Swine Vesicular Disease Virus
LEVELS: Highly unlikely; No human illness; Routine biosecurity keeps it out; Reference or research laboratory required; Minor; Significant disruption; Little; Available, or not needed
| Register id | swine_vesicular_disease_virus |
| Type | virus |
| Scientific name | Swine vesicular disease virus |
| NCBI taxid | 12075 |
| Evidence | 2 document(s) |
| Assigned | 2026-09-04, against criteria version 093366e352a2 |
Overview
Swine vesicular disease virus is an enterovirus, closely related to human coxsackievirus B5, that causes blisters on the feet, snout and mouth of pigs. Clinically it is a mild disease: mortality is not a feature, fever is rare, lameness is almost never seen experimentally, and production losses are very limited, although in bad cases the hoof wall can be damaged enough that the claw sloughs off. Many recent Italian outbreaks were found not by looking at pigs but by serological screening, which means the virus can circulate without producing visible vesicular disease at all. Its whole importance is that its lesions cannot be told apart from those of foot-and-mouth disease. That is why it was kept under official control long after it stopped being economically significant, and why it remains notifiable in many pig-exporting countries even though it has been removed from the WOAH list — modern tests now separate it from FMD easily. Where an outbreak triggers a trade embargo, stamping out the infected herd is the quickest route back to free status. The virus is resistant in the environment and to many disinfectants, but it does not spread easily where hygiene is applied, and feeding untreated swill, historically a major route, should not be permitted. There is no vaccine. Despite its relationship to a human virus, no human illness has ever been confirmed, and it is not regarded as a zoonosis.
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
Basis. ch36 36.3.2: "Shortly after SVDV was identified, it was shown to be closely related to human coxsackievirus B5... This suggested that SVDV infection of humans could be possible, but severe illness in humans caused by SVDV has not been confirmed, not even from laboratories working with large amounts of infectious virus. The absence of reports of human disease leads to the conclusion that SVDV is not a zoonosis."
How this level was decided
The chapter reaches the conclusion explicitly and the evidence behind it is unusually strong for a negative: people handling large quantities of the virus in laboratories, which is the heaviest exposure anyone gets, have not fallen ill. The coxsackievirus B5 relationship made the question worth asking and it was answered. Level 1.
C2 Zoonotic impact
Severity of human illness caused by the agent
No human illness: Agent does not cause illness in people
Basis. ch36 36.3.2: "The absence of reports of human disease leads to the conclusion that SVDV is not a zoonosis."
How this level was decided
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
Routine biosecurity keeps it out: Quarantine of incoming stock, transport and fomite control, cleaning and disinfection, and the usual monitoring reliably exclude it
Basis. ch36 36.3.10.2: "Although SVDV is resistant to environmental factors and many commonly used disinfectants, pigs transported in properly cleaned and disinfected vehicles do not often get infected. Even on farms where infection is present in one compartment, the infection does not spread easily to other compartments if strict hygienic measures are applied. In the past, swill feeding has contributed significantly to transmission of SVDV. Therefore, swill feeding should not be allowed."
How this level was decided
RENUMBERED L2 -> L3 on 2026-09-01, when C3 went from four levels to five. The argument below is unchanged and so is the judgment. What changed is the scale it sits on. C3 now runs on the EFFORT REQUIRED TO EXCLUDE: L1 already in the herd, L2 housing alone keeps it out, L3 routine biosecurity keeps it out, L4 extraordinary biosecurity required, L5 exclusion may not be achievable. A clean level 2, which is rare in this register. The source is other pig herds and contaminated feed, and the chapter says in successive sentences that transport hygiene, compartment hygiene and a swill-feeding ban all work -- routine on-farm and transportation biosecurity closes the routes, which is the level 2 label word for word. SVDV has never been isolated in the Americas, so there is no US reservoir to escalate this.
C4 Detection difficulty
Difficulty of recognizing and confirming infection
Reference or research laboratory required: A validated assay exists, but only at a national reference or research laboratory rather than at local or regional level
CONFIRMED by Eric. The assignment reached this level from the evidence, and he has reviewed and ratified it.
Confirmed by Eric. CONFIRMED. "l3, I am confident the referral labs can make this diagnosis in the US"
Basis. ch36 36.3.7.1: "Lesions are indistinguishable from those induced by FMDV infection. The clinical signs caused by SVDV are, however, much milder than those caused by FMDV. In experimental studies, fever was rare, and lameness was almost never observed." 36.3.1: "Most of the recent outbreaks in Italy were not discovered by clinical inspection, but by serological screening. Therefore, SVDV can be transmitted without causing vesicular disease." 36.3.2: SVD "is still under official control in many WOAH Member States" to avoid missing an FMD outbreak.
How this level was decided
Worse than FMD on the same syndrome, for two reasons the chapter gives. The lesions are indistinguishable from FMD, so the differential still needs the national laboratory. And the disease is often silent -- recent European outbreaks were found by serology, not by looking at pigs -- so there may be no lesion to prompt the test at all. Level 3.
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
Basis. ch36 36.3.2: "The disease was removed from the list as production losses due to SVD are very limited and modern diagnostic techniques make it easy to differentiate between infection by SVDV and FMDV." 36.3.6.2: "Mortality is not a feature of SVDV infection." 36.3.7.1: "The hoof wall and sole may be damaged so extensively that the claw(s) slough(s) off."
How this level was decided
The chapter states the answer and acted on it -- WOAH delisted the disease because production losses are very limited. No mortality, rare fever, lameness almost never seen experimentally. Against that, severe cases can slough a claw, which is a real loss on the affected animal. Small losses rather than none. Level 2. NOTE: this scores the DISEASE. The stamping out that follows a detection is a regulatory response to trade status, not to production loss, and is scored at C6.
C6 Market impact
Duration of material disruption to pork and pig markets
Significant disruption: Material negative effect on supply or demand lasting 1 to 6 months 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. "C6L3, diagnosis of this in the US would be a significant event and would cause a disruption for sure that would last more than a month"
Basis. ch36 36.3.10.1: "SVD is no longer on the WOAH notifiable disease list, but SVD is still considered a notifiable disease in many countries, particularly countries that export pigs and/or pork. In the face of trade embargos resulting from SVD outbreaks, stamping out infected herd(s) is the quickest method to control the outbreak and regain SVDV-free status."
How this level was decided
INFERRED. The chapter names the mechanism directly -- trade embargos, and stamping out undertaken specifically to regain free status rather than to save pigs. SVDV has never been in the Americas, so the standing note SCORING/market_impact does not apply: there is no US history of diagnosis-without-reaction to reason from, and this is scored on what would happen. Regaining a free status takes months of demonstrated absence, which puts it in the one-to-six month band. Level 3 rather than 4, because the losses are limited and the differentiation from FMD is now easy, so the episode resolves faster than an FMD event.
C7 Treatment potential
Potential for treatment to improve outcomes
Little: Effective pathogen-directed treatment is available and works, or animals recover acceptably without it
Basis. ch36 36.3.6.2: "Mortality is not a feature of SVDV infection." 36.3.7.1: clinical signs "are much milder than those caused by FMDV... fever was rare, and lameness was almost never observed. Sudden death due to heart degeneration, often observed in young piglets infected with FMDV, is not seen with SVDV." No antiviral or therapeutic is described anywhere in section 36.3.
How this level was decided
No treatment exists, but the second clause of level 1 carries it: animals recover acceptably without one. The chapter records no mortality, rare fever and almost no lameness, and the pigs that are killed are killed by the eradication policy rather than by the virus. There is very little outcome for a treatment to improve.
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, a bit tricky but in the current environment, L1 is correct. If the diseae became established perhaps vaccine would be a useful management tool but today, the objective would be rapid eradiction and vaccine developemnt would not be part of it, nor is there an imnperative to source or develop this vaccine as a precautionary measure."
Basis. No vaccine is described anywhere in ch36 36.3. Control rests on hygiene, a swill-feeding ban, stamping out and test-and-removal. ch36 36.3.2: "production losses due to SVD are very limited."
How this level was decided
INFERRED. No vaccine exists, and under the reworded criterion the question is whether one is warranted. It is not: production losses are very limited, the disease is absent from the Americas, and a vaccine would actively hurt -- the control programme the chapter describes runs on serological screening, and vaccinating would destroy the ability to detect infection that way. Level 1 on the second clause. FLAGGED, because this is a case where a vaccine is not merely unnecessary but counterproductive, which the level 1 wording does not distinguish from ordinary non-need.
Levels and evidence are generated from data/assignments/swine_vesicular_disease_virus.yml; the overview is authored in data/overviews/swine_vesicular_disease_virus.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.