegivirus has been identified in Germany, Poland, Italy, Great Britain, the United States, and China (Baechlein et al. 2016; Kennedy et al. 2019; Lei et al. 2019; Yang et al. 2018), but its clinical significance remains to be determined." Chapter 30 is about orthoflaviviruses and mentions the pegivirus only to say it is a different genus in the same family. The folder holds nothing else. No treatment is described, and no disease is described for a treatment to address.
How this level was decided
NOT ASSESSED. C7 asks whether outcomes would improve if a treatment existed, and that cannot be answered for an agent whose clinical significance is undetermined. Level 1 would assert there is no imperative to treat -- which may well be true and is not established. Contrast dengue_virus and zika_virus in this same batch, where level 1 IS scored on C7 because studies went looking for disease in pigs and found none. Here nobody has looked.
C8 Vaccine availability
Availability of effective vaccines or bacterins
Available, or not needed: Effective vaccines are widely available in the US or secured for national outbreak response, or the disease does not clinically or economically justify vaccinating
CONFIRMED by Eric. The assignment reached this level from the evidence, and he has reviewed and ratified it.
Confirmed by Eric. CONFIRMED. "c8l1, no current clinical or market imperative to develop a vaccine"
Basis. THE WHOLE OF THE EVIDENCE FOR THIS ENTRY IS ONE SENTENCE. ch30 30.1: "Porcine pegivirus has been identified in Germany, Poland, Italy, Great Britain, the United States, and China (Baechlein et al. 2016; Kennedy et al. 2019; Lei et al. 2019; Yang et al. 2018), but its clinical significance remains to be determined." Chapter 30 is about orthoflaviviruses and mentions the pegivirus only to say it is a different genus in the same family. The folder holds nothing else. No vaccine is described.
How this level was decided
INFERRED. No vaccine exists, and under the reworded criterion the question is whether one is warranted. Nothing on the record justifies vaccinating against a virus of undetermined clinical significance. Level 1 on the second clause. FLAGGED as arguable on the same ground as C5 and C7 -- if the significance is unknown, so is the need.
Levels and evidence are generated from data/assignments/porcine_pegivirus.yml; the overview is authored in data/overviews/porcine_pegivirus.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.