Trueperella abortisuis
LEVELS: Highly unlikely; No human illness; Already in the herd; Laboratory-dependent; Minor; Negligible; NOT ASSIGNED; Available, or not needed
| Register id | trueperella_abortisuis |
| Type | bacteria |
| Scientific name | Trueperella abortisuis |
| NCBI taxid | 445930 |
| Evidence | 1 document(s) |
| Assigned | 2026-09-04, against criteria version 093366e352a2 |
Overview
Trueperella abortisuis is a newly recognised organism, first isolated in Japan from the placenta and tissues of an aborted litter, and its standing as a pig pathogen is still unclear. It has since been recovered from placenta after abortion, vaginal discharges, rectal swabs from piglets, boar semen and extended semen in the United States, and abortions attributed to it have been reported on multiple US farms and one in the United Kingdom. The complication is that it is usually isolated in mixed culture with other bacteria, so a diagnosis requires demonstrating lesions in the fetus or placenta with matching bacteria present in them as well as culturing the organism; finding it in a vaginal discharge or placenta without lesions should be treated cautiously, since environmental and post-mortem contamination can account for it. Genetic analysis of the US isolates found six distinct populations rather than one spreading strain, which argues against an outbreak. Identification is by MALDI-TOF or gene sequencing. No treatment, susceptibility data or vaccine exists, and no human disease is described.
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 is correct, no evidence of human infection"
Basis. Section 58.12 is a single unstructured passage covering isolation history, morphology, identification, lesions and diagnosis. It makes no mention of human infection, foodborne risk or occupational exposure. The organism is described as newly recognised, "first isolated from the placenta and tissues of an 87-day-gestation aborted litter of pigs having lesions and intralesional bacteria in Japan". (ch58 58.12)
How this level was decided
INFERRED, and weaker than the equivalent call elsewhere in this batch. Chapter 58 gives an explicit public health passage to every agent that has one, and states outright that Treponema pedis has none -- so silence here is some evidence. But section 58.12 is the shortest in the chapter and has no subsection structure at all, so it may simply not have reached the question rather than answered it. Level 1 records what the folder supports; it is a fair cell for Eric to reject in favour of NOT ASSESSED.
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, no evidence of human infection"
Basis. No human disease of any kind is described in section 58.12. (ch58 58.12)
How this level was decided
INFERRED, on the same thin silence as C1 and carrying the same caveat. C2 says to score level 1 whenever the agent does not cause disease in people, and the folder records none.
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, little information available to report on national US prevalence in pigs but it is plausible that if one looked hard enough, it will be present on many farms but only causes disease under specific condtions"
Basis. "Additional isolates have been obtained from placenta after abortion, vaginal discharges, rectal swabs from piglets, and boar sperm." "The organism has also been isolated from extended semen samples in the United States (Bussalleu and Althouse 2017)." "Trueperella abortisuis is usually isolated in mixed culture with other bacterial species, making the importance of this novel species unclear." (ch58 58.12)
How this level was decided
INFERRED. Recovery from rectal swabs of piglets and from vaginal discharges, in mixed culture, describes an organism resident in the pigs rather than one arriving from outside -- so there is no introduction event to prevent, which is level 1. NOTE: isolation from extended semen in the US is a genuine between-herd route, and if that is read as the way herds acquire it, this is level 2 with AI screening as the biosecurity that closes it.
C4 Detection difficulty
Difficulty of recognizing and confirming infection
Laboratory-dependent: The presentation does not point to this disease specifically, but local or regional laboratories can confirm it with a validated assay once it is suspected
CONFIRMED by Eric. The assignment reached this level from the evidence, and he has reviewed and ratified it.
Confirmed by Eric. CONFIRMED. "l2, straightforward to diagnose"
Basis. "It is most easily identified by MALDI-TOF mass spectrometry (Hijazin et al. 2012b; Ulbegi-Mohyla et al. 2011) or by amplification and sequencing of 16S rRNA gene sequence and gene sodA encoding superoxide dismutase." "Diagnosis of T. abortisuis abortion requires demonstration of lesions in fetuses or placenta with morphologically consistent intralesional bacteria and culture of T. abortisuis." "Demonstration of T. abortisuis in vaginal discharges or in the placenta absent other lesions should be interpreted with caution given the potential for environmental or postmortem contamination and overgrowth." (ch58 58.12)
How this level was decided
Abortion points at dozens of agents and never at this one, so level 1 is out. Confirmation needs fetal and placental histopathology plus culture, with MALDI-TOF for identification -- all standard regional veterinary diagnostic laboratory work now that MALDI-TOF is widely deployed. Level 2. The real difficulty is interpretive rather than technical: the chapter warns that finding the organism without lesions may be contamination.
C5 Production cost
Financial impact on the infected farm's cost of production
Minor: Small and generally short-lived losses with little effect on overall cost of production
CONFIRMED by Eric. The assignment reached this level from the evidence, and he has reviewed and ratified it.
Confirmed by Eric. CONFIRMED. "c5l2, clinical disease has been demonstrated but this seems to be a very low prevalence condition"
Basis. "Reports of abortions caused by T. abortisuis have also been described in multiple swine farms in the United States (Ford et al. 2022) and from a single farm in the United Kingdom (Jorgensen et al. 2021)." "Trueperella abortisuis is usually isolated in mixed culture with other bacterial species, making the importance of this novel species unclear." "Analysis by multiple genetic techniques indicated that although the strains were closely related, they were sufficiently different to be considered six different populations and not indicative of an outbreak of a single abortifacient strain." (ch58 58.12)
How this level was decided
INFERRED -- no rate and no cost figure anywhere in the section. Abortion is expensive when it occurs, but the chapter twice undercuts attribution: the organism usually appears in mixed culture and its importance is unclear, and the one multi-case investigation found six distinct strains rather than a spreading outbreak. That reads as sporadic individual losses rather than a herd-level event. Level 2.
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 reason to believe the market would respond to a diagnosis and epidemiology does not support multiherd or multistate outbreaks"
Basis. The section describes sporadic abortions on individual farms caused by a newly recognised organism of unclear significance. It records no trade measure, movement control, export restriction or consumer response.
How this level was decided
INFERRED. A sporadic, non-zoonotic, non-reportable cause of abortion has no route to pork supply or demand. Level 1.
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. The pass left C7 with no level because section 58.12 has no prevention and control passage at all -- no susceptibility data, no treatment attempt, nothing about whether treating a sow changes any outcome. Eric on the ch58 gaps sheet: "I think we need to keep this as unexportable given lack of evidence, re-evaluate later." So this is a ruling, not an unreviewed blank: he has looked at the empty cell and decided it stays empty, which is what a null correction records. The entry is deliberately excluded from any 1000minds export until a source arrives that bears on treating T. abortisuis. Same shape as hendra_virus/market_impact above.
Basis. Section 58.12 has no prevention and control passage. It records no antimicrobial susceptibility data, no treatment attempt and no case management for T. abortisuis, and nothing about whether treating affected sows changes any outcome. (ch58 58.12)
How this level was decided
NOT ASSESSED. No level assigned. C7 asks how much better outcomes would be if effective treatment existed, and answering it requires knowing something about what treatment does or fails to do here -- the folder holds nothing on either. An inference from Trueperella pyogenes in section 58.13, which is sensitive to penicillin but poorly served by it because drugs do not reach abscesses, would be an inference across species from a different disease process, and abortion is diagnosed after the loss has happened in any case. THIS MAKES THE ENTRY UNEXPORTABLE until it is resolved, which is the correct signal rather than a problem to score around.
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 AT LEVEL 1. "c8l3 is correct, but again there seems to be no market or welfare imperative to develop or use a vaccine even if it were available" Eric, 2026-08-28: "all seven to L1". Re-ruled after the C8 rewording of the same day. His 2026-08-27 words are unchanged and are quoted above in full -- what has moved is the level they map to. He wrote each of them to say that no vaccine is NEEDED here, and level 3 was then the only place a missing vaccine could go, so the reasoning and the level contradicted each other. The reworded level 1 holds exactly what he was describing: no vaccine exists, and the disease does not justify one. Recorded as a confirmation of the reworded pass rather than an override, because the pass now agrees with him.
Basis. Section 58.12 names no vaccine and frames the organism as a novel species of unclear significance. Eric, 2026-08-27: "there seems to be no market or welfare imperative to develop or use a vaccine even if it were available".
How this level was decided
MOVED L3 -> L1 by the rewording. Sporadic abortions of contested attribution, with the chapter saying the organism usually appears in mixed culture and its importance is unclear. No unmet need to record. NOTE: C7 on this entry remains ruled unassessable by Eric and the entry stays unexportable on that account, not this one.
Levels and evidence are generated from data/assignments/trueperella_abortisuis.yml; the overview is authored in data/overviews/trueperella_abortisuis.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.